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Sample records for peptide directs penicillin

  1. Synthesis and Kinetic Analysis of Two Conformationally Restricted Peptide Substrates of Escherichia coli Penicillin-Binding Protein 5.

    PubMed

    Nemmara, Venkatesh V; Nicholas, Robert A; Pratt, R F

    2016-07-26

    Escherichia coli PBP5 (penicillin-binding protein 5) is a dd-carboxypeptidase involved in bacterial cell wall maturation. Beyond the C-terminal d-alanyl-d-alanine moiety, PBP5, like the essential high-molecular mass PBPs, has little specificity for other elements of peptidoglycan structure, at least as elicited in vitro by small peptidoglycan fragments. On the basis of the crystal structure of a stem pentapeptide derivative noncovalently bound to E. coli PBP6 (Protein Data Bank entry 3ITB ), closely similar in structure to PBP5, we have modeled a pentapeptide structure at the active site of PBP5. Because the two termini of the pentapeptide are directed into solution in the PBP6 crystal structure, we then modeled a 19-membered cyclic peptide analogue by cross-linking the terminal amines by succinylation. An analogous smaller, 17-membered cyclic peptide, in which the l-lysine of the original was replaced by l-diaminobutyric acid, could also be modeled into the active site. We anticipated that, just as the reactivity of stem peptide fragments of peptidoglycan with PBPs in vivo may be entropically enhanced by immobilization in the polymer, so too would that of our cyclic peptides with respect to their acyclic analogues in vitro. This paper describes the synthesis of the peptides described above that were required to examine this hypothesis and presents an analysis of their structures and reaction kinetics with PBP5. PMID:27420403

  2. Purification and sequencing of the active site tryptic peptide from penicillin-binding protein 1b of Escherichia coli

    SciTech Connect

    Nicholas, R.A.; Suzuki, H.; Hirota, Y.; Strominger, J.L.

    1985-07-02

    This paper reports the sequence of the active site peptide of penicillin-binding protein 1b from Escherichia coli. Purified penicillin-binding protein 1b was labeled with (/sup 14/C)penicillin G, digested with trypsin, and partially purified by gel filtration. Upon further purification by high-pressure liquid chromatography, two radioactive peaks were observed, and the major peak, representing over 75% of the applied radioactivity, was submitted to amino acid analysis and sequencing. The sequence Ser-Ile-Gly-Ser-Leu-Ala-Lys was obtained. The active site nucleophile was identified by digesting the purified peptide with aminopeptidase M and separating the radioactive products on high-pressure liquid chromatography. Amino acid analysis confirmed that the serine residue in the middle of the sequence was covalently bonded to the (/sup 14/C)penicilloyl moiety. A comparison of this sequence to active site sequences of other penicillin-binding proteins and beta-lactamases is presented.

  3. In vitro properties of designed antimicrobial peptides that exhibit potent antipneumococcal activity and produces synergism in combination with penicillin

    PubMed Central

    Le, Cheng-Foh; Yusof, Mohd Yasim Mohd; Hassan, Hamimah; Sekaran, Shamala Devi

    2015-01-01

    Antimicrobial peptides (AMPs) represent a promising class of novel antimicrobial agents owing to their potent antimicrobial activity. In this study, two lead peptides from unrelated classes of AMPs were systematically hybridized into a series of five hybrid peptides (DM1- DM5) with conserved N- and C-termini. This approach allows sequence bridging of two highly dissimilar AMPs and enables sequence-activity relationship be detailed down to single amino acid level. Presence of specific amino acids and physicochemical properties were used to describe the antipneumococcal activity of these hybrids. Results obtained suggested that cell wall and/or membrane targeting could be the principal mechanism exerted by the hybrids leading to microbial cell killing. Moreover, the pneumocidal rate was greater than penicillin (PEN). Combination treatment with both DMs and PEN produced synergism. The hybrids were also broad spectrum against multiple common clinical bacteria. Sequence analysis showed that presence of specific residues has a major role in affecting the antimicrobial and cell toxicity of the hybrids than physicochemical properties. Future studies should continue to investigate the mechanisms of actions, in vivo therapeutic potential, and improve rational peptide design based on the current strategy. PMID:25985150

  4. Differential Effects of Penicillin Binding Protein Deletion on the Susceptibility of Enterococcus faecium to Cationic Peptide Antibiotics

    PubMed Central

    Kumaraswamy, Monika; Nonejuie, Poochit; Werth, Brian J.; Rybak, Micahel J.; Pogliano, Joseph; Rice, Louis B.; Nizet, Victor

    2015-01-01

    Beta-lactam antibiotics sensitize Enterococcus faecium to killing by endogenous antimicrobial peptides (AMPs) of the innate immune system and daptomycin through mechanisms yet to be elucidated. It has been speculated that beta-lactam inactivation of select E. faecium penicillin binding proteins (PBPs) may play a pivotal role in this sensitization process. To characterize the specific PBP inactivation that may be responsible for these phenotypes, we utilized a previously characterized set of E. faecium PBP knockout mutants to determine the effects of such mutations on the activity of daptomycin and the AMP human cathelicidin (LL-37). Enhanced susceptibility to daptomycin was dependent more on a cumulative effect of multiple PBP deletions than on inactivation of any single specific PBP. Selective knockout of PBPZ rendered E. faecium more vulnerable to killing by both recombinant LL-37 and human neutrophils, which produce the antimicrobial peptide in high quantities. Pharmacotherapy targeting multiple PBPs may be used as adjunctive therapy with daptomycin to treat difficult E. faecium infections. PMID:26195528

  5. Penicillin acylases revisited: importance beyond their industrial utility.

    PubMed

    Avinash, Vellore Sunder; Pundle, Archana Vishnu; Ramasamy, Sureshkumar; Suresh, Cheravakkattu Gopalan

    2016-01-01

    It is of great importance to study the physiological roles of enzymes in nature; however, in some cases, it is not easily apparent. Penicillin acylases are pharmaceutically important enzymes that cleave the acyl side chains of penicillins, thus paving the way for production of newer semi-synthetic antibiotics. They are classified according to the type of penicillin (G or V) that they preferentially hydrolyze. Penicillin acylases are also used in the resolution of racemic mixtures and peptide synthesis. However, it is rather unfortunate that the focus on the use of penicillin acylases for industrial applications has stolen the spotlight from the study of the importance of these enzymes in natural metabolism. The penicillin acylases, so far characterized from different organisms, show differences in their structural nature and substrate spectrum. These enzymes are also closely related to the bacterial signalling phenomenon, quorum sensing, as detailed in this review. This review details studies on biochemical and structural characteristics of recently discovered penicillin acylases. We also attempt to organize the available insights into the possible in vivo role of penicillin acylases and related enzymes and emphasize the need to refocus research efforts in this direction. PMID:25430891

  6. Hitler's penicillin.

    PubMed

    Wainwright, Milton

    2004-01-01

    During the Second World War, the Germans and their Axis partners could only produce relatively small amounts of penicillin, certainly never enough to meet their military needs; as a result, they had to rely upon the far less effective sulfonamides. One physician who put penicillin to effective use was Hitler's doctor, Theodore Morell. Morell treated the Führer with penicillin on a number of occasions, most notably following the failed assassination attempt in July 1944. Some of this penicillin appears to have been captured from, or inadvertently supplied by, the Allies, raising the intriguing possibility that Allied penicillin saved Hitler's life. PMID:15259203

  7. Structural and computational analysis of peptide recognition mechanism of class-C type penicillin binding protein, alkaline D-peptidase from Bacillus cereus DF4-B.

    PubMed

    Nakano, Shogo; Okazaki, Seiji; Ishitsubo, Erika; Kawahara, Nobuhiro; Komeda, Hidenobu; Tokiwa, Hiroaki; Asano, Yasuhisa

    2015-01-01

    Alkaline D-peptidase from Bacillus cereus DF4-B, called ADP, is a D-stereospecific endopeptidase reacting with oligopeptides containing D-phenylalanine (D-Phe) at N-terminal penultimate residue. ADP has attracted increasing attention because it is useful as a catalyst for synthesis of D-Phe oligopeptides or, with the help of substrate mimetics, L-amino acid peptides and proteins. Structure and functional analysis of ADP is expected to elucidate molecular mechanism of ADP. In this study, the crystal structure of ADP (apo) form was determined at 2.1 Å resolution. The fold of ADP is similar to that of the class C penicillin-binding proteins of type-AmpH. Docking simulations and fragment molecular orbital analyses of two peptides, (D-Phe)4 and (D-Phe)2-(L-Phe)2, with the putative substrate binding sites of ADP indicated that the P1 residue of the peptide interacts with hydrophobic residues at the S1 site of ADP. Furthermore, molecular dynamics simulation of ADP for 50 nsec suggested that the ADP forms large cavity at the active site. Formation of the cavity suggested that the ADP has open state in the solution. For the ADP, having the open state is convenient to bind the peptides having bulky side chain, such as (D-Phe)4. Taken together, we predicted peptide recognition mechanism of ADP. PMID:26370172

  8. Specificity inversion of Ochrobactrum anthropi D-aminopeptidase to a D,D-carboxypeptidase with new penicillin binding activity by directed mutagenesis.

    PubMed

    Delmarcelle, Michaël; Boursoit, Marie-Caroline; Filée, Patrice; Baurin, Stéphane Lucius; Frère, Jean-Marie; Joris, Bernard

    2005-09-01

    The serine penicillin-recognizing proteins have been extensively studied. They show a wide range of substrate specificities accompanied by multidomain features. Their adaptation capacity has resulted in the emergence of pathogenic bacteria resistant to beta-lactam antibiotics. The most divergent enzymatic activities in this protein family are those of the Ochrobactrum anthropi D-aminopeptidase and of the Streptomyces R61 D,D-carboxypeptidase/transpeptidase. With the help of structural data, we have attempted to identify the factors responsible for this opposite specificity. A loop deletion mutant of the Ochrobactrum anthropi D-aminopeptidase lost its original activity in favor of a new penicillin-binding activity. D-aminopeptidase activity of the deletion mutant can be restored by complementation with another deletion mutant corresponding to the noncatalytic domain of the wild-type enzyme. By a second step site-directed mutagenesis, the specificity of the Ochrobactrum anthropi D-aminopeptidase was inverted to a D,D-carboxypeptidase specificity. These results imply a core enzyme with high diversity potential surrounded by specificity modulators. It is the first example of drastic specificity change in the serine penicillin-recognizing proteins. These results open new perspectives in the conception of new enzymes with nonnatural specificities. The structure/specificity relationship in the serine penicillin-recognizing proteins are discussed. PMID:16131658

  9. Chemical Reactions Directed Peptide Self-Assembly

    PubMed Central

    Rasale, Dnyaneshwar B.; Das, Apurba K.

    2015-01-01

    Fabrication of self-assembled nanostructures is one of the important aspects in nanoscience and nanotechnology. The study of self-assembled soft materials remains an area of interest due to their potential applications in biomedicine. The versatile properties of soft materials can be tuned using a bottom up approach of small molecules. Peptide based self-assembly has significant impact in biology because of its unique features such as biocompatibility, straight peptide chain and the presence of different side chain functionality. These unique features explore peptides in various self-assembly process. In this review, we briefly introduce chemical reaction-mediated peptide self-assembly. Herein, we have emphasised enzymes, native chemical ligation and photochemical reactions in the exploration of peptide self-assembly. PMID:25984603

  10. Penicillin G Benzathine Injection

    MedlinePlus

    ... to treat and prevent certain infections caused by bacteria. Penicillin G benzathine injection is in a class of antibiotics called penicillins. It works by killing bacteria that cause infections.Antibiotics such as penicillin G ...

  11. Penicillin G Procaine Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria. Penicillin G procaine injection should not be used ... of medications called penicillins. It works by killing bacteria that cause infections.Antibiotics such as penicillin G ...

  12. Template-Directed Ligation of Peptides to Oligonucleotides

    NASA Technical Reports Server (NTRS)

    Bruick, Richard K.; Dawson, Philip E.; Kent, Stephen BH; Usman, Nassim; Joyce, Gerald F.

    1996-01-01

    Synthetic oligonucleotides and peptides have enjoyed a wide range of applications in both biology and chemistry. As a consequence, oligonucleotide-peptide conjugates have received considerable attention, most notably in the development of antisense constructs with improved pharmacological properties. In addition, oligonucleotide-peptide conjugates have been used as molecular tags, in the assembly of supramolecular arrays and in the construction of encoded combinatorial libraries. To make these chimeric molecules more accessible for a broad range of investigations, we sought to develop a facile method for joining fully deprotected oligonucleotides and peptides through a stable amide bond linkage. Furthermore, we wished to make this ligation reaction addressable, enabling one to direct the ligation of specific oligonucleotide and peptide components.To confer specificity and accelerate the rate of the reaction, the ligation process was designed to be dependent on the presence of a complementary oligonucleotide template.

  13. Penicillin and the reconstruction of Japan.

    PubMed

    Cozzoli, Daniele

    2014-01-01

    This paper explores postwar American strategies regarding penicillin in Japan. Perceived as both an American gift and a symbol of reconstruction, penicillin played a singular role in Washington's postwar policies towards Europe and Japan. Washington encouraged US pharmaceutical companies to penetrate Europe but sought to protect intra-European trade. In Japan, however, importing penicillin from the US or establishing private American factories was forbidden. Jackson W. Foster implemented a smaller-scale, military-directed version of the US's wartime penicillin project. In this paper, it is argued that the MacArthur administration aimed to boost Japanese penicillin production and transfer American industrial culture to Japan. This was initially a major success. However, the Japanese pharmaceutical industry failed to break down barriers to market entry established by first movers and, consequently, was uncompetitive throughout the twentieth century. This paper regards the American penicillin project in Japan as a factor in the weakness of the postwar Japanese pharmaceutical industry. PMID:26054211

  14. Penicillin G Benzathine and Penicillin G Procaine Injection

    MedlinePlus

    ... to treat and prevent certain infections caused by bacteria. Penicillin G benzathine and penicillin G procaine injection ... of medications called penicillins. It works by killing bacteria that cause infections.Antibiotics such as penicillin G ...

  15. Penicillin V Potassium Oral

    MedlinePlus

    Penicillin V potassium is an antibiotic used to treat certain infections caused by bacteria such as pneumonia, ... Penicillin V potassium comes as a tablet and liquid to take by mouth. It is usually taken ...

  16. Temperature sensitive peptides: Engineering hyperthermia-directed therapeutics

    PubMed Central

    MACKAY, J. ANDREW; CHILKOTI, ASHUTOSH

    2009-01-01

    Purpose Recent progress suggests that short peptide motifs can be engineered into biopolymers with specific temperature dependent behavior. This review discusses peptide motifs capable of thermo-responsive behavior, and broadly summarizes design approaches that exploit these peptides as drug carriers. This review focuses on one class of thermally responsive peptide-based biopolymers, elastin-like polypeptides in greater detail. Analysis Four peptide motifs are presented based on leucine zippers, human collagen, human elastin, and silkworm silk that are potential building blocks for thermally responsive biopolymers. When these short motifs (<7 amino acids) are repeated many times, they generate biopolymers with higher order structure and complex temperature triggered behaviors. These structures are thermodynamically modulated, making them intrinsically temperature sensitive. These four motifs can be categorized by the directionality and reversibility of association. Elastin-like polypeptides (ELPs) are one promising motif that reversibly associates during heating. ELPs aggregate sharply above an inverse phase transition temperature, which depends on polymer hydrophobicity, molecular weight, and concentration. ELPs can be modified with chemotherapeutics, are biodegradable, are biocompatible, have low immunogenicity, and have terminal pharmacokinetic half-lives >8 h. ELP block copolymers can reversibly form micelles in response to hyperthermia, and this behavior can modulate the binding avidity of peptide ligands. When high molecular weight ELPs are systemically administered to mice they accumulate in tumors; furthermore, hyperthermia can initiate the ELP phase transition and double the concentration of peptide in the tumor. Conclusions Temperature sensitive peptides are a powerful engineering platform that will enable new strategies for hyperthermia-directed drug delivery. PMID:18608590

  17. Development of a direct ELISA based on carboxy-terminal of penicillin-binding protein BlaR for the detection of β-lactam antibiotics in foods.

    PubMed

    Peng, Juan; Cheng, Guyue; Huang, Lingli; Wang, Yulian; Hao, Haihong; Peng, Dapeng; Liu, Zhenli; Yuan, Zonghui

    2013-11-01

    β-Lactam antibiotics, including penicillins and cephalosporins, are commonly used in veterinary medicine. Illegal use and abuse of β-lactams could cause allergy and selected bacterial resistance. BlaR-CTD, the carboxy-terminal of penicillin-recognizing protein BlaR from Bacillus licheniformis ATCC 14580, was utilized in this study to develop a receptor-based ELISA for detection and determination of β-lactam antibiotics in milk, beef, and chicken. This assay was based on directly competitive inhibition of binding of horseradish peroxidase-labeled ampicillin to the immobilized BlaR-CTD by β-lactams. The assay was developed as screening test with the option as semiquantitative assay, when the identity of a single type of residual β-lactam was known. The IC50 values of 15 β-lactam antibiotics, including benzylpenicillin, ampicillin, amoxicillin, dicloxacillin, oxacillin, nafcillin, cefapirin, cefoperazone, cefalotin, cefazolin, cefquinome, ceftriaxone, cefotaxime, cefalexin, ceftiofur and its metabolite desfuroylceftiofur were evaluated and ranged from 0.18 to 170.81 μg L(-1). Simple sample extraction method was carried out with only phosphate-buffered saline, and the recoveries of selected β-lactam antibiotics in milk, beef, and chicken were in the range of 53.27 to 128.29 %, most ranging from 60 to 120 %. The inter-assay variability was below 30 %. Limits of detection in milk, beef, and chicken muscles with cefquinome matrix calibration were 2.10, 30.68, and 31.13 μg kg(-1), respectively. This study firstly established a rapid, simple, and accurate method for simultaneous detection of 15 β-lactams in edible tissues, among which 11 β-lactams controlled by European Union could be detected below maximum residue limits. PMID:24013636

  18. Penicillin G (Potassium, Sodium) Injection

    MedlinePlus

    ... to treat and prevent certain infections caused by bacteria. Penicillin G injection is in a class of medications called penicillins. It works by killing bacteria that cause infections.Antibiotics such as penicillin G ...

  19. The direct peptide reactivity assay: selectivity of chemical respiratory allergens.

    PubMed

    Lalko, Jon F; Kimber, Ian; Gerberick, G Frank; Foertsch, Leslie M; Api, Anne Marie; Dearman, Rebecca J

    2012-10-01

    It is well known that some chemicals are capable of causing allergic diseases of the skin and respiratory tract. Commonly, though not exclusively, chemical allergens are associated with the selective development of skin or respiratory sensitization. The reason for this divergence is unclear, although it is hypothesized that the nature of interactions between the chemical hapten and proteins is influential. The direct peptide reactivity assay (DPRA) has been developed as a screen for the identification of skin-sensitizing chemicals, and here we describe the use of this method to explore whether differences exist between skin and respiratory allergens with respect to their peptide-binding properties. Known skin and respiratory sensitizers were reacted with synthetic peptides containing either lysine (Lys) or cysteine (Cys) for 24 h. The samples were analyzed by HPLC/UV, and the loss of peptide from the reaction mixture was expressed as the percent depletion compared with the control. The potential for preferential reactivity was evaluated by comparing the ratio of Lys to Cys depletion (Lys:Cys ratio). The results demonstrate that the majority of respiratory allergens are reactive in the DPRA, and that in contrast to most skin-sensitizing chemicals, preferentially react with the Lys peptide. These data suggest that skin and respiratory chemical allergens can result in different protein conjugates, which may in turn influence the quality of induced immune responses. Overall, these investigations reveal that the DPRA has considerable potential to be incorporated into tiered testing approaches for the identification and characterization of chemical respiratory allergens. PMID:22713598

  20. Penicillin G Procaine Injection

    MedlinePlus

    Duracillin A-S ® ... Pfizerpen A-S® ... injection should not be used to treat gonorrhea (a sexually transmitted disease) or early in the treatment ... serious infections. Penicillin G procaine injection is in a class of medications called penicillins. It works by ...

  1. Penicillin V Potassium Oral

    MedlinePlus

    V-Cillin K® ... Penicillin V potassium is an antibiotic used to treat certain infections caused by bacteria such as pneumonia, scarlet fever, ... Penicillin V potassium comes as a tablet and liquid to take by mouth. It is usually taken every 6 ...

  2. Overview of penicillin allergy.

    PubMed

    Chang, Christopher; Mahmood, Mubashar M; Teuber, Suzanne S; Gershwin, M Eric

    2012-08-01

    Allergy to penicillin is the most commonly reported antibiotic allergy. However, most patients who report a positive history of a prior reaction to penicillin are not found to be allergic to penicillin upon skin testing. Often, this history is vague or based on a parent's recollection of an event that occurred in the distant past. Avoidance of penicillin based on self-reported allergic history alone often leads to the use of an alternate antibiotic with greater cost or side effect profile. Patients with a negative skin test to both major and minor determinants may generally be given penicillin, with a statistical risk of developing an allergic reaction similar to that observed in the general population. A more cautious approach in these cases where the degree of suspicion is low, an allergic etiology is unproven, or there is a negative skin test, is to do a graded challenge. If the skin test is positive, an alternate antibiotic should be used. If, however, an alternate antibiotic is not available, then desensitization may be performed, but there are limitations to desensitization as well, and tolerance is not permanent. Avoidance of cephalosporins may be recommended in cases of penicillin allergy, but newer generation cephalosporins have demonstrate less cross-reactivity to penicillin than earlier generation ones. Desensitization protocols for cephalosporins are available but not standardized. The mechanisms of antibiotic sensitization are not clearly understood. PMID:21789743

  3. Untoward penicillin reactions

    PubMed Central

    Guthe, T.; Idsöe, O.; Willcox, R. R.

    1958-01-01

    The literature on untoward reactions following the administration of penicillin is reviewed. These reactions, including a certain number of deaths which have been reported, are of particular interest to health administrations and to WHO in view of the large-scale programmes for controlling the treponematoses which are now under way—programmes affecting millions of people in many parts of the world. The most serious problems are anaphylactic sensitivity phenomena and superinfection or cross-infection with penicillin-resistant organisms, and the reactions involved range in intensity from the mildest to the fatal; the incidence of the latter is estimated at 0.1-0.3 per million injections. The authors point out that with increasing use of penicillin, more persons are likely to become sensitized and the number of reactions can therefore be expected to rise. The best prevention against such an increase is the restriction of the unnecessary use of penicillin. PMID:13596877

  4. A Cell-Penetrating Peptide with a Guanidinylethyl Amine Structure Directed to Gene Delivery

    PubMed Central

    Oba, Makoto; Kato, Takuma; Furukawa, Kaori; Tanaka, Masakazu

    2016-01-01

    A peptide composed of lysine with a guanidinylethyl (GEt) amine structure in the side chain [Lys(GEt)] was developed as a cell-penetrating peptide directed to plasmid DNA (pDNA) delivery. The GEt amine adopted a diprotonated form at neutral pH, which may have led to the more efficient cellular uptake of a Lys(GEt)-peptide than an arginine-peptide at a low concentration. Lys(GEt)-peptide/pDNA complexes showed the highest transfection efficiency due to efficient endosomal escape without any cytotoxicity. Lys(GEt)-peptide may be a promising candidate as a gene delivery carrier. PMID:26814673

  5. A Cell-Penetrating Peptide with a Guanidinylethyl Amine Structure Directed to Gene Delivery

    NASA Astrophysics Data System (ADS)

    Oba, Makoto; Kato, Takuma; Furukawa, Kaori; Tanaka, Masakazu

    2016-01-01

    A peptide composed of lysine with a guanidinylethyl (GEt) amine structure in the side chain [Lys(GEt)] was developed as a cell-penetrating peptide directed to plasmid DNA (pDNA) delivery. The GEt amine adopted a diprotonated form at neutral pH, which may have led to the more efficient cellular uptake of a Lys(GEt)-peptide than an arginine-peptide at a low concentration. Lys(GEt)-peptide/pDNA complexes showed the highest transfection efficiency due to efficient endosomal escape without any cytotoxicity. Lys(GEt)-peptide may be a promising candidate as a gene delivery carrier.

  6. Penicillin G Benzathine and Penicillin G Procaine Injection

    MedlinePlus

    ... It works by killing bacteria that cause infections.Antibiotics such as penicillin G benzathine and penicillin G ... for colds, flu, or other viral infections. Taking antibiotics when they are not needed increases your risk ...

  7. Peptide-directed self-assembly of hydrogels

    PubMed Central

    Kopeček, Jindřich; Yang, Jiyuan

    2009-01-01

    This review focuses on the self-assembly of macromolecules mediated by the biorecognition of peptide/protein domains. Structures forming α-helices and β-sheets have been used to mediate self-assembly into hydrogels of peptides, reactive copolymers and peptide motifs, block copolymers, and graft copolymers. Structural factors governing the self-assembly of these molecules into precisely defined three-dimensional structures (hydrogels) are reviewed. The incorporation of peptide motifs into hybrid systems, composed of synthetic and natural macromolecules, enhances design opportunities for new biomaterials when compared to individual components. PMID:18952513

  8. pH-directed self-assembling helical peptide conformation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The beta-sheet and alpha-helix peptide conformation are two of the most fundamentally ordered secondary structures found in proteins and peptides. They also give rise to self-assembling motifs that form macromolecular channels and nanostructures. Through design these conformations can yield enhance...

  9. Efficient generation of peptide hydrazides via direct hydrazinolysis of Peptidyl-Wang-TentaGel resins.

    PubMed

    Bello, Claudia; Kikul, Frauke; Becker, Christian F W

    2015-03-01

    Peptide hydrazides are valuable building blocks in peptide and protein chemistry, e.g. as precursors of peptide thioesters that allow the preparation of these important intermediates under mild conditions. Additional robust and versatile methods for the generation of peptide hydrazides from standard solid supports are therefore highly desired in order to facilitate access to peptide thioester via Fmoc-based SPPS. Here, the efficient generation of peptide hydrazides from conventional 4-hydroxymethyl phenol Wang-TentalGel peptidyl resins is described. Direct hydrazinolysis of a 19mer mucin1 peptide gives the protected peptide hydrazide in excellent yields. Testing a series of octapeptides carrying the 20 common proteinogenic amino acids at their C-terminus led to preparation of all corresponding peptide hydrazides in very good to excellent yields and purities. The available set of octapeptides allowed analyzing the influence of the nature of the C-terminal amino acid and of the solvent on the hydrazinolysis reaction. Furthermore, the compatibility of the method with posttranslational modifications (here glycosylation) and with potentially sensitive functional groups in amino acid side chains makes this approach a viable alternative for obtaining peptide hydrazides. It combines the advantages of a straightforward synthesis with stereochemical stability and flexibility, as it provides easy access to the peptide acid and the peptide thioester (via the hydrazide) from the same solid support. PMID:25648984

  10. Chemoenzymatic and Template-Directed Synthesis of Bioactive Macrocyclic Peptides

    PubMed Central

    Grünewald, Jan; Marahiel, Mohamed A.

    2006-01-01

    Non-ribosomally synthesized peptides have compelling biological activities ranging from antimicrobial to immunosuppressive and from cytostatic to antitumor. The broad spectrum of applications in modern medicine is reflected in the great structural diversity of these natural products. They contain unique building blocks, such as d-amino acids, fatty acids, sugar moieties, and heterocyclic elements, as well as halogenated, methylated, and formylated residues. In the past decades, significant progress has been made toward the understanding of the biosynthesis of these secondary metabolites by nonribosomal peptide synthetases (NRPSs) and their associated tailoring enzymes. Guided by this knowledge, researchers genetically redesigned the NRPS template to synthesize new peptide products. Moreover, chemoenzymatic strategies were developed to rationally engineer nonribosomal peptides products in order to increase or alter their bioactivities. Specifically, chemical synthesis combined with peptide cyclization mediated by nonribosomal thioesterase domains enabled the synthesis of glycosylated cyclopeptides, inhibitors of integrin receptors, peptide/polyketide hybrids, lipopeptide antibiotics, and streptogramin B antibiotics. In addition to the synthetic potential of these cyclization catalysts, which is the main focus of this review, different enzymes for tailoring of peptide scaffolds as well as the manipulation of carrier proteins with reporter-labeled coenzyme A analogs are discussed. PMID:16524919

  11. Some Active Derivatives of Penicillin

    PubMed Central

    Brown, Loman D.; Zygmunt, Walter A.; Stavely, Homer E.

    1969-01-01

    The antibacterial activities of a number of amide derivatives of penicillin against both penicillin-sensitive and penicillin-resistant cultures were determined. Several of them were found to possess significant inhibitory activity against certain gram-positive bacteria. The amides, although resistant to the destructive action of β-lactamase, did not protect G in competitive experiments. One derivative, the O-benzylhydroxamide of penicillin G, was active against six or eight penicillin-resistant strains of Staphylococcus aureus (minimal inhibitory concentration, 0.2 μg/ml or less), but was found to have only a minimal in vivo activity against mouse Streptococcus infections. PMID:5780394

  12. Twin disulfides for orthogonal disulfide pairing and the directed folding of multicyclic peptides

    NASA Astrophysics Data System (ADS)

    Wu, Chuanliu; Leroux, Jean-Christophe; Gauthier, Marc A.

    2012-12-01

    Multicyclic peptides are emerging as an exciting platform for drug and targeted ligand discovery owing to their expected greater target affinity/selectivity/stability versus linear or monocyclic peptides. However, although the precise pairing of cysteine residues in proteins is routinely achieved in nature, the rational pairing of cysteine residues within polypeptides is a long-standing challenge for the preparation of multicyclic species containing several disulfide bridges. Here, we present an efficient and straightforward approach for directing the intermolecular and intramolecular pairing of cysteine residues within peptides using a minimal CXC motif. Orthogonal disulfide pairing can be exploited in complex redox media to rationally produce dimeric peptides and bi/tricyclic peptides from fully reduced peptides containing 1-6 cysteine residues. This strategy, which does not rely on extensive manipulation of the primary sequence, post-translational modification or protecting groups, should greatly benefit the development of multicyclic peptide therapeutics and targeting ligands.

  13. Orthogonal Cysteine-Penicillamine Disulfide Pairing for Directing the Oxidative Folding of Peptides.

    PubMed

    Zheng, Yiwu; Zhai, Linxiang; Zhao, Yibing; Wu, Chuanliu

    2015-12-01

    Precise disulfide pairing in synthetic peptides usually is achieved using orthogonal protecting group strategies or relies on primary sequence manipulation. Orthogonal disulfide pairing technology should be promising for directing the rational folding of multicyclic peptides from the fully reduced peptides. Here, we report a discovery on the orthogonality between heterodisulfide pairing of cysteine (Cys) and penicillamine (Pen) and formation of Cys-Cys/Pen-Pen homodisulfides. The orthogonal Cys-Pen disulfide pairing can be exploited for highly selective production of certain (multi)cyclic structures (or even a sole structure without isomers) through direct oxidation in air or thiol-disulfide exchanges in redox media. This strategy makes rational folding of multicyclic peptides without protecting groups, sequence manipulation, and complex synthetic reactions a reality, thus providing invaluable assets to peptide communities, and should greatly benefit the development of multicyclic peptide therapeutics and ligands. PMID:26588670

  14. Proteome Analysis of the Penicillin Producer Penicillium chrysogenum

    PubMed Central

    Jami, Mohammad-Saeid; Barreiro, Carlos; García-Estrada, Carlos; Martín, Juan-Francisco

    2010-01-01

    Proteomics is a powerful tool to understand the molecular mechanisms causing the production of high penicillin titers by industrial strains of the filamentous fungus Penicillium chrysogenum as the result of strain improvement programs. Penicillin biosynthesis is an excellent model system for many other bioactive microbial metabolites. The recent publication of the P. chrysogenum genome has established the basis to understand the molecular processes underlying penicillin overproduction. We report here the proteome reference map of P. chrysogenum Wisconsin 54-1255 (the genome project reference strain) together with an in-depth study of the changes produced in three different strains of this filamentous fungus during industrial strain improvement. Two-dimensional gel electrophoresis, peptide mass fingerprinting, and tandem mass spectrometry were used for protein identification. Around 1000 spots were visualized by “blue silver” colloidal Coomassie staining in a non-linear pI range from 3 to 10 with high resolution, which allowed the identification of 950 proteins (549 different proteins and isoforms). Comparison among the cytosolic proteomes of the wild-type NRRL 1951, Wisconsin 54-1255 (an improved, moderate penicillin producer), and AS-P-78 (a penicillin high producer) strains indicated that global metabolic reorganizations occurred during the strain improvement program. The main changes observed in the high producer strains were increases of cysteine biosynthesis (a penicillin precursor), enzymes of the pentose phosphate pathway, and stress response proteins together with a reduction in virulence and in the biosynthesis of other secondary metabolites different from penicillin (pigments and isoflavonoids). In the wild-type strain, we identified enzymes to utilize cellulose, sorbitol, and other carbon sources that have been lost in the high penicillin producer strains. Changes in the levels of a few specific proteins correlated well with the improved penicillin

  15. Directed evolution of FLS2 towards novel flagellin peptide recognition

    DOE PAGESBeta

    Helft, Laura; Thompson, Mikayla; Bent, Andrew F.

    2016-06-06

    Microbe-associated molecular patterns (MAMPs) are molecules, or domains within molecules, that are conserved across microbial taxa and can be recognized by a plant or animal immune system. Although MAMP receptors have evolved to recognize conserved epitopes, the MAMPs in some microbial species or strains have diverged sufficiently to render them unrecognizable by some host immune systems. In this study, we carried out in vitro evolution of the Arabidopsis thaliana flagellin receptor FLAGELLIN-SENSING 2 (FLS2) to isolate derivatives that recognize one or more flagellin peptides from bacteria for which the wild type Arabidopsis FLS2 confers little or no response. A targetedmore » approach generated amino acid variation at FLS2 residues in a region previously implicated in flagellin recognition. The primary screen tested for elevated response to the canonical flagellin peptide from Pseudomonas aeruginosa, flg22. From this pool, we then identified five alleles of FLS2 that confer modest (quantitatively partial) recognition of an Erwinia amylovora flagellin peptide. Use of this Erwinia-based flagellin peptide to stimulate Arabidopsis plants expressing the resulting FLS2 alleles did not lead to a detectable reduction of virulent P. syringae pv. tomato growth. However, combination of two identified mutations into a single allele further increased FLS2-mediated responses to the E. amylovora flagellin peptide. As a result, these studies demonstrate the potential to raise the sensitivity of MAMP receptors toward particular targets.« less

  16. Directed Evolution of FLS2 towards Novel Flagellin Peptide Recognition.

    PubMed

    Helft, Laura; Thompson, Mikayla; Bent, Andrew F

    2016-01-01

    Microbe-associated molecular patterns (MAMPs) are molecules, or domains within molecules, that are conserved across microbial taxa and can be recognized by a plant or animal immune system. Although MAMP receptors have evolved to recognize conserved epitopes, the MAMPs in some microbial species or strains have diverged sufficiently to render them unrecognizable by some host immune systems. In this study, we carried out in vitro evolution of the Arabidopsis thaliana flagellin receptor FLAGELLIN-SENSING 2 (FLS2) to isolate derivatives that recognize one or more flagellin peptides from bacteria for which the wild-type Arabidopsis FLS2 confers little or no response. A targeted approach generated amino acid variation at FLS2 residues in a region previously implicated in flagellin recognition. The primary screen tested for elevated response to the canonical flagellin peptide from Pseudomonas aeruginosa, flg22. From this pool, we then identified five alleles of FLS2 that confer modest (quantitatively partial) recognition of an Erwinia amylovora flagellin peptide. Use of this Erwinia-based flagellin peptide to stimulate Arabidopsis plants expressing the resulting FLS2 alleles did not lead to a detectable reduction of virulent P. syringae pv. tomato growth. However, combination of two identified mutations into a single allele further increased FLS2-mediated responses to the E. amylovora flagellin peptide. These studies demonstrate the potential to raise the sensitivity of MAMP receptors toward particular targets. PMID:27270917

  17. Directed Evolution of FLS2 towards Novel Flagellin Peptide Recognition

    PubMed Central

    Helft, Laura; Thompson, Mikayla

    2016-01-01

    Microbe-associated molecular patterns (MAMPs) are molecules, or domains within molecules, that are conserved across microbial taxa and can be recognized by a plant or animal immune system. Although MAMP receptors have evolved to recognize conserved epitopes, the MAMPs in some microbial species or strains have diverged sufficiently to render them unrecognizable by some host immune systems. In this study, we carried out in vitro evolution of the Arabidopsis thaliana flagellin receptor FLAGELLIN-SENSING 2 (FLS2) to isolate derivatives that recognize one or more flagellin peptides from bacteria for which the wild-type Arabidopsis FLS2 confers little or no response. A targeted approach generated amino acid variation at FLS2 residues in a region previously implicated in flagellin recognition. The primary screen tested for elevated response to the canonical flagellin peptide from Pseudomonas aeruginosa, flg22. From this pool, we then identified five alleles of FLS2 that confer modest (quantitatively partial) recognition of an Erwinia amylovora flagellin peptide. Use of this Erwinia-based flagellin peptide to stimulate Arabidopsis plants expressing the resulting FLS2 alleles did not lead to a detectable reduction of virulent P. syringae pv. tomato growth. However, combination of two identified mutations into a single allele further increased FLS2-mediated responses to the E. amylovora flagellin peptide. These studies demonstrate the potential to raise the sensitivity of MAMP receptors toward particular targets. PMID:27270917

  18. LHRH-Conjugated Lytic Peptides Directly Target Prostate Cancer Cells

    PubMed Central

    Yates, Clayton; Sharp, Starlette; Jones, Jacqueline; Topps, Daphne; Coleman, Mathew; Aneja, Ritu; Jaynes, Jesse; Turner, Timothy

    2010-01-01

    Prostate cancer is the second leading cause of cancer deaths among men. For patients with hormone-refractory disease, few treatments are available once the tumor has metastasized beyond the prostate. In the present study, two conjugated lytic peptide sequences (named JCHLHRH and JC21LHRH) were designed to target luteinizing hormone-releasing hormone receptors (LHRH-R). Our results indicate that human prostate cancer cell lines were sensitive to both LHRH-conjugated and non-conjugated lytic peptides, with IC50 concentrations for LNCaP cells, 4.4 and 9.1 µM; for DU-145 cells, 4.8 and 5.7 µM; and for PC-3 cells, 4.4 and 8.2 µM, respectively. JCHLHRH and JC21LHRH were nontoxic to normal primary human prostate epithelial cells or to bone marrow stromal cells in co-culture. There were morphological changes in PC-3 cells after 3 hr of exposure to either peptide; after 6 hr, there were significant reductions in cell numbers. Exposure of PC-3 cells for 24 hr to either JCHLHRH or JC21LHRH blocked their growth over 3 days. Since JCHLHRH and JC21LHRH have specificity for and anti-proliferative activity against tumor cells, and low toxicity for normal prostate cells, these peptides could serve as a new type of therapy for prostate cancer. PMID:20869347

  19. 21 CFR 211.176 - Penicillin contamination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Penicillin contamination. 211.176 Section 211.176... Penicillin contamination. If a reasonable possibility exists that a non-penicillin drug product has been exposed to cross-contamination with penicillin, the non-penicillin drug product shall be tested for...

  20. 21 CFR 211.176 - Penicillin contamination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Penicillin contamination. 211.176 Section 211.176... Penicillin contamination. If a reasonable possibility exists that a non-penicillin drug product has been exposed to cross-contamination with penicillin, the non-penicillin drug product shall be tested for...

  1. 21 CFR 558.460 - Penicillin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin. 558.460 Section 558.460 Food and Drugs... Animal Feeds § 558.460 Penicillin. (a) Specifications. As penicillin procaine G or feed grade penicillin.... (1) It is used as follows: Penicillin in grams per ton Combination in grams per ton Indications...

  2. 21 CFR 558.460 - Penicillin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin. 558.460 Section 558.460 Food and Drugs... Animal Feeds § 558.460 Penicillin. (a) Specifications. As penicillin procaine G or feed grade penicillin.... (1) It is used as follows: Penicillin in grams per ton Combination in grams per ton Indications...

  3. 21 CFR 558.460 - Penicillin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin. 558.460 Section 558.460 Food and Drugs... Animal Feeds § 558.460 Penicillin. (a) Specifications. As penicillin procaine G or feed grade penicillin.... (1) It is used as follows: Penicillin in grams per ton Combination in grams per ton Indications...

  4. 21 CFR 558.460 - Penicillin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin. 558.460 Section 558.460 Food and Drugs... Animal Feeds § 558.460 Penicillin. (a) Specifications. As penicillin procaine G or feed grade penicillin.... (1) It is used as follows: Penicillin in grams per ton Combination in grams per ton Indications...

  5. 21 CFR 211.176 - Penicillin contamination.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Penicillin contamination. 211.176 Section 211.176... Penicillin contamination. If a reasonable possibility exists that a non-penicillin drug product has been exposed to cross-contamination with penicillin, the non-penicillin drug product shall be tested for...

  6. 21 CFR 211.176 - Penicillin contamination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Penicillin contamination. 211.176 Section 211.176... Penicillin contamination. If a reasonable possibility exists that a non-penicillin drug product has been exposed to cross-contamination with penicillin, the non-penicillin drug product shall be tested for...

  7. 21 CFR 211.176 - Penicillin contamination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Penicillin contamination. 211.176 Section 211.176... Penicillin contamination. If a reasonable possibility exists that a non-penicillin drug product has been exposed to cross-contamination with penicillin, the non-penicillin drug product shall be tested for...

  8. Application of a liquid chromatographic procedure for the analysis of penicillin antibiotics in biological fluids and pharmaceutical formulations using sodium dodecyl sulphate/propanol mobile phases and direct injection.

    PubMed

    Rambla-Alegre, Maria; Martí-Centelles, Rosa; Esteve-Romero, Josep; Carda-Broch, Samuel

    2011-07-29

    A direct injection liquid chromatography procedure was developed for the simultaneous determination of four penicillin antibiotics (amoxicillin, ampicillin, cloxacillin and dicloxacillin) in pharmaceutical formulations and physiological fluids (urine) using hybrid micellar mobile phases. These antimicrobials are used to treat gastrointestinal and systemic infections. The four penicillins were analysed using a Zorbax C18 reversed-phase column and detected at 210 nm. These antibiotics were separated by an interpretive optimisation procedure based on the accurate description of the retention and shape of the chromatographic peaks. Antibiotics were eluted in less than 16 min with no interference by the urine protein band or endogenous compounds using the mobile phase 0.11 M sodium dodecyl sulphate-6% propanol-0.01 M NaH(2)PO(4) buffered at pH 3. The method was validated according to the Food and Drug Administration guideline, including analytical parameters such as linearity (R(2)>0.993), intra- and inter-day precisions (RSD, %: 0.1-4.4 and 1.2-5.9, respectively), and robustness for the four compounds. This method is sensitive enough for the routine analysis of penicillins at therapeutic urine levels, with limits of detection in the 1.5-15 ng mL(-1) range and limits of quantification of 50 ng mL(-1). Recoveries in a micellar medium and a spiked urine matrix were in the 92.4-108.2% and 96-110% ranges, respectively. Finally, the method was successfully applied to determine these antibiotics in urine samples and pharmaceutical formulations. PMID:21190691

  9. 21 CFR 522.1696a - Penicillin G benzathine and penicillin G procaine suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin G benzathine and penicillin G procaine... FORM NEW ANIMAL DRUGS § 522.1696a Penicillin G benzathine and penicillin G procaine suspension. (a) Specifications. Each milliliter of aqueous suspension contains penicillin G benzathine and penicillin G...

  10. 21 CFR 522.1696a - Penicillin G benzathine and penicillin G procaine suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin G benzathine and penicillin G procaine... FORM NEW ANIMAL DRUGS § 522.1696a Penicillin G benzathine and penicillin G procaine suspension. (a) Specifications. Each milliliter of aqueous suspension contains penicillin G benzathine and penicillin G...

  11. 21 CFR 522.1696a - Penicillin G benzathine and penicillin G procaine suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G benzathine and penicillin G procaine... FORM NEW ANIMAL DRUGS § 522.1696a Penicillin G benzathine and penicillin G procaine suspension. (a) Specifications. Each milliliter of aqueous suspension contains penicillin G benzathine and penicillin G...

  12. 21 CFR 522.1696a - Penicillin G benzathine and penicillin G procaine suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin G benzathine and penicillin G procaine... FORM NEW ANIMAL DRUGS § 522.1696a Penicillin G benzathine and penicillin G procaine suspension. (a) Specifications. Each milliliter of aqueous suspension contains penicillin G benzathine and penicillin G...

  13. 21 CFR 522.1696a - Penicillin G benzathine and penicillin G procaine suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin G benzathine and penicillin G procaine... FORM NEW ANIMAL DRUGS § 522.1696a Penicillin G benzathine and penicillin G procaine suspension. (a) Specifications. Each milliliter of aqueous suspension contains penicillin G benzathine and penicillin G...

  14. Elucidation of Peptide-Directed Palladium Surface Structure for Biologically Tunable Nanocatalysts

    SciTech Connect

    Bedford, Nicholas M.; Ramezani-Dakhel, Hadi; Slocik, Joseph M.; Briggs, Beverly D.; Ren, Yang; Frenkel, Anatoly I.; Petkov, Valeri; Heinz, Hendrik; Naik, Rajesh R.; Knecht, Mark R.

    2015-05-01

    Peptide-enabled synthesis of inorganic nanostructures represents an avenue to access catalytic materials with tunable and optimized properties. This is achieved via peptide complexity and programmability that is missing in traditional ligands for catalytic nanomaterials. Unfortunately, there is limited information available to correlate peptide sequence to particle structure and catalytic activity to date. As such, the application of peptide-enabled nanocatalysts remains limited to trial and error approaches. In this paper, a hybrid experimental and computational approach is introduced to systematically elucidate biomolecule-dependent structure/function relationships for peptide-capped Pd nanocatalysts. Synchrotron X-ray techniques were used to uncover substantial particle surface structural disorder, which was dependent upon the amino acid sequence of the peptide capping ligand. Nanocatalyst configurations were then determined directly from experimental data using reverse Monte Carlo methods and further refined using molecular dynamics simulation, obtaining thermodynamically stable peptide-Pd nanoparticle configurations. Sequence-dependent catalytic property differences for C-C coupling and olefin hydrogenation were then eluddated by identification of the catalytic active sites at the atomic level and quantitative prediction of relative reaction rates. This hybrid methodology provides a clear route to determine peptide-dependent structure/function relationships, enabling the generation of guidelines for catalyst design through rational tailoring of peptide sequences

  15. Advantages of RGD peptides for directing cell association with biomaterials

    PubMed Central

    Bellis, Susan L.

    2011-01-01

    Despite many years of in vitro research confirming the effectiveness of RGD in promoting cell attachment to a wide variety of biomaterials, animal studies evaluating tissue responses to implanted RGD-functionalized substrates have yielded more variable results The goals of this report are to present some of the reasons why cell culture studies may not always reliably predict in vivo responses, and more importantly, to highlight potential applications that may benefit from the use of RGD peptides. PMID:21515168

  16. Circular permutation directs orthogonal assembly in complex collagen peptide mixtures.

    PubMed

    Xu, Fei; Silva, Teresita; Joshi, Mihir; Zahid, Sohail; Nanda, Vikas

    2013-11-01

    Multiple types of natural collagens specifically assemble and co-exist in the extracellular matrix. Although noncollagenous trimerization domains facilitate the folding of triple-helical regions, it is intriguing to ask whether collagen sequences are also capable of controlling heterospecific association. In this study, we designed a model system mimicking simultaneous specific assembly of two collagen heterotrimers using a genetically inspired operation, circular permutation. Previously, surface charge-pair interactions were optimized on three collagen peptides to promote the formation of an abc-type heterotrimer. Circular permutation of these sequences retained networks of stabilizing interactions, preserving both triple-helical structure and heterospecificity of assembly. Combining original peptides A, B, and C and permuted peptides D, E, and F resulted primarily in formation of A:B:C and D:E:F, a heterospecificity of 2 of 56 possible stoichiometries. This degree of specificity in collagen molecular recognition is unprecedented in natural or synthetic collagens. Analysis of natural collagen sequences indicates low similarity between the neighboring exons. Combining the synthetic collagen model and bioinformatic analysis provides insight on how fibrillar collagens might have arisen from the duplication of smaller domains. PMID:24043622

  17. Gold-catalyzed direct alkynylation of tryptophan in peptides using TIPS-EBX

    PubMed Central

    Tolnai, Gergely L; Brand, Jonathan P

    2016-01-01

    Summary The selective functionalization of peptides containing only natural amino acids is important for the modification of biomolecules. In particular, the installation of an alkyne as a useful handle for bioconjugation is highly attractive, but the use of a carbon linker is usually required. Herein, we report the gold-catalyzed direct alkynylation of tryptophan in peptides using the hypervalent iodine reagent TIPS-EBX (1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one). The reaction proceeded in 50–78% yield under mild conditions and could be applied to peptides containing other nucleophilic and aromatic amino acids, such as serine, phenylalanine or tyrosine. PMID:27340466

  18. The Molecular Structure of Penicillin

    NASA Astrophysics Data System (ADS)

    Bentley, Ronald

    2004-10-01

    The chemical structure of penicillin was determined between 1942 and 1945 under conditions of secrecy established by the U.S. and U.K. governments. The evidence was not published in the open literature but as a monograph. This complex volume does not present a structure proof that can be readily comprehended by a student. In this article, a basic structural proof for the penicillin molecule is provided, emphasizing the chemical work. The stereochemistry of penicillin is also described, and various rearrangements are considered on the basis of the accepted β-lactam structure.

  19. 21 CFR 556.510 - Penicillin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin. 556.510 Section 556.510 Food and Drugs... Residues of New Animal Drugs § 556.510 Penicillin. Tolerances are established for residues of penicillin and the salts of penicillin in food as follows: (a) 0.05 part per million (negligible residue) in...

  20. 21 CFR 556.510 - Penicillin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin. 556.510 Section 556.510 Food and Drugs... Residues of New Animal Drugs § 556.510 Penicillin. Tolerances are established for residues of penicillin and the salts of penicillin in food as follows: (a) 0.05 part per million (negligible residue) in...

  1. 21 CFR 556.510 - Penicillin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin. 556.510 Section 556.510 Food and Drugs... Residues of New Animal Drugs § 556.510 Penicillin. Tolerances are established for residues of penicillin and the salts of penicillin in food as follows: (a) 0.05 part per million (negligible residue) in...

  2. 21 CFR 556.510 - Penicillin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin. 556.510 Section 556.510 Food and Drugs... Residues of New Animal Drugs § 556.510 Penicillin. Tolerances are established for residues of penicillin and the salts of penicillin in food as follows: (a) 0.05 part per million (negligible residue) in...

  3. 21 CFR 556.510 - Penicillin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin. 556.510 Section 556.510 Food and Drugs... Residues of New Animal Drugs § 556.510 Penicillin. Tolerances are established for residues of penicillin and the salts of penicillin in food as follows: (a) 0.05 part per million (negligible residue) in...

  4. 21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Buffered penicillin powder, penicillin powder with... FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered aqueous diluent. (a) Specifications. When reconstituted, each milliliter contains penicillin G procaine...

  5. The Molecular Structure of Penicillin

    ERIC Educational Resources Information Center

    Bentley, Ronald

    2004-01-01

    Overviews of the observations that constitute a structure proof for penicillin, specifically aimed at the general student population, are presented. Melting points and boiling points were criteria of purity and a crucial tool was microanalysis leading to empirical formulas.

  6. Direct MALDI-TOF mass spectrometric peptide profiling of neuroendocrine tissue of Drosophila.

    PubMed

    Wegener, Christian; Neupert, Susanne; Predel, Reinhard

    2010-01-01

    Direct MALDI-TOF mass spectrometric peptide profiling is increasingly used to analyze the peptide complement in the nervous system of a variety of invertebrate animals, from leech to Aplysia and many arthropod species, especially insects and crustaceans. Proper sample preparation is often the most crucial step to obtain the necessary data. Here, we describe protocols for the use of MALDI-TOF mass spectrometry to directly analyze the peptidome of neuroendocrine tissues of insects, particularly Drosophila melanogaster, by MALDI-TOF MS. PMID:20013204

  7. Pickles, pectin, and penicillin.

    PubMed

    Demain, Arnold L

    2004-01-01

    My professional life has been devoted to the study of microbial products and their biosynthesis, regulation, and overproduction. These have included primary metabolites (glutamic acid, tryptophan, inosinic acid, guanylic acid, vitamin B(12), riboflavin, pantothenic acid, ethanol, and lactic acid) and secondary metabolites (penicillin, cephalosporins, streptomycin, fosfomycin, gramicidin S, rapamycin, indolmycin, microcin B17, fumagillin, mycotoxins, Monascus pigments, and tetramethylpyrazine). Other areas included microbial nutrition, strain improvement, bioconversions of statins and beta-lactams, sporulation and germination, plasmid stability, gel microdroplets, and the production of double-stranded RNA, the polymer xanthan, and enzymes (polygalacturonase, protease, cellulase). Most of the studies were carried out with me by devoted and hardworking industrial scientists for 15 years at Merck & Co. and by similarly characterized students, postdoctorals, and visiting scientists during my 32 years at the Massachusetts Institute of Technology. I owe much of my success to my mentors from academia and industry. My recent research activities with undergraduate students at the Charles A. Dana Research Institute for Scientists Emeriti (R.I.S.E.) at Drew University have been very rewarding and are allowing me to continue my career. PMID:15487928

  8. Polyglutamate directed coupling of bioactive peptides for the delivery of osteoinductive signals on allograft bone

    PubMed Central

    Culpepper, Bonnie K.; Bonvallet, Paul P.; Reddy, Michael S.; Ponnazhagan, Selvarangan; Bellis, Susan L.

    2012-01-01

    Allograft bone is commonly used as an alternative to autograft, however allograft lacks many osteoinductive factors present in autologous bone due to processing. In this study, we investigated a method to reconstitute allograft with osteoregenerative factors. Specifically, an osteoinductive peptide from collagen I, DGEA, was engineered to express a heptaglutamate (E7) domain, which binds the hydroxyapatite within bone mineral. Addition of E7 to DGEA resulted in 9× greater peptide loading on allograft, and significantly greater retention after a 5-day interval with extensive washing. When factoring together greater initial loading and retention, the E7 domain directed a 45-fold enhancement of peptide density on the allograft surface. Peptide-coated allograft was also implanted subcutaneously into rats and it was found that E7DGEA was retained in vivo for at least 3 months. Interestingly, E7DGEA peptides injected intravenously accumulated within bone tissue, implicating a potential role for E7 domains in drug delivery to bone. Finally, we determined that, as with DGEA, the E7 modification enhanced coupling of a bioactive BMP2-derived peptide on allograft. These results suggest that E7 domains are useful for coupling many types of bone-regenerative molecules to the surface of allograft to reintroduce osteoinductive signals and potentially advance allograft treatments. PMID:23182349

  9. Direct mass spectrometric peptide profiling and sequencing of nervous tissues to identify peptides involved in male copulatory behavior in Lymnaea stagnalis

    NASA Astrophysics Data System (ADS)

    Dreisewerd, Klaus; Kingston, Robert; Geraerts, Wijnand P. M.; Li, Ka Wan

    1997-12-01

    Matrix-assisted laser desorption mass spectrometry (MALDI-MS) was performed directly on a small piece of single penis nerve of the pond snail, Lymnaea stagnalis, and reveals the presence of complex peptide profiles, including many hitherto undescribed peptides. Two of the peptides have molecular weights corresponding exactly to the previously described Lymnaea small cardioactive peptides (SCP) A and B. We confirmed their identities by structural characterization of the two peptides directly from a single penis nerve by matrix-assisted laser desorption ionization high-energy collision tandem MS analysis. MALDI-MS of nervous tissues also demonstrates that a cluster of central neurons, which send their axons to the penis nerve, contain the two peptides. As the penis nerve is the nerve that innervates the penis complex, we propose that the peptides are involved in the modulation of male copulatory processes. A bioassay indeed showed that the peptides increase the contraction frequency of the vas deference in a dose-dependent manner. The results demonstrate the potential of direct MALDI-MS analysis of nervous tissue to complement or substitute conventional biochemical techniques for the identification and localization of neuropeptides.

  10. Amyloid β peptide oligomers directly activate NMDA receptors.

    PubMed

    Texidó, Laura; Martín-Satué, Mireia; Alberdi, Elena; Solsona, Carles; Matute, Carlos

    2011-03-01

    Amyloid beta (Aβ) oligomers accumulate in the brain tissue of Alzheimer disease patients and are related to disease pathogenesis. The precise mechanisms by which Aβ oligomers cause neurotoxicity remain unknown. We recently reported that Aβ oligomers cause intracellular Ca(2+) overload and neuronal death that can be prevented by NMDA receptor antagonists. This study investigated whether Aβ oligomers directly activated NMDA receptors (NMDARs) using NR1/NR2A and NR1/NR2B receptors that were heterologously expressed in Xenopus laevis oocytes. Indeed, Aβ oligomers induced inward non-desensitizing currents that were blocked in the presence of the NMDA receptor antagonists memantine, APV, and MK-801. Intriguingly, the amplitude of the responses to Aβ oligomers was greater for NR1/NR2A heteromers than for NR1/NR2B heteromers expressed in oocytes. Consistent with these findings, we observed that the increase in the cytosolic concentration of Ca(2+) induced by Aβ oligomers in cortical neurons is prevented by AP5, a broad spectrum NMDA receptor antagonist, but slightly attenuated by ifenprodil which blocks receptors with the NR2B subunit. Together, these results indicate that Aβ oligomers directly activate NMDA receptors, particularly those with the NR2A subunit, and further suggest that drugs that attenuate the activity of such receptors may prevent Aβ damage to neurons in Alzheimeŕs disease. PMID:21349580

  11. The peptide LSARLAF causes platelet secretion and aggregation by directly activating the integrin alphaIIbbeta3.

    PubMed Central

    Derrick, J M; Taylor, D B; Loudon, R G; Gartner, T K

    1997-01-01

    A novel peptide (designed to bind to alphaIIbbeta3) caused platelet aggregation and aggregation-independent secretion of the contents of alpha-granules in an alphaIIbbeta3-dependent fashion. The agonist peptide induced secretion in the presence of prostaglandin E1. In cell-free assays, alphaIIbbeta3 bound specifically to immobilized agonist peptide and the peptide enhanced the binding of fibrinogen to immobilized alphaIIbbeta3. The agonist peptide apparently activates alphaIIbbeta3 by directly inducing a conformational change in the receptor. This change activates the platelets and causes secretion in a manner independent of fibrinogen binding. PMID:9230107

  12. 213 nm Ultraviolet Photodissociation on Peptide Anions: Radical-Directed Fragmentation Patterns

    NASA Astrophysics Data System (ADS)

    Halim, Mohammad A.; Girod, Marion; MacAleese, Luke; Lemoine, Jérôme; Antoine, Rodolphe; Dugourd, Philippe

    2016-03-01

    Characterization of acidic peptides and proteins is greatly hindered due to lack of suitable analytical techniques. Here we present the implementation of 213 nm ultraviolet photodissociation (UVPD) in high-resolution quadrupole-Orbitrap mass spectrometer in negative polarity for peptide anions. Radical-driven backbone fragmentation provides 22 distinctive fragment ion types, achieving the complete sequence coverage for all reported peptides. Hydrogen-deficient radical anion not only promotes the cleavage of Cα-C bond but also stimulates the breaking of N-Cα and C-N bonds. Radical-directed loss of small molecules and specific side chain of amino acids are detected in these experiments. Radical containing side chain of amino acids (Tyr, Ser, Thr, and Asp) may possibly support the N-Cα backbone fragmentation. Proline comprising peptides exhibit the unusual fragment ions similar to reported earlier. Interestingly, basic amino acids such as Arg and Lys also stimulated the formation of abundant b and y ions of the related peptide anions. Loss of hydrogen atom from the charge-reduced radical anion and fragment ions are rationalized by time-dependent density functional theory (TDDFT) calculation, locating the potential energy surface (PES) of ππ* and repulsive πσ* excited states of a model amide system.

  13. 213 nm Ultraviolet Photodissociation on Peptide Anions: Radical-Directed Fragmentation Patterns.

    PubMed

    Halim, Mohammad A; Girod, Marion; MacAleese, Luke; Lemoine, Jérôme; Antoine, Rodolphe; Dugourd, Philippe

    2016-03-01

    Characterization of acidic peptides and proteins is greatly hindered due to lack of suitable analytical techniques. Here we present the implementation of 213 nm ultraviolet photodissociation (UVPD) in high-resolution quadrupole-Orbitrap mass spectrometer in negative polarity for peptide anions. Radical-driven backbone fragmentation provides 22 distinctive fragment ion types, achieving the complete sequence coverage for all reported peptides. Hydrogen-deficient radical anion not only promotes the cleavage of Cα-C bond but also stimulates the breaking of N-Cα and C-N bonds. Radical-directed loss of small molecules and specific side chain of amino acids are detected in these experiments. Radical containing side chain of amino acids (Tyr, Ser, Thr, and Asp) may possibly support the N-Cα backbone fragmentation. Proline comprising peptides exhibit the unusual fragment ions similar to reported earlier. Interestingly, basic amino acids such as Arg and Lys also stimulated the formation of abundant b and y ions of the related peptide anions. Loss of hydrogen atom from the charge-reduced radical anion and fragment ions are rationalized by time-dependent density functional theory (TDDFT) calculation, locating the potential energy surface (PES) of ππ* and repulsive πσ* excited states of a model amide system. PMID:26545767

  14. Injectable Peptide Decorated Functional Nanofibrous Hollow Microspheres to Direct Stem Cell Differentiation and Tissue Regeneration

    PubMed Central

    Zhang, Zhanpeng; Gupte, Melanie J.; Jin, Xiaobing; Ma, Peter X.

    2015-01-01

    Injectable microspheres are attractive stem cell carriers for minimally invasive procedures. For tissue regeneration, the microspheres need to present the critical cues to properly direct stem cell differentiation. In natural extracellular matrix (ECM), growth factors (GFs) and collagen nanofibers provide critical chemical and physical cues. However, there have been no reported technologies that integrate synthetic nanofibers and GFs into injectable microspheres. In this study, we synthesized functional nanofibrous hollow microspheres (FNF-HMS), which can covalently bind GF-mimicking peptides. Two different GF-mimicking peptides, Transforming Growth Factor-β1 mimicking peptide Cytomodulin (CM) and Bone Morphogenetic Protein-2 mimicking peptide P24, were separately conjugated onto the FNF-HMS to induce distinct differentiation pathways of rabbit bone marrow-derived mesenchymal stem cells (BMSCs). While no existing biomaterials were reported to successfully deliver CM to induce chondrogenesis, the developed FNF-HMS were shown to effectively present CM to BMSCs and successfully induced their chondrogenesis for cartilage formation in both in vitro and in vivo studies. In addition, P24 was conjugated onto the newly developed FNF-HMS and was capable of retaining its bioactivity and inducing ectopic bone formation in nude mice. These results demonstrate that the novel FNF-HMS can effectively deliver GF-mimicking peptides to modulate stem cell fate and tissue regeneration. PMID:26069467

  15. Engineering Biosynthesis of Non-ribosomal Peptides and Polyketides by Directed Evolution.

    PubMed

    Rui, Zhe; Zhang, Wenjun

    2016-01-01

    Non-ribosomal peptides (NRPs) and polyketides (PKs) play key roles in pharmaceutical industry due to their promising biological activities. The structural complexity of NRPs and PKs, however, creates significant synthetic challenges for producing these natural products and their analogues by purely chemical means. Alternatively, difficult syntheses can be achieved by using biosynthetic enzymes with improved efficiency and altered selectivity that are acquired from directed evolution. Key to the successful directed evolution is the methodology of screening/selection. This review summarizes the screening/selection strategies that have been employed to improve or modify the functions of non-ribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), in the hope of triggering the wide adoption of the directed evolution approaches in the engineered biosynthesis of NRPs and PKs for drug discovery. PMID:26456467

  16. 21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520.1696a Section 520.1696a Food and Drugs FOOD AND DRUG ADMINISTRATION... FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

  17. 21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520.1696a Section 520.1696a Food and Drugs FOOD AND DRUG ADMINISTRATION... FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

  18. NHLBI-AbDesigner: an online tool for design of peptide-directed antibodies.

    PubMed

    Pisitkun, Trairak; Hoffert, Jason D; Saeed, Fahad; Knepper, Mark A

    2012-01-01

    Investigation of physiological mechanisms at a cellular level often requires production of high-quality antibodies, frequently using synthetic peptides as immunogens. Here we describe a new, web-based software tool called NHLBI-AbDesigner that allows the user to visualize the information needed to choose optimal peptide sequences for peptide-directed antibody production (http://helixweb.nih.gov/AbDesigner/). The choice of an immunizing peptide is generally based on a need to optimize immunogenicity, antibody specificity, multispecies conservation, and robustness in the face of posttranslational modifications (PTMs). AbDesigner displays information relevant to these criteria as follows: 1) "Immunogenicity Score," based on hydropathy and secondary structure prediction; 2) "Uniqueness Score," a predictor of specificity of an antibody against all proteins expressed in the same species; 3) "Conservation Score," a predictor of ability of the antibody to recognize orthologs in other animal species; and 4) "Protein Features" that show structural domains, variable regions, and annotated PTMs that may affect antibody performance. AbDesigner displays the information online in an interactive graphical user interface, which allows the user to recognize the trade-offs that exist for alternative synthetic peptide choices and to choose the one that is best for a proposed application. Several examples of the use of AbDesigner for the display of such trade-offs are presented, including production of a new antibody to Slc9a3. We also used the program in large-scale mode to create a database listing the 15-amino acid peptides with the highest Immunogenicity Scores for all known proteins in five animal species, one plant species (Arabidopsis thaliana), and Saccharomyces cerevisiae. PMID:21956165

  19. Simulated Batch Production of Penicillin

    ERIC Educational Resources Information Center

    Whitaker, A.; Walker, J. D.

    1973-01-01

    Describes a program in applied biology in which the simulation of the production of penicillin in a batch fermentor is used as a teaching technique to give students experience before handling a genuine industrial fermentation process. Details are given for the calculation of minimum production cost. (JR)

  20. Chromatography of Penicillins, Penicilloates, and Penicilloylamides on Dextran Gels

    PubMed Central

    Hyslop, Newton E.; Milligan, Richard J.

    1974-01-01

    The factors influencing the chromatographic behavior on dextran gels of penicillins and their derivatives were investigated by comparing elution profiles and partition coefficients (KD and KAV) of penicillins differing in side-chain structure and among penicillin derivatives of identical side-chain but different nuclear structure. Under the conditions of pH and ionic strength employed (pH 7.4, 0.145 M NaCl, 0.05 M PO4), side-chain adsorptive effects best explained the anomalous behavior of benzylpenicillin and of oxacillin and its chlorine-substituted analogues. Polar side-chain substituents, such as the amino group of ampicillin and the carboxyl group of carbenicillin, and cleavage of the β-lactam ring, exemplified by penicilloates and penicilloylamines, both appeared to interfere with side-chain-directed adsorption. The differential adsorption of penicillins and their derivatives to dextran gels is not only of theoretical interest relative to the mechanism of chromatography but of practical application to analytical and preparative procedures in penicillin chemistry. PMID:15825415

  1. Penicillins and other acylamino compounds synthesized by the cell-bound penicillin acylase of Escherichia coli

    PubMed Central

    Cole, M.

    1969-01-01

    1. The penicillin acylase of Eschericha coli N.C.I.B. 8743 is a reversible enzyme. Reaction rates for the two directions have been determined. 2. Measurements of the rates of enzymic synthesis of penicillins from 6-aminopenicillanic acid and various carboxylic acids revealed that p-hydroxyphenylacetic acid was the best substrate, followed by phenylacetic, 2-thienylacetic, substituted phenylacetic, 3-hexenoic and n-hexanoic acids. 3. The rate of synthesis of penicillin improved when amides or N-acylglycines were used; α-aminobenzylpenicillin and phenoxymethylpenicillin were only synthesized when using these more energy-rich compounds. 4. Phenyl-acetylglycine was the best substrate for the synthesis of benzylpenicillin compared with other derivatives of phenylacetic acid. 5. The enzyme was specific for acyl-l-amino acids, benzylpenicillin being synthesized from phenylacetyl-l-α-aminophenylacetic acid but not from phenylacetyl-d-α-aminophenylacetic acid. 6. α-Phenoxyethylpenicillin was synthesized from 6-aminopenicillanic acid and α-phenoxypropionylthioglycollic acid non-enzymically, but the rate was faster in the presence of the enzyme. 7. The E. coli acylase catalysed the acylation of hydroxylamine by acids or amides to give hydroxamic acids, the phenylacetyl group being the most suitable acyl group. The enzyme also catalysed other acyl-group transfers. PMID:4982418

  2. Penicillin allergy: a practical approach to management.

    PubMed

    Sussman, G L; Davis, K; Kohler, P F

    1986-06-15

    Although penicillin is nontoxic, it is highly immunogenic and is the most common drug that causes allergic reactions. A previous reaction to penicillin has been shown to be unreliable in predicting sensitivity in 75% to 90% of patients. To more accurately test for penicillin allergy, diagnostic skin test reagents have been developed; these include the major determinant (benzylpenicilloyl-polylysine) and the minor determinant mixture (penicillin G potassium, benzylpenicilloate sodium and benzylpenicilloyl-N-propylamine). Penicillin skin testing has been shown to be safe and useful in predicting immediate IgE-mediated reactions (overall predictive value 99%). Reactions that occur when patients are challenged with penicillin are mild or accelerated urticarial reactions. We outline a practical and rational therapeutic approach based on the current understanding of penicillin allergy. PMID:3518897

  3. An engineered yeast efficiently secreting penicillin.

    PubMed

    Gidijala, Loknath; Kiel, Jan A K W; Douma, Rutger D; Seifar, Reza M; van Gulik, Walter M; Bovenberg, Roel A L; Veenhuis, Marten; van der Klei, Ida J

    2009-01-01

    This study aimed at developing an alternative host for the production of penicillin (PEN). As yet, the industrial production of this beta-lactam antibiotic is confined to the filamentous fungus Penicillium chrysogenum. As such, the yeast Hansenula polymorpha, a recognized producer of pharmaceuticals, represents an attractive alternative. Introduction of the P. chrysogenum gene encoding the non-ribosomal peptide synthetase (NRPS) delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACVS) in H. polymorpha, resulted in the production of active ACVS enzyme, when co-expressed with the Bacillus subtilis sfp gene encoding a phosphopantetheinyl transferase that activated ACVS. This represents the first example of the functional expression of a non-ribosomal peptide synthetase in yeast. Co-expression with the P. chrysogenum genes encoding the cytosolic enzyme isopenicillin N synthase as well as the two peroxisomal enzymes isopenicillin N acyl transferase (IAT) and phenylacetyl CoA ligase (PCL) resulted in production of biologically active PEN, which was efficiently secreted. The amount of secreted PEN was similar to that produced by the original P. chrysogenum NRRL1951 strain (approx. 1 mg/L). PEN production was decreased over two-fold in a yeast strain lacking peroxisomes, indicating that the peroxisomal localization of IAT and PCL is important for efficient PEN production. The breakthroughs of this work enable exploration of new yeast-based cell factories for the production of (novel) beta-lactam antibiotics as well as other natural and semi-synthetic peptides (e.g. immunosuppressive and cytostatic agents), whose production involves NRPS's. PMID:20016817

  4. Mechanism of Cationic Nanoparticles and Cell-Penetrating Peptides Direct Translocate Across Cell Membranes

    NASA Astrophysics Data System (ADS)

    Lin, Jiaqi; Alexander-Katz, Alfredo

    2014-03-01

    Cationic Nanoparticles (NPs) and cell-penetrating peptides (CPPs) are known effective intracellular delivery agents. These positively charged particles can bypass traditional endocytosis route to enter the cytosol, which is known as direct translocation. However, mechanism of direct translocation of both NPs and CPPs is not well understood. Using Coarse-grained (CG) molecular dynamics simulation, we found that gold nanoparticles (AuNPs) as well as HIV-1 Tat peptides can translocate across model biological membranes through nanoscale holes under a transmembrane (TM) potential. After the translocation, the TM is strongly weakened and the holes gradually reseal themselves, while the NPs/CPPs roam freely in the ``intracellular region.'' Both size and shape of the NPs/ CPPs are found to be a determine factor of their translocation behaviour, and the relationship between direct translocation and endocytosis is also discussed. The results provided here establish fundamental rules of direct translocation entry of NPs/CPPs, which may guide the rational design of cationic intracellular nanocarriers.

  5. Transient Focal Membrane Deformation Induced by Arginine-rich Peptides Leads to Their Direct Penetration into Cells

    PubMed Central

    Hirose, Hisaaki; Takeuchi, Toshihide; Osakada, Hiroko; Pujals, Sílvia; Katayama, Sayaka; Nakase, Ikuhiko; Kobayashi, Shouhei; Haraguchi, Tokuko; Futaki, Shiroh

    2012-01-01

    Endocytosis has been implicated in the cellular uptake of arginine-rich, cell-penetrating peptides (CPPs). However, accumulating evidence suggests that certain conditions allow the direct, non-endocytic penetration of arginine-rich peptides through the plasma membrane. We previously showed that Alexa Fluor 488-labeled dodeca-arginine (R12-Alexa488) directly enters cells at specific sites on the plasma membrane and subsequently diffuses throughout cells. In this study, we found that the peptide influx was accompanied by the formation of unique, “particle-like” multivesicular structures on the plasma membrane, together with topical inversion of the plasma membrane. Importantly, the conjugation of dodeca-arginine (R12) to Alexa Fluor 488 or a peptide tag derived from hemagglutinin (HAtag) significantly accelerated particle formation, suggesting that the chemical properties of the attached molecules (cargo molecules) may contribute to translocation of the R12 peptide. Coincubation with R12-HAtag allowed the membrane-impermeable R4-Alexa488 to permeate cells. These results suggest that R12 peptides attached to hydrophobic cargo molecules stimulate dynamic morphological alterations in the plasma membrane, and that these structural changes allow the peptides to permeate the plasma membrane. These findings may provide a novel mode of cell permeabilization by arginine-rich peptides as a means of drug delivery. PMID:22334015

  6. Peptide-Metal Organic Framework Swimmers that Direct the Motion toward Chemical Targets.

    PubMed

    Ikezoe, Yasuhiro; Fang, Justin; Wasik, Tomasz L; Shi, Menglu; Uemura, Takashi; Kitagawa, Susumu; Matsui, Hiroshi

    2015-06-10

    Highly efficient and robust chemical motors are expected for the application in microbots that can selectively swim toward targets and accomplish their tasks in sensing, labeling, and delivering. However, one of major issues for such development is that current artificial swimmers have difficulty controlling their directional motion toward targets like bacterial chemotaxis. To program synthetic motors with sensing capability for the target-directed motion, we need to develop swimmers whose motions are sensitive to chemical gradients in environments. Here we create a new intelligent biochemical swimmer by integrating metal organic frameworks (MOFs) and peptides that can sense toxic heavy metals in solution and swim toward the targets. With the aid of Pb-binding enzymes, the peptide-MOF motor can directionally swim toward PbSe quantum dots (QD) by sensing pH gradient and eventually complete the motion as the swimmer reaches the highest gradient point at the target position in solution. This type of technology could be evolved to miniaturize chemical robotic systems that sense target chemicals and swim toward target locations. PMID:26010172

  7. Cell-Penetrating Peptide as a Means of Directing the Differentiation of Induced Pluripotent Stem Cells

    PubMed Central

    Kaitsuka, Taku; Tomizawa, Kazuhito

    2015-01-01

    Protein transduction using cell-penetrating peptides (CPPs) is useful for the delivery of large protein molecules, including some transcription factors. This method is safer than gene transfection methods with a viral vector because there is no risk of genomic integration of the exogenous DNA. Recently, this method was reported as a means for the induction of induced pluripotent stem (iPS) cells, directing the differentiation into specific cell types and supporting gene editing/correction. Furthermore, we developed a direct differentiation method to obtain a pancreatic lineage from mouse and human pluripotent stem cells via the protein transduction of three transcription factors, Pdx1, NeuroD, and MafA. Here, we discuss the possibility of using CPPs as a means of directing the differentiation of iPS cells and other stem cell technologies. PMID:26561805

  8. Presentation of BMP-2 Mimicking Peptides in 3D Hydrogels Directs Cell Fate Commitment in Osteoblasts and Mesenchymal Stem Cells

    PubMed Central

    Madl, Christopher M.; Mehta, Manav; Duda, Georg N.; Heilshorn, Sarah C.; Mooney, David J.

    2014-01-01

    Many strategies for controlling the fate of transplanted stem cells rely on the concurrent delivery of soluble growth factors that have the potential to produce undesirable secondary effects in surrounding tissue. Such off target effects could be eliminated by locally presenting growth factor peptide mimics from biomaterial scaffolds to control stem cell fate. Peptide mimics of bone morphogenetic protein 2 (BMP-2) were synthesized by solid phase Fmoc-peptide synthesis and covalently bound to alginate hydrogels via either carbodiimide or sulfhydryl-based coupling strategies. Successful peptide conjugation was confirmed by 1H-NMR spectroscopy and quantified by fluorescently labeling the peptides. Peptides derived from the knuckle epitope of BMP-2, presented from both 2D surfaces and 3D alginate hydrogels, were shown to increase alkaline phosphatase activity in clonally derived murine osteoblasts. Furthermore, when presented in 3D hydrogels, these peptides were shown to initiate Smad signaling, upregulate osteopontin production, and increase mineral deposition with clonally derived murine mesenchymal stem cells. These data suggest that these peptide-conjugated hydrogels may be effective alternatives to local BMP-2 release in directly and spatially eliciting osteogenesis from transplanted or host osteoprogenitors in the future. PMID:24400664

  9. Direct electrochemical and AFM detection of amyloid-β peptide aggregation on basal plane HOPG

    NASA Astrophysics Data System (ADS)

    Lopes, Paula; Xu, Meng; Zhang, Min; Zhou, Ting; Yang, Yanlian; Wang, Chen; Ferapontova, Elena E.

    2014-06-01

    Amyloidogenesis is associated with more than 30 human diseases, including Alzheimer's which is related to aggregation of β-amyloid peptide (Aβ). Here, consecutive stages of Aβ42 aggregation and amyloid fibril formation were followed electrochemically via oxidation of tyrosines in Aβ42 adsorbed on the basal plane graphite electrode and directly correlated with Aβ42 morphological changes observed by atomic force microscopy of the same substrate. The results offer new tools for analysis of mechanisms of Aβ aggregation.Amyloidogenesis is associated with more than 30 human diseases, including Alzheimer's which is related to aggregation of β-amyloid peptide (Aβ). Here, consecutive stages of Aβ42 aggregation and amyloid fibril formation were followed electrochemically via oxidation of tyrosines in Aβ42 adsorbed on the basal plane graphite electrode and directly correlated with Aβ42 morphological changes observed by atomic force microscopy of the same substrate. The results offer new tools for analysis of mechanisms of Aβ aggregation. Electronic supplementary information (ESI) available: Experimental details: procedures for Aβ42 aggregation and electrode modification, DPV/AFM measurements and analysis. See DOI: 10.1039/c4nr02413c

  10. Photodissociation of TEMPO-modified peptides: new approaches to radical-directed dissociation of biomolecules.

    PubMed

    Marshall, David L; Hansen, Christopher S; Trevitt, Adam J; Oh, Han Bin; Blanksby, Stephen J

    2014-03-14

    Radical-directed dissociation of gas phase ions is emerging as a powerful and complementary alternative to traditional tandem mass spectrometric techniques for biomolecular structural analysis. Previous studies have identified that coupling of 2-[(2,2,6,6-tetramethylpiperidin-1-oxyl)methyl]benzoic acid (TEMPO-Bz) to the N-terminus of a peptide introduces a labile oxygen-carbon bond that can be selectively activated upon collisional activation to produce a radical ion. Here we demonstrate that structurally-defined peptide radical ions can also be generated upon UV laser photodissociation of the same TEMPO-Bz derivatives in a linear ion-trap mass spectrometer. When subjected to further mass spectrometric analyses, the radical ions formed by a single laser pulse undergo identical dissociations as those formed by collisional activation of the same precursor ion, and can thus be used to derive molecular structure. Mapping the initial radical formation process as a function of photon energy by photodissociation action spectroscopy reveals that photoproduct formation is selective but occurs only in modest yield across the wavelength range (300-220 nm), with the photoproduct yield maximised between 235 and 225 nm. Based on the analysis of a set of model compounds, structural modifications to the TEMPO-Bz derivative are suggested to optimise radical photoproduct yield. Future development of such probes offers the advantage of increased sensitivity and selectivity for radical-directed dissociation. PMID:24473158

  11. Directed Evolution of an LBP/CD14 Inhibitory Peptide and Its Anti-Endotoxin Activity

    PubMed Central

    Fang, Li; Xu, Zhi; Wang, Guan-song; Ji, Fu-yun; Mei, Chun-xia; Liu, Juan; Wu, Guo-ming

    2014-01-01

    Background LPS-binding protein (LBP) and its ligand CD14 are located upstream of the signaling pathway for LPS-induced inflammation. Blocking LBP and CD14 binding might prevent LPS-induced inflammation. In previous studies, we obtained a peptide analog (MP12) for the LBP/CD14 binding site and showed that this peptide analog had anti-endotoxin activity. In this study, we used in vitro directed evolution for this peptide analog to improve its in vivo and in vitro anti-endotoxin activity. Methods We used error-prone PCR (ep-PCR) and induced mutations in the C-terminus of LBP and attached the PCR products to T7 phages to establish a mutant phage display library. The positive clones that competed with LBP for CD14 binding was obtained by screening. We used both in vivo and in vitro experiments to compare the anti-endotoxin activities of a polypeptide designated P1 contained in a positive clone and MP12. Results 11 positive clones were obtained from among target phages. Sequencing showed that 9 positive clones had a threonine (T) to methionine (M) mutation in amino acid 287 of LBP. Compared to polypeptide MP12, polypeptide P1 significantly inhibited LPS-induced TNF-α expression and NF-κB activity in U937 cells (P<0.05). Compared to MP12, P1 significantly improved arterial oxygen pressure, an oxygenation index, and lung pathology scores in LPS-induced ARDS rats (P<0.05). Conclusion By in vitro directed evolution of peptide analogs for the LBP/CD14 binding site, we established a new polypeptide (P1) with a threonine (T)-to-methionine (M) mutation in amino acid 287 of LBP. This polypeptide had high anti-endotoxin activity in vitro and in vivo, which suggested that amino acid 287 in the C-terminus of LBP may play an important role in LBP binding with CD14. PMID:25025695

  12. PbSe nanocrystal growth as nanocubes and nanorods on peptide nanotubes via different directed-assembly pathways

    NASA Astrophysics Data System (ADS)

    Shi, Menglu; Su, Wei; Matsui, Hiroshi

    2010-11-01

    Pb-binding TAR-1 peptides (Ile-Ser-Leu-Leu-His-Ser-Thr) were covalently conjugated on a bolaamphiphile peptide nanotube substrate and the precursors of PbSe were incubated at room temperature. This resulted in the growth of highly crystalline PbSe nanocubes on this biomimetic cylindrical substrate. The growth mechanism to generate nanocubes occurs via the directed self-assembly of nanoparticles and then nanoparticle fusion. The peptide conformation and the cylindrical peptide nanotube substrate play important roles in the mesoscopic crystallization of PbSe nanocubes. Changing the buffer for the peptide immobilization process from 2-(N-morpholino)ethanesulfonic acid to phosphate induces a transformation in the nanocrystal shape from nanocube to nanorods. The conformational change of the TAR-1 peptide on the nanotubes due to the change in the buffer seems to be responsible for aggregating intermediate nanoparticles in different directions for the directed fusion and mesoscopic crystallization of PbSe into the different shapes.

  13. PbSe nanocrystal growth as nanocubes and nanorods on peptide nanotubes via different directed-assembly pathways.

    PubMed

    Shi, Menglu; Su, Wei; Matsui, Hiroshi

    2010-11-01

    Pb-binding TAR-1 peptides (Ile-Ser-Leu-Leu-His-Ser-Thr) were covalently conjugated on a bolaamphiphile peptide nanotube substrate and the precursors of PbSe were incubated at room temperature. This resulted in the growth of highly crystalline PbSe nanocubes on this biomimetic cylindrical substrate. The growth mechanism to generate nanocubes occurs via the directed self-assembly of nanoparticles and then nanoparticle fusion. The peptide conformation and the cylindrical peptide nanotube substrate play important roles in the mesoscopic crystallization of PbSe nanocubes. Changing the buffer for the peptide immobilization process from 2-(N-morpholino)ethanesulfonic acid to phosphate induces a transformation in the nanocrystal shape from nanocube to nanorods. The conformational change of the TAR-1 peptide on the nanotubes due to the change in the buffer seems to be responsible for aggregating intermediate nanoparticles in different directions for the directed fusion and mesoscopic crystallization of PbSe into the different shapes. PMID:20835484

  14. Dermatologic hazards from hidden contacts with penicillin.

    PubMed

    Boonk, W J

    1981-01-01

    The unbridled use of penicillin after its discovery by Fleming has resulted in possible hazards to human health due to traces of the drug being present in food and other hidden sources. These hazards may include toxic effects, hypersensitivity reactions and possibly a raising of the frequency and duration of allergy to penicillin. PMID:7028441

  15. 21 CFR 520.1696 - Penicillin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin. 520.1696 Section 520.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696 Penicillin....

  16. 21 CFR 520.1696 - Penicillin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin. 520.1696 Section 520.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696 Penicillin....

  17. What if Fleming had not discovered penicillin?

    PubMed Central

    Alharbi, Sulaiman Ali; Wainwright, Milton; Alahmadi, Tahani Awad; Salleeh, Hashim Bin; Faden, Asmaa A.; Chinnathambi, Arunachalam

    2014-01-01

    What would have happened had Alexander Fleming not discovered penicillin in 1928? Perhaps the obvious answer is that, someone else would have discovered penicillin during 1930s and the Oxford group, would still have purified it sometime in the early 1940s. Here, however, in this counterfactual account of the penicillin story, it is argued that without Fleming, penicillin might still be undiscovered and the antibiotic age would never have dawned. As a result, many of the recent developments in medicine, such as organ transplantation, might have been delayed or, at best, made more hazardous. Penicillin might have come onto the scene a few years later but, had Fleming overlooked the discovery, it seems certain that penicillin would not have saved countless Allied lives, during and after D-Day. Instead of having enjoyed fifty and more years of the antibiotic age, it is argued here, that we would have had to rely upon highly developed sulphonamides, so-called “supasulfas”, and other chemically-derived antibacterial drugs. Indeed, it might be the case that, even well into this new millennium, the antibiotic age has yet to dawn, and medicine is still waiting for someone to chance upon penicillin. Here we discuss what might have happened had Fleming not discovered penicillin and come to the conclusion that the medical armoury available today would have been far different and might have relied solely upon highly developed varieties of sulphonamides or similar, synthetic, non-antibiotic antibacterial agents. PMID:25183937

  18. Cell penetrating peptide delivery of splice directing oligonucleotides as a treatment for Duchenne muscular dystrophy.

    PubMed

    Betts, Corinne A; Wood, Matthew J A

    2013-01-01

    Duchenne muscular dystrophy is a severe, X-linked muscle wasting disorder caused by the absence of an integral structural protein called dystrophin. This is caused by mutations or deletions in the dystrophin gene which disrupt the reading frame, thereby halting the production of a functional protein. A number of potential therapies have been investigated for the treatment of this disease including utrophin upregulation, 'stop-codon read through' aminoglycosides and adeno-associated virus gene replacement as well as stem cell therapy. However, the most promising treatment to date is the use of antisense oligonucleotides which cause exon skipping by binding to a specific mRNA sequence, skipping the desired exon, thereby restoring the reading frame and producing a truncated yet functional protein. The results from recent 2'OMePS and morpholino clinical trials have renewed hope for Duchenne patients; however in vivo studies in a mouse model, mdx, have revealed low systemic distribution and poor delivery of oligonucleotides to affected tissues such as the brain and heart. However a variety of cell penetrating peptides directly conjugated to antisense oligonucleotides have been shown to enhance delivery in Duchenne model systems with improved systemic distribution and greater efficacy compared to 'naked' antisense oligonucleotides. These cell penetrating peptides, combined with an optimised dose and dosing regimen, as well as thorough toxicity profile have the potential to be developed into a promising treatment which may be progressed to clinical trial. PMID:23140454

  19. Escherichia coli tryptophan operon directs the in vivo synthesis of a leader peptide.

    PubMed Central

    Dekel-Gorodetsky, L; Schoulaker-Schwarz, R; Engelberg-Kulka, H

    1986-01-01

    Here we report the identification of the Escherichia coli trp leader peptide synthesized in vivo. We identified the peptide in UV-irradiated maxicells by selective labeling with radioactive amino acids which are included in the predicted sequence of this peptide. Our results support the hypothesis that translation of the peptide-coding region of the leader RNA has a role in the mechanism of attenuation of biosynthetic operons in general and in the E. coli trp operon in particular. Images PMID:2419306

  20. Use of a novel cytotoxic HEXIM1 peptide in the directed breast cancer therapy

    PubMed Central

    Neo, Shu Hui; Lew, Qiao Jing; Koh, Ser Mei; Zheng, Lu; Bi, Xuezhi; Chao, Sheng-Hao

    2016-01-01

    Hexamethylene bisacetamide-inducible protein 1 (HEXIM1) is best known as the inhibitor of positive transcription elongation factor b (P-TEFb) and is recently identified as a novel positive regulator of p53. We previously showed the basic region (BR) of HEXIM1 mediates the binding of HEXIM1 to a nucleolar protein, nucleophosmin (NPM), and can be ubiquitinated by human double minute 2 protein. Here we identify a cytotoxic peptide derived from the BR of HEXIM1. When fused with a cell-penetrating peptide, the HEXIM1 BR peptide triggers rapid cytotoxic effect independent of p53. Similarly, when the BR peptide is linked with a breast cancer cell targeting peptide, LTV, the LTV-BR fusion peptide exhibits specific killing of breast cancer cells, which is not observed with the commonly used cytotoxic peptide, KLA. Importantly, the BR peptide fails to enter cells by itself and does not induce any cytotoxic effects when it is not guided by any cell-penetrating or cancer targeting peptides. We showed that HEXIM1 BR peptide depolarizes mitochondrial membrane potential in a p53-dependent manner and its cell-killing activity is not suppressed by caspase inhibition. Furthermore, we observed an accumulation of the internalized BR peptide in the nucleoli of treated cells and an altered localization of NPM. These results illustrate a novel mechanism which the BR peptide induces cell death and can potentially be used as a novel therapeutic strategy against breast cancer. PMID:26734838

  1. Putative signal peptides of two BURP proteins can direct proteins to their destinations in tobacco cell system.

    PubMed

    Tang, Yulin; Ou, Zhonghua; Qiu, Jianbin; Mi, Zilan

    2014-11-01

    Plant-specific BURP family proteins have a diverse subcellular localization with different functions. However, only limited studies have investigated the functions of their different domains. In the present study, the role of the N-terminal putative signal peptide in protein subcellular localization was investigated using a tobacco cell system. The results showed that SALI3-2 was present in vacuoles, whereas AtRD22 was directed to the apoplast. The N-terminal putative signal peptides of both proteins were confirmed to be the essential and critical domains for targeting the proteins to their destinations. We also demonstrate that the expression and accumulation of mGFP in tobacco cells was increased when mGFP was fused to the putative signal peptide of SALI3-2. The findings offer the potential application of this short peptide in protein production in plants. PMID:25048229

  2. Overexpression of penicillin V acylase from Streptomyces lavendulae and elucidation of its catalytic residues.

    PubMed

    Torres-Bacete, Jesús; Hormigo, Daniel; Torres-Gúzman, Raquel; Arroyo, Miguel; Castillón, María Pilar; García, Luis José; Acebal, Carmen; de la Mata, Isabel

    2015-02-01

    The pva gene from Streptomyces lavendulae ATCC 13664, encoding a novel penicillin V acylase (SlPVA), has been isolated and characterized. The gene encodes an inactive precursor protein containing a secretion signal peptide that is activated by two internal autoproteolytic cleavages that release a 25-amino-acid linker peptide and two large domains of 18.79 kDa (alpha-subunit) and 60.09 kDA (beta-subunit). Based on sequence alignments and the three-dimensional model of SlPVA, the enzyme contains a hydrophobicpocket involved in catalytic activity, including Serbeta1, Hisbeta23, Valbeta70, and Asnbeta272, which were confirmed by site-directed mutagenesis studies. The heterologous expression of pva in S. lividans led to the production of an extracellularly homogeneous heterodimeric enzyme at a 5-fold higher concentration (959 IU/liter) than in the original host and in a considerably shorter time. According to the catalytic properties of SlPVA, the enzyme must be classified as a new member of the Ntn-hydrolase superfamily, which belongs to a novel subfamily of acylases that recognize substrates with long hydrophobic acyl chains and have biotechnological applications in semisynthetic antifungal production. PMID:25501472

  3. Alkali-treated penicillin G solution is a better option than penicillin G as an alternative source of minor determinants for penicillin skin test.

    PubMed

    Wangrattanasopon, Pongsak; Ruxrungtham, Kiat; Chantaphakul, Hiroshi; Buranapraditkun, Supranee; Klaewsongkram, Jettanong

    2012-01-01

    Both benzylpenicilloyl-polylysine (PPL) and minor determinant mixture (MDM) are the recommended standard reagents for penicillin skin testing. However, penicillin G is commonly suggested as an alternative source of minor determinants. This study evaluated the accuracy of penicillin G and alkali-treated penicillin G compared with the standardized MDM for skin testing. Sixty-eight patients with histories of allergies to penicillin or semisynthetic penicillins were skin tested with commercial Kit penicillin allergenic determinants (DAP) (PPL and DAP-MDM; Diater Laboratorios, Madrid, Spain). The in-house MDM (IH-MDM), prepared by alkali-treated aged penicillin, and fresh penicillin G sodium (PGs) were tested alongside DAP-MDM. Positive penicillin skin test results were identified in 22 patients (32.4%) using commercial reagents (PPL+ DAP-MDM) and 19 of them reacted to DAP-MDM alone or together with PPL. The accuracy of IH-MDM and PGs compared with DAP-MDM was 89.7 and 76.5%, respectively. Our study shows that alkali-treated penicillin G is a better option than penicillin G as an alternative source of MDM for skin testing in case the commercialized MDM is not available. Minor determinants play a significant role for penicillin allergy in Thailand and should be included in the penicillin skin test panel to verify suspected cases of penicillin allergy. (ClinicalTrials.gov number: NCT00789217). PMID:22525392

  4. The peptide agonist-binding site of the glucagon-like peptide-1 (GLP-1) receptor based on site-directed mutagenesis and knowledge-based modelling

    PubMed Central

    Dods, Rachel L.; Donnelly, Dan

    2015-01-01

    Glucagon-like peptide-1 (7–36)amide (GLP-1) plays a central role in regulating blood sugar levels and its receptor, GLP-1R, is a target for anti-diabetic agents such as the peptide agonist drugs exenatide and liraglutide. In order to understand the molecular nature of the peptide–receptor interaction, we used site-directed mutagenesis and pharmacological profiling to highlight nine sites as being important for peptide agonist binding and/or activation. Using a knowledge-based approach, we constructed a 3D model of agonist-bound GLP-1R, basing the conformation of the N-terminal region on that of the receptor-bound NMR structure of the related peptide pituitary adenylate cyclase-activating protein (PACAP21). The relative position of the extracellular to the transmembrane (TM) domain, as well as the molecular details of the agonist-binding site itself, were found to be different from the model that was published alongside the crystal structure of the TM domain of the glucagon receptor, but were nevertheless more compatible with published mutagenesis data. Furthermore, the NMR-determined structure of a high-potency cyclic conformationally-constrained 11-residue analogue of GLP-1 was also docked into the receptor-binding site. Despite having a different main chain conformation to that seen in the PACAP21 structure, four conserved residues (equivalent to His-7, Glu-9, Ser-14 and Asp-15 in GLP-1) could be structurally aligned and made similar interactions with the receptor as their equivalents in the GLP-1-docked model, suggesting the basis of a pharmacophore for GLP-1R peptide agonists. In this way, the model not only explains current mutagenesis and molecular pharmacological data but also provides a basis for further experimental design. PMID:26598711

  5. Spacer-free BODIPY fluorogens in antimicrobial peptides for direct imaging of fungal infection in human tissue

    PubMed Central

    Mendive-Tapia, Lorena; Zhao, Can; Akram, Ahsan R.; Preciado, Sara; Albericio, Fernando; Lee, Martin; Serrels, Alan; Kielland, Nicola; Read, Nick D; Lavilla, Rodolfo; Vendrell, Marc

    2016-01-01

    Fluorescent antimicrobial peptides are promising structures for in situ, real-time imaging of fungal infection. Here we report a fluorogenic probe to image Aspergillus fumigatus directly in human pulmonary tissue. We have developed a fluorogenic Trp-BODIPY amino acid with a spacer-free C-C linkage between Trp and a BODIPY fluorogen, which shows remarkable fluorescence enhancement in hydrophobic microenvironments. The incorporation of our fluorogenic amino acid in short antimicrobial peptides does not impair their selectivity for fungal cells, and enables rapid and direct fungal imaging without any washing steps. We have optimized the stability of our probes in human samples to perform multi-photon imaging of A. fumigatus in ex vivo human tissue. The incorporation of our unique BODIPY fluorogen in biologically relevant peptides will accelerate the development of novel imaging probes with high sensitivity and specificity. PMID:26956772

  6. Spacer-free BODIPY fluorogens in antimicrobial peptides for direct imaging of fungal infection in human tissue.

    PubMed

    Mendive-Tapia, Lorena; Zhao, Can; Akram, Ahsan R; Preciado, Sara; Albericio, Fernando; Lee, Martin; Serrels, Alan; Kielland, Nicola; Read, Nick D; Lavilla, Rodolfo; Vendrell, Marc

    2016-01-01

    Fluorescent antimicrobial peptides are promising structures for in situ, real-time imaging of fungal infection. Here we report a fluorogenic probe to image Aspergillus fumigatus directly in human pulmonary tissue. We have developed a fluorogenic Trp-BODIPY amino acid with a spacer-free C-C linkage between Trp and a BODIPY fluorogen, which shows remarkable fluorescence enhancement in hydrophobic microenvironments. The incorporation of our fluorogenic amino acid in short antimicrobial peptides does not impair their selectivity for fungal cells, and enables rapid and direct fungal imaging without any washing steps. We have optimized the stability of our probes in human samples to perform multi-photon imaging of A. fumigatus in ex vivo human tissue. The incorporation of our unique BODIPY fluorogen in biologically relevant peptides will accelerate the development of novel imaging probes with high sensitivity and specificity. PMID:26956772

  7. 21 CFR 520.1696d - Penicillin V potassium tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin V potassium tablets. 520.1696d Section... Penicillin V potassium tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to... susceptible to penicillin V potassium. (3) Limitations. Administer orally 1 to 2 hours prior to feeding...

  8. 21 CFR 520.1696d - Penicillin V potassium tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin V potassium tablets. 520.1696d Section... Penicillin V potassium tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to... susceptible to penicillin V potassium. (3) Limitations. Administer orally 1 to 2 hours prior to feeding...

  9. 21 CFR 520.1696d - Penicillin V potassium tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin V potassium tablets. 520.1696d Section... Penicillin V potassium tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to... susceptible to penicillin V potassium. (3) Limitations. Administer orally 1 to 2 hours prior to feeding...

  10. 21 CFR 558.155 - Chlortetracycline, sulfathiazole, penicillin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Chlortetracycline, sulfathiazole, penicillin. 558... Specific New Animal Drugs for Use in Animal Feeds § 558.155 Chlortetracycline, sulfathiazole, penicillin... percent (20 grams) sulfathiazole, and procaine penicillin equivalent to 10 grams of penicillin per...

  11. [Evaluation of penicillin expandase mutants and complex substrate inhibition characteristics at high concentrations of penicillin G].

    PubMed

    Wu, Linjun; Fan, Keqiang; Ji, Junjie; Yang, Keqian

    2015-12-01

    Penicillin expandase, also known as deacetoxycephalosporin C synthase (DAOCS), is an essential enzyme involved in cephalosporin C biosynthesis. To evaluate the catalytic behaviors of penicillin expandase under high penicillin G concentration and to identify mutants suitable for industrial applications, the specific activities of wild-type DAOCS and several mutants with increased activities toward penicillin G were determined by HPLC under high penicillin G concentrations. Their specific activity profiles were compared with theoretical predictions by different catalytic dynamics models. We evaluated the specific activities of wild-type DAOCS and previous reported high-activity mutants H4, H5, H6 and H7 at concentrations ranging from 5.6 to 500 mmol/L penicillin G. The specific activities of wild-type DAOCS and mutant H4 increased as penicillin G concentration increased, but decreased when concentrations of substrate go above 200 mmol/L. Other mutants H5, H6 and H7 showed more complex behaviors under high concentration of penicillin G. Among all tested enzymes, mutant H6 showed the highest activity when concentration of penicillin G is above 100 mmol/L. Our results revealed that the substrate inhibition to wild-type DAOCS' by penicillin G is noncompetitive. Other DAOCS mutants showed more complex trends in their specific activities at high concentration of penicillin G (>100 mmol/L), indicating more complex substrate inhibition mechanism might exist. The substrate inhibition and activity of DAOCS mutants at high penicillin G concentration provide important insight to help select proper mutants for industrial application. PMID:27093832

  12. Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum

    SciTech Connect

    Ho, C.S.; Smith, M.D.

    1986-01-01

    The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

  13. Pharmacokinetics of the penicillins in man.

    PubMed

    Barza, M; Weinstein, L

    1976-01-01

    The purpose of this article is to review and summarise those aspects of the pharmacokinetic behaviour of the penicillins that may be of particular interest to the clinician. While these antibiotics differ markedly in their acid stability and oral absorption, misleading inferences may be drawn from simple inspection of the maximal serum concentrations produced by a given dose administered orally. A more accurate picture emerges when serum protein binding and intrinsic activity of the drugs are taken into account. All of the penicillins are readily and actively secreted by the renal tubles and most are eliminated, almost completely unchanged, in the urine. The majority are excreted in small quantities in the bile, but this is a major route for elimination of nafcillin from the body. Distribution of the penicillins in 'non-specialised' sites is excellent. In contrast, penetration of the central nevous system and eye are poor, and of the prostate, minimal. Inflammation reduces the barries to penetration of these areas. However, quantitative data related to this phenomenon in man are few. Probenecid actively competes with the 'export' pump of the meninges and renal tubular cells. This results in an increase in concentrations of the penicillins in the blood and cerebrospinal fluid. The effect of this agent on active secretion of these antibiotics from the eye and biliary tract is minimal. While elimination of the penicillins from the body takes place largely via renal excretion, penicillin V and oxacillin are extensively degraded as well. In contrast to the situation with respect to 'natural' and 'broad-spectrum' penicillins, the serum half-life of the isoxazolyl congeners and nafcillin is only minimally prolonged in the presence of renal failure. These agents are only weakly haemodialyzable, while the other penicillins are rapidly removed from the circulation by this procedure. PMID:797501

  14. Plant elicitor peptides are conserved signals regulating direct and indirect anti-herbivore defense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect-induced defenses occur in nearly all plants and are regulated by conserved signaling pathways. As the first described plant peptide signal, systemin regulates anti-herbivore defenses in the Solanaceae, but in other plant families peptides with analogous activity have remained elusive. In th...

  15. Plant elicitor peptides are conserved signals regulating direct and indirect anti-herbivore defense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect-induced defenses occur in nearly all plants and are regulated by conserved signaling pathways. As the first described plant peptide signal, systemin regulates anti-herbivore defenses in the Solanaceae, but in other plant families peptides with analogous activity have remained elusive. In the ...

  16. Potential transition state analogue inhibitors for the penicillin-binding proteins.

    PubMed

    Pechenov, Aleksandr; Stefanova, Miglena E; Nicholas, Robert A; Peddi, Sridhar; Gutheil, William G

    2003-01-21

    Penicillin-binding proteins (PBPs) are ubiquitous bacterial enzymes involved in cell wall biosynthesis. The development of new PBP inhibitors is a potentially viable strategy for developing new antibacterial agents. Several potential transition state analogue inhibitors for the PBPs were synthesized, including peptide chloromethyl ketones, trifluoromethyl ketones, aldehydes, and boronic acids. These agents were characterized chemically, stereochemically, and as inhibitors of a set of low molecular mass PBPs: Escherichia coli (EC) PBP 5, Neisseria gonorrhoeae (NG) PBP 3, and NG PBP 4. A peptide boronic acid was the most effective PBP inhibitor in the series, with a preference observed for a d-boroAla-based over an l-boroAla-based inhibitor, as expected given that physiological PBP substrates are based on d-Ala at the cleavage site. The lowest K(I) of 370 nM was obtained for NG PBP 3 inhibition by Boc-l-Lys(Cbz)-d-boroAla (10b). Competitive inhibition was observed for this enzyme-inhibitor pair, as expected for an active site-directed inhibitor. For the three PBPs included in this study, an inverse correlation was observed between the values for log K(I) with 10b and the values for log(k(cat)/K(m)) for activity against the analogous substrate, and K(m)/K(I) ratios were 90, 1900, and 9600 for NG PBP 4, EC PBP 5, and NG PBP 3, respectively. These results demonstrate that peptide boronic acids can be effective transition state analogue inhibitors for the PBPs and provide a basis for the use of these agents as probes of PBP structure, function, and mechanism, as well as a possible basis for the development of new PBP-targeted antibacterial agents. PMID:12525187

  17. [Screening of strain producing extracellular penicillin acylase].

    PubMed

    Wang, Z; Han, W; Men, D; Wang, Q

    1992-04-01

    Ninety-eight strains having extracellular penicillin acylase activity were derived from soil samples by colour-developing method. 10 strains of them possess higher activity of penicillin acylase. All of those are found to be Bacillus megaterium. The optimum condition of enzyme production was investigated with the strain No. 46 which is from No. 247 by single colony isolation. The productivity of penicillin acylase in the optimum condition have been enhanced 2.5 times more than that in the screening condition. The mutant strain, Bacillus megaterium UL-81, which penicillin acylase activity reached the level of 723u/100ml of broth was obtained from No. 46 by treatment with physical and chemical factors. The penicillin acylase activity of UL-81 can reach 820u/100 ml in 500L fermentor. The mutant strain differed from parent strain in the morphology of colony, the size of cells, the effect of concentration and the addition time of phenylacetic acid on the production of penicillin acylase. PMID:1598760

  18. Directed peptide amphiphile assembly using aqueous liquid crystal templates in magnetic fields.

    PubMed

    van der Asdonk, Pim; Keshavarz, Masoumeh; Christianen, Peter C M; Kouwer, Paul H J

    2016-08-21

    An alignment technique based on the combination of magnetic fields and a liquid crystal (LC) template uses the advantages of both approaches: the magnetic fields offer non-contact methods that apply to all sample sizes and shapes, whilst the LC templates offer high susceptibilities. The combination introduces a route to control the spatial organization of materials with low intrinsic susceptibilities. We demonstrate that we can unidirectionally align one such material, peptide amphiphiles in water, on a centimeter scale at a tenfold lower magnetic field by using a lyotropic chromonic liquid crystal as a template. We can transform the aligned supramolecular assemblies into optically active π-conjugated polymers after photopolymerization. Lastly, by reducing the magnetic field strength needed for addressing these assemblies, we are able to create more complex structures by initiating self-assembly of our supramolecular materials under competing alignment forces between the magnetically induced alignment of the assemblies (with a positive diamagnetic anisotropy) and the elastic force dominated alignment of the template (with a negative diamagnetic anisotropy), which is directed orthogonally. Although the approach is still in its infancy and many critical parameters need optimization, we believe that it is a very promising technique to create tailor-made complex structures of (aqueous) functional soft matter. PMID:27320385

  19. Heparin binding domain of antithrombin III: Characterization using a synthetic peptide directed polyclonal antibody

    SciTech Connect

    Smith, J.W.; Dey, B.; Knauer, D.J. )

    1990-09-25

    Antithrombin III (ATIII) is a plasma-borne serine protease inhibitor that apparently forms covalent complexes with thrombin. The interaction between ATIII and thrombin is enhanced several thousandfold by the glycosaminoglycan, heparin. The authors have previously proposed that the heparin binding site of ATIII residues within a region extending from amino acid residues 114-156. Computer-assisted analysis of this region revealed the presence of a 22 amino acid domain (residues 124-145), part of which shows a strong potential for the formation of an amphipathic helix: hydrophobic on one face and highly positively charged on the other. In the presence studies, polyclonal antisera were generated against a synthetic peptide corresponding to residues 124-145 in native human ATIII. Affinity-purified IgG from these antisera, as well as monovalent Fab's derived from them, specifically blocked the binding of heparin to ATIII. Additionally, occupancy of the heparin binding site by these same monovalent and bivalent IgG's at least partially substituted for heparin, accelerating linkage formation between ATIII and thrombin. These results provide the first immunological evidence that region 124-145 is directly involved in the binding of heparin to ATIII and that an antibody-induced conformational change within this region can mediate ATIII activation.

  20. Accessing Three-Dimensional Crystals with Incorporated Guests through Metal-Directed Coiled-Coil Peptide Assembly.

    PubMed

    Nepal, Manish; Sheedlo, Michael J; Das, Chittaranjan; Chmielewski, Jean

    2016-08-31

    Obtaining three-dimensional (3D) protein and peptide crystals on demand requires a precisely orchestrated hierarchical assembly of biopolymer building blocks. In this work, we disclose a metal-ion-mediated strategy to assemble trimeric coiled-coil peptides in a head-to-tail fashion into linear strands with interstrand interactions. This design led to hexagonal 3D peptide crystal formation within 30 min in the presence of divalent metal ions. The crystal morphology could be controlled by varying the metal ion/peptide ratio, resulting in hexagonal discs to rods. Diffraction studies elucidated the head-to-tail arrangement of the coiled-coil linear strands and their hexagonal, antiparallel packing within the crystal. Unsatisfied ligands at the hexagonal ends of the crystals were harnessed as a powerful means to direct His-tagged fluorophores to distinct locations within the crystals. Overall, the designed hierarchical assembly provides a facile means to obtain 3D peptide crystals and incorporate His-tag-based cargoes and may have potential use in drug delivery and sensor design. PMID:27500907

  1. Focused Directed Evolution of Aryl-Alcohol Oxidase in Saccharomyces cerevisiae by Using Chimeric Signal Peptides.

    PubMed

    Viña-Gonzalez, Javier; Gonzalez-Perez, David; Ferreira, Patricia; Martinez, Angel T; Alcalde, Miguel

    2015-09-01

    Aryl-alcohol oxidase (AAO) is an extracellular flavoprotein that supplies ligninolytic peroxidases with H2O2 during natural wood decay. With a broad substrate specificity and highly stereoselective reaction mechanism, AAO is an attractive candidate for studies into organic synthesis and synthetic biology, and yet the lack of suitable heterologous expression systems has precluded its engineering by directed evolution. In this study, the native signal sequence of AAO from Pleurotus eryngii was replaced by those of the mating α-factor and the K1 killer toxin, as well as different chimeras of both prepro-leaders in order to drive secretion in Saccharomyces cerevisiae. The secretion of these AAO constructs increased in the following order: preproα-AAO > preαproK-AAO > preKproα-AAO > preproK-AAO. The chimeric preαproK-AAO was subjected to focused-directed evolution with the aid of a dual screening assay based on the Fenton reaction. Random mutagenesis and DNA recombination was concentrated on two protein segments (Met[α1]-Val109 and Phe392-Gln566), and an array of improved variants was identified, among which the FX7 mutant (harboring the H91N mutation) showed a dramatic 96-fold improvement in total activity with secretion levels of 2 mg/liter. Analysis of the N-terminal sequence of the FX7 variant confirmed the correct processing of the preαproK hybrid peptide by the KEX2 protease. FX7 showed higher stability in terms of pH and temperature, whereas the pH activity profiles and the kinetic parameters were maintained. The Asn91 lies in the flavin attachment loop motif, and it is a highly conserved residue in all members of the GMC superfamily, except for P. eryngii and P. pulmonarius AAO. The in vitro involution of the enzyme by restoring the consensus ancestor Asn91 promoted AAO expression and stability. PMID:26162870

  2. Focused Directed Evolution of Aryl-Alcohol Oxidase in Saccharomyces cerevisiae by Using Chimeric Signal Peptides

    PubMed Central

    Viña-Gonzalez, Javier; Gonzalez-Perez, David; Ferreira, Patricia; Martinez, Angel T.

    2015-01-01

    Aryl-alcohol oxidase (AAO) is an extracellular flavoprotein that supplies ligninolytic peroxidases with H2O2 during natural wood decay. With a broad substrate specificity and highly stereoselective reaction mechanism, AAO is an attractive candidate for studies into organic synthesis and synthetic biology, and yet the lack of suitable heterologous expression systems has precluded its engineering by directed evolution. In this study, the native signal sequence of AAO from Pleurotus eryngii was replaced by those of the mating α-factor and the K1 killer toxin, as well as different chimeras of both prepro-leaders in order to drive secretion in Saccharomyces cerevisiae. The secretion of these AAO constructs increased in the following order: preproα-AAO > preαproK-AAO > preKproα-AAO > preproK-AAO. The chimeric preαproK-AAO was subjected to focused-directed evolution with the aid of a dual screening assay based on the Fenton reaction. Random mutagenesis and DNA recombination was concentrated on two protein segments (Met[α1]-Val109 and Phe392-Gln566), and an array of improved variants was identified, among which the FX7 mutant (harboring the H91N mutation) showed a dramatic 96-fold improvement in total activity with secretion levels of 2 mg/liter. Analysis of the N-terminal sequence of the FX7 variant confirmed the correct processing of the preαproK hybrid peptide by the KEX2 protease. FX7 showed higher stability in terms of pH and temperature, whereas the pH activity profiles and the kinetic parameters were maintained. The Asn91 lies in the flavin attachment loop motif, and it is a highly conserved residue in all members of the GMC superfamily, except for P. eryngii and P. pulmonarius AAO. The in vitro involution of the enzyme by restoring the consensus ancestor Asn91 promoted AAO expression and stability. PMID:26162870

  3. B-type natriuretic peptide-directed ultrafiltration improves care in acutely hospitalized dialysis patients.

    PubMed

    Tapolyai, Mihály; Uysal, Aşkin; Maeweathers, Gail; Bahta, Elias; Dossabhoy, Neville R

    2009-01-01

    In an observational study in 19 consecutive acutely hospitalized dialysis patients, ultrafiltration (UF) volume was determined by B-type natriuretic peptide (BNP) levels. Patients were ultrafiltrated daily until they achieved a target BNP level <500 pg/mL. The UF volumes ranged from 2 to 5 L per session. All patients were male veterans aged 68+/-11 years (mean +/- SD), 74% were diabetic, 47% were African Americans, 58% underwent prevalent dialysis, and 53% had an arteriovenous fistula. Left ventricular ejection fraction on 2-dimensional echocardiography was 43.8%+/-27.9% (n=16). The admission BNP was 2412+/-1479 pg/mL (range, 561-5000 pg/mL) and BNP at hospital discharge was 1245+/-1173 pg/mL (range, 345-5000 pg/mL) (nonparametric Wilcoxon P=.0013). Admission weight was 88.9+/-27.9 kg and at discharge was 78.1+/-25.6 kg (P=.0002). The number of antihypertensive medications taken was 3.8+/-2.0 at admission and 2.3+/-1.7 at discharge (P=.0005). The number of patients with >2 blood pressure medications decreased from 14 to 6 (Fisher exact test, P=.02). The systolic/diastolic/mean arterial blood pressure decreased from admission to discharge (153.6+/-43.8/80.6+/-21.8/102.4+/-27.3 to 132.1+/-27.9/68.9+/-14.6/89.9+/-16.5 mm Hg; P=.0222/.0139/.0329, respectively). Although all patients were volume-overloaded at admission according to BNP criteria (>500), only 42% were identified as having heart failure. BNP-directed UF is safe because it minimizes symptomatic hypotension, identifies occult congestive heart failure in a large number of patients, and significantly reduces blood pressure in addition to reducing body weight and number of medications used. PMID:19522962

  4. A Multiple-Labeling Strategy for Nonribosomal Peptide Synthetases Using Active-Site-Directed Proteomic Probes for Adenylation Domains.

    PubMed

    Ishikawa, Fumihiro; Suzuki, Takehiro; Dohmae, Naoshi; Kakeya, Hideaki

    2015-12-01

    Genetic approaches have greatly contributed to our understanding of nonribosomal peptide biosynthetic machinery; however, proteomic investigations are limited. Here, we developed a highly sensitive detection strategy for multidomain nonribosomal peptide synthetases (NRPSs) by using a multiple-labeling technique with active-site-directed probes for adenylation domains. When applied to gramicidin S-producing and -nonproducing strains of Aneurinibacillus migulanus (DSM 5759 and DSM 2895, respectively), the multiple technique sensitively detected an active multidomain NRPS (GrsB) in lysates obtained from the organisms. This functional proteomics method revealed an unknown inactive precursor (or other inactive form) of GrsB in the nonproducing strain. This method provides a new option for the direct detection, functional analysis, and high-resolution identification of low-abundance active NRPS enzymes in native proteomic environments. PMID:26467472

  5. C-Peptide Test

    MedlinePlus

    ... C-peptide is a useful marker of insulin production. The following are some purposes of C-peptide ... it nearly impossible to directly evaluate endogenous insulin production. In these cases, C-peptide measurement is a ...

  6. Relative penicillin G resistance in Neisseria meningitidis and reduced affinity of penicillin-binding protein 3.

    PubMed Central

    Mendelman, P M; Campos, J; Chaffin, D O; Serfass, D A; Smith, A L; Sáez-Nieto, J A

    1988-01-01

    We examined clinical isolates of Neisseria meningitidis relatively resistant to penicillin G (mean MIC, 0.3 micrograms/ml; range, 0.1 to 0.7 micrograms/ml), which were isolated from blood and cerebrospinal fluid for resistance mechanisms, by using susceptible isolates (mean MIC, less than or equal to 0.06 micrograms/ml) for comparison. The resistant strains did not produce detectable beta-lactamase activity, otherwise modify penicillin G, or bind less total penicillin. Penicillin-binding protein (PBP) 3 of the six resistant isolates tested uniformly bound less penicillin G in comparison to the same PBP of four susceptible isolates. Reflecting the reduced binding affinity of PBP 3 of the two resistant strains tested, the amount of 3H-labeled penicillin G required for half-maximal binding was increased in comparison with that of PBP 3 of the two susceptible isolates. We conclude that the mechanism of resistance in these meningococci relatively resistant to penicillin G was decreased affinity of PBP 3. Images PMID:3134848

  7. Quantum chemical study of penicillin: Reactions after acylation

    NASA Astrophysics Data System (ADS)

    Li, Rui; Feng, Dacheng; Zhu, Feng

    The density functional theory methods were used on the model molecules of penicillin to determine the possible reactions after their acylation on ?-lactamase, and the results were compared with sulbactam we have studied. The results show that, the acylated-enzyme tetrahedral intermediate can evolves with opening of ?-lactam ring as well as the thiazole ring; the thiazole ring-open products may be formed via ?-lactam ring-open product or from tetrahedral intermediate directly. Those products, in imine or enamine form, can tautomerize via hydrogen migration. In virtue of the water-assisted, their energy barriers are obviously reduced.

  8. Think You're Allergic to Penicillin? Maybe Not

    MedlinePlus

    ... fullstory_158759.html Think You're Allergic to Penicillin? Maybe Not Only a severe reaction that comes ... Many people who believe they're allergic to penicillin actually aren't, an allergist says. "Hypersensitivity reactions ...

  9. A bacterial signal peptide is functional in plants and directs proteins to the secretory pathway

    PubMed Central

    Moeller, Lorena; Gan, Qinglei; Wang, Kan

    2009-01-01

    The Escherichia coli heat-labile enterotoxin B subunit (LT-B) has been used as a model antigen for the production of plant-derived high-valued proteins in maize. LT-B with its native signal peptide (BSP) has been shown to accumulate in starch granules of transgenic maize kernels. To elucidate the targeting properties of the bacterial LT-B protein and BSP in plant systems, the subcellular localization of visual marker green fluorescent protein (GFP) fused to LT-B and various combinations of signal peptides was examined in Arabidopsis protoplasts and transgenic maize. Biochemical analysis indicates that the LT-B::GFP fusion proteins can assemble and fold properly retaining both the antigenicity of LT-B and the fluorescing properties of GFP. Maize kernel fractionation revealed that transgenic lines carrying BSP result in recombinant protein association with fibre and starch fractions. Confocal microscopy analysis indicates that the fusion proteins accumulate in the endomembrane system of plant cells in a signal peptide-dependent fashion. This is the first report providing evidence of the ability of a bacterial signal peptide to target proteins to the plant secretory pathway. The results provide important insights for further understanding the heterologous protein trafficking mechanisms and for developing effective strategies in molecular farming. PMID:19491306

  10. Studies of the chemical basis of the origin of protein synthesis Initiation and direction of peptide growth

    NASA Technical Reports Server (NTRS)

    Mullins, D. W., Jr.; Lacey, J. C., Jr.

    1980-01-01

    The data presented in this paper show that the ease of nonenzymatic activation of carboxylic acids by ATP at pH 5 varies directly with the pKa of the carboxyl group, and is consistent with the idea that it is the protonated form of the carboxyl group which participates in the activation reaction. Consequently, since most N-blocked amino acids have higher pKas than do their unblocked forms, they are activated more readily, and it has been demonstrated that this principle applies to peptides as well, which are activated more rapidly than single amino acids. It is proposed that this fact may be partly responsible for the origin of two important features still observed in contemporary protein synthesis: (1) initiation in prokaryotes is accomplished with an N-blocked amino acid, and (2) elongation in all living systems occurs at the carboxyl end of the growing peptide.

  11. 21 CFR 526.1696a - Penicillin G procaine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G procaine. 526.1696a Section 526.1696a... DRUGS, FEEDS, AND RELATED PRODUCTS INTRAMAMMARY DOSAGE FORMS § 526.1696a Penicillin G procaine. (a) Specifications. Each 10-milliliter single-dose syringe contains penicillin G procaine equivalent to 100,000...

  12. 21 CFR 526.1696a - Penicillin G procaine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin G procaine. 526.1696a Section 526.1696a... DRUGS, FEEDS, AND RELATED PRODUCTS INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696a Penicillin G procaine. (a) Specifications. Each 10-milliliter single-dose syringe contains penicillin G...

  13. Depletion of penicillin G residues in sows after intramuscular injection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A penicillin G procaine residue depletion study was conducted in heavy sows to estimate the pre-slaughter withdrawal periods necessary to clear penicillin from kidney and muscle. Heavy sows (n = 126) were treated with penicillin G procaine at a 5x dose (33,000 IU/kg) for 3 consecutive days by intra...

  14. 21 CFR 520.1696c - Penicillin V powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin V powder. 520.1696c Section 520.1696c... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696c Penicillin V powder. (a) Specifications. When reconstituted, each milliliter contains 25 milligrams (40,000 units) of penicillin V....

  15. 21 CFR 520.1696c - Penicillin V powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin V powder. 520.1696c Section 520.1696c... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696c Penicillin V powder. (a) Specifications. When reconstituted, each milliliter contains 25 milligrams (40,000 units) of penicillin V....

  16. 21 CFR 526.1696a - Penicillin G procaine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin G procaine. 526.1696a Section 526.1696a... DRUGS, FEEDS, AND RELATED PRODUCTS INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696a Penicillin G procaine. (a) Specifications. Each 10-milliliter single-dose syringe contains penicillin G...

  17. Depletion of penicillin G residues in sows after intramuscular injection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The US-FDA CVM has not established a tolerance for penicillin residues in swine tissues, but across much of Europe and Asia a tolerance of 50 ppb penicillin G is in effect. In the US, heavy sows are often treated with extra-label doses of penicillin G, however appropriate pre-slaughter withdrawal p...

  18. 21 CFR 526.1696a - Penicillin G procaine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin G procaine. 526.1696a Section 526.1696a... DRUGS, FEEDS, AND RELATED PRODUCTS INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696a Penicillin G procaine. (a) Specifications. Each 10-milliliter single-dose syringe contains penicillin G...

  19. 21 CFR 520.1696d - Penicillin V tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin V tablets. 520.1696d Section 520.1696d... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696d Penicillin V tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to 125 milligrams...

  20. 21 CFR 526.1696a - Penicillin G procaine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin G procaine. 526.1696a Section 526.1696a... DRUGS, FEEDS, AND RELATED PRODUCTS INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696a Penicillin G procaine. (a) Specifications. Each 10-milliliter single-dose syringe contains penicillin G...

  1. 21 CFR 520.1696d - Penicillin V tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin V tablets. 520.1696d Section 520.1696d... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696d Penicillin V tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to 125 milligrams...

  2. Molecular bases for the recognition of short peptide substrates and cysteine-directed modifications of human insulin-degrading enzyme

    PubMed Central

    Malito, Enrico; Ralat, Luis A.; Manolopoulou, Marika; Tsay, Julie L.; Wadlington, Natasha L.; Tang, Wei-Jen

    2009-01-01

    Insulin degrading enzyme (IDE) utilizes a large catalytic chamber to selectively bind and degrade peptide substrates such as insulin and amyloid β (Aβ). Tight interactions with substrates occur at an exosite located ~30Å away from the catalytic center that anchors the N-terminus of substrates to facilitate binding and subsequent cleavages at the catalytic site. However, IDE also degrades peptide substrates that are too short to occupy both the catalytic site and the exosite simultaneously. Here, we use kinins as a model system to address the kinetics and regulation of human IDE with short peptides. IDE specifically degrades bradykinin and kallidin at the Pro/Phe site. A 1.9Å crystal structure of bradykinin-bound IDE reveals the binding of bradykinin to the exosite, and not to the catalytic site. In agreement with observed high Km values, this suggests low affinity of bradykinin for IDE. This structure also provides the molecular basis on how the binding of short peptides at the exosite could regulate substrate recognition. We also found that human IDE is potently inhibited by physiologically relevant concentrations of S-nitrosylation and oxidation agents. Cysteine-directed modifications play a key role, since an IDE mutant devoid of all thirteen cysteines is insensitive to the inhibition by S-nitroso-glutathione, hydrogen peroxide, or N-ethylmaleimide. Specifically, cysteine 819 of human IDE is located inside the catalytic chamber pointing towards an extended hydrophobic pocket and is critical for the inactivation. Thiol-directed modification of this residue likely causes local structural perturbation to reduce substrate binding and catalysis. PMID:18986166

  3. 21 CFR 558.460 - Penicillin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... procaine. (b) Sponsors. Type A medicated articles: To 066104, 100 and 227 grams per pound. To 054771, 100 and 227 grams per pound. (c) Related tolerances. See § 556.510 of this chapter. (d) Conditions of use. (1) It is used as follows: Penicillin in grams per ton Combination in grams per ton Indications...

  4. Diatom Mimics: Directing the Formation of Biosilica Nanoparticles by Controlled Folding of Lysine-Leucine Peptides

    PubMed Central

    Baio, Joe E.; Zane, Ariel; Jaeger, Vance; Roehrich, Adrienne M.; Lutz, Helmut; Pfaendtner, Jim; Drobny, Gary P.; Weidner, Tobias

    2015-01-01

    Silaffins, long chain polyamines, and other biomolecules found in diatoms are involved in the assembly of a large number of silica nanostructures under mild, ambient conditions. Nanofabrication researchers have sought to mimic the diatom's biosilica production capabilities by engineering proteins to resemble aspects of naturally occurring biomolecules. Such mimics can produce monodisperse biosilica nanospheres, but in vitro production of the variety of intricate biosilica nanostructures that compose the diatom frustule is not yet possible. In this study we demonstrate how LK peptides, composed solely of lysine (K) and leucine (L) amino acids arranged with varying hydrophobic periodicities, initiate the formation of different biosilica nanostructures in vitro. When L and K residues are arranged with a periodicity of 3.5 the α-helical form of the LK peptide produces monodisperse biosilica nanospheres. However, when the LK periodicity is changed to 3.0, corresponding to a 310 helix, the morphology of the nanoparticles changes to elongated rod-like structures. β-strand LK peptides with a periodicity of 2.0 induce wire-like silica morphologies. This study illustrates how the morphology of biosilica can be changed simply by varying the periodicity of polar and nonpolar amino acids. PMID:25285787

  5. Diatom mimics: directing the formation of biosilica nanoparticles by controlled folding of lysine-leucine peptides.

    PubMed

    Baio, Joe E; Zane, Ariel; Jaeger, Vance; Roehrich, Adrienne M; Lutz, Helmut; Pfaendtner, Jim; Drobny, Gary P; Weidner, Tobias

    2014-10-29

    Silaffins, long chain polyamines, and other biomolecules found in diatoms are involved in the assembly of a large number of silica nanostructures under mild, ambient conditions. Nanofabrication researchers have sought to mimic the diatom's biosilica production capabilities by engineering proteins to resemble aspects of naturally occurring biomolecules. Such mimics can produce monodisperse biosilica nanospheres, but in vitro production of the variety of intricate biosilica nanostructures that compose the diatom frustule is not yet possible. In this study we demonstrate how LK peptides, composed solely of lysine (K) and leucine (L) amino acids arranged with varying hydrophobic periodicities, initiate the formation of different biosilica nanostructures in vitro. When L and K residues are arranged with a periodicity of 3.5 the α-helical form of the LK peptide produces monodisperse biosilica nanospheres. However, when the LK periodicity is changed to 3.0, corresponding to a 310 helix, the morphology of the nanoparticles changes to elongated rod-like structures. β-strand LK peptides with a periodicity of 2.0 induce wire-like silica morphologies. This study illustrates how the morphology of biosilica can be changed simply by varying the periodicity of polar and nonpolar amino acids. PMID:25285787

  6. Rapid and reversible knockdown of endogenous proteins by peptide-directed lysosomal degradation

    PubMed Central

    Fan, Xuelai; Jin, Wu Yang; Lu, Jie; Wang, Jin; Wang, Yu Tian

    2014-01-01

    Rapid and reversible methods for altering the level of endogenous proteins are critically important for studying biological systems and developing therapeutics. Here, we describe a membrane permeable targeting peptide-based method that rapidly and reversibly knocks down endogenous proteins through chaperone-mediated autophagy in vitro and in vivo. We demonstrated the specificity, efficacy and generalizability of the method by showing efficient knockdown of various proteins including death associated protein kinase 1 (160kDa), scaffolding protein PSD-95 (95kDa) and α-synuclein (18kDa) with their respective targeting peptides in a dose-, time- and lysosomal activity-dependent manner in neuronal cultures. More significantly, we showed that when given systemically, the peptide system efficiently knocked down the targeted protein in the brain of intact rats. Our study provides a robust and convenient research tool to manipulate endogenous protein levels, and may also lead to the development of protein knockdown-based novel therapeutics for treating various human diseases. PMID:24464042

  7. Direct Observation of Aggregation-Induced Backbone Conformational Changes in Tau Peptides.

    PubMed

    Jiji, A C; Shine, A; Vijayan, Vinesh

    2016-09-12

    In tau proteins, the hexapeptides in the R2 and R3 repeats are known to initiate tau fibril formation, which causes a class of neurodegenerative diseases called the taupathies. We show that in R3, in addition to the presence of the hexapeptides, the correct turn conformation upstream to it is also essential for producing prion-like fibrils that are capable of propagation. A time-dependent NMR aggregation assay of a slow fibril forming R3-S316P peptide revealed a trans to cis equilibrium shift in the peptide-bond conformation preceding P316 during the growth phase of the aggregation process. S316 was identified as the key residue in the turn that confers templating capacity on R3 fibrils to accelerate the aggregation of the R3-S316P peptide. These results on the specific interactions and conformational changes responsible for tau aggregation could prove useful for developing an efficient therapeutic intervention in Alzheimer's disease. PMID:27513615

  8. Variable domain I of nematode CLEs directs post-translational targeting of CLE peptides to the extracellular space.

    PubMed

    Wang, Jianying; Joshi, Sneha; Korkin, Dmitry; Mitchum, Melissa G

    2010-12-01

    Effector proteins expressed in the esophageal gland cells of cyst nematodes are delivered into plant cells through a hollow, protrusible stylet. Although evidence indicates that effector proteins function in the cytoplasm of the syncytium, technical constraints have made it difficult to directly determine where nematode effector proteins are initially delivered: cytoplasm, extracellular space, or both. Recently, we demonstrated that soybean cyst nematode CLE (HgCLE) propeptides are delivered to the cytoplasm of syncytial cells. Genetic and biochemical analyses indicate that the variable domain (VD) sequence is then required for targeting cytoplasmically delivered nematode CLEs to the apoplast where they function as ligand mimics of endogenous plant CLE peptides. The fact that nematode CLEs are targeted through the gland cell secretory pathway and delivered as mature propeptides into plant cells makes it impossible for these proteins to be subsequently delivered to the extracellular space via co-translational translocation through the endoplasmic reticulum (ER) secretory pathway of the host cell. However, when expressed in transgenic plants, if the mature nematode CLE propeptide harbored a functional cryptic signal peptide, it could possibly traffic to the apoplast through the ER secretory pathway by co-translational translocation. Here, we present evidence that VDI, the N-terminal sequence of the variable domain of HgCLE2, is sufficient for trafficking CLE peptides to the apoplast and that trafficking is indeed through an alternative pathway other than co-translational translocation. PMID:21150256

  9. Preparation of a verifiable peptide-protein immunogen: direction-controlled conjugation of a synthetic fragment of the monitor peptide with myoglobin and application for sequence analysis.

    PubMed

    Iwai, K; Fukuoka, S; Fushiki, T; Kido, K; Sengoku, Y; Semba, T

    1988-06-01

    A useful method for preparing a synthetic peptide-carrying protein for specific antibody production was established. The monitor peptide is a trypsin-sensitive cholecystokinin-releasing peptide purified from rat pancreatic juice on the basis of its stimulatory activity toward pancreatic enzyme secretion. The NH2-terminus fragment of the monitor peptide (residues 1-14) was synthesized by a solid phase method. Cysteine at the COOH terminus of the fragment was conjugated with amino groups of myoglobin using a hetero-bifunctional reagent. Sequence analysis of the fragment-myoglobin conjugate indicated that the peptide/myoglobin conjugation ratio was about 1/1 (mol/mol). Antiserum against the conjugate from a rabbit effectively abolished the stimulatory activity of the monitor peptide in the rat small intestine. PMID:3407924

  10. Cell-Penetrating Peptide as a Means of Directing the Differentiation of Induced-Pluripotent Stem Cells.

    PubMed

    Kaitsuka, Taku; Tomizawa, Kazuhito

    2015-01-01

    Protein transduction using cell-penetrating peptides (CPPs) is useful for the delivery of large protein molecules, including some transcription factors. This method is safer than gene transfection methods with a viral vector because there is no risk of genomic integration of the exogenous DNA. Recently, this method was reported as a means for the induction of induced pluripotent stem (iPS) cells, directing the differentiation into specific cell types and supporting gene editing/correction. Furthermore, we developed a direct differentiation method to obtain a pancreatic lineage from mouse and human pluripotent stem cells via the protein transduction of three transcription factors, Pdx1, NeuroD, and MafA. Here, we discuss the possibility of using CPPs as a means of directing the differentiation of iPS cells and other stem cell technologies. PMID:26561805

  11. A breakthrough in enzyme technology to fight penicillin resistance-industrial application of penicillin amidase.

    PubMed

    Buchholz, Klaus

    2016-05-01

    Enzymatic penicillin hydrolysis by penicillin amidase (also penicillin acylase, PA) represents a Landmark: the first industrially and economically highly important process using an immobilized biocatalyst. Resistance of infective bacteria to antibiotics had become a major topic of research and industrial activities. Solutions to this problem, the antibiotics resistance of infective microorganisms, required the search for new antibiotics, but also the development of derivatives, notably penicillin derivatives, that overcame resistance. An obvious route was to hydrolyse penicillin to 6-aminopenicillanic acid (6-APA), as a first step, for the introduction via chemical synthesis of various different side chains. Hydrolysis via chemical reaction sequences was tedious requiring large amounts of toxic chemicals, and they were cost intensive. Enzymatic hydrolysis using penicillin amidase represented a much more elegant route. The basis for such a solution was the development of techniques for enzyme immobilization, a highly difficult task with respect to industrial application. Two pioneer groups started to develop solutions to this problem in the late 1960s and 1970s: that of Günter Schmidt-Kastner at Bayer AG (Germany) and that of Malcolm Lilly of Imperial College London. Here, one example of this development, that at Bayer, will be presented in more detail since it illustrates well the achievement of a solution to the problems of industrial application of enzymatic processes, notably development of an immobilization method for penicillin amidase suitable for scale up to application in industrial reactors under economic conditions. A range of bottlenecks and technical problems of large-scale application had to be overcome. Data giving an inside view of this pioneer achievement in the early phase of the new field of biocatalysis are presented. The development finally resulted in a highly innovative and commercially important enzymatic process to produce 6-APA that

  12. Synthetic Proteins and Peptides for the Direct Interrogation of α-Synuclein Posttranslational Modifications

    PubMed Central

    Pratt, Matthew R.; Abeywardana, Tharindumala; Marotta, Nicholas P.

    2015-01-01

    α-Synuclein is the aggregation-prone protein associated with Parkinson’s disease (PD) and related neurodegenerative diseases. Complicating both its biological functions and toxic aggregation are a variety of posttranslational modifications. These modifications have the potential to either positively or negatively affect α-synuclein aggregation, raising the possibility that the enzymes that add or remove these modifications could be therapeutic targets in PD. Synthetic protein chemistry is uniquely positioned to generate site-specifically and homogeneously modified proteins for biochemical study. Here, we review the application of synthetic peptides and proteins towards understanding the effects of α-synuclein posttranslational modifications. PMID:26120904

  13. Peptide-directed self-assembly of functionalized polymeric nanoparticles part I: design and self-assembly of peptide-copolymer conjugates into nanoparticle fibers and 3D scaffolds.

    PubMed

    Ding, Xiaochu; Janjanam, Jagadeesh; Tiwari, Ashutosh; Thompson, Martin; Heiden, Patricia A

    2014-06-01

    A robust self-assembly of nanoparticles into fibers and 3D scaffolds is designed and fabricated by functionalizing a RAFT-polymerized amphiphilic triblock copolymer with designer ionic complementary peptides so that the assembled core-shell polymeric nanoparticles are directed by peptide assembly into continuous "nanoparticle fibers," ultimately leading to 3D fiber scaffolds. The assembled nanostructure is confirmed by FESEM and optical microscopy. The assembly is not hindered when a protein (insulin) is incorporated within the nanoparticles as an active ingredient. MTS cytotoxicity tests on SW-620 cell lines show that the peptides, copolymers, and peptide-copolymer conjugates are biocompatible. The methodology of self-assembled nanoparticle fibers and 3D scaffolds is intended to combine the advantages of a flexible hydrogel scaffold with the versatility of controlled release nanoparticles to offer unprecedented ability to incorporate desired drug(s) within a self-assembled scaffold system with individual control over the release of each drug. PMID:24610743

  14. Serum concentrations of penicillin after intramuscular administration of procaine, benzyl, and benethamine penicillin in children with pneumonia.

    PubMed

    Shann, F; Linnemann, V; Gratten, M

    1987-02-01

    Serum concentrations of penicillin were measured in 37 children with pneumonia. The mean serum concentration of penicillin was greater than 1.0 microgram/mL for 11 hours after intramuscular administration of 48,000 U/kg benethamine penicillin compound (nine children), for 26 hours after 48,000 U/kg aqueous procaine penicillin (10 children), and for 40 hours after 79,000 U/kg aqueous procaine penicillin (seven children). After intramuscular administration of 35,000 U/kg benzyl penicillin in 11 children, the serum concentration was 13.3 +/- 7.4 micrograms/mL (mean +/- SD) 30 minutes after the injection, and 4.9 +/- 3.2 micrograms/mL after 3 hours. Our findings lend support to the World Health Organization recommendation that children with mild pneumonia in developing countries be given daily intramuscular injections of 50,000 U/kg aqueous procaine penicillin. PMID:3806306

  15. Chloroplast Hsp93 Directly Binds to Transit Peptides at an Early Stage of the Preprotein Import Process.

    PubMed

    Huang, Po-Kai; Chan, Po-Ting; Su, Pai-Hsiang; Chen, Lih-Jen; Li, Hsou-min

    2016-02-01

    Three stromal chaperone ATPases, cpHsc70, Hsp90C, and Hsp93, are present in the chloroplast translocon, but none has been shown to directly bind preproteins in vivo during import, so it remains unclear whether any function as a preprotein-translocating motor and whether they have different functions during the import process. Here, using protein crosslinking followed by ionic detergent solubilization, we show that Hsp93 directly binds to the transit peptides of various preproteins undergoing active import into chloroplasts. Hsp93 also binds to the mature region of a preprotein. A time course study of import, followed by coimmunoprecipitation experiments, confirmed that Hsp93 is present in the same complexes as preproteins at an early stage when preproteins are being processed to the mature size. In contrast, cpHsc70 is present in the same complexes as preproteins at both the early stage and a later stage after the transit peptide has been removed, suggesting that cpHsc70, but not Hsp93, is important in translocating processed mature proteins across the envelope. PMID:26676256

  16. Chloroplast Hsp93 Directly Binds to Transit Peptides at an Early Stage of the Preprotein Import Process1[OPEN

    PubMed Central

    Huang, Po-Kai; Chan, Po-Ting; Chen, Lih-Jen

    2016-01-01

    Three stromal chaperone ATPases, cpHsc70, Hsp90C, and Hsp93, are present in the chloroplast translocon, but none has been shown to directly bind preproteins in vivo during import, so it remains unclear whether any function as a preprotein-translocating motor and whether they have different functions during the import process. Here, using protein crosslinking followed by ionic detergent solubilization, we show that Hsp93 directly binds to the transit peptides of various preproteins undergoing active import into chloroplasts. Hsp93 also binds to the mature region of a preprotein. A time course study of import, followed by coimmunoprecipitation experiments, confirmed that Hsp93 is present in the same complexes as preproteins at an early stage when preproteins are being processed to the mature size. In contrast, cpHsc70 is present in the same complexes as preproteins at both the early stage and a later stage after the transit peptide has been removed, suggesting that cpHsc70, but not Hsp93, is important in translocating processed mature proteins across the envelope. PMID:26676256

  17. A complementary density gradient of zwitterionic polymer brushes and NCAM peptides for selectively controlling directional migration of Schwann cells.

    PubMed

    Ren, Tanchen; Yu, Shan; Mao, Zhengwei; Gao, Changyou

    2015-07-01

    Selective enhancement of directional migration of Schwann cells (SCs) over fibroblasts (FIBs) plays a significant role in peripheral nerve regeneration, because this behavior facilitates neuron repair and avoids fibrosis. Herein a complementary density gradient of poly(3-dimethyl-methacryloyloxyethyl ammonium propane sulfonate) (PDMAPS, a zwitterionic polymer with antifouling property) and KHIFSDDSSE peptide (KHI, derived from neural cell adhesion molecule NCAM which mediates cell-cell adhesion) was fabricated. The gradient was visualized by fluorescent labeling, and further characterized by X-ray photoelectron spectrometry (XPS) and quartz crystal microbalance with dissipation (QCM-d). The SCs exhibited preferential orientation and enhanced directional migration on the gradient surface toward the region of lower PDMAPS density and higher KHI peptide density, while FIBs showed random migration. Moreover, the migration rate of the SCs was significantly enhanced to 2 folds, whereas that of the FIBs was reduced to 60% compared to their natural state on glass, leading to a faster migration rate of SCs than FIBs. The success of the complementary gradient relies on the appropriate interplay between the PDMAPS brushes and the cell-specific ligands, enabling the selective guidance of SCs migration. PMID:25934279

  18. [Determination of penicillin intermediate and three penicillins in milk by high performance capillary electrophoresis].

    PubMed

    Tian, Chunqiu; Tan, Huarong; Gao, Liping; Shen, Huqin; Qi, Kezong

    2011-11-01

    A high performance capillary electrophoresis (HPCE) method was developed for the simultaneous determination of penicillin intermediate and penicillins in milk, including 6-amino-penicillanic acid (6-APA), penicillin G (PEN), ampicillin (AMP) and amoxicillin (AMO). The main parameters including the ion concentration and pH value of running buffer, separation voltage and column temperature were optimized systematically by orthogonal test. The four penicillins (PENs) were baseline separated within 4.5 min with the running buffer of 40 mmol/L potassium dihydrogen phosphate-20 mmol/L borax solution (pH 7.8), separation voltage of 28 kV and column temperature of 30 degrees C. The calibration curves showed good linearity in the range of 1.56 - 100 mg/L, and the correlation coefficients (r2) were between 0.9979 and 0.9998. The average recoveries at three spiked levels were in the range of 84.91% - 96.72% with acceptable relative standard deviations (RSDs) of 1.11% - 9.11%. The method is simple, fast, accurate and suitable for the determination of penicillins in real samples. PMID:22393704

  19. Information transfer from peptide nucleic acids to RNA by template-directed syntheses

    NASA Technical Reports Server (NTRS)

    Schmidt, J. G.; Nielsen, P. E.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1997-01-01

    Peptide nucleic acids (PNAs) are uncharged analogs of DNA and RNA in which the ribose-phosphate backbone is substituted by a backbone held together by amide bonds. PNAs are interesting as models of alternative genetic systems because they form potentially informational base paired helical structures. A PNA C10 oligomer has been shown to act as template for efficient formation of oligoguanylates from activated guanosine ribonucleotides. In a previous paper we used heterosequences of DNA as templates in sequence-dependent polymerization of PNA dimers. In this paper we show that information can be transferred from PNA to RNA. We describe the reactions of activated mononucleotides on heterosequences of PNA. Adenylic, cytidylic and guanylic acids were incorporated into the products opposite their complement on PNA, although less efficiently than on DNA templates.

  20. Photoinduced electron transfer through peptide-based self-assembled monolayers chemisorbed on gold electrodes: directing the flow-in and flow-out of electrons through peptide helices.

    PubMed

    Venanzi, Mariano; Gatto, Emanuela; Caruso, Mario; Porchetta, Alessandro; Formaggio, Fernando; Toniolo, Claudio

    2014-08-21

    Photoinduced electron transfer (PET) experiments have been carried out on peptide self-assembled monolayers (SAM) chemisorbed on a gold substrate. The oligopeptide building block was exclusively formed by C(α)-tetrasubstituted α-aminoisobutyric residues to attain a helical conformation despite the shortness of the peptide chain. Furthermore, it was functionalized at the C-terminus by a pyrene choromophore to enhance the UV photon capture cross-section of the compound and by a lipoic group at the N-terminus for linking to gold substrates. Electron transfer across the peptide SAM has been studied by photocurrent generation experiments in an electrochemical cell employing a gold substrate modified by chemisorption of a peptide SAM as a working electrode and by steady-state and time-resolved fluorescence experiments in solution and on a gold-coated glass. The results show that the electronic flow through the peptide bridge is strongly asymmetric; i.e., PET from the C-terminus to gold is highly favored with respect to PET in the opposite direction. This effect arises from the polarity of the Au-S linkage (Au(δ+)-S(δ-), junction effect) and from the electrostatic field generated by the peptide helix. PMID:24901672

  1. Bax-derived membrane-active peptides act as potent and direct inducers of apoptosis in cancer cells

    PubMed Central

    Valero, Juan Garcia; Sancey, Lucie; Kucharczak, Jérôme; Guillemin, Yannis; Gimenez, Diana; Prudent, Julien; Gillet, Germain; Salgado, Jesús; Coll, Jean-Luc; Aouacheria, Abdel

    2011-01-01

    SUMMARY Although many cancer cells are primed for apoptosis, they usually develop resistance to cell death at multiple levels. Permeabilization of the outer mitochondrial membrane, which is mediated by proapoptotic Bcl-2 family members like Bax, is considered as a point-of-no-return for initiating apoptotic cell death. This crucial role has placed Bcl-2 family proteins as recurrent targets for anticancer drug development. Here, we propose and demonstrate a new concept based on using minimal active version of Bax to induce cell death independently of endogenous Bcl-2 proteins. We show that membrane-active segments of Bax can directly induce the release of mitochondria-residing apoptogenic factors and commit tumor cells promptly and irreversibly to caspase-dependent apoptosis. On this basis, we designed a peptide encompassing part of the Bax pore-forming domain, able to target mitochondria, induce cytochrome c release and trigger caspase-dependent apoptosis. Moreover, this Bax-derived poropeptide produced effective tumor regression after peritumoral injection in a nude mouse xenograft model. Thus, peptides derived from proteins evolutionary functionalized to form pores in the mitochondrial outer membrane represent novel templates for anticancer agents. PMID:21245196

  2. Direct measurement of agonist binding to genetically engineered peptides of the acetylcholine receptor by selective T sub 1 NMR relaxation

    SciTech Connect

    Fraenkel, Y.; Navon, G. ); Aronheim, A.; Gershoni, J.M. )

    1990-03-13

    Interactions of four ligands of the nicotinic acetylcholine receptor with genetically engineered peptides have been studied by NMR. A recombinant cholinergic binding site was prepared as a fusion protein between a truncated form of the bacterial protein trpE and a peptide corresponding to the sequence {alpha}184-200 from the Torpedo californica receptor. This construct binds {alpha}-bungarotoxin while the trpE protein alone does not, and thus serves as a negative control. In this study agonist binding to {alpha}184-200 is demonstrated by monitoring the T{sub 1} relaxation of the ligand's protons in the presence and absence of the recombinant binding site. This binding is specific as it can be competed with {alpha}-bungarotoxin. Quantitative analyses of such competitions yielded the concentration of binding sites, which corresponded to 3.3% and 16.5% of the total protein, for partially purified and affinity-purified {alpha}184-200 constructs, respectively. The K{sub D} values for the binding of acetylcholine, nicotine, d-tubocurarine, and gallamine to the affinity-purified construct were 1.4, 1.4, 0.20, and 0.21 mM, respectively, while K{sub D}'s with the nontoxin binding protein were all above 10 mM. Thus, this is a direct demonstration that the toxin binding domain {alpha}184-200 may comprise a major component of the cholinergic agonist site.

  3. Screening and productivity of penicillin antibiotic from Penicillium sp.

    PubMed

    Sivakumari, V; Dhinakaran, J; Rajendran, A

    2009-10-01

    This paper highlights the antagonism effect of Penicillium isolates, which were screened against the test organisms such as Staphylococcus aureus, E. coli and Penicillium sp. Penicillium notatum and Penicillium chrysogenum isolates were used for penicillin biosynthesis. The antibacterial activities of fermented crude penicillin extract were assayed by disc diffusion method. Maximum antibacterial activity was observed in Gram positive organisms (Staphylococcus aureus) when compared with Gram negative organisms. The isolated Penicillium chrysogenum can be used for large-scale penicillin antibiotic production. PMID:21117415

  4. Neisseria meningitidis with decreased susceptibility to penicillin in Saskatchewan, Canada.

    PubMed Central

    Blondeau, J M; Ashton, F E; Isaacson, M; Yaschuck, Y; Anderson, C; Ducasse, G

    1995-01-01

    Moderately penicillin-resistant Neisseria meningitidis is rare in North America. We report an outbreak of meningococcal disease in Saskatoon, Saskatchewan, Canada, with serogroup C N. meningitidis. The MICs of penicillin ranged from 0.12 to 0.25 micrograms/ml, and all isolates showing decreased susceptibility had identical genomic fingerprints when they were compared by pulsed-field gel electrophoresis. Our data indicate that N. meningitidis that is moderately resistant to penicillin is prevalent in Saskatchewan, Canada. PMID:7665646

  5. Engineering and overexpression of periplasmic forms of the penicillin-binding protein 3 of Escherichia coli.

    PubMed Central

    Fraipont, C; Adam, M; Nguyen-Distèche, M; Keck, W; Van Beeumen, J; Ayala, J A; Granier, B; Hara, H; Ghuysen, J M

    1994-01-01

    Replacement of the 36 and 56 N-terminal amino acid residues of the 588-amino-acid-residue membrane-bound penicillin-binding protein 3 (PBP3) of Escherichia coli by the OmpA signal peptide allows export of F37-V577 PBP3 and G57-V577 PBP3 respectively into the periplasm. The modified ftsI genes were placed under the control of the fused lpp promoter and lac promoter/operator; expression of the truncated PBP3s was optimized by varying the copy number of the recombinant plasmids and the amount of LacI repressor, and export was facilitated by increasing the SecB content of the producing strain. The periplasmic PBP3s (yield 8 mg/l of culture) were purified to 70% protein homogeneity. They require the presence of 0.25 M NaCl to remain soluble. Like the membrane-bound PBP3, they undergo processing by elimination of the C-terminal decapeptide I578-S588, they bind penicillin in a 1:1 molar ratio and they catalyse hydrolysis and aminolysis of acyclic thioesters that are analogues of penicillin. The membrane-anchor-free PBP3s have ragged N-termini. The G57-V577 PBP3, however, is less prone to proteolytic degradation than the F37-V577 PBP3. Images Figure 3 PMID:8129719

  6. Short peptide-directed synthesis of one-dimensional platinum nanostructures with controllable morphologies

    PubMed Central

    Tao, Kai; Wang, Jiqian; Li, Yanpeng; Xia, Daohong; Shan, Honghong; Xu, Hai; Lu, Jian R.

    2013-01-01

    Although one dimensional (1D) Pt nanostructures with well-defined sizes and shapes have fascinating physiochemical properties, their preparation remains a great challenge. Here we report an easy and novel synthesis of 1D Pt nanostructures with controllable morphologies, through the combination of designer self-assembling I3K and phage-displayed P7A peptides. The nanofibrils formed via I3K self-assembly acted as template. Pt precursors ((PtCl4)2− and (PtCl6)2−) were immobilized by electrostatic interaction on the positively charged template surface and subsequent reduction led to the formation of 1D Pt nanostructures. P7A was applied to tune the continuity of the Pt nanostructures. Here, the electrostatic repulsion between the deprotonated C-terminal carboxyl groups of P7A molecules was demonstrated to play a key role. We finally showed that continuous and ordered 1D Pt morphology had a significantly improved electrochemical performance for the hydrogen and methanol electro-oxidation in comparison with either 1D discrete Pt nanoparticle assemblies or isolated Pt nanoparticles. PMID:23995118

  7. Information transfer from DNA to peptide nucleic acids by template-directed syntheses

    NASA Technical Reports Server (NTRS)

    Schmidt, J. G.; Christensen, L.; Nielsen, P. E.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1997-01-01

    Peptide nucleic acids (PNAs) are analogs of nucleic acids in which the ribose-phosphate backbone is replaced by a backbone held together by amide bonds. PNAs are interesting as models of alternative genetic systems because they form potentially informational base paired helical structures. Oligocytidylates have been shown to act as templates for formation of longer oligomers of G from PNA G2 dimers. In this paper we show that information can be transferred from DNA to PNA. DNA C4T2C4 is an efficient template for synthesis of PNA G4A2G4 using G2 and A2 units as substrates. The corresponding synthesis of PNA G4C2G4 on DNA C4G2C4 is less efficient. Incorporation of PNA T2 into PNA products on DNA C4A2C4 is the least efficient of the three reactions. These results, obtained using PNA dimers as substrates, parallel those obtained using monomeric activated nucleotides.

  8. Direct Interrogation of Viral Peptides Presented by the Class I HLA of HIV-Infected T Cells

    PubMed Central

    Yaciuk, Jane C.; Skaley, Matthew; Bardet, Wilfried; Schafer, Fredda; Mojsilovic, Danijela; Cate, Steven; Stewart, Christopher J.; McMurtrey, Curtis; Jackson, Kenneth W.; Buchli, Rico; Olvera, Alex; Cedeño, Samandhy; Plana, Montserrat; Mothe, Beatriz; Brander, Christian; West, John T.

    2014-01-01

    ABSTRACT Identification of CD8+ cytotoxic T lymphocyte (CTL) epitopes has traditionally relied upon testing of overlapping peptide libraries for their reactivity with T cells in vitro. Here, we pursued deep ligand sequencing (DLS) as an alternative method of directly identifying those ligands that are epitopes presented to CTLs by the class I human leukocyte antigens (HLA) of infected cells. Soluble class I HLA-A*11:01 (sHLA) was gathered from HIV-1 NL4-3-infected human CD4+ SUP-T1 cells. HLA-A*11:01 harvested from infected cells was immunoaffinity purified and acid boiled to release heavy and light chains from peptide ligands that were then recovered by size-exclusion filtration. The ligands were first fractionated by high-pH high-pressure liquid chromatography and then subjected to separation by nano-liquid chromatography (nano-LC)–mass spectrometry (MS) at low pH. Approximately 10 million ions were selected for sequencing by tandem mass spectrometry (MS/MS). HLA-A*11:01 ligand sequences were determined with PEAKS software and confirmed by comparison to spectra generated from synthetic peptides. DLS identified 42 viral ligands presented by HLA-A*11:01, and 37 of these were previously undetected. These data demonstrate that (i) HIV-1 Gag and Nef are extensively sampled, (ii) ligand length variants are prevalent, particularly within Gag and Nef hot spots where ligand sequences overlap, (iii) noncanonical ligands are T cell reactive, and (iv) HIV-1 ligands are derived from de novo synthesis rather than endocytic sampling. Next-generation immunotherapies must factor these nascent HIV-1 ligand length variants and the finding that CTL-reactive epitopes may be absent during infection of CD4+ T cells into strategies designed to enhance T cell immunity. IMPORTANCE HIV-1 epitopes catalogued by the Los Alamos National Laboratory (LANL) have yielded limited success in vaccine trials. Because the HLA of infected cells have not previously been assessed for HIV-1 ligands, the

  9. A Structural Study of Norovirus 3C Protease Specificity: Binding of a Designed Active Site-Directed Peptide Inhibitor†

    PubMed Central

    2010-01-01

    Noroviruses are the major cause of human epidemic nonbacterial gastroenteritis. Viral replication requires a 3C cysteine protease that cleaves a 200 kDa viral polyprotein into its constituent functional proteins. Here we describe the X-ray structure of the Southampton norovirus 3C protease (SV3CP) bound to an active site-directed peptide inhibitor (MAPI) which has been refined at 1.7 Å resolution. The inhibitor, acetyl-Glu-Phe-Gln-Leu-Gln-X, which is based on the most rapidly cleaved recognition sequence in the 200 kDa polyprotein substrate, reacts covalently through its propenyl ethyl ester group (X) with the active site nucleophile, Cys 139. The structure permits, for the first time, the identification of substrate recognition and binding groups in a noroviral 3C protease and thus provides important new information for the development of antiviral prophylactics. PMID:21128685

  10. Direct detection of peptides and small proteins in fingermarks and determination of sex by MALDI mass spectrometry profiling.

    PubMed

    Ferguson, Leesa Susanne; Wulfert, Florian; Wolstenholme, Rosalind; Fonville, Judith Marlou; Clench, Malcolm Ronald; Carolan, Vikki Amanda; Francese, Simona

    2012-10-21

    Matrix Assisted Laser Desorption Ionisation Mass Spectrometry (MALDI MS) can detect and image a variety of endogenous and exogenous compounds from latent fingermarks. This opportunity potentially provides investigators with both an image for suspect identification and chemical information to be used as additional intelligence. The latter becomes particularly important when the fingermark is distorted or smudged or when the suspect is not a previously convicted offender and therefore their fingerprints are not present in the National Fingerprint Database. One of the desirable pieces of intelligence would be the sex of the suspect from the chemical composition of a fingermark. In this study we show that the direct detection of peptides and proteins from fingermarks by MALDI MS Profiling (MALDI MSP), along with the multivariate modeling of the spectra, enables the determination of sex with 85% accuracy. The chemical analysis of the fingermark composition is expected to additionally provide information on traits such as nutritional habits, drug use or hormonal status. PMID:22950080

  11. Peptide arrays for screening cancer specific peptides.

    PubMed

    Ahmed, Sahar; Mathews, Anu Stella; Byeon, Nara; Lavasanifar, Afsaneh; Kaur, Kamaljit

    2010-09-15

    In this paper, we describe a novel method to screen peptides for specific recognition by cancer cells. Seventy peptides were synthesized on a cellulose membrane in an array format, and a direct method to study the peptide-whole cell interaction was developed. The relative binding affinity of the cells for different peptides with respect to a lead 12-mer p160 peptide, identified by phage display, was evaluated using the CyQUANT fluorescence of the bound cells. Screening allowed identification of at least five new peptides that displayed higher affinity (up to 3-fold) for MDA-MB-435 and MCF-7 human cancer cells compared to the p160 peptide. These peptides showed very little binding to the control (noncancerous) human umbilical vein endothelial cells (HUVECs). Three of these peptides were synthesized separately and labeled with fluorescein isothiocyanate (FITC) to study their uptake and interaction with the cancer and control cells using confocal laser scanning microscopy and flow cytometry. The results confirmed the high and specific affinity of an 11-mer peptide 11 (RGDPAYQGRFL) and a 10-mer peptide 18 (WXEAAYQRFL) for the cancer cells versus HUVECs. Peptide 11 binds different receptors on target cancer cells as its sequence contains multiple recognition motifs, whereas peptide 18 binds mainly to the putative p160 receptor. The peptide array-whole cell binding assay reported here is a complementary method to phage display for further screening and optimization of cancer targeting peptides for cancer therapy and diagnosis. PMID:20799711

  12. Direct visualisation of peptide hormones in cultured pancreatic islet alpha- and beta-cells by intact-cell mass spectrometry.

    PubMed

    Buchanan, Christina M; Malik, Arpita S; Cooper, Garth J S

    2007-01-01

    The application of intact-cell mass spectrometry (ICM) by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry to achieve direct protein-profiling of bacterial species is now well established. However, this methodology has not to our knowledge been applied to the analysis of mammalian cells in routine culture. Here, we describe a novel application of ICM by which we have identified proteins in intact cells from two lines representative of pancreatic islet alpha- and beta-cells. Adherent alphaTC1 clone 9 and betaTC6 F7 cells were harvested into phosphate-buffered saline (PBS) using enzyme-free dissociation buffer before 1 microL of cell suspension was spotted onto MALDI plates. Cells were overlaid with sinapinic acid then washed with pure water before application of a final coat of sinapinic acid. Data in the 2000-20,000 m/z range were acquired in linear mode on a Voyager DE-Pro mass spectrometer. The proteins which ionised were composed in large part of peptide hormones (e.g. insulin and glucagon) known to be packaged into the secretory granules of the beta- and alpha-cells respectively. However, in addition to visualising the peptides expected to be associated with these cells, a mass consistent with oxyntomodulin was identified in the cultured alpha-cells, a finding not previously reported to our knowledge. In summary, this paper describes, for the first time, a rapid and direct method useful for identifying secretory products in intact endocrine cells. PMID:17918213

  13. Design of penicillin fermentation process simulation system

    NASA Astrophysics Data System (ADS)

    Qi, Xiaoyu; Yuan, Zhonghu; Qi, Xiaoxuan; Zhang, Wenqi

    2011-10-01

    Real-time monitoring for batch process attracts increasing attention. It can ensure safety and provide products with consistent quality. The design of simulation system of batch process fault diagnosis is of great significance. In this paper, penicillin fermentation, a typical non-linear, dynamic, multi-stage batch production process, is taken as the research object. A visual human-machine interactive simulation software system based on Windows operation system is developed. The simulation system can provide an effective platform for the research of batch process fault diagnosis.

  14. Nonhemolytic Cell-Penetrating Peptides: Site Specific Introduction of Glutamine and Lysine Residues into the α-Helical Peptide Causes Deletion of Its Direct Membrane Disrupting Ability but Retention of Its Cell Penetrating Ability.

    PubMed

    Kim, Seoyeon; Hyun, Soonsil; Lee, Yuri; Lee, Yan; Yu, Jaehoon

    2016-09-12

    Cell-penetrating peptides (CPPs) often have cationic and amphipathic characteristics that are commonly associated with α-helical peptides. These features give CPPs both membrane demolishing and penetrating abilities. To make CPPs safe for biomedical applications, their toxicities resulting from their membrane demolishing abilities must be removed while their cell penetrating abilities must be retained. In this study, we systematically constructed mutants of the amphipathic α-helical model peptide (LKKLLKLLKKLLKLAG, LK peptide). The hydrophobic amino acid leucine in the LK peptide was replaced with hydrophilic amino acids to reduce hemolytic or cell toxicity. Most of the mutants were found to have weakened membrane disrupting abilities, but their cell penetrating abilities were also weakened. However, the L8Q and L8K mutants were found to have low micromolar range cell penetrating ability and almost no membrane disrupting ability. These selected mutants utilize energy-dependent endocytosis mechanisms instead of an energy-independent direct cell penetrating mechanism to enter cells. In addition, the mutants can be used to deliver the anticancer drug methotrexate (MTX) to cells, thereby overcoming resistance to this drug. To determine if the effect of these mutations on the membrane disrupting and cell penetrating abilities is general, Q and K mutations of the natural amphipathic α-helical antimicrobial peptide (AMP), LL37, were introduced. Specific positional Q and K mutants of LL37 were found to have lower hemolytic toxicities and preserved the ability to penetrate eukaryotic cells such as MDA-MB-231 cells. Taken together, observations made in this work suggest that interrupting the global hydrophobicity of amphipathic α-helical CPPs and AMPs, by replacing hydrophobic residues with mildly hydrophilic amino acids such as Q and K, might be an ideal strategy for constructing peptides that have strong cell penetrating abilities and weak cell membrane disrupting

  15. Biochemistry and Comparative Genomics of SxxK Superfamily Acyltransferases Offer a Clue to the Mycobacterial Paradox: Presence of Penicillin-Susceptible Target Proteins versus Lack of Efficiency of Penicillin as Therapeutic Agent

    PubMed Central

    Goffin, Colette; Ghuysen, Jean-Marie

    2002-01-01

    The bacterial acyltransferases of the SxxK superfamily vary enormously in sequence and function, with conservation of particular amino acid groups and all-α and α/β folds. They occur as independent entities (free-standing polypeptides) and as modules linked to other polypeptides (protein fusions). They can be classified into three groups. The group I SxxK d,d-acyltransferases are ubiquitous in the bacterial world. They invariably bear the motifs SxxK, SxN(D), and KT(S)G. Anchored in the plasma membrane with the bulk of the polypeptide chain exposed on the outer face of it, they are implicated in the synthesis of wall peptidoglycans of the most frequently encountered (4→3) type. They are inactivated by penicillin and other β-lactam antibiotics acting as suicide carbonyl donors in the form of penicillin-binding proteins (PBPs). They are components of a morphogenetic apparatus which, as a whole, controls multiple parameters such as shape and size and allows the bacterial cells to enlarge and duplicate their particular pattern. Class A PBP fusions comprise a glycosyltransferase module fused to an SxxK acyltransferase of class A. Class B PBP fusions comprise a linker, i.e., protein recognition, module fused to an SxxK acyltransferase of class B. They ensure the remodeling of the (4→3) peptidoglycans in a cell cycle-dependent manner. The free-standing PBPs hydrolyze d,d peptide bonds. The group II SxxK acyltransferases frequently have a partially modified bar code, but the SxxK motif is invariant. They react with penicillin in various ways and illustrate the great plasticity of the catalytic centers. The secreted free-standing PBPs, the serine β-lactamases, and the penicillin sensors of several penicillin sensory transducers help the d,d-acyltransferases of group I escape penicillin action. The group III SxxK acyltransferases are indistinguishable from the PBP fusion proteins of group I in motifs and membrane topology, but they resist penicillin. They are

  16. Armadillidin: a novel glycine-rich antibacterial peptide directed against gram-positive bacteria in the woodlouse Armadillidium vulgare (Terrestrial Isopod, Crustacean).

    PubMed

    Herbinière, Juline; Braquart-Varnier, Christine; Grève, Pierre; Strub, Jean-Marc; Frère, Jacques; Van Dorsselaer, Alain; Martin, Gilbert

    2005-01-01

    We report the isolation and the characterization of a novel antibacterial peptide from hemocytes of the woodlouse Armadillidium vulgare, naturally infected or uninfected by Wolbachia, an intracellular Gram-negative bacterium. This molecule displays antibacterial activity against Gram-positive bacteria despite its composition which classes it into the glycine-rich antibacterial peptide family, usually directed against fungi and Gram-negative bacteria. The complete sequence was determined by a combination of Edman degradation, mass spectrometry and cDNA cloning using a hemocyte library. The mature peptide (53 residues) has a 5259 Da molecular mass and is post-translationally modified by a C-terminal amidation. This peptide is characterized by a high level of glycine (47%) and a fivefold repeated motif GGGFH(R/S). As no evident sequence homology to other hitherto described antibacterial peptides has been found out, this antibacterial peptide was named armadillidin. Armadillidin is constitutively expressed in hemocytes and appears to be specific of A. vulgare. PMID:15752546

  17. Anaphylactic shock following oral penicillin--report of two cases.

    PubMed

    Myre, S; Zaske, D

    1976-03-01

    Two cases of anaphylactic shock secondary to oral penicillin therapy are presented. The clinical course and treatment of the two patients are discussed. Ways in which physicians and pharmacists may reduce the incidence and severity of anaphylactic reactions to penicillin are reviewed. PMID:1258884

  18. Think You're Allergic to Penicillin? Maybe Not

    MedlinePlus

    ... problem in the use of penicillin," said Dr. Thomas Leath, an allergist with the Texas A&M College of Medicine. "Many people who report a penicillin allergy don't even know why. It could be because they had a reaction when they were very young, or because a family member had an allergic ...

  19. 21 CFR 520.1696 - Penicillin oral dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin oral dosage forms. 520.1696 Section 520.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696 Penicillin...

  20. 21 CFR 526.1696 - Penicillin intramammary dosage forms.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin intramammary dosage forms. 526.1696 Section 526.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Penicillin intramammary dosage forms....

  1. Depletion of penicillin G residues in sows after intramuscular injection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2011, the Food Safety Inspection Service (FSIS) switched from using the Fast Antimicrobial Screen Test (FAST) for screening animal tissues for penicillin to using the Charm-Kidney Inhibition Swab test (KIS). The switch provided a quicker test and lower detection limits for penicillin when used o...

  2. 21 CFR 526.1696 - Penicillin intramammary dosage forms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin intramammary dosage forms. 526.1696 Section 526.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Penicillin intramammary dosage forms....

  3. 21 CFR 520.1696 - Penicillin oral dosage forms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin oral dosage forms. 520.1696 Section 520.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696 Penicillin...

  4. Improved fiber-optic chemical sensor for penicillin

    SciTech Connect

    Healy, B.G.; Walt, D.R.

    1995-12-15

    An optical penicillin biosensor is described, based on the enzyme penicillinase. The sensor is fabricated by selective photodeposition of analyte-sensitive polymer matrices on optical imaging fibers. The penicillin-sensitive matrices are fabricated by immobilizing the enzyme as micrometer-sized particles in a polymer hydrogel with a covalently bound pH indicator. An array of penicillin-sensitive and pH-sensitive matrices are fabricated on the same fiber. This array allows for the simultaneous, independent measurement of pH and penicillin. Independent measurement of the two analytes allows penicillin to be quantitated in the presence of a concurrent pH change. An analysis was conducted of enzyme kinetic parameters in order to model the penicillin response of the sensor at all pH values. This analysis accounts for the varying activity of the immobilized penicillinase at different pH values. The sensor detects penicillin in the range 0.25-10.0 mM in the pH range 6.2-7.5. The sensor was used to quantify penicillin concentration produced during a Penicillium chrysogenum fermentation. 27 refs., 7 figs., 1 tab.

  5. 21 CFR 526.1696 - Penicillin intramammary dosage forms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin intramammary dosage forms. 526.1696 Section 526.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Penicillin intramammary dosage forms....

  6. 21 CFR 526.1696 - Penicillin intramammary dosage forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin intramammary dosage forms. 526.1696 Section 526.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Penicillin intramammary dosage forms....

  7. 21 CFR 520.1696 - Penicillin oral dosage forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin oral dosage forms. 520.1696 Section 520.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696 Penicillin...

  8. Penicillin Hydrolysis: A Kinetic Study of a Multistep, Multiproduct Reaction.

    ERIC Educational Resources Information Center

    McCarrick, Thomas A.; McLafferty, Fred W.

    1984-01-01

    Background, procedures used, and typical results are provided for an experiment in which students carry out the necessary measurements on the acid-catalysis of penicillin in two hours. By applying kinetic theory to the data obtained, the reaction pathways for the hydrolysis of potassium benzyl penicillin are elucidated. (JN)

  9. 21 CFR 558.155 - Chlortetracycline, sulfathiazole, penicillin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... (a) Approvals. Type A medicated articles: (1) 20 grams of chlortetracycline hydrochloride, 4.4 percent (20 grams) sulfathiazole, and procaine penicillin equivalent to 10 grams of penicillin per pound to No. 046573 in § 510.600(c) of this chapter. (2) 40 grams of chlortetracycline hydrochloride,...

  10. 21 CFR 558.155 - Chlortetracycline, sulfathiazole, penicillin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (a) Approvals. Type A medicated articles: (1) 20 grams of chlortetracycline hydrochloride, 4.4 percent (20 grams) sulfathiazole, and procaine penicillin equivalent to 10 grams of penicillin per pound to No. 046573 in § 510.600(c) of this chapter. (2) 40 grams of chlortetracycline hydrochloride,...

  11. 21 CFR 558.155 - Chlortetracycline, sulfathiazole, penicillin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (a) Approvals. Type A medicated articles: (1) 20 grams of chlortetracycline hydrochloride, 4.4 percent (20 grams) sulfathiazole, and procaine penicillin equivalent to 10 grams of penicillin per pound to No. 046573 in § 510.600(c) of this chapter. (2) 40 grams of chlortetracycline hydrochloride,...

  12. Peptide-enhanced mRNA transfection in cultured mouse cardiac fibroblasts and direct reprogramming towards cardiomyocyte-like cells

    PubMed Central

    Lee, Kunwoo; Yu, Pengzhi; Lingampalli, Nithya; Kim, Hyun Jin; Tang, Richard; Murthy, Niren

    2015-01-01

    The treatment of myocardial infarction is a major challenge in medicine due to the inability of heart tissue to regenerate. Direct reprogramming of endogenous cardiac fibroblasts into functional cardiomyocytes via the delivery of transcription factor mRNAs has the potential to regenerate cardiac tissue and to treat heart failure. Even though mRNA delivery to cardiac fibroblasts has the therapeutic potential, mRNA transfection in cardiac fibroblasts has been challenging. Herein, we develop an efficient mRNA transfection in cultured mouse cardiac fibroblasts via a polyarginine-fused heart-targeting peptide and lipofectamine complex, termed C-Lipo and demonstrate the partial direct reprogramming of cardiac fibroblasts towards cardiomyocyte cells. C-Lipo enabled the mRNA-induced direct cardiac reprogramming due to its efficient transfection with low toxicity, which allowed for multiple transfections of Gata4, Mef2c, and Tbx5 (GMT) mRNAs for a period of 2 weeks. The induced cardiomyocyte-like cells had α-MHC promoter-driven GFP expression and striated cardiac muscle structure from α-actinin immunohistochemistry. GMT mRNA transfection of cultured mouse cardiac fibroblasts via C-Lipo significantly increased expression of the cardiomyocyte marker genes, Actc1, Actn2, Gja1, Hand2, and Tnnt2, after 2 weeks of transfection. Moreover, this study provides the first direct evidence that the stoichiometry of the GMT reprogramming factors influence the expression of cardiomyocyte marker genes. Our results demonstrate that mRNA delivery is a potential approach for cardiomyocyte generation. PMID:25834424

  13. The opioid peptide dynorphin directly blocks NMDA receptor channels in the rat.

    PubMed Central

    Chen, L; Gu, Y; Huang, L Y

    1995-01-01

    1. The actions of dynorphin on N-methyl-D-aspartate (NMDA) responses were examined in acutely dissociated trigeminal neurons in rat. Whole-cell and single-channel currents were recorded using the patch clamp technique. 2. Dynorphins reduced NMDA-activated currents (INMDA). The IC50 was 0.25 microM for dynorphin (1-32), 1.65 microM for dynorphin (1-17) and 1.8 microM for dynorphin (1-13). 3. The blocking action of dynorphin is voltage independent. 4. The inhibitory action of dynorphin cannot be blocked by high concentration of the non-selective opioid receptor antagonist naloxone, nor by the specific kappa-opioid receptor antagonist nor-Binaltorphimine (nor-BNI). 5. Single-channel analyses indicate that dynorphin reduces the fraction of time the channel is open without altering the channel conductance. 6. We propose that dynorphin acts directly on NMDA receptors. PMID:7537820

  14. Discovery of a Direct Ras Inhibitor by Screening a Combinatorial Library of Cell-Permeable Bicyclic Peptides

    PubMed Central

    2015-01-01

    Cyclic peptides have great potential as therapeutic agents and research tools. However, their applications against intracellular targets have been limited, because cyclic peptides are generally impermeable to the cell membrane. It was previously shown that fusion of cyclic peptides with a cyclic cell-penetrating peptide resulted in cell-permeable bicyclic peptides that are proteolytically stable and biologically active in cellular assays. In this work, we tested the generality of the bicyclic approach by synthesizing a combinatorial library of 5.7 × 106 bicyclic peptides featuring a degenerate sequence in the first ring and an invariant cell-penetrating peptide in the second ring. Screening of the library against oncoprotein K-Ras G12V followed by hit optimization produced a moderately potent and cell-permeable K-Ras inhibitor, which physically blocks the Ras-effector interactions in vitro, inhibits the signaling events downstream of Ras in cancer cells, and induces apoptosis of the cancer cells. Our approach should be generally applicable to developing cell-permeable bicyclic peptide inhibitors against other intracellular proteins. PMID:26645887

  15. T-Tropic Human Immunodeficiency Virus Type 1 (HIV-1)-Derived V3 Loop Peptides Directly Bind to CXCR-4 and Inhibit T-Tropic HIV-1 Infection

    PubMed Central

    Sakaida, Hitoshi; Hori, Toshiyuki; Yonezawa, Akihito; Sato, Akihiko; Isaka, Yoshitaka; Yoshie, Osamu; Hattori, Toshio; Uchiyama, Takashi

    1998-01-01

    Certain types of chemokine receptors have been identified as coreceptors for HIV-1 infection. The process of viral entry is initiated by the interaction between an envelope protein gp120 of HIV-1, CD4, and one of the relevant coreceptors. To understand the precise mechanism of the Env-mediated fusion and entry of HIV-1, we examined whether the V3 region of gp120 of T-cell line tropic (T-tropic) virus directly interacts with the coreceptor, CXCR-4, by using five synthetic V3 peptides: two cyclized V3 peptides (V3-BH10 and V3-ELI) which correspond to the V3 regions of the T-tropic HIV-1 IIIB and HIV-1 ELI strains, respectively, a linear V3 peptide (CTR36) corresponding to that of HIV-1 IIIB strain; and cyclized V3 peptides corresponding to that of the macrophage-tropic (M-tropic) HIV-1 ADA strain (V3-ADA) or the dualtropic HIV-1 89.6 strain (V3-89.6). FACScan analysis with a CXCR-4+ human B-cell line, JY, showed that V3-BH10, V3-ELI, and V3-89.6 but not CTR36 or V3-ADA blocked the binding of IVR7, an anti-CXCR-4 monoclonal antibody (MAb), to CXCR-4 with different magnitudes in a dose-dependent manner, while none of the V3 peptides influenced binding of an anti-CD19 MAb at all. Next, the effects of the V3 peptides on SDF-1β-induced transient increases in intracellular Ca2+ were investigated. Three V3 peptides (V3-BH10, V3-ELI, and V3-89.6) prevented Ca2+ mobilization. Furthermore, the three peptides inhibited infection by T-tropic HIV-1 in a dose-dependent manner as revealed by an MTT assay and a reverse transcriptase assay, while the other peptides had no effects. These results present direct evidence that the V3 loop of gp120 of T-tropic HIV-1 can interact with its coreceptor CXCR-4 independently of the V1/V2 regions of gp120 or cellular CD4. PMID:9811711

  16. Penicillin-binding site on the Escherichia coli cell envelope

    SciTech Connect

    Amaral, L.; Lee, Y.; Schwarz, U.; Lorian, V.

    1986-08-01

    The binding of /sup 35/S-labeled penicillin to distinct penicillin-binding proteins (PBPs) of the cell envelope obtained from the sonication of Escherichia coli was studied at different pHs ranging from 4 to 11. Experiments distinguishing the effect of pH on penicillin binding by PBP 5/6 from its effect on beta-lactamase activity indicated that although substantial binding occurred at the lowest pH, the amount of binding increased with pH, reaching a maximum at pH 10. Based on earlier studies, it is proposed that the binding at high pH involves the formation of a covalent bond between the C-7 of penicillin and free epsilon amino groups of the PBPs. At pHs ranging from 4 to 8, position 1 of penicillin, occupied by sulfur, is considered to be the site that establishes a covalent bond with the sulfhydryl groups of PBP 5. The use of specific blockers of free epsilon amino groups or sulfhydryl groups indicated that wherever the presence of each had little or no effect on the binding of penicillin by PBP 5, the presence of both completely prevented binding. The specific blocker of the hydroxyl group of serine did not affect the binding of penicillin.

  17. Site-directed gene mutation at mixed sequence targets by psoralen-conjugated pseudo-complementary peptide nucleic acids.

    PubMed

    Kim, Ki-Hyun; Nielsen, Peter E; Glazer, Peter M

    2007-01-01

    Sequence-specific DNA-binding molecules such as triple helix-forming oligonucleotides (TFOs) provide a means for inducing site-specific mutagenesis and recombination at chromosomal sites in mammalian cells. However, the utility of TFOs is limited by the requirement for homopurine stretches in the target duplex DNA. Here, we report the use of pseudo-complementary peptide nucleic acids (pcPNAs) for intracellular gene targeting at mixed sequence sites. Due to steric hindrance, pcPNAs are unable to form pcPNA-pcPNA duplexes but can bind to complementary DNA sequences by Watson-Crick pairing via double duplex-invasion complex formation. We show that psoralen-conjugated pcPNAs can deliver site-specific photoadducts and mediate targeted gene modification within both episomal and chromosomal DNA in mammalian cells without detectable off-target effects. Most of the induced psoralen-pcPNA mutations were single-base substitutions and deletions at the predicted pcPNA-binding sites. The pcPNA-directed mutagenesis was found to be dependent on PNA concentration and UVA dose and required matched pairs of pcPNAs. Neither of the individual pcPNAs alone had any effect nor did complementary PNA pairs of the same sequence. These results identify pcPNAs as new tools for site-specific gene modification in mammalian cells without purine sequence restriction, thereby providing a general strategy for designing gene targeting molecules. PMID:17977869

  18. Investigation on natural diets of larval marine animals using peptide nucleic acid-directed polymerase chain reaction clamping.

    PubMed

    Chow, Seinen; Suzuki, Sayaka; Matsunaga, Tadashi; Lavery, Shane; Jeffs, Andrew; Takeyama, Haruko

    2011-04-01

    The stomach contents of the larvae of marine animals are usually very small in quantity and amorphous, especially in invertebrates, making morphological methods of identification very difficult. Nucleotide sequence analysis using polymerase chain reaction (PCR) is a likely approach, but the large quantity of larval (host) DNA present may mask subtle signals from the prey genome. We have adopted peptide nucleic acid (PNA)-directed PCR clamping to selectively inhibit amplification of host DNA for this purpose. The Japanese spiny lobster (Panulirus japonicus) and eel (Anguilla japonica) were used as model host and prey organisms, respectively. A lobster-specific PNA oligomer (20 bases) was designed to anneal to the sequence at the junction of the 18 S rDNA gene and the internal transcribed spacer 1 (ITS1) of the lobster. PCR using eukaryote universal primers for amplifying the ITS1 region used in conjunction with the lobster-specific PNA on a mixed DNA template of lobster and eel demonstrated successful inhibition of lobster ITS1 amplification while allowing efficient amplification of eel ITS1. This method was then applied to wild-caught lobster larvae of P. japonicus and P. longipes bispinosus collected around Ryukyu Archipelago, Japan. ITS1 sequences of a wide variety of animals (Ctenophora, Cnidaria, Crustacea, Teleostei, Mollusca, and Chaetognatha) were detected. PMID:20535520

  19. Fusion activity of African henipavirus F proteins with a naturally occurring start codon directly upstream of the signal peptide.

    PubMed

    Weis, Michael; Behner, Laura; Binger, Tabea; Drexler, Jan Felix; Drosten, Christian; Maisner, Andrea

    2015-04-01

    Compared to the fusion proteins of pathogenic Nipah and Hendra viruses, the F protein of prototype African henipavirus GH-M74a displays a drastically reduced surface expression and fusion activity. A probable reason for limited F expression is the unusually long sequence located between the gene start and the signal peptide (SP) not present in other henipaviruses. Such a long pre-SP extension can prevent efficient ER translocation or protein maturation and processing. As its truncation can therefore enhance surface expression, the recent identification of a second in-frame start codon directly upstream of the SP in another African henipavirus F gene (GH-UP28) raised the question if such a naturally occurring minor sequence variation can lead to the synthesis of a pre-SP truncated translation product, thereby increasing the production of mature F proteins. To test this, we analyzed surface expression and biological activity of F genes carrying the second SP-proximal start codon of GH-UP28. Though we observed minor differences in the expression levels, introduction of the additional start codon did not result in an increased fusion activity, even if combined with further mutations in the pre-SP region. Thus, limited bioactivity of African henipavirus F protein is maintained even after sequence changes that alter the gene start allowing the production of F proteins without an unusually long pre-SP. PMID:25725148

  20. Direct one-step labeling of cysteine residues on peptides with [(11)C]methyl triflate for the synthesis of PET radiopharmaceuticals.

    PubMed

    Chin, Joshua; Vesnaver, Matthew; Bernard-Gauthier, Vadim; Saucke-Lacelle, Erin; Wängler, Björn; Wängler, Carmen; Schirrmacher, Ralf

    2013-11-01

    Radiolabeled peptides have emerged as an attractive platform for the diagnostic and therapeutic oncology. However, the (11)C-radiolabeling of peptides for positron emission tomography (PET) has been poorly explored, owing to the relatively short half-life of carbon-11 (t 1/2 = 20.3 min) and time-consuming multi-step radiochemical reactions. Existing methods have found limited use and are not routinely encountered in the production of radiotracers. Herein, we propose a facile one-step direct (11)C-methylation of cysteine residues in peptides using [(11)C]methyl triflate under ambient temperatures (20 °C) and short reaction times, on the order of seconds. Good regioselectivity of this method was demonstrated by HPLC in a simple peptide (glutathione, GSH) and a more complex test decapeptide (Trp-Tyr-Trp-Ser-Arg-Cys-Lys-Trp-Thr-Gly) bearing multiple nucleophilic sites. In addition, we extend this method towards the synthesis of [(11)C]Cys(Me)-[Tyr(3)-octreotate] as a demonstration of applicability for peptides of biological interest. This octreotate derivative was obtained in non-decay-corrected radiochemical yields of 11 ± 2 % (n = 3) with a synthesis time of approx. 30 min. PMID:23921782

  1. How Nature Morphs Peptide Scaffolds into Antibiotics

    PubMed Central

    Nolan, Elizabeth M.; Walsh, Christopher T.

    2010-01-01

    The conventional notion that peptides are poor candidates for orally available drugs because of protease-sensitive peptide bonds, intrinsic hydrophilicity, and ionic charges contrasts with the diversity of antibiotic natural products with peptide-based frameworks that are synthesized and utilized by Nature. Several of these antibiotics, including penicillin and vancomycin, are employed to treat bacterial infections in humans and have been best-selling therapeutics for decades. Others might provide new platforms for the design of novel therapeutics to combat emerging antibiotic-resistant bacterial pathogens. PMID:19058272

  2. 21 CFR 522.1696b - Penicillin G procaine aqueous suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G procaine aqueous suspension. 522... ANIMAL DRUGS § 522.1696b Penicillin G procaine aqueous suspension. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsors. See...

  3. 21 CFR 522.1696c - Penicillin G procaine in oil.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin G procaine in oil. 522.1696c Section... § 522.1696c Penicillin G procaine in oil. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsor. See No. 053501 in § 510.600(c) of...

  4. 21 CFR 522.1696b - Penicillin G procaine aqueous suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin G procaine aqueous suspension. 522... ANIMAL DRUGS § 522.1696b Penicillin G procaine aqueous suspension. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsors. See...

  5. 21 CFR 522.1696c - Penicillin G procaine in oil.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G procaine in oil. 522.1696c Section... § 522.1696c Penicillin G procaine in oil. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsor. See No. 053501 in § 510.600(c) of...

  6. 21 CFR 522.1696c - Penicillin G procaine in oil.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin G procaine in oil. 522.1696c Section... § 522.1696c Penicillin G procaine in oil. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsor. See No. 054771 in § 510.600(c) of...

  7. 21 CFR 522.1696b - Penicillin G procaine aqueous suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin G procaine aqueous suspension. 522... ANIMAL DRUGS § 522.1696b Penicillin G procaine aqueous suspension. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsors. See...

  8. 21 CFR 522.1696c - Penicillin G procaine in oil.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin G procaine in oil. 522.1696c Section... § 522.1696c Penicillin G procaine in oil. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsor. See No. 053501 in § 510.600(c) of...

  9. 21 CFR 522.1696b - Penicillin G procaine aqueous suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin G procaine aqueous suspension. 522... ANIMAL DRUGS § 522.1696b Penicillin G procaine aqueous suspension. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsors. See...

  10. 21 CFR 522.1696b - Penicillin G procaine aqueous suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin G procaine aqueous suspension. 522... ANIMAL DRUGS § 522.1696b Penicillin G procaine aqueous suspension. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsors. See...

  11. 21 CFR 522.1696c - Penicillin G procaine in oil.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin G procaine in oil. 522.1696c Section... § 522.1696c Penicillin G procaine in oil. (a) Specifications. Each milliliter contains penicillin G procaine equivalent to 300,000 units of penicillin G. (b) Sponsor. See No. 053501 in § 510.600(c) of...

  12. Resistance to penicillin and identification of penicillinase-producing Neisseria gonorrhoeae among clinical isolates in Thailand.

    PubMed Central

    Crum, J W; Duangmani, C; Vibulyasekha, S; Suthisomboon, K

    1980-01-01

    Penicillin-resistant Neisseria gonorrhoeae from 405 patients were studied by determination of penicillin minimal inhibitory concentrations an penicillinase production. Eighteen percent were identified as penicillin-producing N. gonorrhoeae and the mean minimal inhibitory concentration, for all except penicillin-producing strains, was 0.805 micrograms/ml. PMID:6778382

  13. Cloning, preparation and preliminary crystallographic studies of penicillin V acylase autoproteolytic processing mutants

    SciTech Connect

    Chandra, P. Manish; Brannigan, James A.; Prabhune, Asmita; Pundle, Archana; Turkenburg, Johan P.; Dodson, G. Guy; Suresh, C. G.

    2005-01-01

    The production, crystallization and characterization of three inactive mutants of penicillin V acylase from B. sphaericus in their respective precursor and processed forms are reported. The space groups are different for the native enzyme and the mutants. The crystallization of three catalytically inactive mutants of penicillin V acylase (PVA) from Bacillus sphaericus in precursor and processed forms is reported. The mutant proteins crystallize in different primitive monoclinic space groups that are distinct from the crystal forms for the native enzyme. Directed mutants and clone constructs were designed to study the post-translational autoproteolytic processing of PVA. The catalytically inactive mutants will provide three-dimensional structures of precursor PVA forms, plus open a route to the study of enzyme–substrate complexes for this industrially important enzyme.

  14. Family shuffling of expandase genes to enhance substrate specificity for penicillin G.

    PubMed

    Hsu, Jyh-Shing; Yang, Yunn-Bor; Deng, Chan-Hui; Wei, Chia-Li; Liaw, Shwu-Huey; Tsai, Ying-Chieh

    2004-10-01

    Deacetoxycephalosporin C synthase (expandase) from Streptomyces clavuligerus, encoded by cefE, is an important industrial enzyme for the production of 7-aminodeacetoxycephalosporanic acid from penicillin G. To improve the substrate specificity for penicillin G, eight cefE-homologous genes were directly evolved by using the DNA shuffling technique. After the first round of shuffling and screening, using an Escherichia coli ESS bioassay, four chimeras with higher activity were subjected to a second round. Subsequently, 20 clones were found with significantly enhanced activity. The kinetic parameters of two isolates that lack substrate inhibition showed 8.5- and 118-fold increases in the k(cat)/K(m) ratio compared to the S. clavuligerus expandase. The evolved enzyme with the 118-fold increase is the most active obtained to date anywhere. Our shuffling results also indicate the remarkable plasticity of the expandase, suggesting that more-active chimeras might be achievable with further rounds. PMID:15466573

  15. Beta-lactamase-free penicillin amidase from Alcaligenes sp.: isolation strategy, strain characteristics, and enzyme immobilization.

    PubMed

    Pal, A; Samanta, T B

    1999-11-01

    Isolation and characterization of a beta-lactamase (EC 3.5.2.6)-free, penicillin amidase (penicillin amidohydrolase, EC 3.5.1. 11)-producing organism is reported. The test strain was isolated by an enrichment technique with a substrate other than penicillins. The isolated strain belongs to the genus Alcaligenes. Phenylacetic acid was found to be the inducer of penicillin amidase. The amidase has a broad substrate spectrum. It is very active against penicillin G and semisynthetic cephalosporins, whereas penicillin V and semisynthetic penicillins acted moderately as a substrate. Immobilized cells of Alcaligenes sp. were shown to act as a reversible enzyme. PMID:10489431

  16. Osmotic Pressure, Bacterial Cell Walls, and Penicillin: A Demonstration.

    ERIC Educational Resources Information Center

    Lennox, John E.

    1984-01-01

    An easily constructed apparatus that models the effect of penicillin on the structure of bacterial cells is described. Background information and procedures for using the apparatus during a classroom demonstration are included. (JN)

  17. Radiation-induced polymerization for the immobilization of penicillin acylase

    SciTech Connect

    Boccu, E.; Carenza, M.; Lora, S.; Palma, G.; Veronese, F.M.

    1987-06-01

    The immobilization of Escherichia coli penicillin acylase was investigated by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperature. A leak-proof composite that does not swell in water was obtained by adding the cross-linking agent trimethylolpropane trimethacrylate to the monomer-aqueous enzyme mixture. Penicillin acylase, which was immobilized with greater than 70% yield, possessed a higher Km value toward the substrate 6-nitro-3-phenylacetamidobenzoic acid than the free enzyme form (Km = 1.7 X 10(-5) and 1 X 10(-5) M, respectively). The structural stability of immobilized penicillin acylase, as assessed by heat, guanidinium chloride, and pH denaturation profiles, was very similar to that of the free-enzyme form, thus suggesting that penicillin acylase was entrapped in its native state into aqueous free spaces of the polymer matrix.

  18. Possible Mechanism of Decreased Susceptibility of Neisseria gonorrhoeae to Penicillin

    PubMed Central

    Rodriguez, William; Saz, Arthur K.

    1975-01-01

    By use of 14C-labeled benzyl penicillin, it has been established that β-lactamases and/or acylases play no role in the resistance of Neisseria gonorrhoeae to penicillin. It has been found, however, that very susceptible strains of the organisms (minimal inhibitory concentration, 0.008 μg/ml) bind 10 to 15 times as much penicillin as do moderately to highly resistant strains of the gonoccoccus (minimal inhibitory concentration, 0.125 to 2.0 μg/ml). It is postulated that this degree of change in binding components of the whole cell and whole cytoplasmic membrane is sufficient to account for the decreased susceptibility of the organism to penicillin. PMID:808158

  19. The role of penicillin in the pathogenesis of chronic urticaria.

    PubMed

    Boonk, W J; van Ketel, W G

    1982-02-01

    Intracutaneous tests with penicilloyl-polylysine (PPL) and benzyl-penicillin G (PG) were performed in 245 patients suffering form chronic recurrent urticaria, including physical urticaria. Positive results were observed in fifty-nine patients (24%). Sera from fifty-seven of these fifty-nine patients were investigated for circulating anti-penicilloyl antibodies by an enzyme-linked immunosorbent assay (ELISA) and a passive haemagglutination test (HA). The results were compared to those form the ELISA and HA in a control group of thirty-five patients who had shown clinical allergic reactions to penicillin and had positive skin tests to PPL and/or PG. The in vitro tests revealed positive results in 12.3% and 37.1% respectively. In forty-three patients the course of the positive intracutaneous tests to penicillin, together with the duration of chronic urticaria, was followed over a period of time up to 3.5 years. In twenty-two out of forty-two patients with positive intracutaneous tests to penicillin, a diet free of dairy products proved to have a curative effect, compared to two out of forty control subjects with chronic urticaria and negative skin tests to penicillin. These studies indicate that penicillin has an important role in the aetiology and maintenance of chronic urticaria. PMID:6277360

  20. Effect of gentamicin dosing interval on efficacy of penicillin or ceftriaxone treatment of experimental endocarditis due to penicillin-susceptible, ceftriaxone-tolerant viridans group streptococci.

    PubMed Central

    Brandt, C M; Warner, C B; Rouse, M S; Steckelberg, J M; Wilson, W R

    1996-01-01

    The efficacy of ceftriaxone or penicillin alone or combined with gentamicin at different dosing intervals was evaluated in experimental endocarditis due to a penicillin-susceptible, ceftriaxone-tolerant strain of Streptococcus sanguis I. The difference between monotherapy with ceftriaxone and procaine penicillin approached statistical significance (P = 0.052). Ceftriaxone combined with gentamicin administered as a single daily dose was less effective than was procaine penicillin combined with gentamicin administered in a single daily dose or in three divided doses. PMID:9124865

  1. Structural Evidence for Direct Interactions Between the BRCT Domains of Human BRCA1 and a Phospho-Peptide from Human ACC1

    SciTech Connect

    Shen,Y.; Tong, L.

    2008-01-01

    The tandem BRCA1 C-terminal (BRCT) domains are phospho-serine/threonine recognition modules essential for the function of BRCA1. Recent studies suggest that acetyl-CoA carboxylase 1 (ACC1), an enzyme with crucial roles in de novo fatty acid biosynthesis and lipogenesis and essential for cancer cell survival, may be a novel binding partner for BRCA1, through interactions with its BRCT domains. We report here the crystal structure at 3.2 Angstroms resolution of human BRCA1 BRCT domains in complex with a phospho-peptide from human ACC1 (p-ACC1 peptide, with the sequence 1258-DSPPQ-pS-PTFPEAGH-1271), which provides molecular evidence for direct interactions between BRCA1 and ACC1. The p-ACC1 peptide is bound in an extended conformation, located in a groove between the tandem BRCT domains. There are recognizable and significant structural differences to the binding modes of two other phospho-peptides to these domains, from BACH1 and CtIP, even though they share a conserved pSer-Pro-(Thr/Val)-Phe motif. Our studies establish a framework for understanding the regulation of lipid biosynthesis by BRCA1 through its inhibition of ACC1 activity, which could be a novel tumor suppressor function of BRCA1.

  2. Simplifying and expanding the screening for peptides <2 kDa by direct urine injection, liquid chromatography, and ion mobility mass spectrometry.

    PubMed

    Thomas, Andreas; Görgens, Christian; Guddat, Sven; Thieme, Detlef; Dellanna, Frank; Schänzer, Wilhelm; Thevis, Mario

    2016-01-01

    The analysis of low-molecular-mass peptides in doping controls has become a mandatory aspect in sports drug testing and, thus, the number of samples that has to be tested for these analytes has been steadily increasing. Several peptides <2 kDa with performance-enhancing properties are covered by the list of prohibited substances of the World Anti-Doping Agency including Desmopressin, LH-RH, Buserelin, Triptorelin, Leuprolide, GHRP-1, GHRP-2, GHRP-3, GHRP-4, GHRP-5,GHRP-6, Alexamorelin, Ipamorelin, Hexarelin, ARA-290, AOD-9604, TB-500 and Anamorelin. With the presented method employing direct urine injection into a liquid chromatograph followed by ion-mobility time-of-flight mass spectrometry, a facile, specific and sensitive assay for the aforementioned peptidic compounds is provided. The accomplished sensitivity allows for limits of detection between 50 and 500 pg/mL and thus covers the minimum required performance level of 2 ng/mL accordingly. The method is precise (imprecision <20%) and linear in the estimated working range between 0 and 10 ng/mL. The stability of the peptides in urine was tested, and -20°C was found to be the appropriate storage temperature for sports drug testing. Finally, proof-of-concept was shown by analysing elimination study urine samples collected from individuals having administered GHRP-6, GHRP-2, or LHRH. PMID:26578461

  3. T cell receptor cross-reactivity directed by antigen-dependent tuning of peptide-MHC molecular flexibility

    SciTech Connect

    Borbulevych, O.Y.; Piepenbrink, K.H.; Gloor, B.E.; Scott, D.R.; Sommese, R.F.; Cole, D.K.; Sewell, A.K.; Baker, B.M.

    2010-09-07

    T cell-mediated immunity requires T cell receptor (TCR) cross-reactivity, the mechanisms behind which remain incompletely elucidated. The {alpha}{beta} TCR A6 recognizes both the Tax (LLFGYPVYV) and Tel1p (MLWGYLQYV) peptides presented by the human class I MHC molecule HLA-A2. Here we found that although the two ligands are ideal structural mimics, they form substantially different interfaces with A6, with conformational differences in the peptide, the TCR, and unexpectedly, the MHC molecule. The differences between the Tax and Tel1p ternary complexes could not be predicted from the free peptide-MHC structures and are inconsistent with a traditional induced-fit mechanism. Instead, the differences were attributable to peptide and MHC molecular motion present in Tel1p-HLA-A2 but absent in Tax-HLA-A2. Differential tuning of the dynamic properties of HLA-A2 by the Tax and Tel1p peptides thus facilitates cross-recognition and impacts how structural diversity can be presented to and accommodated by receptors of the immune system.

  4. Non-hydrolyzed in digestive tract and blood natural L-carnosine peptide ("bioactivated Jewish penicillin") as a panacea of tomorrow for various flu ailments: signaling activity attenuating nitric oxide (NO) production, cytostasis, and NO-dependent inhibition of influenza virus replication in macrophages in the human body infected with the virulent swine influenza A (H1N1) virus.

    PubMed

    Babizhayev, Mark A; Deyev, Anatoliy I; Yegorov, Yegor E

    2013-01-01

    in excessive amounts mediate the overreaction of the host's immune response against the organs or tissues in which viruses are replicating, and this may explain the mechanism of tissue injuries observed in influenza virus infection of various types. In this article, the types of protection of carnosine in its bioavailable non-hydrolyzed forms in formulations are considered against reactive oxygen radical species-dependent injury, peroxynitrite damage, and other types of viral injuries in which impaired immune responses to viral pathogens are usually involved. Carnosine (β-alanyl-L-histidine) shows the pharmacological intracellular correction of NO release, which might be one of the important factors of natural immunity in controlling the initial stages of influenza A virus infection (inhibition of virus replication) and virus-induced regulation of cytokine gene expression. The protective effects of orally applied non-hydrolyzed formulated species of carnosine include at least the direct interaction with NO, inhibition of cytotoxic NO-induced proinflammatory condition, and attenuation of the effects of cytokines and chemokines that can exert profound effects on inflammatory cells. These data are consistent with the hypothesis that natural products, such as chicken soup and chicken breast extracts rich in carnosine and its derivative anserine (β-alanyl-1-methyl-L-histidine), could contribute to the pathogenesis and prevention of influenza virus infections and cold but have a limitation due to the susceptibility to enzymatic hydrolysis of dipeptides with serum carnosinase and urine excretion after oral ingestion of a commercial chicken extract. The formulations of non-hydrolyzed in digestive tract and blood natural carnosine peptide and isopeptide (γ-glutamyl-carnosine) products, manufactured at the cGMP-certified facility and patented by the authors, have promise in the control and prevention of influenza A (H1N1) virus infection, cough, and cold. PMID:23425625

  5. A Novel Direct Factor Xa Inhibitory Peptide with Anti-Platelet Aggregation Activity from Agkistrodon acutus Venom Hydrolysates

    PubMed Central

    Chen, Meimei; Ye, Xiaohui; Ming, Xin; Chen, Yahui; Wang, Ying; Su, Xingli; Su, Wen; Kong, Yi

    2015-01-01

    Snake venom is a natural substance that contains numerous bioactive proteins and peptides, nearly all of which have been identified over the last several decades. In this study, we subjected snake venom to enzymatic hydrolysis to identify previously unreported bioactive peptides. The novel peptide ACH-11 with the sequence LTFPRIVFVLG was identified with both FXa inhibition and anti-platelet aggregation activities. ACH-11 inhibited the catalytic function of FXa towards its substrate S-2222 via a mixed model with a Ki value of 9.02 μM and inhibited platelet aggregation induced by ADP and U46619 in a dose-dependent manner. Furthermore, ACH-11 exhibited potent antithrombotic activity in vivo. It reduced paralysis and death in an acute pulmonary thrombosis model by 90% and attenuated thrombosis weight in an arterio-venous shunt thrombosis model by 57.91%, both at a dose of 3 mg/kg. Additionally, a tail cutting bleeding time assay revealed that ACH-11 did not prolong bleeding time in mice at a dose of 3 mg/kg. Together, our results reveal that ACH-11 is a novel antithrombotic peptide exhibiting both FXa inhibition and anti-platelet aggregation activities, with a low bleeding risk. We believe that it could be a candidate or lead compound for new antithrombotic drug development. PMID:26035670

  6. Development of a penicillin biosensor using a single optical imaging fiber

    NASA Astrophysics Data System (ADS)

    Healey, Brian G.; Walt, David R.

    1995-05-01

    A penicillin biosensor has been fabricated by photodepositing penicillin-sensitive polymer matrices and pH-sensitive polymer matrices on different regions of an optical imaging fiber. Penicillin is detected by coupling the enzymatic activity of penicillinase with the pH sensitivity of fluorescein. Penicillin concentration is correlated to the pH change in the microenvironment of the penicillin-sensitive matrix relative to the pH of the sample solution. This dual sensor removes the need to maintain a constant solution pH when measuring penicillin and should enhance greatly the application of biosensors.

  7. Electronic structure and physicochemical properties of selected penicillins

    NASA Astrophysics Data System (ADS)

    Soriano-Correa, Catalina; Ruiz, Juan F. Sánchez; Raya, A.; Esquivel, Rodolfo O.

    Traditionally, penicillins have been used as antibacterial agents due to their characteristics and widespread applications with few collateral effects, which have motivated several theoretical and experimental studies. Despite the latter, their mechanism of biological action has not been completely elucidated. We present a theoretical study at the Hartree-Fock and density functional theory (DFT) levels of theory of a selected group of penicillins such as the penicillin-G, amoxicillin, ampicillin, dicloxacillin, and carbenicillin molecules, to systematically determine the electron structure of full ?-lactam antibiotics. Our results allow us to analyze the electronic properties of the pharmacophore group, the aminoacyl side-chain, and the influence of the substituents (R and X) attached to the aminoacyl side-chain at 6? (in contrast with previous studies focused at the 3? substituents), and to corroborate the results of previous studies performed at the semiempirical level, solely on the ?-lactam ring of penicillins. Besides, several density descriptors are determined with the purpose of analyzing their link to the antibacterial activity of these penicillin compounds. Our results for the atomic charges (fitted to the electrostatic potential), the bond orders, and several global reactivity descriptors, such as the dipole moments, ionization potential, hardness, and the electrophilicity index, led us to characterize: the active sites, the effect of the electron-attracting substituent properties and their physicochemical features, which altogether, might be important to understand the biological activity of these type of molecules.

  8. Documenting Penicillin Allergy: The Impact of Inconsistency

    PubMed Central

    Shah, Nirav S.; Ridgway, Jessica P.; Pettit, Natasha; Fahrenbach, John; Robicsek, Ari

    2016-01-01

    Background Allergy documentation is frequently inconsistent and incomplete. The impact of this variability on subsequent treatment is not well described. Objective To determine how allergy documentation affects subsequent antibiotic choice. Design Retrospective, cohort study. Participants 232,616 adult patients seen by 199 primary care providers (PCPs) between January 1, 2009 and January 1, 2014 at an academic medical system. Main Measures Inter-physician variation in beta-lactam allergy documentation; antibiotic treatment following beta-lactam allergy documentation. Key Results 15.6% of patients had a reported beta-lactam allergy. Of those patients, 39.8% had a specific allergen identified and 22.7% had allergic reaction characteristics documented. Variation between PCPs was greater than would be expected by chance (all p<0.001) in the percentage of their patients with a documented beta-lactam allergy (7.9% to 24.8%), identification of a specific allergen (e.g. amoxicillin as opposed to “penicillins”) (24.0% to 58.2%) and documentation of the reaction characteristics (5.4% to 51.9%). After beta-lactam allergy documentation, patients were less likely to receive penicillins (Relative Risk [RR] 0.16 [95% Confidence Interval: 0.15–0.17]) and cephalosporins (RR 0.28 [95% CI 0.27–0.30]) and more likely to receive fluoroquinolones (RR 1.5 [95% CI 1.5–1.6]), clindamycin (RR 3.8 [95% CI 3.6–4.0]) and vancomycin (RR 5.0 [95% CI 4.3–5.8]). Among patients with beta-lactam allergy, rechallenge was more likely when a specific allergen was identified (RR 1.6 [95% CI 1.5–1.8]) and when reaction characteristics were documented (RR 2.0 [95% CI 1.8–2.2]). Conclusions Provider documentation of beta-lactam allergy is highly variable, and details of the allergy are infrequently documented. Classification of a patient as beta-lactam allergic and incomplete documentation regarding the details of the allergy lead to beta-lactam avoidance and use of other antimicrobial

  9. Regulation and the circulation of knowledge: penicillin patents in Spain.

    PubMed

    Romero de Pablos, Ana

    2011-01-01

    This paper tells the early history of penicillin patenting in Spain. Patents turn out to be useful instruments for analysing the management of knowledge and its circulation in different professional and geographical domains. They protected knowledge while contributing to standardisation. Patents also ensured quality and guaranteed reliability in manufacturing, delivering and prescribing new drugs. They gained special prominence by allowing the creation of a network in which political, economic and business, industrial power, public health and international cooperation fields came together. The main source of information used for this purpose has been the earliest patent applications for penicillin in Spain between 1948 and 1950, which are kept in the Historical Archives of the Oficina Española de Patentes y Marcas. The study of these patents for penicillin shows their role as agents in introducing this drug in Spain. PMID:22332464

  10. Automatic classification of penicillin-induced epileptic EEG spikes.

    PubMed

    Kortelainen, Jukka; Silfverhuth, Minna; Suominen, Kalervo; Sonkajarvi, Eila; Alahuhta, Seppo; Jantti, Ville; Seppanen, Tapio

    2010-01-01

    Penicillin-induced focal epilepsy is a well-known model in epilepsy research. In this model, epileptic activity is generated by delivering penicillin focally to the cortex. The drug induces interictal electroencephalographic (EEG) spikes which evolve in time and may later change to ictal discharges. This paper proposes a method for automatic classification of these interictal epileptic spikes using iterative K-means clustering. The method is shown to be able to detect different spike waveforms and describe their characteristic occurrence in time during penicillin-induced focal epilepsy. The study offers potential for future research by providing a method to objectively and quantitatively analyze the time sequence of interictal epileptic activity. PMID:21096740

  11. Anaplasma marginale major surface protein 1a directs cell surface display of tick BM95 immunogenic peptides on Escherichia coli.

    PubMed

    Canales, Mario; Almazán, Consuelo; Pérez de la Lastra, José M; de la Fuente, José

    2008-07-31

    The surface display of heterologous proteins on live Escherichia coli using anchoring motifs from outer membranes proteins has impacted on many areas of biochemistry, molecular biology and biotechnology. The Anaplasma marginale major surface protein 1a (MSP1a) contains N-terminal surface-exposed repeated peptides (28-289 amino acids) that are involved in pathogen interaction with host cell receptors and is surface-displayed when the recombinant protein is expressed in E. coli. Therefore, it was predicted that MSP1a would surface display on E. coli peptides inserted in the N-terminal repeats region of the protein. The Rhipicephalus (Boophilus) microplus BM86 and BM95 glycoproteins are homologous proteins that protect cattle against tick infestations. In this study, we demonstrated that a recombinant protein comprising tick BM95 immunogenic peptides fused to the A. marginale MSP1a N-terminal region is displayed on the E. coli surface and is recognized by anti-BM86 and anti-MSP1a antibodies. This system provides a novel approach to the surface display of heterologous antigenic proteins on live E. coli and suggests the possibility to use the recombinant bacteria for immunization studies against cattle tick infestations. PMID:18582976

  12. The Tipper-Strominger Hypothesis and Triggering of Allostery in Penicillin-Binding Protein 2a of Methicillin-Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Fishovitz, Jennifer; Taghizadeh, Negin; Fisher, Jed F.; Chang, Mayland; Mobashery, Shahriar

    2015-01-01

    The transpeptidases involved in the synthesis of the bacterial cell wall (also known as penicillin-binding proteins, PBPs) have evolved to bind the acyl-d-Ala-d-Ala segment of the stem peptide of the nascent peptidoglycan for the physiologically important crosslinking of the cell wall. The Tipper-Strominger hypothesis stipulates that β-lactam antibiotics mimic the acyl-d-Ala-d-Ala moiety of the stem, and thus are recognized by the PBPs with bactericidal consequences. We document that this mimicry exists also at the allosteric site of PBP2a of methicillin-resistant Staphylococcus aureus (MRSA). Interactions of different classes of β-lactam antibiotics, as mimics of the acyl-d-Ala-d-Ala moiety at the allosteric site, lead to a conformational change, across a distance of 60 Å to the active site. We directly visualize this change using an environmentally sensitive fluorescent probe affixed to the protein loops that frame the active site. This conformational mobility, documented in real time, allows antibiotic access to the active site of PBP2a. Furthermore, we document that this allosteric trigger enables synergy between two different β-lactam antibiotics, wherein occupancy at the allosteric site by one facilitates occupancy by a second at the transpeptidase catalytic site, thus lowering the minimal-inhibitory concentration. This synergy has important implications for the mitigation of facile emergence of resistance to these antibiotics by MRSA. PMID:25964995

  13. [Penicillin-binding proteins of various strains of Lactobacillus].

    PubMed

    Griaznova, N S; Subbotina, N A; Beliavskaia, I V; Taisova, A S; Afonin, V I; Tiurin, M V; Shenderov, B A; Sazykina, Iu O; Navashin, S M

    1990-02-01

    Sensitivity of different species of Lactobacillus i.e. L. casei, L. plantarum, L. acidophillus, L. buchneri, L. jugurti and others to penicillins and cephalosporins of various generations was studied. Penicillin binding proteins (PBPs) of the Lactobacillus species were specified. It was shown that the number of PBPs depended on the Lactobacillus species. L. casei had the least number of PBPs (4) and L. brevis had the highest number of PBPs (11). Competition of 14C-benzylpenicillin with ampicillin, cefotaxime, ceftizoxime and cefoperazone for binding to separate PBPs in three strains of different Lactobacillus species was investigated. PMID:2110806

  14. Antimicrobial peptides.

    PubMed

    Zhang, Ling-Juan; Gallo, Richard L

    2016-01-11

    Antimicrobial peptides and proteins (AMPs) are a diverse class of naturally occurring molecules that are produced as a first line of defense by all multicellular organisms. These proteins can have broad activity to directly kill bacteria, yeasts, fungi, viruses and even cancer cells. Insects and plants primarily deploy AMPs as an antibiotic to protect against potential pathogenic microbes, but microbes also produce AMPs to defend their environmental niche. In higher eukaryotic organisms, AMPs can also be referred to as 'host defense peptides', emphasizing their additional immunomodulatory activities. These activities are diverse, specific to the type of AMP, and include a variety of cytokine and growth factor-like effects that are relevant to normal immune homeostasis. In some instances, the inappropriate expression of AMPs can also induce autoimmune diseases, thus further highlighting the importance of understanding these molecules and their complex activities. This Primer will provide an update of our current understanding of AMPs. PMID:26766224

  15. High-affinity Anticalins with aggregation-blocking activity directed against the Alzheimer β-amyloid peptide

    PubMed Central

    Rauth, Sabine; Hinz, Dominik; Börger, Michael; Uhrig, Markus; Mayhaus, Manuel; Riemenschneider, Matthias; Skerra, Arne

    2016-01-01

    Amyloid beta (Aβ) peptides, in particular Aβ42 and Aβ40, exert neurotoxic effects and their overproduction leads to amyloid deposits in the brain, thus constituting an important biomolecular target for treatments of Alzheimer's disease (AD). We describe the engineering of cognate Anticalins as a novel type of neutralizing protein reagent based on the human lipocalin scaffold. Phage display selection from a genetic random library comprising variants of the human lipocalin 2 (Lcn2) with mutations targeted at 20 exposed amino acid positions in the four loops that form the natural binding site was performed using both recombinant and synthetic target peptides and resulted in three different Anticalins. Biochemical characterization of the purified proteins produced by periplasmic secretion in Escherichia coli revealed high folding stability in a monomeric state, with Tm values ranging from 53.4°C to 74.5°C, as well as high affinities for Aβ40, between 95 pM and 563 pM, as measured by real-time surface plasmon resonance analysis. The central linear VFFAED epitope within the Aβ sequence was mapped using a synthetic peptide array on membranes and was shared by all three Anticalins, despite up to 13 mutual amino acid differences in their binding sites. All Anticalins had the ability–with varying extent–to inhibit Aβ aggregation in vitro according to the thioflavin-T fluorescence assay and, furthermore, they abolished Aβ42-mediated toxicity in neuronal cell culture. Thus, these Anticalins provide not only useful protein reagents to study the molecular pathology of AD but they also show potential as alternative drug candidates compared with antibodies. PMID:27029347

  16. High-affinity Anticalins with aggregation-blocking activity directed against the Alzheimer β-amyloid peptide.

    PubMed

    Rauth, Sabine; Hinz, Dominik; Börger, Michael; Uhrig, Markus; Mayhaus, Manuel; Riemenschneider, Matthias; Skerra, Arne

    2016-06-01

    Amyloid beta (Aβ) peptides, in particular Aβ42 and Aβ40, exert neurotoxic effects and their overproduction leads to amyloid deposits in the brain, thus constituting an important biomolecular target for treatments of Alzheimer's disease (AD). We describe the engineering of cognate Anticalins as a novel type of neutralizing protein reagent based on the human lipocalin scaffold. Phage display selection from a genetic random library comprising variants of the human lipocalin 2 (Lcn2) with mutations targeted at 20 exposed amino acid positions in the four loops that form the natural binding site was performed using both recombinant and synthetic target peptides and resulted in three different Anticalins. Biochemical characterization of the purified proteins produced by periplasmic secretion in Escherichia coli revealed high folding stability in a monomeric state, with Tm values ranging from 53.4°C to 74.5°C, as well as high affinities for Aβ40, between 95 pM and 563 pM, as measured by real-time surface plasmon resonance analysis. The central linear VFFAED epitope within the Aβ sequence was mapped using a synthetic peptide array on membranes and was shared by all three Anticalins, despite up to 13 mutual amino acid differences in their binding sites. All Anticalins had the ability-with varying extent-to inhibit Aβ aggregation in vitro according to the thioflavin-T fluorescence assay and, furthermore, they abolished Aβ42-mediated toxicity in neuronal cell culture. Thus, these Anticalins provide not only useful protein reagents to study the molecular pathology of AD but they also show potential as alternative drug candidates compared with antibodies. PMID:27029347

  17. 21 CFR 520.1696b - Penicillin G potassium in drinking water.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin G potassium in drinking water. 520....1696b Penicillin G potassium in drinking water. (a) Specifications. When reconstituted, each milliliter contains penicillin G potassium equivalent to 20,000, 25,000, 40,000, 50,000, 80,000, or 100,000 units...

  18. 21 CFR 520.1696b - Penicillin G potassium in drinking water.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G potassium in drinking water. 520....1696b Penicillin G potassium in drinking water. (a) Specifications. When reconstituted, each milliliter contains penicillin G potassium equivalent to 20,000, 25,000, 40,000, 50,000, 80,000, or 100,000 units...

  19. 21 CFR 520.1696c - Penicillin V potassium for oral solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin V potassium for oral solution. 520....1696c Penicillin V potassium for oral solution. (a) Specifications. When reconstituted, each milliliter... infections and septicemia caused by pathogens susceptible to penicillin V potassium. (3)...

  20. 21 CFR 520.1696b - Penicillin G potassium in drinking water.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin G potassium in drinking water. 520....1696b Penicillin G potassium in drinking water. (a) Specifications. When reconstituted, each milliliter contains penicillin G potassium equivalent to 20,000, 25,000, 40,000, 50,000, 80,000, or 100,000 units...

  1. 21 CFR 520.1696c - Penicillin V potassium for oral solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin V potassium for oral solution. 520....1696c Penicillin V potassium for oral solution. (a) Specifications. When reconstituted, each milliliter... infections and septicemia caused by pathogens susceptible to penicillin V potassium. (3)...

  2. 21 CFR 520.1696c - Penicillin V potassium for oral solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin V potassium for oral solution. 520....1696c Penicillin V potassium for oral solution. (a) Specifications. When reconstituted, each milliliter... infections and septicemia caused by pathogens susceptible to penicillin V potassium. (3)...

  3. 21 CFR 524.1484h - Neomycin, penicillin, polymyxin, hydrocortisone suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Neomycin, penicillin, polymyxin, hydrocortisone... NEW ANIMAL DRUGS § 524.1484h Neomycin, penicillin, polymyxin, hydrocortisone suspension. (a... milligrams of neomycin, 10,000 international units of penicillin G procaine, 5,000 international units...

  4. 21 CFR 524.1484h - Neomycin, penicillin, polymyxin, hydrocortisone suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Neomycin, penicillin, polymyxin, hydrocortisone... NEW ANIMAL DRUGS § 524.1484h Neomycin, penicillin, polymyxin, hydrocortisone suspension. (a... milligrams of neomycin, 10,000 international units of penicillin G procaine, 5,000 international units...

  5. 75 FR 55798 - North American Bioproducts Corporation; Filing of Food Additive Petition (Animal Use); Penicillin...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-14

    ... Additive Petition (Animal Use); Penicillin G Procaine AGENCY: Food and Drug Administration, HHS. ACTION... safe use of penicillin G procaine as an antimicrobial processing aid in fuel- ethanol fermentations... safe use of penicillin G procaine as an antimicrobial processing aid in fuel- ethanol...

  6. 21 CFR 524.1484h - Neomycin, penicillin, polymyxin, hydrocortisone suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin, penicillin, polymyxin, hydrocortisone... NEW ANIMAL DRUGS § 524.1484h Neomycin, penicillin, polymyxin, hydrocortisone suspension. (a... milligrams of neomycin, 10,000 international units of penicillin G procaine, 5,000 international units...

  7. 21 CFR 524.1484h - Neomycin, penicillin, polymyxin, hydrocortisone suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Neomycin, penicillin, polymyxin, hydrocortisone... NEW ANIMAL DRUGS § 524.1484h Neomycin, penicillin, polymyxin, hydrocortisone suspension. (a... milligrams of neomycin, 10,000 international units of penicillin G procaine, 5,000 international units...

  8. Actinomycosis after allogeneic hematopoietic stem cell transplantation despite penicillin prophylaxis.

    PubMed

    Barraco, F; Labussière-Wallet, H; Valour, F; Ducastelle-Leprêtre, S; Nicolini, F-E; Thomas, X; Ferry, T; Dumitrescu, O; Michallet, M; Ader, F

    2016-08-01

    Actinomycosis is a rare chronic and multifaceted disease caused by Actinomyces species frequently mimicking malignancy or other chronic granulomatous lung diseases. We report 4 original presentations of actinomycosis arising under supposed penicillin prophylaxis in allogeneic stem cell transplantation recipients. PMID:27203624

  9. 21 CFR 526.1696 - Penicillin intramammary dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin intramammary dosage forms. 526.1696 Section 526.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS INTRAMAMMARY DOSAGE FORMS § 526.1696...

  10. Penicillin amidohydrolase productivity of locally isolated bacterial species.

    PubMed

    Mahmood, Z A; Shaikh, D; Zoha, S M

    1991-01-01

    Penicillin amidohydrolase productivity of four locally isolated bacterial species is described. Organisms were identified as Escherichia coli, Pseudomonas aeruginosa, Sarcina lutea and Bacillus megaterium. Highest enzyme productivity of 3.2 U/mL with a corresponding dry cell mass of 4.5 g/L was recorded from S. lutea. PMID:1821869

  11. Direct Measurement of Pore Dynamics and Leakage Induced by a Model Antimicrobial Peptide in Single Vesicles and Cells.

    PubMed

    Burton, Matthew G; Huang, Qi M; Hossain, Mohammed A; Wade, John D; Palombo, Enzo A; Gee, Michelle L; Clayton, Andrew H A

    2016-06-28

    Antimicrobial peptides are promising therapeutic alternatives to counter growing antimicrobial resistance. Their precise mechanism of action remains elusive, however, particularly with respect to live bacterial cells. We investigated the interaction of a fluorescent melittin analogue with single giant unilamellar vesicles, giant multilamellar vesicles, and bilamellar Gram-negative Escherichia coli (E. coli) bacteria. Time-lapse fluorescence lifetime imaging microscopy was employed to determine the population distribution of the fluorescent melittin analogue between pore state and membrane surface state, and simultaneously measure the leakage of entrapped fluorescent species from the vesicle (or bacterium) interior. In giant unilamellar vesicles, leakage from vesicle interior was correlated with an increase in level of pore states, consistent with a stable pore formation mechanism. In giant multilamellar vesicles, vesicle leakage occurred more gradually and did not appear to correlate with increased pore states. Instead pore levels remained at a low steady-state level, which is more in line with coupled equilibria. Finally, in single bacterial cells, significant increases in pore levels were observed over time, which were correlated with only partial loss of cytosolic contents. These observations suggested that pore formation, as opposed to complete dissolution of membrane, was responsible for the leakage of contents in these systems, and that the bacterial membrane has an adaptive capacity that resists peptide attack. We interpret the three distinct pore dynamics regimes in the context of the increasing physical and biological complexity of the membranes. PMID:27281288

  12. Evaluation of aerobic co-composting of penicillin fermentation fungi residue with pig manure on penicillin degradation, microbial population dynamics and composting maturity.

    PubMed

    Zhang, Zhenhua; Zhao, Juan; Yu, Cigang; Dong, Shanshan; Zhang, Dini; Yu, Ran; Wang, Changyong; Liu, Yan

    2015-12-01

    Improper treatment of penicillin fermentation fungi residue (PFFR), one of the by-products of penicillin production process, may result in environmental pollution due to the high concentration of penicillin. Aerobic co-composting of PFFR with pig manure was determined to degrade penicillin in PFFR. Results showed that co-composting of PFFR with pig manure can significantly reduce the concentration of penicillin in PFFR, make the PFFR-compost safer as organic fertilizer for soil application. More than 99% of penicillin in PFFR were removed after 7-day composting. PFFR did not affect the composting process and even promote the activity of the microorganisms in the compost. Quantitative PCR (qPCR) indicated that the bacteria and actinomycetes number in the AC samples were 40-80% higher than that in the pig-manure compost (CK) samples in the same composting phases. This research indicated that the aerobic co-composting was a feasible PFFR treatment method. PMID:26409851

  13. Peptide folding simulations.

    PubMed

    Gnanakaran, S; Nymeyer, Hugh; Portman, John; Sanbonmatsu, Kevin Y; García, Angel E

    2003-04-01

    Developments in the design of small peptides that mimic proteins in complexity, recent advances in nanosecond time-resolved spectroscopy methods to study peptides and the development of modern, highly parallel simulation algorithms have come together to give us a detailed picture of peptide folding dynamics. Two newly implemented simulation techniques, parallel replica dynamics and replica exchange molecular dynamics, can now describe directly from simulations the kinetics and thermodynamics of peptide formation, respectively. Given these developments, the simulation community now has the tools to verify and validate simulation protocols and models (forcefields). PMID:12727509

  14. Efficient cascade synthesis of ampicillin from penicillin G potassium salt using wild and mutant penicillin G acylase from Alcaligenes faecalis.

    PubMed

    Deng, Senwen; Ma, Xiaoqiang; Su, Erzheng; Wei, Dongzhi

    2016-02-10

    To avoid isolation and purification of the intermediate 6-aminopenicillanic acid (6-APA), a two-enzyme two-step cascade synthesis of ampicillin from penicillin G was established. In purely aqueous medium, penicillin G hydrolysis and ampicillin synthesis were catalyzed by immobilized wild-type and mutagenized penicillin G acylases from Alcaligenes faecalis (Af PGA), respectively (Fig. 1). The βF24 G mutant Af PGA (the 24th Phenylalanine of the β-subunit was replaced by Glycine) was employed for its superior performance in enzymatic synthesis of ampicillin. By optimizing the reaction conditions, including enzyme loading, temperature, initial pH and D-PGME/6-APA ratio, the conversion of the second step of ampicillin synthesis reached approximately 90% in 240 min and less than 1.7 mole D-PGME were required to produce 1 mole ampicillin. Overall, in a 285 min continuous two-step procedure, an ampicillin yield of 87% was achieved, demonstrating the possibility of improving the cascade synthesis of ampicillin by mutagenized PGA, providing an economically efficient and environmentally benign procedure for semi-synthetic penicillins antibiotics synthesis. PMID:26732414

  15. Direct Identification of On-Bead Peptides Using Surface-Enhanced Raman Spectroscopic Barcoding System for High-Throughput Bioanalysis

    PubMed Central

    Kang, Homan; Jeong, Sinyoung; Koh, Yul; Geun Cha, Myeong; Yang, Jin-Kyoung; Kyeong, San; Kim, Jaehi; Kwak, Seon-Yeong; Chang, Hye-Jin; Lee, Hyunmi; Jeong, Cheolhwan; Kim, Jong-Ho; Jun, Bong-Hyun; Kim, Yong-Kweon; Hong Jeong, Dae; Lee, Yoon-Sik

    2015-01-01

    Recently, preparation and screening of compound libraries remain one of the most challenging tasks in drug discovery, biomarker detection, and biomolecular profiling processes. So far, several distinct encoding/decoding methods such as chemical encoding, graphical encoding, and optical encoding have been reported to identify those libraries. In this paper, a simple and efficient surface-enhanced Raman spectroscopic (SERS) barcoding method using highly sensitive SERS nanoparticles (SERS ID) is presented. The 44 kinds of SERS IDs were able to generate simple codes and could possibly generate more than one million kinds of codes by incorporating combinations of different SERS IDs. The barcoding method exhibited high stability and reliability under bioassay conditions. The SERS ID encoding based screening platform can identify the peptide ligand on the bead and also quantify its binding affinity for specific protein. We believe that our SERS barcoding technology is a promising method in the screening of one-bead-one-compound (OBOC) libraries for drug discovery. PMID:26017924

  16. A Synthetic, Xeno-Free Peptide Surface for Expansion and Directed Differentiation of Human Induced Pluripotent Stem Cells

    PubMed Central

    Jin, Sha; Yao, Huantong; Weber, Jennifer L.; Melkoumian, Zara K.; Ye, Kaiming

    2012-01-01

    Human induced pluripotent stem cells have the potential to become an unlimited cell source for cell replacement therapy. The realization of this potential, however, depends on the availability of culture methods that are robust, scalable, and use chemically defined materials. Despite significant advances in hiPSC technologies, the expansion of hiPSCs relies upon the use of animal-derived extracellular matrix extracts, such as Matrigel, which raises safety concerns over the use of these products. In this work, we investigated the feasibility of expanding and differentiating hiPSCs on a chemically defined, xeno-free synthetic peptide substrate, i.e. Corning Synthemax® Surface. We demonstrated that the Synthemax Surface supports the attachment, spreading, and proliferation of hiPSCs, as well as hiPSCs’ lineage-specific differentiation. hiPSCs colonies grown on Synthemax Surfaces exhibit less spread and more compact morphology compared to cells grown on Matrigel™. The cytoskeleton characterization of hiPSCs grown on the Synthemax Surface revealed formation of denser actin filaments in the cell-cell interface. The down-regulation of vinculin and up-regulation of zyxin expression were also observed in hiPSCs grown on the Synthemax Surface. Further examination of cell-ECM interaction revealed that hiPSCs grown on the Synthemax Surface primarily utilize αvβ5 integrins to mediate attachment to the substrate, whereas multiple integrins are involved in cell attachment to Matrigel. Finally, hiPSCs can be maintained undifferentiated on the Synthemax Surface for more than ten passages. These studies provide a novel approach for expansion of hiPSCs using synthetic peptide engineered surface as a substrate to avoid a potential risk of contamination and lot-to-lot variability with animal derived materials. PMID:23226418

  17. Cloning, expression and purification of penicillin-binding protein 3 from Pseudomonas aeruginosa CMCC 10104.

    PubMed

    An, Yan Dong; Du, Qi Zhen; Tong, Li Yan; Yu, Zhao Wu; Gong, Xing Wen

    2015-06-01

    Penicillin-binding protein 3 (PBP3) of Pseudomonas aeruginosa is the primary target of β-lactams used to treat pseudomonas infections. Meanwhile, structure change and overproduction of PBP3 play important roles in the drug resistance of P. aeruginosa. Therefore, studies on the gene and structure of PBP3 are urgently needed. P. aeruginosa CMCC 10104 is a type culture strain common used in China. However, there is no report on its genomic and proteomic profiles. In this study, based on ftsI of P. aeruginosa PAO1, the gene encoding PBP3 was cloned from CMCC 10104. A truncated version of the ftsI gene, omitting the bases encoding the hydrophobic leader peptide (amino acids 1-34), was amplified by PCR. The cloned DNA shared 99.76% identity with ftsI from PAO1. Only four bases were different (66 C-A, 1020 T-C, 1233 T-C, and 1527 T-C). However, there were no differences between their deduced amino acid sequences. The recombinant PBP3 (rPBP3), containing a 6-histidine tag, was expressed in Escherichia coli BL21 (DE3). Immobilized metal affinity chromatography (IMAC) with Ni(2+)-NTA agarose was used for its purification. The purified rPBP3 was identified by SDS-PAGE and western blot analysis, and showed a single band at about 60kDa with purity higher than 95%. The penicillin-binding assay indicated that the obtained rPBP3 was functional and not hindered by the presence of the C-terminal His-tag. The protocol described in this study offers a method for obtaining purified recombinant PBP3 from P. aeruginosa CMCC 10104. PMID:25514204

  18. 21 CFR 526.1696b - Penicillin G procaine-dihydrostreptomycin in soybean oil for intramammary infusion (dry cows).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin G procaine-dihydrostreptomycin in... INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696b Penicillin G procaine-dihydrostreptomycin in soybean oil... penicillin G procaine equivalent to 200,000 units of penicillin G and dihydrostreptomycin sulfate...

  19. 21 CFR 526.1696b - Penicillin G procaine-dihydrostreptomycin in soybean oil for intramammary infusion (dry cows).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin G procaine-dihydrostreptomycin in... INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696b Penicillin G procaine-dihydrostreptomycin in soybean oil... penicillin G procaine equivalent to 200,000 units of penicillin G and dihydrostreptomycin sulfate...

  20. 21 CFR 526.1696b - Penicillin G procaine-dihydrostreptomycin in soybean oil for intramammary infusion (dry cows).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin G procaine-dihydrostreptomycin in... INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696b Penicillin G procaine-dihydrostreptomycin in soybean oil... penicillin G procaine equivalent to 200,000 units of penicillin G and dihydrostreptomycin sulfate...

  1. 21 CFR 526.1696b - Penicillin G procaine-dihydrostreptomycin in soybean oil for intramammary infusion (dry cows).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin G procaine-dihydrostreptomycin in... INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696b Penicillin G procaine-dihydrostreptomycin in soybean oil... penicillin G procaine equivalent to 200,000 units of penicillin G and dihydrostreptomycin sulfate...

  2. Direct measurement of peptide-specific CD8+ T cells using HLA-A2:Ig dimer for monitoring the in vivo immune response to a HER2/neu vaccine in breast and prostate cancer patients.

    PubMed

    Woll, Michael M; Fisher, Christine M; Ryan, Gayle B; Gurney, Jennifer M; Storrer, Catherine E; Ioannides, Constantin G; Shriver, Craig D; Moul, Judd W; McLeod, David G; Ponniah, Sathibalan; Peoples, George E

    2004-07-01

    HER2/neu is a proto-oncogene and a member of the epidermal growth factor receptor family of proteins that is overexpressed in numerous types of human cancer. We are currently conducting clinical trials with the HER2/neu E75 peptide vaccine in breast and prostate cancer patients. We have evaluated the use of HLA-A2 dimer molecule for the immunological monitoring of cancer patients receiving the E75 peptide vaccine. Peripheral blood samples from patients receiving the vaccine were stained with HLA-A2 dimers containing the vaccine peptide E75 or control peptides and analyzed by flow cytometry. We compared the HLA-A2 dimer assay to standard methods of immunologic monitoring (IFN-gamma release, lymphocyte proliferation, and cytotoxicity). The HLA-A2 dimer assay was also compared with the HLA-A2 tetramer assay. E75 peptide-specific CD8 T cells were detected directly in the peripheral blood of patients by staining with E75-HLA-A2 dimers and CD8 antibodies. T cell cultures generated by repeated stimulations using E75 peptide-pulsed dendritic cells showed increased staining with E75-peptide loaded HLA-A2 dimers. Simultaneously analysis by the dimer assay and standard immunologic assays demonstrated that the dimer-staining assay correlated well with these methods of immunologic monitoring. A direct comparison using E75-specific HLA-A2 tetramers and HLA-A2 dimers for the detection of E75-specific CD8 T cells in peripheral blood showed comparable results with the two assays. Our findings indicate that the HLA-A2 dimer is a powerful new tool for directly quantifying and monitoring immune responses of antigen-specific T cells in peptide vaccine clinical trials. PMID:15163902

  3. Use of Mutated Self-Cleaving 2A Peptides as a Molecular Rheostat to Direct Simultaneous Formation of Membrane and Secreted Anti-HIV Immunoglobulins

    PubMed Central

    Yu, Kenneth K.; Aguilar, Kiefer; Tsai, Jonathan; Galimidi, Rachel; Gnanapragasam, Priyanthi; Yang, Lili; Baltimore, David

    2012-01-01

    In nature, B cells produce surface immunoglobulin and secreted antibody from the same immunoglobulin gene via alternative splicing of the pre-messenger RNA. Here we present a novel system for genetically programming B cells to direct the simultaneous formation of membrane-bound and secreted immunoglobulins that we term a “Molecular Rheostat”, based on the use of mutated “self-cleaving” 2A peptides. The Molecular Rheostat is designed so that the ratio of secreted to membrane-bound immunoglobulins can be controlled by selecting appropriate mutations in the 2A peptide. Lentiviral transgenesis of Molecular Rheostat constructs into B cell lines enables the simultaneous expression of functional b12-based IgM-like BCRs that signal to the cells and mediate the secretion of b12 IgG broadly neutralizing antibodies that can bind and neutralize HIV-1 pseudovirus. We show that these b12-based Molecular Rheostat constructs promote the maturation of EU12 B cells in an in vitro model of B lymphopoiesis. The Molecular Rheostat offers a novel tool for genetically manipulating B cell specificity for B-cell based gene therapy. PMID:23209743

  4. Casein is an essential cofactor in autoantibody reactivity directed against the C-terminal SmD1 peptide AA 83-119 in systemic lupus erythematosus.

    PubMed

    Riemekasten, Gabriela; Marell, Jeannette; Hentschel, Christian; Klein, Rolf; Burmester, Gerd-R; Schoessler, Werner; Hiepe, Falk

    2002-12-01

    The C-terminal peptide SmD1(83-119) has been identified as an important autoantigen in systemic lupus erythematosus (SLE). ELISA studies have shown that roughly 70% of all sera from patients with SLE react with this peptide. Previous findings revealed that the addition of blocking agents and sample dilution buffers influences the discrimination between positive and negative anti-SmD1(83-119) sera in SLE. The aim of the present study was to identify possible cofactors in the anti-SmD1(83-119) reactivity. We therefore tested SLE sera (n=6) for anti-SmD1(83-119) reactivity by ELISA and analysed the effects of different blocking agents (1% skim milk, 1% gelatin, and 1% BSA). In our investigation, lipids were extracted from skim milk using dichlomethane, and the putative fraction was tested to assess the assay's ability to discriminate between positive and negative sera. The effects of enzymatic digestion by casein were analyzed, and different concentrations of casein were used to determine the role of this protein in the detection of anti-SmD1(83-119) antibodies by ELISA. Furthermore, rabbits were immunized with SmD1(83-119) adsorbed to casein and control proteins. One percent skim milk was the most effective blocking agent and sample dilution buffer for the discrimination between positive and negative sera. As demonstrated by SDS electrophoresis, the discriminative capacity was influenced by enzymatic digestion of skim milk proteins, but not by lipid extraction. Differences in anti-SmD1(83-119) reactivity upon variation of the casein concentration suggest that the protein plays a significant role in the detection of anti-SmD1(83-119) antibodies. However, our immunisation studies did not show any effect of casein on anti-SmD1(83-119) reactivity, suggesting that it has no immunogenic effect on the anti-SmD1(83-119) response. In conclusion, casein seems to be an important cofactor in autoantibody reactivity directed against the C-terminal SmD1(83-119) peptide and

  5. Polycyclic peptide therapeutics.

    PubMed

    Baeriswyl, Vanessa; Heinis, Christian

    2013-03-01

    Owing to their excellent binding properties, high stability, and low off-target toxicity, polycyclic peptides are an attractive molecule format for the development of therapeutics. Currently, only a handful of polycyclic peptides are used in the clinic; examples include the antibiotic vancomycin, the anticancer drugs actinomycin D and romidepsin, and the analgesic agent ziconotide. All clinically used polycyclic peptide drugs are derived from natural sources, such as soil bacteria in the case of vancomycin, actinomycin D and romidepsin, or the venom of a fish-hunting coil snail in the case of ziconotide. Unfortunately, nature provides peptide macrocyclic ligands for only a small fraction of therapeutic targets. For the generation of ligands of targets of choice, researchers have inserted artificial binding sites into natural polycyclic peptide scaffolds, such as cystine knot proteins, using rational design or directed evolution approaches. More recently, large combinatorial libraries of genetically encoded bicyclic peptides have been generated de novo and screened by phage display. In this Minireview, the properties of existing polycyclic peptide drugs are discussed and related to their interesting molecular architectures. Furthermore, technologies that allow the development of unnatural polycyclic peptide ligands are discussed. Recent application of these technologies has generated promising results, suggesting that polycyclic peptide therapeutics could potentially be developed for a broad range of diseases. PMID:23355488

  6. X-ray structure at 1.75 resolution of a norovirus 3C protease linked to an active site-directed peptide inhibitor

    SciTech Connect

    Cooper, Jon; Coates, Leighton; Hussey, Robert

    2010-01-01

    Noroviruses are recognized universally as the most important cause of human epidemic non-bacterial gastroenteritis. Viral replication requires a 3C cysteine protease that cleaves a 200kDa viral polyprotein into its constituent functional proteins. Here we describe the X-ray structure of the Southampton norovirus 3C protease (SV3CP) bound to an active site-directed peptide inhibitor (MAPI) which has been refined at 1.75 resolution, following initial MAD phasing with a selenomethionine derivative. The inhibitor, acetyl-Glu-Phe-Gln-Leu-Gln-X, based on a 3C protease cleavage recognition sequences in the 200kDa polyprotein substrate, reacts covalently through its propenylethylester group (X) with the active site nucleophile, Cys 139. The 3C protease-inhibitor structure permits, for the first time, the identification of substrate recognition and binding groups and provides important new information for the development of antiviral prophylactics.

  7. Staphylococci in community-acquired infections: Increased resistance to penicillin.

    PubMed

    Hughes, G B; Chidi, C C; Macon, W L

    1976-04-01

    One hundred patients with community-acquired staphylococcal infections of the skin and soft tissues were treated in the Emergency Ward of Cleveland Metropolitan General Hospital from June to October of 1974. Each staphylococcal infection was considered community-acquired if, within two weeks prior to being treated for the first time, the patient had not received antibiotics, had not been hospitalized, and had not been in contact with other recently hospitalized persons. Of 100 community-acquired staphylococcal infections, 85 were resistant to penicillin. Almost no resistance to other tested antibiotics was observed. Unless indicated otherwise by bacteriologic testing, penicillin is a poor drug of choice in those skin and soft tissue infections suspected of harboring staphylococci. PMID:1267491

  8. Subfamily-specific adaptations in the structures of two penicillin-binding proteins from Mycobacterium tuberculosis

    DOE PAGESBeta

    Prigozhin, Daniil M.; Krieger, Inna V.; Huizar, John P.; Mavrici, Daniela; Waldo, Geoffrey S.; Hung, Li -Wei; Sacchettini, James C.; Terwilliger, Thomas C.; Alber, Tom; Mayer, Claudine

    2014-12-31

    Beta-lactam antibiotics target penicillin-binding proteins including several enzyme classes essential for bacterial cell-wall homeostasis. To better understand the functional and inhibitor-binding specificities of penicillin-binding proteins from the pathogen, Mycobacterium tuberculosis, we carried out structural and phylogenetic analysis of two predicted D,D-carboxypeptidases, Rv2911 and Rv3330. Optimization of Rv2911 for crystallization using directed evolution and the GFP folding reporter method yielded a soluble quadruple mutant. Structures of optimized Rv2911 bound to phenylmethylsulfonyl fluoride and Rv3330 bound to meropenem show that, in contrast to the nonspecific inhibitor, meropenem forms an extended interaction with the enzyme along a conserved surface. Phylogenetic analysis shows thatmore » Rv2911 and Rv3330 belong to different clades that emerged in Actinobacteria and are not represented in model organisms such as Escherichia coli and Bacillus subtilis. Clade-specific adaptations allow these enzymes to fulfill distinct physiological roles despite strict conservation of core catalytic residues. The characteristic differences include potential protein-protein interaction surfaces and specificity-determining residues surrounding the catalytic site. Overall, these structural insights lay the groundwork to develop improved beta-lactam therapeutics for tuberculosis.« less

  9. Subfamily-Specific Adaptations in the Structures of Two Penicillin-Binding Proteins from Mycobacterium tuberculosis

    PubMed Central

    Prigozhin, Daniil M.; Krieger, Inna V.; Huizar, John P.; Mavrici, Daniela; Waldo, Geoffrey S.; Hung, Li-Wei; Sacchettini, James C.; Terwilliger, Thomas C.; Alber, Tom

    2014-01-01

    Beta-lactam antibiotics target penicillin-binding proteins including several enzyme classes essential for bacterial cell-wall homeostasis. To better understand the functional and inhibitor-binding specificities of penicillin-binding proteins from the pathogen, Mycobacterium tuberculosis, we carried out structural and phylogenetic analysis of two predicted D,D-carboxypeptidases, Rv2911 and Rv3330. Optimization of Rv2911 for crystallization using directed evolution and the GFP folding reporter method yielded a soluble quadruple mutant. Structures of optimized Rv2911 bound to phenylmethylsulfonyl fluoride and Rv3330 bound to meropenem show that, in contrast to the nonspecific inhibitor, meropenem forms an extended interaction with the enzyme along a conserved surface. Phylogenetic analysis shows that Rv2911 and Rv3330 belong to different clades that emerged in Actinobacteria and are not represented in model organisms such as Escherichia coli and Bacillus subtilis. Clade-specific adaptations allow these enzymes to fulfill distinct physiological roles despite strict conservation of core catalytic residues. The characteristic differences include potential protein-protein interaction surfaces and specificity-determining residues surrounding the catalytic site. Overall, these structural insights lay the groundwork to develop improved beta-lactam therapeutics for tuberculosis. PMID:25551456

  10. Optimization of culture medium and conditions for penicillin acylase production by Streptomyces lavendulae ATCC 13664.

    PubMed

    Torres-Bacete, Jesús; Arroyo, Miguel; Torres-Guzmán, Raquel; De La Mata, Isabel; Acebal, Carmen; Castillón, M Pilar

    2005-08-01

    The culture medium for Streptomyces lavendulae ATCC 13664 was optimized on a shake-flask scale by using a statistical factorial design for enhanced production of penicillin acylase. This extracellular enzyme recently has been reported to be a penicillin K acylase, presenting also high hydrolytic activity against penicillin V and other natural aliphatic penicillins such as penicillin K, penicillin F, and penicillin dihydroF. The factorial design indicated that the main factors that positively affect penicillin acylase production by S. lavendulae were the concentration of yeast extract and the presence of oligoelements in the fermentation medium, whereas the presence of olive oil in the medium had no effect on enzyme production. An initial concentration of 2.5% (w/v) yeast extract and 3 microg/mL of CuSO4 x 5H2O was found to be best for acylase production. In such optimized culture medium, fermentation of the microorganism yielded 289 IU/L of enzyme in 72 h when employing a volume medium/volume flask ratio of 0.4 and a 300-rpm shaking speed. The presence of copper, alone and in combination with other metals, stimulated biomass as well as penicillin acylase production. The time course of penicillin acylase production was also studied in the optimized medium and conditions. Enzyme production showed catabolite repression by different carbon sources such as glucose, lactose, citrate, glycerol, and glycine. PMID:16118466

  11. Affinity of cefoperazone for penicillin-binding proteins.

    PubMed Central

    Matsubara, N; Minami, S; Matsuhashi, M; Takaoka, M; Mitsuhashi, S

    1980-01-01

    Cefoperazone (T-1551, CFP) a new semisynthetic cephalosporin, has a broad spectrum of antibacterial activity. We investigated the affinity of CFP to penicillin-binding proteins (PBPs) and the inhibition of peptidoglycan synthesis by CFP. CFP had high affinities for Escherichia coli PBP-3, -1Bs, -2, and -1A, in descending order, and low affinities for PBP-4, -5, and -6. Similarly, CFP showed high affinity for Pseudomonas aeruginosa PBP-3, -1A, -1B, -2, and -4, in descending order. It is known that E. coli PBP-3 and P. aeruginosa PBP-3 participate in cell division. These results are in good agreement with the formation of filamentous cells of E. coli and P. aeruginosa treated with CFP. CFP had lower inhibitory activities on D-alanine carboxypeptidase IA and IB of E. coli than that of penicillin G, but its inhibitory activities on the cross-link formation in peptidoglycan synthesis were the same as those of penicillin G and higher than those of ampicillin. Images PMID:6448021

  12. Polymer immobilized enzyme optrodes for the detection of penicillin

    SciTech Connect

    Kulp, T.J.; Camins, I.; Angel, S.M.; Munkholm, C.; Walt, D.R.

    1987-12-15

    The preparation and performance of two enzyme-based fiber-optic sensors (optrodes) capable of detecting penicillin are described. Each sensor consists of a polymer membrane that is covalently attached to the tip of a glass optical fiber. The membrane contains the enzyme penicillinase and a pH-sensitive fluorescent dye. A signal is produced when the enzyme catalyzes the cleavage of the ..beta..-lactam ring of penicillin to produce penicilloic acid and, consequently, a pH change in the microenvironment of the membrane. The sensors differ in the way the polymer membrane is constructed and in the type of pH indicator dye used. Both optrodes exhibit response times (40-60 s) significantly lower than those of the corresponding enzyme electrodes (2 min). Each gives a linear response over the concentration range of 0.00025 to 0.01 M penicillin G, when measured in a 0.005 M phosphate buffer. The data indicate that these immobilization strategies produce similar results and may be considered complementary alternatives in future enzyme optrode applications.

  13. Effect of aeration rate on composting of penicillin mycelial dreg.

    PubMed

    Chen, Zhiqiang; Zhang, Shihua; Wen, Qinxue; Zheng, Jun

    2015-11-01

    Pilot scale experiments with forced aeration were conducted to estimate effects of aeration rates on the performance of composting penicillin mycelial dreg using sewage sludge as inoculation. Three aeration rates of 0.15, 0.50 and 0.90L/(min·kg) organic matter (OM) were examined. The principal physicochemical parameters were monitored during the 32day composting period. Results showed that the higher aeration rate of 0.90L/(min·kg) did not corresponded to a longer thermophilic duration and higher rates of OM degradation; but the lower aeration rate of 0.15L/(min·kg) did induce an accumulation of NH4(+)-N contents due to the inhibition of nitrification. On the other hand, aeration rate has little effect on degradation of penicillin. The results show that the longest phase of thermophilic temperatures≥55°C, the maximum NO3(-)-N content and seed germination, and the minimum C/N ratio were obtained with 0.50L/(min·kg) OM. Therefore, aeration rates of 0.50L/(min·kg) OM can be recommended for composting penicillin mycelial dreg. PMID:26574101

  14. Uncertainty analysis of penicillin V production using Monte Carlo simulation.

    PubMed

    Biwer, Arno; Griffith, Steve; Cooney, Charles

    2005-04-20

    Uncertainty and variability affect economic and environmental performance in the production of biotechnology and pharmaceutical products. However, commercial process simulation software typically provides analysis that assumes deterministic rather than stochastic process parameters and thus is not capable of dealing with the complexities created by variance that arise in the decision-making process. Using the production of penicillin V as a case study, this article shows how uncertainty can be quantified and evaluated. The first step is construction of a process model, as well as analysis of its cost structure and environmental impact. The second step is identification of uncertain variables and determination of their probability distributions based on available process and literature data. Finally, Monte Carlo simulations are run to see how these uncertainties propagate through the model and affect key economic and environmental outcomes. Thus, the overall variation of these objective functions are quantified, the technical, supply chain, and market parameters that contribute most to the existing variance are identified and the differences between economic and ecological evaluation are analyzed. In our case study analysis, we show that final penicillin and biomass concentrations in the fermenter have the highest contribution to variance for both unit production cost and environmental impact. The penicillin selling price dominates return on investment variance as well as the variance for other revenue-dependent parameters. PMID:15742389

  15. The Human Antimicrobial Peptide LL-37 Binds Directly to CsrS, a Sensor Histidine Kinase of Group A Streptococcus, to Activate Expression of Virulence Factors*

    PubMed Central

    Velarde, Jorge J.; Ashbaugh, Melissa; Wessels, Michael R.

    2014-01-01

    Group A Streptococcus (GAS) responds to subinhibitory concentrations of LL-37 by up-regulation of virulence factors through the CsrRS (CovRS) two-component system. The signaling mechanism, however, is unclear. To determine whether LL-37 signaling reflects specific binding to CsrS or rather a nonspecific response to LL-37-mediated membrane damage, we tested LL-37 fragments for CsrRS signaling and for GAS antimicrobial activity. We identified a 10-residue fragment (RI-10) of LL-37 as the minimal peptide that retains the ability to signal increased expression of GAS virulence factors, yet it has no detectable antimicrobial activity against GAS. Substitution of individual key amino acids in RI-10 reduced or abrogated signaling. These data do not support the hypothesis that CsrS detects LL-37-induced damage to the bacterial cell membrane but rather suggest that LL-37 signaling is mediated by a direct interaction with CsrS. To test whether LL-37 binds to CsrS, we used the purified CsrS extracellular domain to pull down LL-37 in vitro, a result that provides further evidence that LL-37 binds to CsrS. The dissociation of CsrS-mediated signaling from membrane damage by LL-37 fragments together with in vitro evidence for a direct LL-37-CsrS binding interaction constitute compelling evidence that signal transduction by LL-37 through CsrS reflects a direct ligand/receptor interaction. PMID:25378408

  16. Identification of Penicillin G Metabolites under Various Environmental Conditions Using UHPLC-MS/MS.

    PubMed

    Aldeek, Fadi; Canzani, Daniele; Standland, Matthew; Crosswhite, Mark R; Hammack, Walter; Gerard, Ghislain; Cook, Jo-Marie

    2016-08-10

    In this work, we investigate the stability of penicillin G in various conditions including acidic, alkaline, natural acidic matrices and after treatment of citrus trees that are infected with citrus greening disease. The identification, confirmation, and quantitation of penicillin G and its various metabolites were evaluated using two UHPLC-MS/MS systems with variable capabilities (i.e., Thermo Q Exactive Orbitrap and Sciex 6500 QTrap). Our data show that under acidic and alkaline conditions, penicillin G at 100 ng/mL degrades quickly, with a determined half-life time of approximately 2 h. Penillic acid, penicilloic acid, and penilloic acid are found to be the most abundant metabolites of penicillin G. These major metabolites, along with isopenillic acid, are found when penicillin G is used for treatment of citrus greening infected trees. The findings of this study will provide insight regarding penicillin G residues in agricultural and biological applications. PMID:26906275

  17. A New Method to Determine the Half-Life for Penicillin Using Microcalorimeter

    NASA Astrophysics Data System (ADS)

    Li, Z. X.; Zhao, W. W.

    2015-01-01

    The dissolution process of penicillin in normal saline and isotonic glucose solution was reported using a microcalorimeter. Both the integral and differential heats of solution were measured. The quantitative relationships between the amount of heat released and the quantity of dissolved penicillin were established. Meanwhile, the kinetics and the half-life of the dissolution processes as well as the enthalpy of solution, the entropy of dissolution, and the free energy of dissolution were determined. The results showed that a change of the solvent from normal saline to isotonic glucose solution had little effect on the half-life of penicillin in the dissolution process, and there was no significant difference between the stabilities of penicillin in isotonic glucose solution and normal saline. Moreover, the dissolution process of penicillin in isotonic glucose solution followed the first-order kinetics. These results could provide a theoretical basis for the clinical applications of penicillin.

  18. Antimicrobial peptides

    PubMed Central

    2014-01-01

    With increasing antibiotics resistance, there is an urgent need for novel infection therapeutics. Since antimicrobial peptides provide opportunities for this, identification and optimization of such peptides have attracted much interest during recent years. Here, a brief overview of antimicrobial peptides is provided, with focus placed on how selected hydrophobic modifications of antimicrobial peptides can be employed to combat also more demanding pathogens, including multi-resistant strains, without conferring unacceptable toxicity. PMID:24758244

  19. A Novel Peptide Hydrogel for an Antimicrobial Bandage Contact Lens.

    PubMed

    Gallagher, Andrew G; Alorabi, Jamal A; Wellings, Donald A; Lace, Rebecca; Horsburgh, Mal J; Williams, Rachel L

    2016-08-01

    A peptide hydrogel with an antimicrobial activity is developed as a bandage contact lens. The antimicrobial activity is enhanced with the addition of the biomolecules penicillin G or poly-ε-lysine and is positive against Staphylococcus aureus and Escherichia coli. The lens is also noncytotoxic toward a human corneal epithelial cell line and as a consequence is of great potential as a drug-eluting bandage lens replacing conventional corneal ulcer treatment. PMID:27276231

  20. Cell-penetrating peptides do not cross mitochondrial membranes even when conjugated to a lipophilic cation: evidence against direct passage through phospholipid bilayers

    PubMed Central

    2004-01-01

    CPPs (cell-penetrating peptides) facilitate the cellular uptake of covalently attached oligonucleotides, proteins and other macromolecules, but the mechanism of their uptake is disputed. Two models are proposed: direct movement through the phospholipid bilayer and endocytic uptake. Mitochondria are a good model system to distinguish between these possibilities, since they have no vesicular transport systems. Furthermore, CPP-mediated delivery of macromolecules to the mitochondrial matrix would be a significant breakthrough in the study of mitochondrial function and dysfunction, and could also lead to new therapies for diseases caused by mitochondrial damage. Therefore we investigated whether two CPPs, penetratin and Tat, could act as mitochondrial delivery vectors. We also determined whether conjugation of the lipophilic cation TPP (triphenylphosphonium) to penetratin or Tat facilitated their uptake into mitochondria, since TPP leads to uptake of attached molecules into mitochondria driven by the membrane potential. Neither penetratin nor Tat, nor their TPP conjugates, are internalized by isolated mitochondria, indicating that these CPPs cannot cross mitochondrial phospholipid bilayers. Tat and TPP–Tat are taken up by cells, but they accumulate in endosomes and do not reach mitochondria. We conclude that CPPs cannot cross mitochondrial phospholipid bilayers, and therefore cannot deliver macromolecules directly to mitochondria. Our findings shed light on the mechanism of uptake of CPPs by cells. The lack of direct movement of CPPs through mitochondrial phospholipid bilayers, along with the observed endosomal accumulation of Tat and TPP–Tat in cells, makes it unlikely that CPPs enter cells by direct membrane passage, and instead favours cellular uptake via an endocytic pathway. PMID:15270716

  1. 21 CFR 524.1484h - Neomycin, penicillin, polymyxin B, and hydrocortisone suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., atopic dermatitis, interdigital eczema, and otitis externa caused by bacteria susceptible to neomycin... caused by bacteria susceptible to neomycin, penicillin, and polymyxin B. (3) Limitations. For use in...

  2. Efficacy of Targeted 5-day Combined Parenteral and Intramammary Treatment of Clinical Mastitis Caused by Penicillin-Susceptible or Penicillin-Resistant Staphylococcus aureus

    PubMed Central

    Taponen, S; Jantunen, A; Pyörälä, E; Pyörälä, S

    2003-01-01

    Combined parenteral and intramammary treatment of mastitis caused by Staphylococcus aureus was compared to parenteral treatment only. Cows with clinical mastitis (166 mastitic quarters) caused by S. aureus treated by veterinarians of the Ambulatory Clinic of the Faculty of Veterinary Medicine during routine farm calls were included. Treatment was based on in vitro susceptibility testing of the bacterial isolate. Procaine penicillin G (86 cases due to β-lactamase negative strains) or amoxycillin-clavulanic acid (24 cases due to β-lactamase positive strains) was administered parenterally and intramammarily for 5 days. Efficacy of treatments was assessed 2 and 4 weeks later by physical examination, bacteriological culture, determination of CMT, somatic cell count and NAGase activity in milk. Quarters with growth of S. aureus in at least one post-treatment sample were classified as non-cured. As controls we used 41 clinical mastitis cases caused by penicillin-susceptible S. aureus isolates treated with procaine penicillin G parenterally for 5 days and 15 cases due to penicillin-resistant isolates treated with spiramycin parenterally for 5 days from the same practice area. Bacteriological cure rate after the combination treatment was 75.6% for quarters infected with penicillin-susceptible S. aureus isolates, and 29.2% for quarters infected with penicillin-resistant isolates. Cure rate for quarters treated only parenterally with procaine penicillin G was 56.1% and that for quarters treated with spiramycin 33.3%. The difference in cure rates between mastitis due to penicillin-susceptible and penicillin-resistant S. aureus was highly significant. Combined treatment was superior over systemic treatment only in the β-lactamase negative group. PMID:14650544

  3. Purification and preliminary crystallographic studies of penicillin G acylase from Providencia rettgeri.

    PubMed Central

    Klei, H. E.; Daumy, G. O.; Kelly, J. A.

    1995-01-01

    Two isoforms of the heterodimeric enzyme penicillin G acylase (EC 3.5.1.11) from Providencia rettgeri ATCC 31052 (strain Bro1) were purified to near homogeneity. The isoforms exhibited comparable enzymatic activities but differed slightly in the molecular weight and pI of their respective alpha-subunit. The origin of this difference was traced to the partial conversion of the N-terminal Gln of the alpha-subunit to pyrrolidonecarboxylic acid (pyro-Glu). The boundaries of the mature enzyme within the translated DNA sequence of the wild-type propeptide (GenBank M86533) were determined. The results conclusively identified the length of the signal peptide and the position of the spacer cleaved from the propeptide to form the active heterodimer. The molecular weights of the alpha- and beta-subunits, based on these termini, were 23.7 and 62.2 kDa, respectively. Both isoforms were crystallized independently as hexagonal bipyramids up to 0.60 mm in diameter in either space group P6(1)22 or P6(5)22 (a = b = 140.5 A and c = 209.5 A) from ammonium sulfate solutions buffered by 50 mM potassium phosphate at pH 7.5. The presence of glycerol, although not required, facilitated crystal growth. Native and heavy atom derivative data were collected to 3.0 A resolution, and the calculation of isomorphous replacement phases is under way. PMID:7795527

  4. Effective antimicrobial activity of Cbf-14, derived from a cathelin-like domain, against penicillin-resistant bacteria.

    PubMed

    Ma, Lingman; Wang, Yanrong; Wang, Mengxiao; Tian, Yuwei; Kang, Wei; Liu, Hanhan; Wang, Hui; Dou, Jie; Zhou, Changlin

    2016-05-01

    Cbf-14, a cationic peptide derived from a cathelin-like domain, was designed by inserting the highly α-helical sequence RLLR into an antibacterial sequence and deleting the inactive amino acids in Cbf-K16. Clinical penicillin-resistant isolates as well as NDM-1-carrying Escherichia coli and a correspondingly infected mice model were employed to evaluate Cbf-14 antibacterial activity. The results showed that Cbf-14 possessed potent antimicrobial effects with an MIC of 8-64 μg/ml, and killed almost all bacteria within 240 min. Cbf-14-treated mice achieved an 80% survival rate and approximate 2.5 log unit reduction in CFU in tissues; additionally, this peptide significantly suppressed the production of pro-inflammatory cytokines by the disaggregation of lipopolysaccharide (LPS), suggesting its anti-inflammatory effects. Furthermore, Cbf-14, concentration higher than 2 × MIC value, increased membrane uptake to NPN and PI dye by 96.2% and 63.7%, respectively, neutralised the negative zeta potential of LPS and bacteria surface, and induced 100% leakage of liposome-entrapped calcein and cytoplasmic membrane disruption of E. coli, indicating obvious membrane permeation. Finally, it bound to DNA and respectively evoked 85.0% and 63.3% inhibition of gene replication and protein expression of NDM-1 at sub-MIC concentration in E. coli BL21 (DE3)-NDM-1. These data indicated that Cbf-14 possessed effective antimicrobial activity against penicillin-resistant bacteria in vitro/vivo through membrane disruption, DNA binding, down-regulating NDM-1 expression by plasmid replication inhibition, and anti-inflammatory activity by LPS disaggregation, suggesting a potential anti-infective clinical agent. PMID:26897538

  5. Penicillin and Cell Wall Synthesis: A Study of Bacillus cereus by Electron Microscopy

    PubMed Central

    Highton, Peter J.; Hobbs, D. G.

    1972-01-01

    The changes in wall structure of a penicillinase micro-constitutive strain of Bacillus cereus (569/H/24), on exposure to penicillin, and after its removal by addition of penicillinase, have suggested the following model for the growth of the walls of these cylindrical cells. Longitudinal extension is by addition of material to a large and continuously increasing number of growing points uniformly distributed over the cylindrical surface. Addition is only in the longitudinal direction so that the cell diameter remains constant. Cross walls grow by addition to their inner edge, and on completion the two new rounded ends of the daughter cells are formed by splitting at the outer edge and continued addition at the center. The ends are conserved. Images PMID:4110923

  6. Function and Localization Dynamics of Bifunctional Penicillin-Binding Proteins in Caulobacter crescentus

    PubMed Central

    Strobel, Wolfgang; Möll, Andrea; Kiekebusch, Daniela; Klein, Kathrin E.

    2014-01-01

    The peptidoglycan cell wall of bacteria is a complex macromolecule composed of glycan strands that are cross-linked by short peptide bridges. Its biosynthesis involves a conserved group of enzymes, the bifunctional penicillin-binding proteins (bPBPs), which contain both a transglycosylase and a transpeptidase domain, thus being able to elongate the glycan strands and, at the same time, generate the peptide cross-links. The stalked model bacterium Caulobacter crescentus possesses five bPBP paralogs, named Pbp1A, PbpC, PbpX, PbpY, and PbpZ, whose function is still incompletely understood. In this study, we show that any of these proteins except for PbpZ is sufficient for growth and normal morphogenesis when expressed at native or elevated levels, whereas inactivation of all five paralogs is lethal. Growth analyses indicate a central role of PbpX in the resistance of C. crescentus against the noncanonical amino acid d-alanine. Moreover, we show that PbpX and PbpY localize to the cell division site. Their recruitment to the divisome is dependent on the essential cell division protein FtsN and likely involves interactions with FtsL and the putative peptidoglycan hydrolase DipM. The same interaction pattern is observed for Pbp1A and PbpC, although these proteins do not accumulate at midcell. Our findings demonstrate that the bPBPs of C. crescentus are, to a large extent, redundant and have retained the ability to interact with the peptidoglycan biosynthetic machineries responsible for cell elongation, cytokinesis, and stalk growth. Nevertheless, they may preferentially act in specific peptidoglycan biosynthetic complexes, thereby facilitating the independent regulation of distinct growth processes. PMID:24532768

  7. A role for the class A penicillin-binding protein PonA2 in the survival of Mycobacterium smegmatis under conditions of nonreplication.

    PubMed

    Patru, Maria-Magdalena; Pavelka, Martin S

    2010-06-01

    Class A penicillin-binding proteins (PBPs) are large, bifunctional proteins that are responsible for glycan chain assembly and peptide cross-linking of bacterial peptidoglycan. Bacteria in the genus Mycobacterium have been reported to have only two class A PBPs, PonA1 and PonA2, that are encoded in their genomes. We report here that the genomes of Mycobacterium smegmatis and other soil mycobacteria contain an additional gene encoding a third class A penicillin-binding protein, PonA3, which is a paralog of PonA2. Both the PonA2 and PonA3 proteins contain a penicillin-binding protein and serine/threonine protein kinase-associated (PASTA) domain that we propose may be involved in sensing the cell cycle and a C-terminal proline-rich region (PRR) that may have a role in protein-protein or protein-carbohydrate interactions. We show here that an M. smegmatis Delta ponA2 mutant has an unusual antibiotic susceptibility profile, exhibits a spherical morphology and an altered cell surface in stationary phase, and is defective for stationary-phase survival and recovery from anaerobic culture. In contrast, a Delta ponA3 mutant has no discernible phenotype under laboratory conditions. We demonstrate that PonA2 and PonA3 can bind penicillin and that PonA3 can partially substitute for PonA2 when ponA3 is expressed from a constitutive promoter on a multicopy plasmid. Our studies suggest that PonA2 is involved in adaptation to periods of nonreplication in response to starvation or anaerobiosis and that PonA3 may have a similar role. However, the regulation of PonA3 is likely different, suggesting that its importance could be related to stresses encountered in the environmental niches occupied by M. smegmatis and other soil-dwelling mycobacteria. PMID:20400545

  8. Sub-inhibitory concentrations of penicillin G induce biofilm formation by field isolates of Actinobacillus pleuropneumoniae.

    PubMed

    Hathroubi, S; Fontaine-Gosselin, S-È; Tremblay, Y D N; Labrie, J; Jacques, M

    2015-09-30

    Actinobacillus pleuropneumoniae is a Gram-negative bacterium and causative agent of porcine pleuropneumonia. This is a highly contagious disease that causes important economic losses to the swine industry worldwide. Penicillins are extensively used in swine production and these antibiotics are associated with high systemic clearance and low oral bioavailability. This may expose A. pleuropneumoniae to sub-inhibitory concentrations of penicillin G when the antibiotic is administered orally. Our goal was to evaluate the effect of sub-minimum inhibitory concentration (MIC) of penicillin G on the biofilm formation of A. pleuropneumoniae. Biofilm production of 13 field isolates from serotypes 1, 5a, 7 and 15 was tested in the presence of sub-MIC of penicillin G using a polystyrene microtiter plate assay. Using microscopy techniques and enzymatic digestion, biofilm architecture and composition were also characterized after exposure to sub-MIC of penicillin G. Sub-MIC of penicillin G significantly induced biofilm formation of nine isolates. The penicillin G-induced biofilms contained more poly-N-acetyl-D-glucosamine (PGA), extracellular DNA and proteins when compared to control biofilms grown without penicillin G. Additionally, penicillin G-induced biofilms were sensitive to DNase which was not observed with the untreated controls. Furthermore, sub-MIC of penicillin G up-regulated the expression of pgaA, which encodes a protein involved in PGA synthesis, and the genes encoding the envelope-stress sensing two-component regulatory system CpxRA. In conclusion, sub-MICs of penicillin G significantly induce biofilm formation and this is likely the result of a cell envelope stress sensed by the CpxRA system resulting in an increased production of PGA and other matrix components. PMID:26130517

  9. The twin-arginine signal peptide of Bacillus subtilis YwbN can direct either Tat- or Sec-dependent secretion of different cargo proteins: secretion of active subtilisin via the B. subtilis Tat pathway.

    PubMed

    Kolkman, Marc A B; van der Ploeg, René; Bertels, Michael; van Dijk, Maurits; van der Laan, Joop; van Dijl, Jan Maarten; Ferrari, Eugenio

    2008-12-01

    Proteins that are produced for commercial purposes in Bacillus subtilis are commonly secreted via the Sec pathway. Despite its high secretion capacity, the secretion of heterologous proteins via the Sec pathway is often unsuccessful. Alternative secretion routes, like the Tat pathway, are therefore of interest. Two parallel Tat pathways with distinct specificities have previously been discovered in B. subtilis. To explore the application potential of these Tat pathways, several commercially relevant or heterologous model proteins were fused to the signal peptides of the known B. subtilis Tat substrates YwbN and PhoD. Remarkably, the YwbN signal peptide directed secretion of active subtilisin, a typical Sec substrate, via the B. subtilis TatAyCy route. In contrast, the same signal peptide directed Tat-independent secretion of the Bacillus licheniformis alpha-amylase (AmyL). Moreover, the YwbN signal peptide directed secretion of SufI, an Escherichia coli Tat substrate, in a Tat-independent manner, most likely via Sec. Our results suggest that cytoplasmic protein folding prior to translocation is probably a major determinant of Tat-dependent protein secretion in B. subtilis, as is the case with E. coli. We conclude that future applications for the Tat system of B. subtilis will most likely involve commercially interesting proteins that are Sec incompatible. PMID:18931290

  10. Direct influence of culture dimensionality on human mesenchymal stem cell differentiation at various matrix stiffnesses using a fibrous self-assembling peptide hydrogel.

    PubMed

    Hogrebe, Nathaniel J; Gooch, Keith J

    2016-09-01

    Much is unknown about the effects of culture dimensionality on cell behavior due to the lack of biomimetic substrates that are suitable for directly comparing cells grown on two-dimensional (2D) and encapsulated within three-dimensional (3D) matrices of the same stiffness and biochemistry. To overcome this limitation, we used a self-assembling peptide hydrogel system that has tunable stiffness and cell-binding site density as well as a fibrous microarchitecture resembling the structure of collagen. We investigated the effect of culture dimensionality on human mesenchymal stem cell differentiation at different values of matrix stiffness (G' = 0.25, 1.25, 5, and 10 kPa) and a constant RGD (Arg-Gly-Asp) binding site concentration. In the presence of the same soluble induction factors, culture on top of stiff gels facilitated the most efficient osteogenesis, while encapsulation within the same stiff gels resulted in a switch to predominantly terminal chondrogenesis. Adipogenesis dominated at soft conditions, and 3D culture induced better adipogenic differentiation than 2D culture at a given stiffness. Interestingly, initial matrix-induced cell morphology was predictive of these end phenotypes. Furthermore, optimal culture conditions corresponded to each cell type's natural niche within the body, highlighting the importance of incorporating native matrix dimensionality and stiffness into tissue engineering strategies. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2356-2368, 2016. PMID:27163888

  11. Use of antibodies directed against synthetic peptides for identifying cDNA clones, establishing reading frames, and deducing the gene order of measles virus.

    PubMed Central

    Richardson, C D; Berkovich, A; Rozenblatt, S; Bellini, W J

    1985-01-01

    A number of cDNA clones complementary to measles virus mRNA and 50S genome RNA have been generated. These clones have been mapped by restriction enzyme analysis and were subsequently sequenced by the method of Maxam and Gilbert (A. M. Maxam and W. Gilbert, Methods Enzymol. 65:499-560, 1980). Computer analysis of these DNA sequences revealed open reading frames which potentially could code for a number of gene products. Portions of these putative polypeptides were synthesized, and rabbit antibodies directed against peptide-hemocyanin conjugates were produced. These antibodies were used to immunoprecipitate virus-specific polypeptides which were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. For each of the antisera tested, a unique protein was precipitated whose migration on polyacrylamide gels corresponded to standard gene products identified by monoclonal antibodies and antisera against measles virus. By using this method, we were able to assign the coding regions of cDNA clones to specific protein products and, subsequently, to order the genes of the 3'-terminal third of measles genome RNA. Images PMID:3838350

  12. [Penicillin production in Chile between 1944 and 1954].

    PubMed

    Ibarra, Cecilia; Parada, Mirtha

    2015-02-01

    Penicillin production in Chile was a pioneering development; however there is not much information to learn about it. The Chilean Institute for Bacteriology (Instituto Bacteriológico de Chile) produced penicillin between 1944 and 1973. The stage starting in 1953 is better known since there was an agreement with United Nations. Our research focused on building a story about production between 1944 and 1954 based on archival information and the national and international historic context. Our results place Chile amongst the pioneer countries in the successful industrialization of the drug. Our conclusions are that this was a proper industrial production as opposite to a pilot plant - a name commonly used to call the early factory. We explain the production plant trajectory by making relations between technological change and governance. Finally, we believe the later expansion of the plant, in the context of the agreement with the United Nations, took place under unpromising governance conditions, which called for passive innovation and technology management. PMID:25860052

  13. Penicillin-induced liver injury during treatment for ocular neurosyphilis.

    PubMed

    Wilkinson, Janelle; Zainal, Abir; Naqvi, Syed Yaseen

    2016-01-01

    A 51-year-old man, homosexual, recently diagnosed with ocular neurosyphilis, presented to the emergency room with a 1-day history of fevers and chills. His vital signs were significant for a temperature of 102.8°F and tachycardia of 125 bpm. The patient had experienced blurred vision in his left eye and was diagnosed with ocular neurosyphilis 10 days prior to the current presentation. He was treated with a 14-day course of high-dose intravenous penicillin and oral prednisone. His laboratory studies were significant for transaminitis, with an aspartate aminotransferase of 1826 U/L, alanine aminotransferase of 1743 U/L, total bilirubin of 1.2 mg/dL and alkaline phosphatase of 68 U/L. After ruling out viral aetiologies and toxin-induced hepatic injury, penicillin was discontinued on the day following admission and transaminases promptly improved with resolution of symptoms. The patient's vision returned to normal within 2 weeks after discharge from hospital. PMID:27389728

  14. Myositis complicating benzathine penicillin-G injection in a case of rheumatic heart disease

    PubMed Central

    Francis, Joshua R.; Wyber, Rosemary; Remenyi, Bo; Croser, David; Carapetis, Jonathan

    2016-01-01

    A 7-year old boy developed myositis secondary to intramuscular injection of benzathine penicillin-G in the context of secondary prophylaxis for rheumatic heart disease. Side effects of intramuscular delivery of benzathine penicillin-G are well described and include injection site pain and inflammation, but myositis, as depicted on magnetic resonance imaging in this case, has not previously been described. PMID:27051573

  15. Determination of penicillin G in heavy sow urine using immunochromatographic assay and microbial inhibition swab tests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Penicillin is a commonly used antibiotic in food animals. Unfortunately, violative penicillin residues in animal carcasses are sometimes identified by the USDA Food Safety and Inspection Service. Ante-mortem matrices such as urine could prove valuable for predicting possible violativ...

  16. 21 CFR 522.1696 - Penicillin G procaine implantation and injectable dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G procaine implantation and injectable dosage forms. 522.1696 Section 522.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... DOSAGE FORM NEW ANIMAL DRUGS § 522.1696 Penicillin G procaine implantation and injectable dosage forms....

  17. 21 CFR 522.1696 - Penicillin G procaine implantation and injectable dosage forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin G procaine implantation and injectable dosage forms. 522.1696 Section 522.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... DOSAGE FORM NEW ANIMAL DRUGS § 522.1696 Penicillin G procaine implantation and injectable dosage forms....

  18. 21 CFR 522.1696 - Penicillin G procaine injectable dosage forms.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin G procaine injectable dosage forms. 522.1696 Section 522.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... ANIMAL DRUGS § 522.1696 Penicillin G procaine injectable dosage forms....

  19. 21 CFR 522.1696 - Penicillin G procaine implantation and injectable dosage forms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin G procaine implantation and injectable dosage forms. 522.1696 Section 522.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... DOSAGE FORM NEW ANIMAL DRUGS § 522.1696 Penicillin G procaine implantation and injectable dosage forms....

  20. 21 CFR 522.1696 - Penicillin G procaine implantation and injectable dosage forms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin G procaine implantation and injectable dosage forms. 522.1696 Section 522.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... DOSAGE FORM NEW ANIMAL DRUGS § 522.1696 Penicillin G procaine implantation and injectable dosage forms....

  1. Involvement of transposon-like elements in penicillin gene cluster regulation.

    PubMed

    Shaaban, Mona; Palmer, Jonathan M; El-Naggar, Wael A; El-Sokkary, M A; Habib, El-Sayed E; Keller, Nancy P

    2010-05-01

    Subtelomeric secondary metabolite (SM) gene clusters are frequently surrounded by DNA repeats and transposon-like elements. The Aspergillus nidulans penicillin cluster, 30kb from the telomere of chromosome VI, is bordered by such elements. Deletions of penicillin telomere proximal and distal border regions resulted in decreased penicillin production. A 3.7kb distal region called PbIa, consisting of the putative transposable element DNA-2, was examined further where its replacement by a pyrG marker presented a similar phenotype as loss of the global SM regulator LaeA, resulting in a decrease in penicillin gene expression and product formation. In contrast, placement of the pyrG marker on either side of PbIa had no effect on penicillin synthesis. A requirement for PbIa in penicillin production was also apparent in a histone deacetylase mutant, DeltahdaA, enhanced for penicillin production. Trans-complementation of the PbIa element near and within the terrequinone A cluster on chromosome V did not restore penicillin biosynthesis or increase production of terrequinone A. Taken together, this data provides evidence for transposon involvement in SM cluster regulation. PMID:20219692

  2. Beta-lactamase gene expression in a penicillin-resistant Bacillus anthracis strain.

    PubMed

    Chen, Yahua; Tenover, Fred C; Koehler, Theresa M

    2004-12-01

    Expression of the bla1 and bla2 genes in an archetypal Bacillus anthracis strain is insufficient for penicillin resistance. In a penicillin-resistant clinical isolate, both genes are highly transcribed, but bla1 is the major contributor to high-level resistance to ampicillin. Differential expression of the bla genes is dependent upon strain background. PMID:15561870

  3. 21 CFR 526.1696c - Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Penicillin G procaine-dihydrostreptomycin sulfate... INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696c Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows). (a) Specifications. Each 10 milliliters of suspension contains penicillin...

  4. 21 CFR 526.1696c - Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Penicillin G procaine-dihydrostreptomycin sulfate... INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696c Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows). (a) Specifications. Each 10 milliliters of suspension contains penicillin...

  5. 21 CFR 526.1696c - Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin G procaine-dihydrostreptomycin sulfate... INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696c Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows). (a) Specifications. Each 10 milliliters of suspension contains penicillin...

  6. 21 CFR 526.1696c - Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin G procaine-dihydrostreptomycin sulfate... INTRAMAMMARY DOSAGE FORM NEW ANIMAL DRUGS § 526.1696c Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows). (a) Specifications. Each 10 milliliters of suspension contains penicillin...

  7. 21 CFR 526.1696b - Penicillin G procaine-dihydrostreptomycin in soybean oil for intramammary infusion (dry cows).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G procaine-dihydrostreptomycin in... INTRAMAMMARY DOSAGE FORMS § 526.1696b Penicillin G procaine-dihydrostreptomycin in soybean oil for intramammary infusion (dry cows). (a) Specifications. Each 10 milliliters of suspension contains penicillin G...

  8. Identification of a group of Haemophilus influenzae penicillin-binding proteins that may have complementary physiological roles

    SciTech Connect

    Malouin, F.; Parr, T.R. Jr.; Bryan, L.E. )

    1990-02-01

    (35S)penicillin bound to different Haemophilus influenzae proteins in assays performed at 20, 37, or 42{degrees}C. Penicillin-binding proteins 3a, 3b, 4, and 4' formed a group characterized by their affinity for moxalactam, cefotaxime, and piperacillin. Penicillin-binding protein 4' showed specific properties that may reflect its complementary role in septation.

  9. 21 CFR 526.1696c - Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G procaine-dihydrostreptomycin sulfate... INTRAMAMMARY DOSAGE FORMS § 526.1696c Penicillin G procaine-dihydrostreptomycin sulfate for intramammary infusion (dry cows). (a) Specifications. Each 10 milliliters of suspension contains penicillin G...

  10. 75 FR 35044 - Notice of Approval of a Supplemental New Animal Drug Application; Penicillin G Procaine Suspension

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... Application; Penicillin G Procaine Suspension AGENCY: Food and Drug Administration, HHS. ACTION: Notice... for a revised formulation of penicillin G procaine injectable suspension that includes lecithin as a... 6JP, Northern Ireland, filed a supplement to NADA 065-010 for use of NOROCILLIN (penicillin G...

  11. β-Lactam formation by a non-ribosomal peptide synthetase during antibiotic biosynthesis

    PubMed Central

    Gaudelli, Nicole M.; Long, Darcie H.; Townsend, Craig A.

    2014-01-01

    Non-ribosomal peptide synthetases (NRPSs) are giant enzymes comprised of modules that house repeated sets of functional domains, which select, activate and couple amino acids drawn from a pool of nearly 500 potential building blocks.1 The structurally and stereochemically diverse peptides generated in this manner underlie the biosynthesis of a large sector of natural products. Many of their derived metabolites are bioactive such as the antibiotics vancomycin, bacitracin, daptomycin and the β-lactam-containing penicillins, cephalosporins and nocardicins. Although penicillins and cephalosporins are synthesised from a classically derived NRPS tripeptide (from ACVS, δ-(L-α-aminoadipyl)–L-cysteinyl–D-valine synthetase)2, we now report an unprecedented NRPS activity to both assemble a serine-containing peptide and mediate its cyclisation to the critical β-lactam ring of the nocardicin family of antibiotics. A histidine-rich condensation (C) domain, which typically carries out peptide bond formation during product assembly, was found to also synthesise the embedded 4-membered ring. Here, a mechanism is proposed and supporting experiments are described, which is distinct from the pathways that have evolved to the three other β-lactam antibiotic families: penicillin/cephalosporins, clavams and carbapenems. These findings raise the possibility that β-lactam rings can be regio- and stereospecifically integrated into engineered peptides for application as, for example, targeted protease inactivators.3,4 PMID:25624104

  12. Accurate Detection of Adenylation Domain Functions in Nonribosomal Peptide Synthetases by an Enzyme-linked Immunosorbent Assay System Using Active Site-directed Probes for Adenylation Domains.

    PubMed

    Ishikawa, Fumihiro; Miyamoto, Kengo; Konno, Sho; Kasai, Shota; Kakeya, Hideaki

    2015-12-18

    A significant gap exists between protein engineering and enzymes used for the biosynthesis of natural products, largely because there is a paucity of strategies that rapidly detect active-site phenotypes of the enzymes with desired activities. Herein, we describe a proof-of-concept study of an enzyme-linked immunosorbent assay (ELISA) system for the adenylation (A) domains in nonribosomal peptide synthetases (NRPSs) using a combination of active site-directed probes coupled to a 5'-O-N-(aminoacyl)sulfamoyladenosine scaffold with a biotin functionality that immobilizes probe molecules onto a streptavidin-coated solid support. The recombinant NRPSs have a C-terminal His-tag motif that is targeted by an anti-6×His mouse antibody as the primary antibody and a horseradish peroxidase-linked goat antimouse antibody as the secondary antibody. These probes can selectively capture the cognate A domains by ligand-directed targeting. In addition, the ELISA technique detected A domains in the crude cell-free homogenates from the Escherichia coli expression systems. When coupled with a chromogenic substrate, the antibody-based ELISA technique can visualize probe-protein binding interactions, which provides accurate readouts of the A-domain functions in NRPS enzymes. To assess the ELISA-based engineering of the A domains of NRPSs, we reprogramed 2,3-dihydroxybenzoic acid (DHB)-activating enzyme EntE toward salicylic acid (Sal)-activating enzymes and investigated a correlation between binding properties for probe molecules and enzyme catalysts. We generated a mutant of EntE that displayed negligible loss in the kcat/Km value with the noncognate substrate Sal and a corresponding 48-fold decrease in the kcat/Km value with the cognate substrate DHB. The resulting 26-fold switch in substrate specificity was achieved by the replacement of a Ser residue in the active site of EntE with a Cys toward the nonribosomal codes of Sal-activating enzymes. Bringing a laboratory ELISA technique

  13. Unsaturated fatty acids show clear elicitation responses in a modified local lymph node assay with an elicitation phase, and test positive in the direct peptide reactivity assay.

    PubMed

    Yamashita, Kunihiko; Shinoda, Shinsuke; Hagiwara, Saori; Miyazaki, Hiroshi; Itagaki, Hiroshi

    2015-12-01

    The Organisation for Economic Co-operation and Development (OECD) Test Guidelines (TG) adopted the murine local lymph node assay (LLNA) and guinea pig maximization test (GPMT) as stand-alone skin sensitization test methods. However, unsaturated carbon-carbon double-bond and/or lipid acids afforded false-positive results more frequently in the LLNA compared to those in the GPMT and/or in human subjects. In the current study, oleic, linoleic, linolenic, undecylenic, fumaric, maleic, and succinic acid and squalene were tested in a modified LLNA with an elicitation phase (LLNA:DAE), and in a direct peptide reactivity assay (DPRA) to evaluate their skin-sensitizing potential. Oleic, linoleic, linolenic, undecylenic and maleic acid were positive in the LLNA:DAE, of which three, linoleic, linolenic, and maleic acid were positive in the DPRA. Furthermore, the results of the cross-sensitizing tests using four LLNA:DAE-positive chemicals were negative, indicating a chemical-specific elicitation response. In a previous report, the estimated concentration needed to produce a stimulation index of 3 (EC3) of linolenic acid, squalene, and maleic acid in the LLNA was < 10%. Therefore, these chemicals were classified as moderate skin sensitizers in the LLNA. However, the skin-sensitizing potential of all LLNA:DAE-positive chemicals was estimated as weak. These results suggested that oleic, linoleic, linolenic, undecylenic, and maleic acid had skin-sensitizing potential, and that the LLNA overestimated the skin-sensitizing potential compared to that estimated by the LLNA:DAE. PMID:26558466

  14. Natriuretic peptides in fish physiology.

    PubMed

    Loretz, C A; Pollina, C

    2000-02-01

    natriuretic peptides; in the elasmobranchs, hypervolemia is the predominant physiological stimulus for secretion. Natriuretic peptides may be seawater-adapting hormones with appropriate target organs including the gills, rectal gland, kidney, and intestine, with each regulated via, predominantly, either A- or B-type (or C- or D-type?) natriuretic peptide receptors. Natriuretic peptides act both directly on ion-transporting cells of osmoregulatory tissues, and indirectly through increased vascular flow to osmoregulatory tissues, through inhibition of drinking, and through effects on other endocrine systems. PMID:10825690

  15. Nicolau livedoid dermatitis following intramuscular benzathine penicillin injection.

    PubMed

    Andrade, P; Pereira, N; Brites, M M; Gonçalo, M; Figueiredo, A

    2010-01-01

    We report the case of a 64-year-old male presenting with a rapidly enlarging painful violaceous plaque in the left buttock and posterior thigh, following a gluteal intramuscular injection of benzathine penicillin. Associated urinary incontinence and lower left limb paresis were consistent with sciatic and lower sacral nerve damage, as confirmed by electromyography. Additional underlying muscular damage was observed in ultrasound and computer tomodensitometry scans and supported by high serum levels of creatine kinase and lactate dehydrogenase. Aggressive treatment was performed with fluid expansion, intravenous steroid bolus, vasodilators and anticoagulation, resulting in slow improvement of cutaneous and muscular lesions. However, no significant effect was observed on neurologic dysfunction after 6 months of regular neuromuscular rehabilitation. Nicolau Livedoid Dermatitis is a rare and potentially fatal condition showing variable levels of tissue impairment and unpredictable course and prognosis. Specific treatment is not consensual and the efficacy of any particular treatment remains to be established. PMID:21199637

  16. Rapid emergence of penicillin-resistant pneumococci in Hong Kong.

    PubMed

    Lyon, D J; Scheel, O; Fung, K S; Cheng, A F; Henrichsen, J

    1996-01-01

    The prevalence of penicillin resistance in Streptococcus pneumoniae isolated at the Prince of Wales Hospital, Hong Kong, rose from 6.6% of sputum isolates in the first quarter of 1993 to 55.8% of isolates in the second quarter of 1995. Most of the isolates were also resistant to co-trimoxazole, tetracycline, choramphenicol and erythromycin. Type 19F was the most common capsular type in 1993-1994, comprising 40.0% of typed isolates in this period. Type 23F emerged in 1995 as the predominant type, making up 62.2% of typed isolates in the first 2 quarters of 1995. A high population density and excessive community use of antibiotics are likely to be factors promoting the rapid emergence of multiply-resistant pneumococci in Hong Kong. PMID:8893401

  17. Evaluating effects of penicillin treatment on the metabolome of rats.

    PubMed

    Sun, Jinchun; Schnackenberg, Laura K; Khare, Sangeeta; Yang, Xi; Greenhaw, James; Salminen, William; Mendrick, Donna L; Beger, Richard D

    2013-08-01

    Penicillin (PEN) V, a well-known antibiotic widely used in the treatment of Gram-positive bacterial infections, was evaluated in this study. LC/MS- and NMR-based metabolic profiling were employed to examine the effects of PEN on the host's metabolic phenotype. Male Sprague Dawley rats were randomly divided into groups that were orally administered either 0.5% methylcellulose vehicle, 100 or 2400mg PEN/kg body weight once daily for up to 14 consecutive days. Urine, plasma and tissue were collected from groups sacrificed at 6h, 24h or 14d. The body fluids were subjected to clinical chemistry and metabolomics analysis; the tissue samples were processed for histopathology. The only notable clinical chemistry observation was that gamma glutamyltransferase (GGT) significantly decreased at 24h for both dose groups, and significantly decreased at 14d for the high-dose groups. Partial least squares discriminant analysis scores plots of the metabolomics data from urine and plasma samples showed dose- and time-dependent grouping patterns. Time- and dose-dependent decreases in urinary metabolites including indole-containing metabolites (such as 3-methyldioxyindole sulfate generated from bacterial metabolism of tryptophan), organic acids containing phenyl groups (such as hippuric acid, phenyllactic acid and 3-hydroxyanthranilic acid), and metabolites conjugated with sulfate or glucuronide (such as cresol sulfate and aminophenol sulfate) indicated that the gut microflora population was suppressed. Decreases in many host-gut microbiota urinary co-metabolites (indole- and phenyl-containing metabolites, amino acids, vitamins, nucleotides and bile acids) suggested gut microbiota play important roles in the regulation of host metabolism, including dietary nutrient absorption and reprocessing the absorbed nutrients. Decreases in urinary conjugated metabolites (sulfate, glucuronide and glycine conjugates) implied that gut microbiota might have an impact on chemical detoxification

  18. Sample stacking for the analysis of penicillins by microemulsion electrokinetic chromatography.

    PubMed

    Huang, Hsi-Ya; Hsieh, Shih-Huan

    2008-09-01

    In this study, on-line sample concentration methods, which coupled field-amplified sample injection and sweeping technology with MEEKC, were used to detect and analyze eight common penicillin antibiotics (nafcillin, dicloxacillin, ampicillin, oxacillin, penicillin V, cloxacillin, penicillin G, and amoxicillin). During the optimization of field-amplified sample injection-sweeping MEEKC, the composition of sample matrix and the length of acidic plug were found to be the predominant influences for penicillin stacking. Both zwitterionic ampicillin and amoxicillin could only be stacked through cation-selective-exhaustive-injection sweeping, whereas the other six penicillin compounds were found to be concentrated by anion-selective-exhaustive-injection sweeping. Hence, in order to simultaneously concentrate the eight penicillins in a single-run sweeping step, a combination of successive anion- and cation-selective injections was used. When compared with previous CE-UV methods, the proposed on-line concentration MEEKC method provided better detection sensitivity and faster separation for these penicillins either in single ion-selective injection or in successive anion-/cation-selective injection where the LODs were in the range of 0.2-2.8 microg/L and 0.5-5.8 microg/L, respectively. PMID:18850659

  19. Penicillin G-Induced Chlamydial Stress Response in a Porcine Strain of Chlamydia pecorum

    PubMed Central

    Leonard, Cory Ann; Dewez, Frederic; Borel, Nicole

    2016-01-01

    Chlamydia pecorum causes asymptomatic infection and pathology in ruminants, pigs, and koalas. We characterized the antichlamydial effect of the beta lactam penicillin G on Chlamydia pecorum strain 1710S (porcine abortion isolate). Penicillin-exposed and mock-exposed infected host cells showed equivalent inclusions numbers. Penicillin-exposed inclusions contained aberrant bacterial forms and exhibited reduced infectivity, while mock-exposed inclusions contained normal bacterial forms and exhibited robust infectivity. Infectious bacteria production increased upon discontinuation of penicillin exposure, compared to continued exposure. Chlamydia-induced cell death occurred in mock-exposed controls; cell survival was improved in penicillin-exposed infected groups. Similar results were obtained both in the presence and in the absence of the eukaryotic protein translation inhibitor cycloheximide and at different times of initiation of penicillin exposure. These data demonstrate that penicillin G induces the chlamydial stress response (persistence) and is not bactericidal, for this chlamydial species/strain in vitro, regardless of host cell de novo protein synthesis. PMID:26997956

  20. In vivo kinetic analysis of the penicillin biosynthesis pathway using PAA stimulus response experiments.

    PubMed

    Deshmukh, Amit T; Verheijen, Peter J T; Maleki Seifar, Reza; Heijnen, Joseph J; van Gulik, Walter M

    2015-11-01

    In this study we combined experimentation with mathematical modeling to unravel the in vivo kinetic properties of the enzymes and transporters of the penicillin biosynthesis pathway in a high yielding Penicillium chrysogenum strain. The experiment consisted of a step response experiment with the side chain precursor phenyl acetic acid (PAA) in a glucose-limited chemostat. The metabolite data showed that in the absence of PAA all penicillin pathway enzymes were expressed, leading to the production of a significant amount of 6-aminopenicillanic acid (6APA) as end product. After the stepwise perturbation with PAA, the pathway produced PenG within seconds. From the extra- and intracellular metabolite measurements, hypotheses for the secretion mechanisms of penicillin pathway metabolites were derived. A dynamic model of the penicillin biosynthesis pathway was then constructed that included the formation and transport over the cytoplasmic membrane of pathway intermediates, PAA and the product penicillin-G (PenG). The model parameters and changes in the enzyme levels of the penicillin biosynthesis pathway under in vivo conditions were simultaneously estimated using experimental data obtained at three different timescales (seconds, minutes, hours). The model was applied to determine changes in the penicillin pathway enzymes in time, calculate fluxes and analyze the flux control of the pathway. This led to a reassessment of the in vivo behavior of the pathway enzymes and in particular Acyl-CoA:Isopenicillin N Acyltransferase (AT). PMID:26476338

  1. Determination of eight penicillin antibiotics in pharmaceuticals, milk and porcine tissues by nano-liquid chromatography.

    PubMed

    Hsieh, Shih-Huan; Huang, Hsi-Ya; Lee, Szetsen

    2009-10-23

    This study describes the ability of nanoscale liquid chromatography (nano-LC) coupled with UV or mass spectrometry (MS) for the simultaneous determination of eight common penicillin antibiotics (amoxicillin, ampicillin, penicillin G, penicillin V, oxacillin, cloxacillin, nafcillin and dicloxacillin) in commercial samples (pharmaceuticals, milk, porcine tissues (liver and kidney)) for the first time. Material types of the on-column polymeric frits (polystyrene-based and polymethacrylate-based monoliths) and the packed stationary phase materials (C8 and C18 particles of 3 microm) used in the nano-LC for the influence of penicillin separation were evaluated. The nano-LC and MS parameters such as the composition and flow rate of mobile phase, capillary voltage and temperature of dry gas were examined in order to acquire high separation resolution and detection sensitivity for penicillin analyses. Furthermore, a home-made in-line filter (a nylon membrane of 0.2 microm pore size), was first used to connect with the flow cell of high sensitivity UV detector or the nanoelectrospray needle in MS detection. The result indicated it could effectively improve the reproducibility of penicillin mass signals or prolong the lifetime of the flow cell. The nano-LC methods provided good quantitative precisions in the range of 89.5-111.2% for UV detection at 0.5 microg/mL penicillins, and 83. 1-94.9% for MS detection at 5 mcirog/L penicillins), respectively, as well as offered stable retention repeatabilities (the relative standard deviation (RSD) of retention time was lower 0.30% in both the UV and MS detections). Compared to other LC-MS methods, the proposed nano-LC systems provided better detection sensitivity for these penicillins (the limits of detection (LOD) was of 2.27-4.06 microg/L for UV mode, and 0.01-0.51 microg/L for MS mode) when either UV or MS detector was employed. PMID:19523644

  2. Activities of oral and parenteral agents against penicillin-susceptible and -resistant pneumococci.

    PubMed

    Pankuch, G A; Visalli, M A; Jacobs, M R; Appelbaum, P C

    1995-07-01

    This study examined bacteriostatic and bactericidal activities of oral and parenteral antibiotics for penicillin-susceptible and intermediately and fully penicillin-resistant pneumococci. beta-Lactamase inhibitors did not affect beta-lactam results. The activities of ampicillin, amoxicillin +/- clavulanate, WY-49605, cefuroxime, cefpodoxime, cefdinir, cefixime, and cefaclor against two penicillin-susceptible, two intermediately penicillin-resistant, and two fully penicillin-resistant pneumococcal strains were tested. For all three groups, bacteriostatic values of amoxicillin and WY-49605 were lower than were those of other beta-lactams tested. Of the cephalosporins, cefdinir, cefuroxime, and cefpodoxime yielded the lowest bacteriostatic values. All beta-lactams were bactericidal (reduced original counts by > or = 3 log10 CFU/ml) at 1 dilution above bacteriostatic values, except for cefpodoxime (bactericidal at 2 dilutions above bacteriostatic values for one susceptible strain and one intermediately resistant strain), cefuroxime (bactericidal at 2 dilutions above bacteriostatic values for one intermediately resistant strain), and ampicillin (bactericidal at 2 dilutions above bacteriostatic values for one intermediately resistant strain). The activities of piperacillin, piperacillin-tazobactam, ticarcillin, ticarcillin-clavulanate, ampicillin, ampicillin-sulbactam, ceftriaxone, ceftazidime, and ciprofloxacin against four penicillin-susceptible, two intermediately penicillin-resistant, and four fully penicillin-resistant pneumococcal strains were evaluated. Bacteriostatic values of piperacillin, ampicillin, and ceftriaxone for all groups were lower than were those of ticarcillin and ceftazidime. Bacteriostatic values of ciprofloxacin were unaffected by penicillin susceptibility. All beta-lactams were bactericidal at 1 dilution above the bacteriostatic value, except for piperacillin (bactericidal at 2 dilutions above the bacteriostatic value for one intermediately

  3. Prevalence and characteristics of reported penicillin allergy in an urban outpatient adult population

    PubMed Central

    Agarwal, Shradha

    2014-01-01

    Penicillin allergy remains the most common drug allergy, with a reported prevalence of 10% in the United States. Epidemiology of penicillin allergy in outpatient populations is relatively scarce. This study sought to determine the prevalence and characteristics of reported penicillin allergy in an urban outpatient population and to identify trends in clinical evaluation and management from a tertiary center serving a large inner-city population. A retrospective review of electronic medical records was performed of adult patients seen in the Internal Medicine Associates Clinic of Mount Sinai Hospital between January 31, 2012, and July 31, 2012. Medical records were selected based on the documentation of penicillin in patient's allergy section. Of the 11,761 patients seen in the clinic, 1348 patients (11.5%) reported a history of penicillin allergy. The most common allergic reactions were rash (37%), unknown/undocumented (20.2%), hives (18.9%), swelling/angioedema (11.8%), and anaphylaxis (6.8%). There was an increased prevalence of penicillin allergy in female patients compared with male patients (odds ratio [OR] = 1.82; 95% CI = 1.60, 2.08; p < 0.0001), and there were significantly fewer Asians with penicillin allergy compared with Caucasians (OR = 0.51; 95% CI = 0.32, 0.83; p = 0.007). However, only 78 (6%) of the patients reporting penicillin allergy had a referral to an allergy specialist. Overall, improved referral to an allergist will help to identify patients who have penicillin allergy requiring avoidance. PMID:25584917

  4. Biological characterization of a new radioactive labeling reagent for bacterial penicillin-binding proteins

    SciTech Connect

    Preston, D.A.; Wu, C.Y.; Blaszczak, L.C.; Seitz, D.E.; Halligan, N.G. )

    1990-05-01

    Radiolabeled penicillin G is widely used as the imaging agent in penicillin-binding protein (PBP) assays. The disadvantages of most forms of labeled penicillin G are instability on storage and the long exposure times usually required for autoradiography or fluorography of electrophoretic gels. We investigated the utility of radioiodinated penicillin V as an alternative reagent. Radioiodination of p-(trimethylstannyl)penicillin V with ({sup 125}I)Na, using a modification of the chloramine-T method, is simple, high yielding, and site specific. We demonstrated the general equivalence of commercially obtained ({sup 3}H)penicillin G and locally synthesized ({sup 125}I)penicillin V (IPV) in their recognition of bacterial PBPs. Profiles of PBPs in membranes from Bacteroides fragilis, Escherichia coli, Providencia rettgeri, Staphylococcus aureus, Streptococcus pyogenes, Enterococcus faecalis, and Enterococcus faecium labeled with IPV or (3H)penicillin G were virtually identical. Use of IPV as the imaging agent in competition experiments for determination of the affinities of various beta-lactam antibiotics for the PBPs of E. coli yielded results similar to those obtained in experiments with ({sup 3}H)penicillin G. Dried electrophoretic gels from typical PBP experiments, using IPV at 37.3 Ci/mmol and 30 micrograms/ml, exposed X-ray film in 8 to 24 h. The stability of IPV on storage at 4{degrees}C was inversely proportional to specific activity. At 37.3 Ci/mmol and 60 micrograms/ml, IPV retained useful activity for at least 60 days at 4{degrees}C. IPV represents a practical and stable reagent for rapid PBP assays.

  5. Structural Aspects for Evolution of [beta]-Lactamases from Penicillin-Binding Proteins

    SciTech Connect

    Meroueh, Samy O.; Minasov, George; Lee, Wenlin; Shoichet, Brian K.; Mobashery, Shahriar

    2010-03-08

    Penicillin-binding proteins (PBPs), biosynthetic enzymes of bacterial cell wall assembly, and {beta}-lactamases, resistance enzymes to {beta}-lactam antibiotics, are related to each other from an evolutionary point of view. Massova and Mobashery (Antimicrob. Agents Chemother. 1998, 42, 1-17) have proposed that for {beta}-lactamases to have become effective at their function as antibiotic resistance enzymes, they would have had to undergo structure alterations such that they would not interact with the peptidoglycan, which is the substrate for PBPs. A cephalosporin analogue, 7{beta}-[N-Acetyl-L-alanyl-{gamma}-D-glutamyl-L-lysine]-3-acetoxymethyl-3-cephem-carboxylic acid (compound 6), was conceived and synthesized to test this notion. The X-ray structure of the complex of this cephalosporin bound to the active site of the deacylation-deficient Q120L/Y150E variant of the class C AmpC {beta}-lactamase from Escherichia coli was solved at 1.71 {angstrom} resolution. This complex revealed that the surface for interaction with the strand of peptidoglycan that acylates the active site, which is present in PBPs, is absent in the {beta}-lactamase active site. Furthermore, insertion of a peptide in the {beta}-lactamase active site at a location where the second strand of peptidoglycan in some PBPs binds has effectively abolished the possibility for such interaction with the {beta}-lactamase. A 2.6 ns dynamics simulation was carried out for the complex, which revealed that the peptidoglycan surrogate (i.e., the active-site-bound ligand) undergoes substantial motion and is not stabilized for binding within the active site. These factors taken together disclose the set of structure modifications in the antibiotic resistance enzyme that prevent it from interacting with the peptidoglycan, en route to achieving catalytic proficiency for their intended function.

  6. [Progress in Proteomic Study of the Penicillin Producer---Penicillium Chrysogenum].

    PubMed

    Wang, Shun; Wang, Peihong; Zhang, Nan; Gao, Ruichang

    2015-12-01

    Penicillin is a kind of β-lactam drug which has been applied in the clinical treatment firstly in the world, and it has still been widely used at present. The synthesis and regulation mechanism of Penicillium chrysogenum, which is used to produce penicillin, has been studied quite maturely, but its proteomics research started relatively late and fewer reports were published. This paper reviews the synthesis and application of penicillin, transformation of Penicillium chrysogenum, and the research progress of its proteomics. On this basis, the study highlights the advantages of proteomics in the research of protein expression. PMID:27079113

  7. Neutral β-Lactams Inactivate High Molecular Mass Penicillin-Binding Proteins of Class B1, Including PBP2a of MRSA.

    PubMed

    Dave, Kinjal; Palzkill, Timothy; Pratt, R F

    2014-02-13

    The targets of β-lactam antibiotics are bacterial DD-peptidases (penicillin-binding proteins). β-Lactam SAR studies over many years have demonstrated the importance of a specifically placed negative charge, usually carboxylate, on these molecules. We show here that neutral analogues of classical β-lactam antibiotics are of comparable activity to the originals against β-lactam-resistant high molecular mass DD-peptidases of the B1 class, a group that includes PBP2a of methicillin-resistant Staphylococcus aureus. These neutral β-lactams may direct new development of antibiotics against certain penicillin-resistant bacteria. These molecules do have antibiotic activity against Gram-positive bacteria. PMID:24900789

  8. Peptide identification

    DOEpatents

    Jarman, Kristin H [Richland, WA; Cannon, William R [Richland, WA; Jarman, Kenneth D [Richland, WA; Heredia-Langner, Alejandro [Richland, WA

    2011-07-12

    Peptides are identified from a list of candidates using collision-induced dissociation tandem mass spectrometry data. A probabilistic model for the occurrence of spectral peaks corresponding to frequently observed partial peptide fragment ions is applied. As part of the identification procedure, a probability score is produced that indicates the likelihood of any given candidate being the correct match. The statistical significance of the score is known without necessarily having reference to the actual identity of the peptide. In one form of the invention, a genetic algorithm is applied to candidate peptides using an objective function that takes into account the number of shifted peaks appearing in the candidate spectrum relative to the test spectrum.

  9. Glycosaminoglycan-Mimetic Signals Direct the Osteo/Chondrogenic Differentiation of Mesenchymal Stem Cells in a Three-Dimensional Peptide Nanofiber Extracellular Matrix Mimetic Environment.

    PubMed

    Arslan, Elif; Guler, Mustafa O; Tekinay, Ayse B

    2016-04-11

    Recent efforts in bioactive scaffold development focus strongly on the elucidation of complex cellular responses through the use of synthetic systems. Designing synthetic extracellular matrix (ECM) materials must be based on understanding of cellular behaviors upon interaction with natural and artificial scaffolds. Hence, due to their ability to mimic both the biochemical and mechanical properties of the native tissue environment, supramolecular assemblies of bioactive peptide nanostructures are especially promising for development of bioactive ECM-mimetic scaffolds. In this study, we used glycosaminoglycan (GAG) mimetic peptide nanofiber gel as a three-dimensional (3D) platform to investigate how cell lineage commitment is altered by external factors. We observed that amount of fetal bovine serum (FBS) presented in the cell media had synergistic effects on the ability of GAG-mimetic nanofiber gel to mediate the differentiation of mesenchymal stem cells into osteogenic and chondrogenic lineages. In particular, lower FBS concentration in the culture medium was observed to enhance osteogenic differentiation while higher amount FBS promotes chondrogenic differentiation in tandem with the effects of the GAG-mimetic 3D peptide nanofiber network, even in the absence of externally administered growth factors. We therefore demonstrate that mesenchymal stem cell differentiation can be specifically controlled by the combined influence of growth medium components and a 3D peptide nanofiber environment. PMID:26840042

  10. Purification and properties of inducible penicillin beta-lactamase isolated from Alcaligenes faecalis.

    PubMed

    Fujii, T; Sato, K; Inoue, M; Mitsuhashi, S

    1985-04-01

    An inducible penicillin beta-lactamase was purified from a strain of Alcaligenes faecalis resistant to beta-lactam antibiotics. The purified enzyme preparation gave a single protein band on polyacrylamide gel electrophoresis, and its molecular weight was 29,000 based on sodium dodecyl sulfate-acrylamide gel electrophoresis. Its isoelectric point was 5.9. The enzyme more rapidly hydrolyzed penicillins, such as penicillin G, ampicillin, carbenicillin, piperacillin, and cloxacillin, than it hydrolyzed cephalosporins. For the hydrolysis of penicillin G, the optimal pH was 5.5, and the optimal temperature was 35 degrees C. The enzyme activity was inhibited by iodine, Cu2+, Hg2+, and EDTA but was not inhibited by clavulanic acid and sulbactam. PMID:3873902

  11. Onset of penicillin-induced bacteriolysis in staphylococci is cell cycle dependent.

    PubMed Central

    Maidhof, H; Johannsen, L; Labischinski, H; Giesbrecht, P

    1989-01-01

    Synchronously growing staphylococci were treated with "lytic" concentrations of penicillin at different stages of their division cycle. Coulter Counter measurements and light microscopy were used to determine the onset of bacteriolysis. Independent of the stage of the division cycle at which penicillin was added, (i) the cells were always able to perform the next cell division; (ii) the following division, however, did not take place; and (iii) instead, at this time, when the onset of the subsequent cell separation was observed in control cultures, lysis of the penicillin-treated cells occurred. These results support a recent model (P. Giesbrecht, H. Labischinski, and J. Wecke, Arch. Microbiol. 141:315-324, 1985) explaining penicillin-induced bacteriolysis of staphylococci as the result of a special morphogenetic mistake during cross wall formation. Images PMID:2703473

  12. Single-dose pharmacokinetics of oxytetracycline and penicillin G in tammar wallabies (Macropus eugenii).

    PubMed

    McLelland, D J; Barker, I K; Crawshaw, G; Hinds, L A; Spilsbury, L; Johnson, R

    2011-04-01

    The pharmacokinetics of oxytetracycline and penicillin G was investigated in tammar wallabies (Macropus eugenii). Groups of eight healthy tammar wallabies were administered i.v. oxytetracycline hydrochloride (40 mg/kg), i.m. long-acting-oxytetracycline (20 mg/kg), i.v. sodium penicillin G (30 mg/kg), or i.m. procaine/benzathine penicillin G (30 mg/kg). Plasma concentrations of oxytetracycline were determined using high-performance liquid chromatography. Pharmacokinetic parameters were comparable to those reported for eutherians of equivalent size and suggest that the practice of adjusting allometrically scaled doses to account for the lower metabolic rate of marsupials may not be valid. Long-acting oxytetracycline and penicillin G both demonstrated depot effects. However, the plasma concentrations achieved question the therapeutic efficacy of the long-acting preparations. PMID:21395607

  13. Hydrogel coated monoliths for enzymatic hydrolysis of penicillin G

    PubMed Central

    Smeltink, M. W.; Straathof, A. J. J.; Paasman, M. A.; van de Sandt, E. J. A. X.; Kapteijn, F.; Moulijn, J. A.

    2008-01-01

    The objective of this work was to develop a hydrogel-coated monolith for the entrapment of penicillin G acylase (E. coli, PGA). After screening of different hydrogels, chitosan was chosen as the carrier material for the preparation of monolithic biocatalysts. This protocol leads to active immobilized biocatalysts for the enzymatic hydrolysis of penicillin G (PenG). The monolithic biocatalyst was tested in a monolith loop reactor (MLR) and compared with conventional reactor systems using free PGA, and a commercially available immobilized PGA. The optimal immobilization protocol was found to be 5 g l−1 PGA, 1% chitosan, 1.1% glutaraldehyde and pH 7. Final PGA loading on glass plates was 29 mg ml−1 gel. For 400 cpsi monoliths, the final PGA loading on functionalized monoliths was 36 mg ml−1 gel. The observed volumetric reaction rate in the MLR was 0.79 mol s−1 m−3monolith. Apart from an initial drop in activity due to wash out of PGA at higher ionic strength, no decrease in activity was observed after five subsequent activity test runs. The storage stability of the biocatalysts is at least a month without loss of activity. Although the monolithic biocatalyst as used in the MLR is still outperformed by the current industrial catalyst (immobilized preparation of PGA, 4.5 mol s−1 m−3catalyst), the rate per gel volume is slightly higher for monolithic catalysts. Good activity and improved mechanical strength make the monolithic bioreactor an interesting alternative that deserves further investigation for this application. Although moderate internal diffusion limitations have been observed inside the gel beads and in the gel layer on the monolith channel, this is not the main reason for the large differences in reactor performance that were observed. The pH drop over the reactor as a result of the chosen method for pH control results in a decreased performance of both the MLR and the packed bed reactor compared to the batch system. A different

  14. Subfamily-specific adaptations in the structures of two penicillin-binding proteins from Mycobacterium tuberculosis

    SciTech Connect

    Prigozhin, Daniil M.; Krieger, Inna V.; Huizar, John P.; Mavrici, Daniela; Waldo, Geoffrey S.; Hung, Li -Wei; Sacchettini, James C.; Terwilliger, Thomas C.; Alber, Tom; Mayer, Claudine

    2014-12-31

    Beta-lactam antibiotics target penicillin-binding proteins including several enzyme classes essential for bacterial cell-wall homeostasis. To better understand the functional and inhibitor-binding specificities of penicillin-binding proteins from the pathogen, Mycobacterium tuberculosis, we carried out structural and phylogenetic analysis of two predicted D,D-carboxypeptidases, Rv2911 and Rv3330. Optimization of Rv2911 for crystallization using directed evolution and the GFP folding reporter method yielded a soluble quadruple mutant. Structures of optimized Rv2911 bound to phenylmethylsulfonyl fluoride and Rv3330 bound to meropenem show that, in contrast to the nonspecific inhibitor, meropenem forms an extended interaction with the enzyme along a conserved surface. Phylogenetic analysis shows that Rv2911 and Rv3330 belong to different clades that emerged in Actinobacteria and are not represented in model organisms such as Escherichia coli and Bacillus subtilis. Clade-specific adaptations allow these enzymes to fulfill distinct physiological roles despite strict conservation of core catalytic residues. The characteristic differences include potential protein-protein interaction surfaces and specificity-determining residues surrounding the catalytic site. Overall, these structural insights lay the groundwork to develop improved beta-lactam therapeutics for tuberculosis.

  15. Enzyme reaction engineering: synthesis of antibiotics catalysed by stabilized penicillin G acylase in the presence of organic cosolvents.

    PubMed

    Fernandez-Lafuente, R; Rosell, C M; Guisán, J M

    1991-11-01

    By using very active and very stable penicillin G acylase (PGA)--agarose derivatives we have studied the industrial design of equilibrium-controlled synthesis of lactamic antibiotics. In the presence of high concentrations of organic cosolvents we have carried out the direct enzymatic condensation of phenylacetic acid and 6-aminopenicillanic acid to yield the model antibiotic penicillin G. We have mainly studied the integrated effect of different variables that define the reaction medium on a number of parameters of industrial interest:time course of antibiotic synthesis, highest synthetic yields, stability of the catalyst, and solubility and stability of substrates and products. The main variables tested were the nature and concentration of the organic cosolvent, pH, and temperature. The effects of the variables tested on different parameters were quite different and sometimes opposite. Hence, the optimal experimental conditions for antibiotic synthesis catalysed by PGA were established, as a compromise solution, in order to obtain good values for every parameter of industrial interest. These conditions seem to be important parameters for scale-up (e.g. we have been able to reach more than 95% of synthetic yields with productivities around 0.5 tons of model antibiotic per year per liter of catalyst). PMID:1368000

  16. Reported Rates of Diarrhea Following Oral Penicillin Therapy in Pediatric Clinical Trials

    PubMed Central

    Kuehn, Jemima; Ismael, Zareen; Long, Paul F.; Barker, Charlotte I.S.

    2015-01-01

    OBJECTIVES: Antibiotic-associated diarrhea (AAD) is a well-recognized adverse reaction to oral penicillins. This review analyzed the literature to determine the incidence of AAD following amoxicillin, amoxicillin/clavulanate, and penicillin V oral therapy in pediatric clinical trials. METHODS: An advanced search was conducted in MEDLINE and Embase databases for articles in any language reporting the incidence of AAD following oral penicillin therapy for any indicated infection in children (0–17 years). The search was limited to clinical trials. Articles were excluded if treatment was related to chronic conditions, involved concomitant antimicrobials, or if the dose or number of patients was not specified. RESULTS: Four hundred thirty-five articles relating to clinical trials were identified (307 from Embase; 128 from MEDLINE). Thirty-five articles reporting on 42 studies were included for analysis. The indications included acute otitis media, sinusitis, pharyngitis, and pneumonia. Thirty-three trials reported on amoxicillin/clavulanate, 6 on amoxicillin, and 3 on penicillin V. In total, the 42 trials included 7729 children who were treated with an oral penicillin. On average, 17.2% had AAD. Data were pooled for each penicillin. The AAD incidence was 19.8% for amoxicillin/clavulanate, 8.1% for amoxicillin, and 1.2% for penicillin V. The amoxicillin/clavulanate data were analyzed according to formulation: pooled-average. The incidence of ADD was 24.6% for the 4:1 formulation, 12.8% for the 7:1 formulation, 19.0% for the 8:1 formulation, and 20.2% for the 14:1 formulation. CONCLUSIONS: These results demonstrate substantially increased incidence of AAD following use of amoxicillin/clavulanate, compared to use of amoxicillin and penicillin V, as well as varying AAD rates with diffierent amoxicillin/clavulanate formulations. These findings warrant consideration when prescribing. The underlying mechanisms of AAD in children remain unclear. PMID:25964726

  17. Concentrations of doxycycline and penicillin G in sera and cerebrospinal fluid of patients treated for neuroborreliosis.

    PubMed Central

    Karlsson, M; Hammers, S; Nilsson-Ehle, I; Malmborg, A S; Wretlind, B

    1996-01-01

    Concentrations of doxycycline and penicillin G in serum and cerebrospinal fluid (CSF) were analyzed in 46 patients during treatment for neuroborreliosis. Twenty patients were treated intravenously with penicillin G at 3 g every 6 h (q6h), and 26 patients were treated orally with doxycycline at 200 mg q24h. All samples were collected on day 13 of treatment. The median concentrations of penicillin G in serum were 0.5, 37, and 5.6 micrograms/ml before and 1 and 3 h after drug administration, and that in CSF was 0.5 (range, 0.3 to 1.6) microgram/ml after 2 to 3 h. The median concentrations of doxycycline in serum were 2.1, 6.1, and 4.7 micrograms/ml before and 2 and 6 h after drug administration, and that in CSF was 0.6 (range, 0.4 to 2.5) microgram/ml after 4 h. All patients had concentrations of penicillin G or doxycycline in CSF above the lowest reported MICs of penicillin G (0.003 microgram/ml) and doxycycline (0.12 microgram/ml) for Borrelia burgdorferi. However, no patients had a drug concentration in CSF above the highest reported MIC of penicillin G (8 micrograms/ml), and only one had a drug concentration in CSF above the highest reported MIC of doxycycline (2 micrograms/ml), despite good clinical response to treatment. No treatment failure or relapse was observed during a 1-year follow-up, although one patient treated with penicillin G and one treated with doxycycline were retreated because of residual pain. The chosen dosages of penicillin G and doxycycline seem to give sufficient concentrations in serum and CSF for the treatment of neuroborreliosis. PMID:8723448

  18. The role of the media in influencing public attitudes to penicillin during World War II.

    PubMed

    Shama, Gilbert

    2015-01-01

    Penicillin's trajectory towards becoming an effective antibacterial chemotherapeutic agent took place during World War II. Its strategic military value was immediately recognised by the Allies, and mass production was undertaken with the prime objective of meeting the needs of the armed forces. News of its development came to be widely reported on in the media and is examined here. These reports frequently combined accounts of penicillin's prodigious clinical effectiveness with the fact that it was to remain unavailable to the civilian population essentially until the war had ended. More penicillin was to be made available to the civilian population in the United States than in Britain, but the sense that it was severely rationed remained as high. It was in response to this that the idea of "homemade penicillin" was hatched. News of this was also widely promulgated by both the British and American media. Although the numbers treated with penicillin produced in this way was never to be significant, knowledge of the existence of such endeavours may have served to assuage in some measure the feelings of frustration felt by the civilian population at penicillin's non-availability. PMID:26012339

  19. Crystallization and X-ray structure analysis of a thermostable penicillin G acylase from Alcaligenes faecalis.

    PubMed

    Varshney, Nishant Kumar; Kumar, R Suresh; Ignatova, Zoya; Prabhune, Asmita; Pundle, Archana; Dodson, Eleanor; Suresh, C G

    2012-03-01

    The enzyme penicillin G acylase (EC 3.5.1.11) catalyzes amide-bond cleavage in benzylpenicillin (penicillin G) to yield 6-aminopenicillanic acid, an intermediate chemical used in the production of semisynthetic penicillins. A thermostable penicillin G acylase from Alcaligenes faecalis (AfPGA) has been crystallized using the hanging-drop vapour-diffusion method in two different space groups: C222(1), with unit-cell parameters a = 72.9, b = 86.0, c = 260.2 , and P4(1)2(1)2, with unit-cell parameters a = b = 85.6, c = 298.8 . Data were collected at 293 and the structure was determined using the molecular-replacement method. Like other penicillin acylases, AfPGA belongs to the N-terminal nucleophilic hydrolase superfamily, has undergone post-translational processing and has a serine as the N-terminal residue of the β-chain. A disulfide bridge has been identified in the structure that was not found in the other two known penicillin G cylase structures. The presence of the disulfide bridge is perceived to be one factor that confers higher stability to this enzyme. PMID:22442220

  20. Cloning, purification, crystallization and preliminary structural studies of penicillin V acylase from Bacillus subtilis

    SciTech Connect

    Rathinaswamy, Priya; Pundle, Archana V.; Prabhune, Asmita A.; SivaRaman, Hepzibah; Brannigan, James A. Dodson, Guy G.; Suresh, C. G.

    2005-07-01

    An unannotated protein reported from B. subtilis has been expressed in E. coli and identified as possessing penicillin V acylase activity. The crystallization and preliminary crystallographic analysis of this penicillin V acylase is presented. Penicillin acylase proteins are amidohydrolase enzymes that cleave penicillins at the amide bond connecting the side chain to their β-lactam nucleus. An unannotated protein from Bacillus subtilis has been expressed in Escherichia coli, purified and confirmed to possess penicillin V acylase activity. The protein was crystallized using the hanging-drop vapour-diffusion method from a solution containing 4 M sodium formate in 100 mM Tris–HCl buffer pH 8.2. Diffraction data were collected under cryogenic conditions to a spacing of 2.5 Å. The crystals belonged to the orthorhombic space group C222{sub 1}, with unit-cell parameters a = 111.0, b = 308.0, c = 56.0 Å. The estimated Matthews coefficient was 3.23 Å{sup 3} Da{sup −1}, corresponding to 62% solvent content. The structure has been solved using molecular-replacement methods with B. sphaericus penicillin V acylase (PDB code 2pva) as the search model.

  1. Optimal milk penicillin levels for the treatment of experimentally induced mastitis in cows.

    PubMed Central

    Haley, K; Black, W D; Barnum, D A

    1981-01-01

    Infection of the mammary gland (mastitis) was produced by infusing ten quarters 2/cow x 5 cows) with Staphylococcus aureus strain 305. Mastitic and normal quarters were then infused with a preparation containing two levels of penicillin G (100,000 and 200,000 IU) in 10 mL of 3% aluminum monostearate and peanut oil. Milk penicillin levels were determined prior to treatment and twice daily for eight milkings after treatment. Normal and mastitic quarters infused with 200,000 IU had higher peak levels than those infused with 100,000 IU. Milk penicillin levels were similar in mastitic and normal quarters for the first three milkings after treatment. However, residues persisted for a longer time in milk from mastitic quarters. Penicillin was not detected in milk from the untreated control quarters nor in serum samples assayed during the experiment. The in vitro penicillin G sensitivity of the udder pathogen (MIC=0.039 and MBC=0.078 IU) was well below the milk penicillin levels for the first five milkings in all cases. However, infection recurred in two of the ten quarters (one receiving 100,000 IU and one receiving 200,000 IU). PMID:7340909

  2. Removal of Penicillin G and Erythromycin with Ionizing Radiation Followed by Biological Treatment.

    PubMed

    Ben Salem, Issam; Mezni, Mohamed; Boulila, Abdennacer; Hamdi, Mokhtar; Saidi, Mouldi

    2016-10-01

    The decomposition of penicillin G and erythromycin antibiotics at concentration of 0.2 mg ml(-1) by gamma irradiation at 50 kGy followed by biological treatment with Cupriavidus metallidurans CH34 was evaluated. Degradation of penicillin G and erythromycin was analyzed using nuclear magnetic resonance analysis (NMR), fourier transform infrared spectroscopy (FTIR), and chemical oxygen demand (COD). The exposure to the absorbed dose of 50 kGy caused degradation of penicillin G and erythromycin in the aqueous solution. The complete disappearance of NMR and FTIR peaks following irradiation confirmed the breakage of the β-lactam ring in penicillin G, and the decarboxylation and cleavage of the thiazolidine ring and for erythromycin, the complete destruction of the three aromatic rings. Irradiation alone removed 52.8 and 65.5 % of penicillin G and erythromycin, respectively. Further reduction to 12.6 and 14 % of the original penicillin G and erythromycin COD, respectively, was achieved using treatment of the irradiation products with C. metallidurans. PMID:27447798

  3. Growth of Streptococcus mutans protoplasts is not inhibited by penicillin.

    PubMed Central

    Parks, L C; Shockman, G D; Higgins, M L

    1980-01-01

    A method is described in which cells of Streptococcus mutans BHT can be converted to spherical, osmotically fragile protoplasts. Exponential-phase cells were suspended in a solution containing 0.5 M melezitose, and their cell walls were hydrolyzed with mutanolysin (M-1 enzyme). When the resultant protoplasts were incubated in a chemically defined growth medium containing 0.5 M NH4Cl, the protoplast suspensions increased in turbidity, protein, ribonucleic acid, and deoxyribonucleic acid in a balanced fashion. In the presence of benzylpenicillin (5 microgram/ml), balanced growth of protoplasts was indistinguishable from untreated controls. This absence of inhibition of protoplast growth in the presence of benzylpenicillin was apparently not due to inactivation of the antibiotic. When exponential-phase cells of S. mutans BHT were first exposed to 5 microgram of benzyl-penicillin per ml for 1 h and then converted to protoplasts, these protoplasts were also able to grow in chemically defined, osmotically stabilized medium. The ability of wall-free protoplasts to grow and to synthesize ribonucleic acid and protein in the presence of a relatively high concentration of benzylpenicillin contrasts with the previously reported rapid inhibition of ribonucleic acid and protein synthesis in intact streptococci. These data suggest that this secondary inhibition of ribonucleic acid and protein synthesis in whole cells is due to factors involved with the continued assembly of an intact, insoluble cell wall rather than with earlier stages of peptidoglycan synthesis. Images PMID:6997274

  4. Functionalized nanoporous silicas for the immobilization of penicillin acylase

    NASA Astrophysics Data System (ADS)

    Maria Chong, A. S.; Zhao, X. S.

    2004-10-01

    Nanoporous silica materials with uniform pore size and ordered structure have drawn growing interest of researchers since 1990s. A large-pore nanoporous material, SBA-15, was functionalized with organosilanes by co-condensation method in the presence of nonionic triblock copolymer P123 as a template under acidic conditions. The functionalization was demonstrated by using five organosilanes, namely 3-aminopropyltriethoxysilane (APTES), 3-mercaptopropyltrimethoxysilane (MPTMS), phenyltrimethoxysilane (PTMS), vinyltriethoxysilane (VTES), and 4-(triethoxysilyl)butyronitrile (TSBN), which modified the surface properties of the silica materials, enabling the materials to be a promising support for immobilization of biological molecules. The functionalized SBA-15 materials exhibited long-range ordering of two-dimensional hexagonal pore arrays of size ranging from 66 to 90 Å as demonstrated by small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and physical adsorption techniques. A variety of organosilane density in the range of 0.5-2.6 mmol/g was achieved as revealed by elemental analysis and solid-state nuclear magnetic resonance (NMR) techniques. The functionalized materials displayed improved properties for immobilization of penicillin acylase (PA) in comparison with pure-silica SBA-15. Such improvement is believed to be due to the enhanced surface hydrophobicity and electrostatic interactions of the functional groups with the enzyme.

  5. Sensitive monitoring of penicillin antibiotics in milk and honey treated by stir bar sorptive extraction based on monolith and LC-electrospray MS detection.

    PubMed

    Huang, Xiaojia; Chen, Linli; Chen, Meng; Yuan, Dongxing; Nong, Shuyu

    2013-03-01

    In the present study, a convenient and sensitive method for determination of six penicillin antibiotics (amoxicillin, ampicillin, penicillin G, oxacillin, cloxacillin, and dicloxacillin) in milk and honey samples was developed. Milk and honey samples were diluted with water, then directly treated by stir bar sorptive extraction based on poly (vinylimidazole-divinylbenzene) monolithic material as coating. The analytes were analyzed by LC/ESI- MS/MS. Several extraction parameters including extraction and desorption time, pH value, and ionic strength in sample matrix were investigated in detail. Under the optimized extraction conditions, the calculated detection limits for the target compounds were as low as 0.23-2.66 ng/kg in milk and 0.18-1.42 ng/kg in honey, respectively. Good linearity was obtained for analytes with the correlation coefficients (R(2)) above 0.997. Excellent method reproducibility was achieved in terms of intraday and interday precisions, indicated by the RSDs of <5.0 and <10.0%, respectively. Finally, the proposed method was successfully applied to the determination of penicillin antibiotics residues in different milk and honey samples. PMID:23378165

  6. Phage displayed peptides and anti-idiotype antibodies recognised by a monoclonal antibody directed against a diagnostic antigen of Mycoplasma capricolum subsp. capripneumoniae.

    PubMed

    Bengurić, D R; Dungu, B; Thiaucourt, F; du Plessis, D H

    2001-07-26

    A monoclonal antibody (Mab 4.52) raised against Mycoplasma capricolum subsp. capripneumoniae (Mccp) cell lysate was used as a template to obtain substitute antigens recognised by its paratope. Two approaches were investigated: a 17-mer random peptide library displayed on the surface of a filamentous phage was screened by panning on the immobilised Mab 4.52 and anti-idiotype antibodies were generated by immunising a chicken with the F(ab')(2) fragments of the antibody. Analysis of the peptide sequences displayed by the isolated phages identified two peptides. Both contained two cysteine residues and had identical or similar amino acids in positions 5 (P), 8 (I/L) and 13 (L). The fusion phages were also recognised by Mab 4.52 in enzyme-linked immunosorbent assay (ELISA) and binding was shown by surface plasmon resonance. One of the peptides was a markedly better inhibitor (67%) of the binding of Mab 4.52 to its original antigen than the other (20%) at 1mg/ml. After absorption, to remove isotypic and allotypic reactivities, the anti-idiotype IgY was specifically recognised by Mab 4.52 in ELISA and was able to inhibit its binding to the original antigen, whereas anti-idiotype antibodies raised against a bluetongue virus-specific antibody had no effect. In spite of unequivocal binding of the anti-idiotype antibodies and the fusion phages to the paratope of Mab 4.52, goat antisera appeared not to react with either of the surrogate antigens. In contrast, the test sera bound to the original antigen suggesting that Mab 4.52 does not recognise exactly the same antigenic site as antibodies in the goat antisera. PMID:11376960

  7. Directed Evolution of a Cyclized Peptoid-Peptide Chimera against a Cell-Free Expressed Protein and Proteomic Profiling of the Interacting Proteins to Create a Protein-Protein Interaction Inhibitor.

    PubMed

    Kawakami, Takashi; Ogawa, Koji; Hatta, Tomohisa; Goshima, Naoki; Natsume, Tohru

    2016-06-17

    N-alkyl amino acids are useful building blocks for the in vitro display evolution of ribosomally synthesized peptides because they can increase the proteolytic stability and cell permeability of these peptides. However, the translation initiation substrate specificity of nonproteinogenic N-alkyl amino acids has not been investigated. In this study, we screened various N-alkyl amino acids and nonamino carboxylic acids for translation initiation with an Escherichia coli reconstituted cell-free translation system (PURE system) and identified those that efficiently initiated translation. Using seven of these efficiently initiating acids, we next performed in vitro display evolution of cyclized peptidomimetics against an arbitrarily chosen model human protein (β-catenin) cell-free expressed from its cloned cDNA (HUPEX) and identified a novel β-catenin-binding cyclized peptoid-peptide chimera. Furthermore, by a proteomic approach using direct nanoflow liquid chromatography-tandem mass spectrometry (DNLC-MS/MS), we successfully identified which protein-β-catenin interaction is inhibited by the chimera. The combination of in vitro display evolution of cyclized N-alkyl peptidomimetics and in vitro expression of human proteins would be a powerful approach for the high-speed discovery of diverse human protein-targeted cyclized N-alkyl peptidomimetics. PMID:27010125

  8. BhSGAMP-1, a gene that encodes an antimicrobial peptide, is developmentally regulated by the direct action of 20-OH ecdysone in the salivary gland of Bradysia hygida (Diptera, Sciaridae).

    PubMed

    Zanarotti, Gabriela Morilha; Cândido-Silva, Juliana A; de Almeida, Jorge Cury

    2009-12-01

    Recently we have shown that BhSGAMP-1 is a developmentally regulated reiterated gene that encodes an antimicrobial peptide (AMP) and is expressed exclusively in the salivary glands, at the end of the larval stage. We show, for the first time, that a gene for an AMP is directly activated by 20-OH ecdysone. This control probably involves the participation of short-lived repressor(s). We also found that the promoter of BhSGAMP-1 is not equipped with elements that respond to infection, provoked by the injection of microorganisms, in the salivary glands or in the fat body. We produced polyclonal antibodies against the synthetic peptide and found that the BhSGAMP-1 peptide is secreted in the saliva. The BhSGAMP-1 gene was also activated during the third larval molt. These facts confirm our hypothesis that this preventive system of defense was selected to produce an environment free of harmful microorganisms in the insect's immediate vicinity, during molts. PMID:19882668

  9. Cerebrospinal fluid outflow resistance in rabbits with experimental meningitis. Alterations with penicillin and methylprednisolone.

    PubMed Central

    Scheld, W M; Dacey, R G; Winn, H R; Welsh, J E; Jane, J A; Sande, M A

    1980-01-01

    Acute bacterial meningitis may be associated with increased intracranial pressure, neurological sequelae such as communicating hydrocephalus, and a slow response to antibiotic therapy. Alterations in cerebrospinal hydrodynamics are at least partially responsible for these complications. Constant, low-flow short-duration manometric infusion studies through a hollow-bore pressure monitoring device in direct continuity with the supracortical subarachnoid space were performed in rabbits with experimental meningitis. Maximal resistance to cerebrospinal fluid (CSF) outflow from the subarachnoid to vascular space was markedly increaed in acute pneumococcal meningitis when compared to control, uninfected animals (6.77 +/- 3.52 vs. 0.26 +/- 0.04 mm Hg/microliter per min, P less than 0.001). Similar elevations (8.93 +/- 4.15 mm Hg/microliter per min were found in experimental Escherichia coli meningitis. Despite eradication of viable bacteria from the CSF by penicillin therapy during the acute stage of pneumococcal meningitis, resistance remained elevated (6.07 +/- 4.68 mm Hg/microliter per min) and had not returned to normal up to 15 d later. Administration of methylprednisolone during the early stages of acute pneumococcal meningitis reduced mean peak outflow resistance towards control values (0.59 mm Hg/microliter per min) and no "rebound" effect was apparent 24 h later. These hydrodynamic alterations in experimental meningitis prevent normal CSF absorption and decrease the ability of the bran to compensate for changes in intracranial volume and pressure. PMID:6995482

  10. The long postwar and the politics of penicillin: early circulation and smuggling in Spain, 1944-1954.

    PubMed

    Santesmases, María Jesús

    2014-01-01

    In this paper I explore the early circulation of penicillin. I review the early distribution in Spain of a scarce product, reflect on the available sources about the illegal penicillin trade and discuss some cases of smuggling. I argue the early distribution of penicillin involved time and geography, a particular chronology of post Second World War geopolitics. Penicillin practices and experiences belong to this period, in a dictatorship that tolerated smuggling and illegal trade of other products, some, like penicillin, produced in neighbouring countries. As a commodity that crossed borders, penicillin, transiting between the law and hidden trade, between countries and social domains--between war fronts and from a war front to an urban site to be sold--reveals practices of the early years of prosperity in the 1950s. These transits were permanent tests of a society based on taxes and exchanges, law and bureaucracy, control, discipline and the creation of standards. PMID:26054216

  11. Inhibition of Growth and Gene Expression by PNA-peptide Conjugates in Streptococcus pyogenes

    PubMed Central

    Patenge, Nadja; Pappesch, Roberto; Krawack, Franziska; Walda, Claudia; Mraheil, Mobarak Abu; Jacob, Anette; Hain, Torsten; Kreikemeyer, Bernd

    2013-01-01

    While Streptococcus pyogenes is consistently susceptible toward penicillin, therapeutic failure of penicillin treatment has been reported repeatedly and a considerable number of patients exhibit allergic reactions to this substance. At the same time, streptococcal resistance to alternative antibiotics, e.g., macrolides, has increased. Taken together, these facts demand the development of novel therapeutic strategies. In this study, S. pyogenes growth was inhibited by application of peptide-conjugated antisense-peptide nucleic acids (PNAs) specific for the essential gyrase A gene (gyrA). Thereby, HIV-1 Tat peptide-coupled PNAs were more efficient inhibitors of streptococcal growth as compared with (KFF)3K-coupled PNAs. Peptide-anti-gyrA PNAs decreased the abundance of gyrA transcripts in S. pyogenes. Growth inhibition by antisense interference was enhanced by combination of peptide-coupled PNAs with protein-level inhibitors. Antimicrobial synergy could be detected with levofloxacin and novobiocin, targeting the gyrase enzyme, and with spectinomycin, impeding ribosomal function. The prospective application of carrier peptide-coupled antisense PNAs in S. pyogenes covers the use as an antimicrobial agent and the employment as a knock-down strategy for the investigation of virulence factor function. PMID:24193033

  12. Non-toxigenic penicillin-resistant cutaneous C. diphtheriae infection: a case report and review of the literature.

    PubMed

    FitzGerald, Rosemarie Philippa; Rosser, Andrew J; Perera, Dona Nelun

    2015-01-01

    Here, we report a case of non-toxigenic Corynebacterium diphtheriae in a previously healthy 14-year-old girl that was acquired in Ethiopia and presented locally. This is the first clinical case of penicillin-resistant C. diphtheriae in the UK. This is significant finding because penicillin is the recommended first-line agent for the prophylaxis against and treatment of C. diphtheriae in patients who are not allergic to penicillin. PMID:25027172

  13. Interspecies mixed-effect pharmacokinetic modeling of penicillin G in cattle and swine.

    PubMed

    Li, Mengjie; Gehring, Ronette; Tell, Lisa; Baynes, Ronald; Huang, Qingbiao; Riviere, Jim E

    2014-08-01

    Extralabel drug use of penicillin G in food-producing animals may cause an excess of residues in tissue which will have the potential to damage human health. Of all the antibiotics, penicillin G may have the greatest potential for producing allergic responses to the consumer of food animal products. There are, however, no population pharmacokinetic studies of penicillin G for food animals. The objective of this study was to develop a population pharmacokinetic model to describe the time-concentration data profile of penicillin G across two species. Data were collected from previously published pharmacokinetic studies in which several formulations of penicillin G were administered to diverse populations of cattle and swine. Liver, kidney, and muscle residue data were also used in this study. Compartmental models with first-order absorption and elimination were fit to plasma and tissue concentrations using a nonlinear mixed-effect modeling approach. A 3-compartment model with extra tissue compartments was selected to describe the pharmacokinetics of penicillin G. Typical population parameter estimates (interindividual variability) were central volumes of distribution of 3.45 liters (12%) and 3.05 liters (8.8%) and central clearance of 105 liters/h (32%) and 16.9 liters/h (14%) for cattle and swine, respectively, with peripheral clearance of 24.8 liters/h (13%) and 9.65 liters/h (23%) for cattle and 13.7 liters/h (85%) and 0.52 liters/h (40%) for swine. Body weight and age were the covariates in the final pharmacokinetic models. This study established a robust model of penicillin for a large and diverse population of food-producing animals which could be applied to other antibiotics and species in future analyses. PMID:24867969

  14. Crystal structures of penicillin-binding protein 2 from penicillin-susceptible and -resistant strains of Neisseria gonorrhoeae reveal an unexpectedly subtle mechanism for antibiotic resistance.

    PubMed

    Powell, Ailsa J; Tomberg, Joshua; Deacon, Ashley M; Nicholas, Robert A; Davies, Christopher

    2009-01-01

    Penicillin-binding protein 2 (PBP2) from N. gonorrhoeae is the major molecular target for beta-lactam antibiotics used to treat gonococcal infections. PBP2 from penicillin-resistant strains of N. gonorrhoeae harbors an aspartate insertion after position 345 (Asp-345a) and 4-8 additional mutations, but how these alter the architecture of the protein is unknown. We have determined the crystal structure of PBP2 derived from the penicillin-susceptible strain FA19, which shows that the likely effect of Asp-345a is to alter a hydrogen-bonding network involving Asp-346 and the SXN triad at the active site. We have also solved the crystal structure of PBP2 derived from the penicillin-resistant strain FA6140 that contains four mutations near the C terminus of the protein. Although these mutations lower the second order rate of acylation for penicillin by 5-fold relative to wild type, comparison of the two structures shows only minor structural differences, with the positions of the conserved residues in the active site essentially the same in both. Kinetic analyses indicate that two mutations, P551S and F504L, are mainly responsible for the decrease in acylation rate. Melting curves show that the four mutations lower the thermal stability of the enzyme. Overall, these data suggest that the molecular mechanism underlying antibiotic resistance contributed by the four mutations is subtle and involves a small but measurable disordering of residues in the active site region that either restricts the binding of antibiotic or impedes conformational changes that are required for acylation by beta-lactam antibiotics. PMID:18986991

  15. Crystal Structures of Penicillin-Binding Protein 2 From Penicillin-Susceptible And -Resistant Strains of Neisseria Gonorrhoeae Reveal An Unexpectedly Subtle Mechanism for Antibiotic Resistance

    SciTech Connect

    Powell, A.J.; Tomberg, J.; Deacon, A.M.; Nicholas, R.A.; Davies, C.

    2009-05-21

    Penicillin-binding protein 2 (PBP2) from N. gonorrhoeae is the major molecular target for {beta}-lactam antibiotics used to treat gonococcal infections. PBP2 from penicillin-resistant strains of N. gonorrhoeae harbors an aspartate insertion after position 345 (Asp-345a) and 4-8 additional mutations, but how these alter the architecture of the protein is unknown. We have determined the crystal structure of PBP2 derived from the penicillin-susceptible strain FA19, which shows that the likely effect of Asp-345a is to alter a hydrogen-bonding network involving Asp-346 and the SXN triad at the active site. We have also solved the crystal structure of PBP2 derived from the penicillin-resistant strain FA6140 that contains four mutations near the C terminus of the protein. Although these mutations lower the second order rate of acylation for penicillin by 5-fold relative to wild type, comparison of the two structures shows only minor structural differences, with the positions of the conserved residues in the active site essentially the same in both. Kinetic analyses indicate that two mutations, P551S and F504L, are mainly responsible for the decrease in acylation rate. Melting curves show that the four mutations lower the thermal stability of the enzyme. Overall, these data suggest that the molecular mechanism underlying antibiotic resistance contributed by the four mutations is subtle and involves a small but measurable disordering of residues in the active site region that either restricts the binding of antibiotic or impedes conformational changes that are required for acylation by {beta}-lactam antibiotics.

  16. Do patients with sore throat benefit from penicillin? A randomized double-blind placebo-controlled clinical trial with penicillin V in general practice.

    PubMed Central

    Dagnelie, C F; van der Graaf, Y; De Melker, R A

    1996-01-01

    BACKGROUND: The effect of antibiotic therapy in sore throat is questionable and this dilemma has been complicated by the emergence of multiple resistant strains of micro-organisms. AIM: A randomized double-blind placebo-controlled clinical trial was undertaken in patients aged 4-60 years to assess the efficacy of penicillin V on the clinical course and bacteriological response in patients with sore throat in general practice. METHOD: Two hundred and thirty-nine patients presenting with an acute sore throat to 37 general practices in the Netherlands who were clinically suspected of group A beta-haemolytic streptococci (GABHS) were randomized for treatment with penicillin V (n = 121) or placebo (n = 118). Resolution of sore throat, fever and return to daily activities were evaluated by the general practitioner 2 days after the start of treatment and by the patients keeping a diary for 7 days. The result of throat culture after 2 days was evaluated. RESULTS: A difference in resolution of sore throat was present after 2 days in all patients, but was a result of GABHS-positive patients (n = 111; 46%) in favour of those randomized for penicillin V (adjusted odds ratio 5.3; 95% CI 1.9-15.1). An effect in the course of fever was also seen in GABHS-positive patients (adjusted odds ratio 5.3; 95% CI 1.02-27.7). A difference of 1-2 days was seen in clinical recovery. No difference was found in daily activities between the treatment groups. After 2 days, 4% of the penicillin-treated patients harboured GABHS compared with 75% of the placebo group. CONCLUSION: Only GABHS-positive patients benefit from penicillin V in their clinical cure in the first few days. Therefore, rapid testing is necessary. Treatment may be beneficial with regard to the clinical course, but it is not necessary. PMID:8945796

  17. Requirement of de novo synthesis of the OdhI protein in penicillin-induced glutamate production by Corynebacterium glutamicum.

    PubMed

    Kim, Jongpill; Fukuda, Hirohisa; Hirasawa, Takashi; Nagahisa, Keisuke; Nagai, Kazuo; Wachi, Masaaki; Shimizu, Hiroshi

    2010-04-01

    We found that penicillin-induced glutamate production by Corynebacterium glutamicum is inhibited when a de novo protein synthesis inhibitor, chloramphenicol, is added simultaneously with penicillin. When chloramphenicol was added 4 h after penicillin addition, glutamate production was essentially unaffected. (3)H-Leucine incorporation experiments revealed that protein synthesis continued for 1 h after penicillin addition and then gradually decreased. These results suggest that de novo protein synthesis within 4 h of penicillin treatment is required for the induction of glutamate production. To identify the protein(s) necessary for penicillin-induced glutamate production, proteome analysis of penicillin-treated C. glutamicum cells was performed with two-dimensional gel electrophoresis. Of more than 500 proteins detected, the amount of 13 proteins, including OdhI (an inhibitory protein for 2-oxoglutarate dehydrogenase complex), significantly increased upon penicillin treatment. Artificial overexpression of the odhI gene resulted in the decreased specific activity of the 2-oxoglutarate dehydrogenase complex and increased glutamate production without any triggers. These results suggest that the de novo synthesis of OdhI is the necessary factor for penicillin-induced glutamate overproduction by C. glutamicum. Moreover, continuous glutamate production was achieved by overexpression of odhI without any triggers. Thus, the odhI-overexpressing strain of C. glutamicum can be useful for efficient glutamate production. PMID:19956942

  18. Penicillin Induced Persistence in Chlamydia trachomatis: High Quality Time Lapse Video Analysis of the Developmental Cycle

    PubMed Central

    Barlow, David; Wang, Yibing; Salim, Omar; Lambden, Paul R.; Clarke, Ian N.

    2009-01-01

    Background Chlamydia trachomatis is a major human pathogen with a unique obligate intracellular developmental cycle that takes place inside a modified cytoplasmic structure known as an inclusion. Following entry into a cell, the infectious elementary body (EB) differentiates into a non - infectious replicative form known as a reticulate body (RB). RBs divide by binary fission and at the end of the cycle they redifferentiate into EBs. Treatment of C.trachomatis with penicillin prevents maturation of RBs which survive and enlarge to become aberrant RBs within the inclusion in a non - infective persistent state. Persistently infected individuals may be a reservoir for chlamydial infection. The C.trachomatis genome encodes the enzymes for peptidoglycan (PG) biosynthesis but a PG sacculus has never been detected. This coupled to the action of penicillin is known as the chlamydial anomaly. We have applied video microscopy and quantitative DNA assays to the chlamydial developmental cycle to assess the effects of penicillin treatment and establish a framework for investigating penicillin induced chlamydial persistence. Principal Findings Addition of penicillin at the time of cell infection does not prevent uptake and the establishment of an inclusion. EB to RB transition occurs but bacterial cytokinesis is arrested by the second binary fission. RBs continue to enlarge but not divide in the presence of penicillin. The normal developmental cycle can be recovered by the removal of penicillin although the large, aberrant RBs do not revert to the normal smaller size but remain present to the completion of the developmental cycle. Chromosomal and plasmid DNA replication is unaffected by the addition of penicillin but the arrest of bacterial cytokinesis under these conditions results in RBs accumulating multiple copies of the genome. Conclusions We have applied video time lapse microscopy to the study of the chlamydial developmental cycle. Linked with accurate measures of genome

  19. Beijerinckia indica var. penicillanicum penicillin V acylase: enhanced enzyme production by catabolite repression-resistant mutant and effect of solvents on enzyme activity.

    PubMed

    Ambedkar, S S; Deshpande, B S; Sudhakaran, V K; Shewale, J G

    1991-04-01

    Beijerinckia indica var. penicillanicum mutant UREMS-5, producing 168% more penicillin V acylase, was obtained by successive treatment with UV, gamma-irradiation and ethylmethane sulfonate. Penicillin V acylase production by the mutant strain was resistant to catabolite repression by glucose. Incorporation of glucose, sodium glutamate and vegetable oils in the medium enhanced enzyme production. The maximum specific production of penicillin V acylase was 244 IU/g dry weight of cells. Effect of solvents on hydrolysis of penicillin V by soluble penicillin V acylase and whole cells was studied. Methylene chloride, chloroform and carbon tetrachloride significantly stimulated the rate of penicillin V hydrolysis by whole cells. PMID:1367509

  20. Utilization of a depsipeptide substrate for trapping acyl—enzyme intermediates of penicillin-sensitive D-alanine carboxypeptidases

    PubMed Central

    Rasmussen, James R.; Strominger, Jack L.

    1978-01-01

    The penicillin-sensitive D-alanine carboxypeptidases of Bacillus subtilis, Escherichia coli, and Staphylococcus aureus catalyzed the hydrolysis of the D-lactic acid residue from the depsipeptide diacetyl-L-lysyl-D-alanyl-D-lactic acid. The ester substrate was hydrolyzed faster than the peptide analogue, diacetyl-L-lysyl-D-alanyl-D-alanine, by the B. subtilis (15-fold) and E. coli (4-fold) carboxypeptidases, presumably because acylation (k2), which is the rate-limiting step of the peptidase reaction, occurred more rapidly during cleavage of the ester bond than during cleavage of the amide bond. No rate acceleration was observed with the S. aureus carboxypeptidase for which deacylation (k3) is already the rate-determining step with the peptide substrate. The efficiency of utilization of the depsipeptide (Vmax/Km) was greatly enhanced (19- to 147-fold) for all three enzymes. After incubation of the B. subtilis carboxypeptidase and [14C]diacetyl-L-lysyl-D-alanyl-D-lactic acid at pH 5.0 and lowering of the pH to 3.0, a radioactive acyl-enzyme intermediate containing 0.43 mol of substrate per mol of enzyme was isolated by Sephadex G-50 chromatography. After acetone precipitation, the acyl group of the denatured acyl-enzyme complex appeared to be bound to the protein by an ester bond. Acyl enzymes were also detected for the S. aureus and E. coli carboxypeptidases after sodium dodecyl sulfate/polyacrylamide gel electrophoresis and fluorography of enzyme incubated with [14C]depsipeptide and precipitated with acetone. Images PMID:415311

  1. Randomized, single-blind evaluation of cefadroxil and phenoxymethyl penicillin in the treatment of streptococcal pharyngitis.

    PubMed Central

    Pichichero, M E; Disney, F A; Aronovitz, G H; Talpey, W B; Green, J L; Francis, A B

    1987-01-01

    A total of 150 children from two pediatric practices with clinical and bacteriologic evidence of acute group A beta-hemolytic streptococcal (GABHS) pharyngitis randomly received cefadroxil monohydrate (75 children) or phenoxymethyl penicillin (75 children). Cefadroxil was given once daily, while penicillin was given three times daily. The treatment groups were similar in age, sex, race, illness severity, and acute GABHS symptomatology. Throat cultures were routine 3 to 5 days after the start of therapy and 2 and 14 days after the end of therapy. The bacterial cure rates were 90% (62 of 69) for cefadroxil-treated patients and 76% (52 of 68) for penicillin-treated patients. This difference was significant (P less than 0.04). The clinical response was satisfactory in 91% of cefadroxil-treated patients and 89% of penicillin-treated patients. We conclude that once-daily cefadroxil is at least as effective as three-times-daily penicillin in producing bacteriologic eradication and clinical symptomatic improvement in children with GABHS pharyngitis. PMID:3113329

  2. Pharmacokinetics of a combination of amikacin sulfate and penicillin G sodium for intravenous regional limb perfusion in adult horses.

    PubMed

    Nieto, Jorge E; Trela, Jan; Stanley, Scott D; Yamout, Sawsan; Snyder, Jack R

    2016-07-01

    The aim of this study was to determine the pharmacokinetics of amikacin and penicillin G sodium when administered in combination as an intravenous regional limb perfusion (IVRLP) to horses. Seven healthy adult horses underwent an IVRLP in the cephalic vein with 2 g of amikacin sulfate and 10 mill IU of penicillin G sodium diluted to 60 mL in 0.9% saline. A pneumatic tourniquet set at 450 mmHg was left in place for 30 min. Synovial fluid was collected from the metacarpophalangeal joint 35 min and 2, 6, 12, and 24 h after infusion of the antimicrobials. Concentrations of amikacin and penicillin in synovial fluid were quantitated by liquid chromatography tandem-mass spectrometry analysis. Therapeutic concentrations of amikacin and penicillin for equine-susceptible pathogens were achieved in the synovial fluid. Maximum synovial concentrations (Cmax) (mean ± SE) for amikacin and penicillin were 132 ± 33 μg/mL and 8474 ± 5710 ng/mL, respectively. Only 3 horses had detectable levels of penicillin at 6 h and 1 at the 12 h sample. The combination of amikacin with penicillin G sodium via IVDLP resulted in reported therapeutic concentrations of both antibiotics in the synovial fluid. The Cmax:MIC (minimum inhibitory concentration) ratio for amikacin was 8:1 and Time > MIC for penicillin was 6 h. At 24 h, the mean concentration of amikacin was still above 4 μg/mL. Terminal elimination rate constants (T1/2 lambdaz) were 13.6 h and 2.8 h for amikacin and penicillin, respectively. The use of IVDLP with penicillin may therefore not be practical as rapid clearance of penicillin from the synovial fluid requires frequent perfusions to maintain acceptable therapeutic concentrations. PMID:27408337

  3. Biotechnological advances on penicillin G acylase: pharmaceutical implications, unique expression mechanism and production strategies.

    PubMed

    Srirangan, Kajan; Orr, Valerie; Akawi, Lamees; Westbrook, Adam; Moo-Young, Murray; Chou, C Perry

    2013-12-01

    In light of unrestricted use of first-generation penicillins, these antibiotics are now superseded by their semisynthetic counterparts for augmented antibiosis. Traditional penicillin chemistry involves the use of hazardous chemicals and harsh reaction conditions for the production of semisynthetic derivatives and, therefore, is being displaced by the biosynthetic platform using enzymatic transformations. Penicillin G acylase (PGA) is one of the most relevant and widely used biocatalysts for the industrial production of β-lactam semisynthetic antibiotics. Accordingly, considerable genetic and biochemical engineering strategies have been devoted towards PGA applications. This article provides a state-of-the-art review in recent biotechnological advances associated with PGA, particularly in the production technologies with an emphasis on using the Escherichia coli expression platform. PMID:23721991

  4. Preliminary consultation on preferred product characteristics of benzathine penicillin G for secondary prophylaxis of rheumatic fever.

    PubMed

    Wyber, Rosemary; Boyd, Ben J; Colquhoun, Samantha; Currie, Bart J; Engel, Mark; Kado, Joseph; Karthikeyan, Ganesan; Sullivan, Mark; Saxena, Anita; Sheel, Meru; Steer, Andrew; Mucumbitsi, Joseph; Zühlke, Liesl; Carapetis, Jonathan

    2016-10-01

    Rheumatic fever is caused by an abnormal immune reaction to group A streptococcal infection. Secondary prophylaxis with antibiotics is recommended for people after their initial episode of rheumatic fever to prevent recurrent group A streptococcal infections, recurrences of rheumatic fever and progression to rheumatic heart disease. This secondary prophylaxis must be maintained for at least a decade after the last episode of rheumatic fever. Benzathine penicillin G is the first line antibiotic for secondary prophylaxis, delivered intramuscularly every 2 to 4 weeks. However, adherence to recommended secondary prophylaxis regimens is a global challenge. This paper outlines a consultation with global experts in rheumatic heart disease on the characteristics of benzathine penicillin G formulations which could be changed to improve adherence with secondary prophylaxis. Characteristics included dose interval, pain, administration mechanism, cold chain independence and cost. A sample target product profile for reformulated benzathine penicillin G is presented. PMID:27465618

  5. [Penicillin and streptomycin penetration into tissue by a modified electrophoretic method].

    PubMed

    Ragelis, S Iu

    1981-09-01

    A total of 377 experiments with healthy rabbits of the same species, age, weight and sex were performed with the use of the galvanization apparatus "Potok-1". The penetration levels of penicillin and streptomycin into the tissues, i.e. the skin, muscles and bone after their administration with the modified method of electrophoresis were determined. It was found that the tissue levels of the antibiotics administered with the modified method of electrophoresis increased with an increase in the current density, the procedure time and the antibiotic concentrations. The levels of penicillin and streptomycin in the skin, muscles and bones on administration with the modified method of electrophoresis were higher than those on administration of the antibiotics with the routine method of electrophoresis. The higher the time of the material storage in a refrigerator, the lower the penicillin level in the tissues. PMID:7294762

  6. Influence of matrix porosity on the immobilization of penicillin acylase by radiation-induced polymerization

    NASA Astrophysics Data System (ADS)

    Carenza, M.; Lora, S.; Palma, G.; Boccù, E.; Largajolli, R.; Veronese, F. M.

    Penicillin acylase was immobilized by low temperature radiation-induced polymerization into polymer matrices obtained from monomers of different hydrophilicities, at various ratios of monomer to enzyme solution and at different polymerization conversions. It was found that the penicillin acylase retention (60-85% of the starting enzyme) is independent of the monomer used in thepolymerization, of the polymerization conversion and of the porosity of the polymer matrix. On the other hand, the penicillin acylase retention strongly depends on the presence in the irradiation mixture of the hydrophobic crosslinking agent, trimethylolpropane trimethacrylate, even in low amounts. The data suggest that the enzyme is bound to the polymer matrix by hydrophobic interactions through crosslinking agent molecules.

  7. Lysozyme and Penicillin Inhibit the Growth of Anaerobic Ammonium-Oxidizing Planctomycetes

    PubMed Central

    Hu, Ziye; van Alen, Theo; Jetten, Mike S. M.

    2013-01-01

    Anaerobic ammonium-oxidizing (anammox) planctomycetes oxidize ammonium in the absence of molecular oxygen with nitrite as the electron acceptor. Although planctomycetes are generally assumed to lack peptidoglycan in their cell walls, recent genome data imply that the anammox bacteria have the genes necessary to synthesize peptidoglycan-like cell wall structures. In this study, we investigated the effects of two antibacterial agents that target the integrity and synthesis of peptidoglycan (lysozyme and penicillin G) on the anammox bacterium Kuenenia stuttgartiensis. The effects of these compounds were determined in both short-term batch incubations and long-term (continuous-cultivation) growth experiments in membrane bioreactors. Lysozyme at 1 g/liter (20 mM EDTA) lysed anammox cells in less than 60 min, whereas penicillin G did not have any observable short-term effects on anammox activity. Penicillin G (0.5, 1, and 5 g/liter) reversibly inhibited the growth of anammox bacteria in continuous-culture experiments. Furthermore, transcriptome analyses of the penicillin G-treated reactor and the control reactor revealed that penicillin G treatment resulted in a 10-fold decrease in the ribosome levels of the cells. One of the cell division proteins (Kustd1438) was downregulated 25-fold. Our results suggested that anammox bacteria contain peptidoglycan-like components in their cell wall that can be targeted by lysozyme and penicillin G-sensitive proteins were involved in their synthesis. Finally, we showed that a continuous membrane reactor system with free-living planktonic cells was a very powerful tool to study the physiology of slow-growing microorganisms under physiological conditions. PMID:24096424

  8. Anticodon recognition in evolution: switching tRNA specificity of an aminoacyl-tRNA synthetase by site-directed peptide transplantation.

    PubMed

    Brevet, Annie; Chen, Josiane; Commans, Stéphane; Lazennec, Christine; Blanquet, Sylvain; Plateau, Pierre

    2003-08-15

    The highly conserved aspartyl-, asparaginyl-, and lysyl-tRNA synthetases compose one subclass of aminoacyl-tRNA synthetases, called IIb. The three enzymes possess an OB-folded extension at their N terminus. The function of this extension is to specifically recognize the anticodon triplet of the tRNA. Three-dimensional models of bacterial aspartyl- and lysyl-tRNA synthetases complexed to tRNA indicate that a rigid scaffold of amino acid residues along the five beta-strands of the OB-fold accommodates the base U at the center of the anticodon. The binding of the adjacent anticodon bases occurs through interactions with a flexible loop joining strands 4 and 5 (L45). As a result, a switching of the specificity of lysyl-tRNA synthetase from tRNALys (anticodon UUU) toward tRNAAsp (GUC) could be attempted by transplanting the small loop L45 of aspartyl-tRNA synthetase inside lysyl-tRNA synthetase. Upon this transplantation, lysyl-tRNA synthetase loses its capacity to aminoacylate tRNALys. In exchange, the chimeric enzyme acquires the capacity to charge tRNAAsp with lysine. Upon giving the tRNAAsp substrate the discriminator base of tRNALys, the specificity shift is improved. The change of specificity was also established in vivo. Indeed, the transplanted lysyl-tRNA synthetase succeeds in suppressing a missense Lys --> Asp mutation inserted into the beta-lactamase gene. These results functionally establish that sequence variation in a small peptide region of subclass IIb aminoacyl-tRNA synthetases contributes to specification of nucleic acid recognition. Because this peptide element is not part of the core catalytic structure, it may have evolved independently of the active sites of these synthetases. PMID:12766171

  9. A synthetic peptide vaccine directed against the 2ß2-2ß3 loop of domain 2 of protective antigen protects rabbits from inhalation anthrax.

    PubMed

    Oscherwitz, Jon; Yu, Fen; Cease, Kemp B

    2010-09-15

    The current vaccines for anthrax in the United States and United Kingdom are efficacious in the two most accepted animal models of inhalation anthrax, nonhuman primates and rabbits, but require extensive immunization protocols. We previously demonstrated that a linear determinant in domain 2 of Bacillus anthracis protective Ag (PA) is a potentially important target for an epitope-specific vaccine for anthrax, as Abs specific for this site, referred to as the loop-neutralizing determinant (LND), neutralize lethal toxin in vitro, yet are virtually absent in PA-immunized rabbits. In this study, we evaluated the immunogenicity and protective efficacy in rabbits of multiple antigenic peptides (MAPs) consisting of aa 304-319 from the LND of PA colinearly synthesized at the C terminus (T-B MAP) or N terminus (B-T MAP) with a heterologous T cell epitope from Plasmodium falciparum. Immunogenicity studies demonstrated that both MAPs elicited toxin-neutralizing Ab in rabbits. To evaluate the MAPs as potential anthrax vaccines, we immunized groups of rabbits (n = 7) with each MAP in Freund's adjuvant and then exposed all rabbits to a 200-LD(50) challenge with aerosolized spores of B. anthracis Ames strain. All seven rabbits immunized with the B-T MAP and 89% (six of seven) of rabbits immunized with the T-B MAP survived the spore challenge. Corollary studies with reference sera from human vaccinees immunized with rPA or anthrax vaccine absorbed and nonhuman primates immunized with PA revealed no detectable Ab with specificity for the LND. We conclude that a synthetic peptide vaccine targeting the LND would be a potentially efficacious vaccine for anthrax. PMID:20696862

  10. QSRR analysis of β-lactam antibiotics on a penicillin G targeted MIP stationary phase.

    PubMed

    Kempe, Henrik; Kempe, Maria

    2010-12-01

    The imprinting factors of the β-lactam antibiotics penicillin V, methicillin, nafcillin, oxacillin, cloxacillin, dicloxacillin, and piperacillin on a poly(methacrylic acid-co-trimethylolpropane trimethacrylate) molecularly imprinted stationary phase targeted for penicillin G were correlated with molecular descriptors obtained by molecular computation. One-parameter linear regression and multivariate data analysis by principal component analysis and partial least square regression indicated that descriptors associated with molecular topology, shape, size, and volume were highly correlated with the imprinting factor and influential on the derived models. PMID:20936264

  11. Immobilization of penicillin acylase on copolymer of butyl acrylate and ethylene glycol dimethacrylate.

    PubMed

    Bryjak, J; Noworyta, A

    1993-01-01

    The effects of glutaraldehyde, enzyme concentrations and reactants volumes, ionic strength, pH value and carrier particle diameter on immobilization of penicillin acylase onto acrylic carriers were studied. The activity of immobilized enzyme preparations was also studied over a range of pH values and temperatures and thermal and pH stabilities were determined. The use of the immobilized preparation for penicillin G hydrolysis in a batch reactor was investigated. The immobilized enzyme gave a significant reduction in hydrolysis time compared to hydrolysis by the native enzyme. PMID:7763686

  12. Burkholderia cepacia endophthalmitis, in a penicillin allergic patient, following a ranibizumab injection.

    PubMed

    Saffra, Norman; Moriarty, Emily

    2014-01-01

    Burkholderia cepacia, a Gram-negative bacterium commonly found in water and soil, is a rare cause of endophthalmitis. The authors report a case of a penicillin-allergic patient who presented 15 days after an uneventful injection of ranibizumab for neovascular age-related macular degeneration with culture-positive B cepacia endophthalmitis. Initial antibiotic therapy using non-penicillin-based medications was not successful in eradicating the bacteria. Subsequent treatment with a third-generation cephalosporin resulted in complete resolution of the infection. B cepacia should be included among the bacterial species that may cause endophthalmitis after intravitreal injections. PMID:24526197

  13. Large-scale outbreak of infection with Mycobacterium chelonae subsp. abscessus after penicillin injection.

    PubMed

    Zhibang, Yang; BiXia, Zhang; Qishan, Lu; Lihao, Chen; Xiangquan, Liu; Huaping, Li

    2002-07-01

    An outbreak of infection with Mycobacterium chelonae subsp. abscessus after the injection of penicillin in 86 patients attending a factory hospital is reported. The bacterium was isolated both from lids and from the soil where the drug was stored. Molecular analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins and plasmids revealed a pattern identical to that of the strains isolated from the wounds. The source of the infections was soil contamination of the vial lids and was caused by improper use and sterilization of penicillin vials. PMID:12089291

  14. One-Electron Reduction of Penicillins in Relation to the Oxidative Stress Phenomenon

    PubMed Central

    Szabó, László; Tóth, Tünde; Takács, Erzsébet; Wojnárovits, László

    2015-01-01

    Certain bactericidal antibiotics target mitochondrial components and, due to the leakage of electrons from the electron transport chain, one-electron reduction might occur that can lead to intermediates passing the electron to suitable acceptors. This study aimed at investigating the one-electron reduction mechanism of selected penicillin derivatives using pulse radiolysis techniques. Penicillins can accommodate the electron on each of their carbonyl carbon. Ketyl radicals are thus produced, which are reducing agents with possibility to interact with suitable biomolecules. A detailed mechanism of the reduction is reported. PMID:26690427

  15. Prophylactic Antibiotic Management of Surgical Patients Noted as "Allergic" to Penicillin at Two Academic Hospitals.

    PubMed

    Epstein, Richard H; Jacques, Paul St; Wanderer, Jonathan P; Bombulie, Mark R; Agarwalla, Niraj

    2016-05-01

    We studied prophylactic antibiotics administered at 2 academic medical centers during a 6-year period where a cephalosporin was indicated but an "allergy" to penicillin was noted. Another drug (typically vancomycin or clindamycin) was substituted approximately 80% of the time; this occurred frequently even when symptoms unrelated to acute hypersensitivity were listed. In >50% of cases, the reaction was either omitted or vague (e.g., simply "rash"). Given the estimated 1% cross-reactivity between penicillins and cephalosporins with similar R1 side chains, many of these patients could have received either the prescribed cephalosporin or another cephalosporin with a different R1 side chain. PMID:26556109

  16. 76 FR 14024 - Draft Guidance for Industry on Non-Penicillin Beta-Lactam Risk Assessment: A CGMP Framework...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-15

    ... guidance describes the importance of implementing appropriate steps during the manufacturing process to... manufacturing process to prevent cross-contamination of finished pharmaceuticals and APIs with non-penicillin... critical aspect of manufacturing non-penicillin beta-lactam drugs is preventing cross-contamination...

  17. Peptide nanostructures in biomedical technology.

    PubMed

    Feyzizarnagh, Hamid; Yoon, Do-Young; Goltz, Mark; Kim, Dong-Shik

    2016-09-01

    Nanostructures of peptides have been investigated for biomedical applications due to their unique mechanical and electrical properties in addition to their excellent biocompatibility. Peptides may form fibrils, spheres and tubes in nanoscale depending on the formation conditions. These peptide nanostructures can be used in electrical, medical, dental, and environmental applications. Applications of these nanostructures include, but are not limited to, electronic devices, biosensing, medical imaging and diagnosis, drug delivery, tissue engineering and stem cell research. This review offers a discussion of basic synthesis methods, properties and application of these nanomaterials. The review concludes with recommendations and future directions for peptide nanostructures. WIREs Nanomed Nanobiotechnol 2016, 8:730-743. doi: 10.1002/wnan.1393 For further resources related to this article, please visit the WIREs website. PMID:26846352

  18. A microplate assay for the coupled transglycosylase-transpeptidase activity of the penicillin binding proteins; a vancomycin-neutralizing tripeptide combination prevents penicillin inhibition of peptidoglycan synthesis.

    PubMed

    Kumar, Vidya P; Basavannacharya, Chandrakala; de Sousa, Sunita M

    2014-07-18

    A microplate, scintillation proximity assay to measure the coupled transglycosylase-transpeptidase activity of the penicillin binding proteins in Escherichia coli membranes was developed. Membranes were incubated with the two peptidoglycan sugar precursors UDP-N-acetyl muramylpentapeptide (UDP-MurNAc(pp)) and UDP-[(3)H]N-acetylglucosamine in the presence of 40 μM vancomycin to allow in situ accumulation of lipid II. In a second step, vancomycin inhibition was relieved by addition of a tripeptide (Lys-D-ala-D-ala) or UDP-MurNAc(pp), resulting in conversion of lipid II to cross-linked peptidoglycan. Inhibitors of the transglycosylase or transpeptidase were added at step 2. Moenomycin, a transglycosylase inhibitor, had an IC50 of 8 nM. Vancomycin and nisin also inhibited the assay. Surprisingly, the transpeptidase inhibitors penicillin and ampicillin showed no inhibition. In a pathway assay of peptidoglycan synthesis, starting from the UDP linked sugar precursors, inhibition by penicillin was reversed by a 'neutral' combination of vancomycin plus tripeptide, suggesting an interaction thus far unreported. PMID:24944023

  19. Long-term effects of penicillin resistance and fitness cost on pneumococcal transmission dynamics in a developed setting

    PubMed Central

    Tilevik, Diana

    2016-01-01

    Background The increasing prevalence of penicillin non-susceptible pneumococci (PNSP) throughout the world threatens successful treatment of infections caused by this important bacterial pathogen. The rate at which PNSP clones spread in the community is thought to mainly be determined by two key determinants; the volume of penicillin use and the magnitude of the fitness cost in the absence of treatment. The aim of the study was to determine the impacts of penicillin consumption and fitness cost on pneumococcal transmission dynamics in a developed country setting. Methods An individual-based network model based on real-life demographic data was constructed and applied in a developed country setting (Sweden). A population structure with transmission of carriage taking place within relevant mixing groups, i.e. families, day care groups, school classes, and other close contacts, was considered to properly assess the transmission dynamics for susceptible and PNSP clones. Several scenarios were simulated and model outcomes were statistically analysed. Results Model simulations predicted that with an outpatient penicillin use corresponding to the sales in Sweden 2010 (118 recipes per 1,000 inhabitants per year), the magnitude of a fitness cost for resistance must be at least 5% to offset the advantage of penicillin resistance. Moreover, even if there is a fitness cost associated with penicillin resistance, a considerable reduction of penicillin usage appears to be required to significantly decrease the incidence of PNSP in a community. Conclusion The frequency of PNSP clones is hard to reverse by simply reducing the penicillin consumption even if there is a biological cost associated with resistance. However, because penicillin usage does promote further spread of PNSP clones, it is important to keep down penicillin consumption considering future resistance problems. PMID:27206408

  20. Enhanced pharmacological activity of Vitamin B12 and Penicillin as nanoparticles

    PubMed Central

    Yariv, Inbar; Lipovsky, Anat; Gedanken, Aharon; Lubart, Rachel; Fixler, Dror

    2015-01-01

    Sonochemistry has become a well-known technique for fabricating nanomaterials. Since one of the advantages of nanomaterials is that they have higher chemical activities compared with particles in the bulk form, efforts are being made to produce nano organic compounds with enhanced biological activities that could be exploited in the medical area. This study uses the sonication technique to prepare nano Vitamin B12 and nano Penicillin, and demonstrates their enhanced biological and pharmacological activity. The size and morphology of the nano Penicillin and nano Vitamin B12 were investigated using electron microscopy as well as dynamic light scattering techniques. The sizes of Penicillin and Vitamin B12 nanoparticles (NPs) were found to be 70 and 120–180 nm, respectively. The bactericidal effect of nano Penicillin was studied and found to be higher than that of the bulk form. Reducing the size of Vitamin B12 resulted in their enhanced antioxidative activity as observed using the electron paramagnetic spectroscopy technique. The penetration depth of these organic NPs can be detected by an optical iterative method. It is believed that nano organic drugs fabrication will have a great impact on the medical field. PMID:26028970

  1. Penicillin V acylase from Pectobacterium atrosepticum exhibits high specific activity and unique kinetics.

    PubMed

    Avinash, V S; Ramasamy, Sureshkumar; Suresh, C G; Pundle, Archana

    2015-08-01

    Penicillin V acylases (PVAs, E.C.3.5.11) belong to the Ntn hydrolase super family of enzymes that catalyze the deacylation of the side chain from phenoxymethyl penicillin (penicillin V). Penicillin acylases find use in the pharmaceutical industry for the production of semi-synthetic antibiotics. PVAs employ the N-terminal cysteine residue as catalytic nucleophile and are structurally and evolutionarily related to bile salt hydrolases (BSHs). Here, we report the cloning and characterization of a PVA enzyme from the Gram-negative plant pathogen, Pectobacterium atrosepticum (PaPVA). The enzyme was cloned and expressed in Escherichia coli attaining a very high yield (250 mg/l) and a comparatively high specific activity (430 IU/mg). The enzyme showed marginally better pH and thermo-stability over PVAs characterized from Gram-positive bacteria. The enzyme also showed enhanced activity in presence of organic solvents and detergents. The enzyme kinetics turned out to be significantly different from that of previously reported PVAs, displaying positive cooperativity and substrate inhibition. The presence of bile salts had a modulating effect on PaPVA activity. Sequence analysis and characterization reveal the distinctive nature of these enzymes and underscore the need to study PVAs from Gram-negative bacteria. PMID:25931393

  2. Distribution of Penicillin G Residues in Culled Dairy Cow Muscles: Implications for Residue Monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The U.S. Food and Drug Administration sets tolerances for veterinary drug residues in muscle, but does not specify which type of muscle should be analyzed. In order to determine if antibiotic residue levels are dependent on muscle type, 7 culled dairy cows were dosed with Penicillin G (Pen G) from ...

  3. Depletion of penicillin G residues in heavy sows after intramuscular injection. Part I: Tissue residue depletion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heavy sows (n=126) were treated with penicillin G procaine at a 5x label dose (33,000 IU/kg) for 3 consecutive days by intramuscular (IM) injection using 3 separate patterns (treatments) of drug administration (42 sows per treatment). Treatments differed by pattern and maximum injection volume per s...

  4. From Petroleum to Penicillin. The First Hundred Years of Modern Chemical Engineering: 1859-1959.

    ERIC Educational Resources Information Center

    Burnett, J. N.

    1986-01-01

    Presents a description of the course "From Petroleum to Penicillin" which examines chemical engineering and the chemical industry from a scientific, social and symbolic view. Explains the goals, organization, and requirements of the course. Lists case study and lecture topics. (ML)

  5. [Standardization of the Neisseria meningitidis antibiogram. Detection of strains relatively resistant to penicillin].

    PubMed

    Nicolas, P; Cavallo, J D; Fabre, R; Martet, G

    1998-01-01

    Studying the susceptibility of 189 Neisseria meningitidis strains to penicillin, amoxicillin, cefotaxime, ceftriaxone, chloramphenicol and rifampicin by determination of minimum inhibitory concentrations (MICs) by agar dilution (reference method), E-test and disc diffusion method on Mueller-Hinton agar at 37 degrees C with 5% CO2 enabled us to standardize the antibiograms. While MIC determination by agar dilution is still the reference method, it is possible to obtain exact or approximate MIC values using the E-test. For laboratories that cannot determine penicillin MICs, it is impossible to detect strains that are relatively resistant to penicillin (RRP strains: 0.1 < or = MIC < or = 1 mg/l) using a 10-U penicillin disc. A 1 microgram-oxacillin disc allows MIC to be determined in most cases when the oxacillin inhibition zone is < or = 10 mm. Such strains must be sent to a reference laboratory for exact MIC determination. Based on our results and literature data on pharmacokinetics, we propose critical concentrations for these various antibiotics as well as critical diameters for chloramphenicol and rifampicin discs. PMID:9803590

  6. Yeast HXK2 gene reverts glucose regulation mutation of penicillin biosynthesis in P. chrysogenum

    PubMed Central

    Pérez, Edmundo A.; Fernández, Francisco J.; Fierro, Francisco; Mejía, Armando; Marcos, Ana T.; Martín, Juan F.; Barrios-González, Javier

    2014-01-01

    The mutant Penicillium chrysogenum strain dogR5, derived from strain AS-P-78, does not respond to glucose regulation of penicillin biosynthesis and β-galactosidase, and is partially deficient in D-glucose phosphorilating activity. We have transformed strain dogR5 with the (hexokinase) hxk2 gene from Saccharomyces cerevisiae. Transformants recovered glucose control of penicillin biosynthesis in different degrees, and acquired a hexokinase (fructose phosphorylating) activity absent in strains AS- P-78 and dogR5. Interestingly, they also recovered glucose regulation of β-galactosidase. On the other hand, glucokinase activity was affected in different ways in the transformants; one of which showed a lower activity than the parental dogR5, but normal glucose regulation of penicillin biosynthesis. Our results show that Penicillium chrysogenum AS-P-78 and dogR5 strains lack hexokinase, and suggest that an enzyme with glucokinase activity is involved in glucose regulation of penicillin biosynthesis and β-galactosidase, thus signaling glucose in both primary and secondary metabolism; however, catalytic and signaling activities seem to be independent. PMID:25477921

  7. Yeast HXK2 gene reverts glucose regulation mutation of penicillin biosynthesis in P. chrysogenum.

    PubMed

    Pérez, Edmundo A; Fernández, Francisco J; Fierro, Francisco; Mejía, Armando; Marcos, Ana T; Martín, Juan F; Barrios-González, Javier

    2014-01-01

    The mutant Penicillium chrysogenum strain dogR5, derived from strain AS-P-78, does not respond to glucose regulation of penicillin biosynthesis and β-galactosidase, and is partially deficient in D-glucose phosphorilating activity. We have transformed strain dogR5 with the (hexokinase) hxk2 gene from Saccharomyces cerevisiae. Transformants recovered glucose control of penicillin biosynthesis in different degrees, and acquired a hexokinase (fructose phosphorylating) activity absent in strains AS- P-78 and dogR5. Interestingly, they also recovered glucose regulation of β-galactosidase. On the other hand, glucokinase activity was affected in different ways in the transformants; one of which showed a lower activity than the parental dogR5, but normal glucose regulation of penicillin biosynthesis. Our results show that Penicillium chrysogenum AS-P-78 and dogR5 strains lack hexokinase, and suggest that an enzyme with glucokinase activity is involved in glucose regulation of penicillin biosynthesis and β-galactosidase, thus signaling glucose in both primary and secondary metabolism; however, catalytic and signaling activities seem to be independent. PMID:25477921

  8. Determination of Penicillin Using an Immobilized Enzyme Electrode: An Undergraduate Experiment.

    ERIC Educational Resources Information Center

    Mifflin, Theodore E.; And Others

    1984-01-01

    Background information, procedures, and results are provided for an experiment in which students: (1) construct an immobilized penicillinase electrode; (2) evaluate electron response as a function of penicillin concentration; and (3) study effects of solvent compositions, ionic strength, and equilibrium time upon electrode response. (JN)

  9. Safety of Benzathine Penicillin for Preventing Congenital Syphilis: A Systematic Review

    PubMed Central

    Galvao, Tais F.; Silva, Marcus T.; Serruya, Suzanne J.; Newman, Lori M.; Klausner, Jeffrey D.; Pereira, Mauricio G.; Fescina, Ricardo

    2013-01-01

    Objective To estimate the risk of serious adverse reactions to benzathine penicillin in pregnant women for preventing congenital syphilis. Methods We searched for clinical trials or cohorts that assessed the incidence of serious adverse reactions to benzathine penicillin in pregnant women and the general population (indirect evidence). MEDLINE, EMBASE, Scopus and other databases were searched up to December 2012. The GRADE approach was used to assess quality of evidence. Absolute risks of each study were calculated along with their 95% confidence intervals (95% CI). We employed the DerSimonian and Laird random effects model in the meta-analyses. Results From 2,765 retrieved studies we included 13, representing 3,466,780 patients. The studies that included pregnant women were conducted to demonstrate the effectiveness of benzathine penicillin: no serious adverse reactions were reported among the 1,244 pregnant women included. In the general population, among 2,028,982 patients treated, 4 died from an adverse reaction. The pooled risk of death was virtually zero. Fifty-four cases of anaphylaxis were reported (pooled absolute risk = 0.002%; 95% CI: 0%–0.003% I2 = 12%). From that estimate, penicillin treatment would be expected to result in an incidence of 0 to 3 cases of anaphylaxis per 100,000 treated. Any adverse reactions were reported in 6,377 patients among 3,465,322 treated with penicillin (pooled absolute risk = 0.169%; 95% CI: 0.073%–0.265% I2 = 97%). The quality of evidence was very low. Conclusion Studies that assessed the risk of serious adverse events due to benzathine penicillin treatment in pregnant women were scarce, but no reports of adverse reactions were found. The incidence of severe adverse outcomes was very low in the general population. The risk of treating pregnant women with benzathine penicillin to prevent congenital syphilis appears very low and does not outweigh its benefits. Further research is needed to improve the

  10. Stability of peptide drugs in the colon.

    PubMed

    Wang, Jie; Yadav, Vipul; Smart, Alice L; Tajiri, Shinichiro; Basit, Abdul W

    2015-10-12

    This study was the first to investigate the colonic stability of 17 peptide molecules (insulin, calcitonin, glucagon, secretin, somatostatin, desmopressin, oxytocin, Arg-vasopressin, octreotide, ciclosporin, leuprolide, nafarelin, buserelin, histrelin, [D-Ser(4)]-gonadorelin, deslorelin, and goserelin) in a model of the large intestine using mixed human faecal bacteria. Of these, the larger peptides - insulin, calcitonin, somatostatin, glucagon and secretin - were metabolized rapidly, with complete degradation observed within 5 min. In contrast, a number of the smaller peptides - Arg-vasopressin, desmopressin, oxytocin, gonadorelin, goserelin, buserelin, leuprolide, nafarelin and deslorelin - degraded more slowly, while octreotide, histrelin and ciclosporin were seen to be more stable as compared to the other small peptides under the same conditions. Peptide degradation rate was directly correlated to peptide lipophilicity (logP); those peptides with a higher logP were more stable in the colonic model (R(2)=0.94). In the absence of human faecal bacteria, all peptides were stable. This study highlights the impact of the colonic environment - in particular, the gut microbiota - on the metabolism of peptide drugs, and identifies potential peptide candidates for drug delivery to the colon. PMID:26111980

  11. Novel Penicillin Analogues as Potential Antimicrobial Agents; Design, Synthesis and Docking Studies

    PubMed Central

    Ashraf, Zaman; Bais, Abdul; Manir, Md. Maniruzzaman; Niazi, Umar

    2015-01-01

    A number of penicillin derivatives (4a-h) were synthesized by the condensation of 6-amino penicillinic acid (6-APA) with non-steroidal anti-inflammatory drugs as antimicrobial agents. In silico docking study of these analogues was performed against Penicillin Binding Protein (PDBID 1CEF) using AutoDock Tools 1.5.6 in order to investigate the antimicrobial data on structural basis. Penicillin binding proteins function as either transpeptidases or carboxypeptidases and in few cases demonstrate transglycosylase activity in bacteria. The excellent antibacterial potential was depicted by compounds 4c and 4e against Escherichia coli, Staphylococcus epidermidus and Staphylococcus aureus compared to the standard amoxicillin. The most potent penicillin derivative 4e exhibited same activity as standard amoxicillin against S. aureus. In the enzyme inhibitory assay the compound 4e inhibited E. coli MurC with an IC50 value of 12.5 μM. The docking scores of these compounds 4c and 4e also verified their greater antibacterial potential. The results verified the importance of side chain functionalities along with the presence of central penam nucleus. The binding affinities calculated from docking results expressed in the form of binding energies ranges from -7.8 to -9.2kcal/mol. The carboxylic group of penam nucleus in all these compounds is responsible for strong binding with receptor protein with the bond length ranges from 3.4 to 4.4 Ǻ. The results of present work ratify that derivatives 4c and 4e may serve as a structural template for the design and development of potent antimicrobial agents. PMID:26267242

  12. Fan-shaped ejections of regularly arranged murosomes involved in penicillin-induced death of staphylococci.

    PubMed Central

    Giesbrecht, P; Kersten, T; Wecke, J

    1992-01-01

    Electron microscopic research into the murosomes of staphylococci has shown that the number of murosomes involved in penicillin-induced death varies depending on the experimental conditions employed. With 0.1 micrograms of penicillin G per ml, only 1 of a total of about 20 murosomes, the "killing murosome," completely perforated the pressure-stabilized peripheral cell wall during a three-step process. This strictly localized event was mainly attributed to a mechanical effect being comparable to the process of aneurysm formation. Wall perforation was also considered to mark the very moment of penicillin-induced death ("nonlytic killing event"), while bacteriolysis started only postmortem. By varying the osmolarity of the growth medium, the number of murosomes involved in penicillin-induced killing increased considerably, which resulted in the ejection of a fan-shaped row of murosomes at the second division plane. These data are compatible with the finding that, in untreated or chloramphenicol-treated staphylococci, the activation of the murosomes resulted in (i) the formation of regularly arranged "blebs" on the cell surface, containing traces of disintegrated wall material, and (ii) the subsequent liberation of the murosomes lying underneath, leaving behind their former sites in the peripheral wall as a row of regularly arranged "pores" in every division plane. The number, distribution, and positioning of these blebs corresponded with those of the pores and the original murosomes. The significance of wall autolysins liberated from the first division plane for penicillin-induced wall perforation at the second division plane is discussed. Images PMID:1551845

  13. Decrease in penicillin susceptibility due to heat shock protein ClpL in Streptococcus pneumoniae.

    PubMed

    Tran, Thao Dang-Hien; Kwon, Hyog-Young; Kim, Eun-Hye; Kim, Ki-Woo; Briles, David E; Pyo, Suhkneung; Rhee, Dong-Kwon

    2011-06-01

    Antibiotic resistance and tolerance are increasing threats to global health as antibiotic-resistant bacteria can cause severe morbidity and mortality and can increase treatment cost 10-fold. Although several genes contributing to antibiotic tolerance among pneumococci have been identified, we report here that ClpL, a major heat shock protein, could modulate cell wall biosynthetic enzymes and lead to decreased penicillin susceptibility. On capsular type 1, 2, and 19 genetic backgrounds, mutants lacking ClpL were more susceptible to penicillin and had thinner cell walls than the parental strains, whereas a ClpL-overexpressing strain showed a higher resistance to penicillin and a thicker cell wall. Although exposure of Streptococcus pneumoniae D39 to penicillin inhibited expression of the major cell wall synthesis gene pbp2x, heat shock induced a ClpL-dependent increase in the mRNA levels and protein synthesized by pbp2x. Inducible ClpL expression correlated with PBP2x expression and penicillin susceptibility. Fractionation and electron micrograph data revealed that ClpL induced by heat shock is localized at the cell wall, and the ΔclpL showed significantly reduced net translocation of PBP2x into the cell wall. Moreover, coimmunoprecipitation with either ClpL or PBP2x antibody followed by reprobing with ClpL or PBP2x antibody showed an interaction between ClpL and PBP2x after heat stress. This interaction was confirmed by His tag pulldown assay with either ClpLHis₆ or PBP2xHis₆. Thus, ClpL stabilized pbp2x expression, interacted with PBP2x, and facilitated translocation of PBP2x, a key protein of cell wall synthesis process, contributing to the decrease of antibiotic susceptibility in S. pneumoniae. PMID:21422206

  14. Sequential and competitive adsorption of peptides at pendant PEO layers.

    PubMed

    Wu, Xiangming; Ryder, Matthew P; McGuire, Joseph; Snider, Joshua L; Schilke, Karl F

    2015-06-01

    Earlier work provided direction for development of responsive drug delivery systems based on modulation of the structure, amphiphilicity, and surface density of bioactive peptides entrapped within pendant polyethylene oxide (PEO) brush layers. In this work, we describe the sequential and competitive adsorption behavior of such peptides at pendant PEO layers. Three cationic peptides were used for this purpose: the arginine-rich, amphiphilic peptide WLBU2, a peptide chemically identical to WLBU2 but of scrambled sequence (S-WLBU2), and the non-amphiphilic peptide poly-L-arginine (PLR). Optical waveguide lightmode spectroscopy (OWLS) was used to quantify the rate and extent of peptide adsorption and elution at surfaces coated with PEO. UV spectroscopy and time-of-flight secondary ion mass spectrometry (TOF-SIMS) were used to quantify the extent of peptide exchange during the course of sequential and competitive adsorption. Circular dichroism (CD) was used to evaluate conformational changes after adsorption of peptide mixtures at PEO-coated silica nanoparticles. Results indicated that amphiphilic peptides are able to displace adsorbed, non-amphiphilic peptides in PEO layers, while non-amphiphilic peptides were not able to displace more amphiphilic peptides. In addition, peptides of greater amphiphilicity dominated the adsorption at the PEO layer from mixtures with less amphiphilic or non-amphiphilic peptides. PMID:25909181

  15. Unusual conformation of the SxN motif in the crystal structure of penicillin-binding protein A from Mycobacterium tuberculosis.

    SciTech Connect

    Fedarovich, Alena; Nicholas, Robert A.; Davies, Christopher

    2010-07-19

    PBPA from Mycobacterium tuberculosis is a class B-like penicillin-binding protein (PBP) that is not essential for cell growth in M. tuberculosis, but is important for proper cell division in Mycobacterium smegmatis. We have determined the crystal structure of PBPA at 2.05 {angstrom} resolution, the first published structure of a PBP from this important pathogen. Compared to other PBPs, PBPA has a relatively small N-terminal domain, and conservation of a cluster of charged residues within this domain suggests that PBPA is more related to class B PBPs than previously inferred from sequence analysis. The C-terminal domain is a typical transpeptidase fold and contains the three conserved active-site motifs characterisitic of penicillin-interacting enzymes. While the arrangement of the SxxK and KTG motifs is similar to that observed in other PBPs, the SxN motif is markedly displaced away from the active site, such that its serine (Ser281) is not involved in hydrogen bonding with residues of the other two motifs. A disulfide bridge between Cys282 (the 'x' of the SxN motif) and Cys266, which resides on an adjacent loop, may be responsible for this unusual conformation. Another interesting feature of the structure is a relatively long connection between {beta}5 and {alpha}11, which restricts the space available in the active site of PBPA and suggests that conformational changes would be required to accommodate peptide substrate or {beta}-lactam antibiotics during acylation. Finally, the structure shows that one of the two threonines postulated to be targets for phosphorylation is inaccessible (Thr362), whereas the other (Thr437) is well placed on a surface loop near the active site.

  16. Surface-associated material from the bacterium Actinobacillus actinomycetemcomitans contains a peptide which, in contrast to lipopolysaccharide, directly stimulates fibroblast interleukin-6 gene transcription.

    PubMed

    Reddi, K; Nair, S P; White, P A; Hodges, S; Tabona, P; Meghji, S; Poole, S; Wilson, M; Henderson, B

    1996-03-15

    -exchange, reverse-phase and size-exclusion HPLC. The active moiety is a peptide of molecular mass 2kDa which may be the product of a bacterial short open reading frame. PMID:8665908

  17. Antimicrobial Activity of Penicillin G and N-acetylcystein on Planktonic and Sessile Cells of Streptococcus suis.

    PubMed

    Espinosa, Ivette; Báez, Michel; Lobo, Evelyn; Martínez, Siomara; Gottschalk, Marcelo

    2016-01-01

    The aim of this study was to investigate the capacity of Streptococcus suis strains to form biofilms and to evaluate the antimicrobial activity of Penicillin G and N-acetylcystein (NAC) on both S. suis sessile and planktonic forms. Only non-typeable isolates of S. suis were correlated with a greater biofilm formation capacity. The MCI of Penicillin G and NAC required for inhibiting biofilm growth were higher than the required concentration for inhibiting planktonic growth. The combinations of NAC and Penicillin G showed a strong synergistic activity that inhibited biofilm formation and disrupted the pre-formed biofilm of S. suis. PMID:27282001

  18. Penicillin G extraction from model media using an emulsion liquid membrane: a theoretical model of product decomposition.

    PubMed

    Lee, K H; Lee, S C; Lee, W K

    1994-04-01

    To confirm the applicability for the extraction of penicillin G by an emulsion liquid membrane (ELM), the degree of decomposition of penicillin G during extraction was theoretically calculated. Decomposition was less than 1% provided that the initial sodium carbonate concentration in the internal phase was correctly determined, which proved the applicability of the ELM process. The procedure to determine the initial carbonate concentration in the internal phase was also described in order that the pH in the internal phase should be within the relatively stable range for penicillin G at the end of the extraction. PMID:7764816

  19. Selection of resistant Streptococcus pneumoniae during penicillin treatment in vitro and in three animal models.

    PubMed

    Knudsen, Jenny Dahl; Odenholt, Inga; Erlendsdottir, Helga; Gottfredsson, Magnus; Cars, Otto; Frimodt-Møller, Niels; Espersen, Frank; Kristinsson, Karl G; Gudmundsson, Sigurdur

    2003-08-01

    Pharmacokinetic (PK) and pharmacodynamic (PD) properties for the selection of resistant pneumococci were studied by using three strains of the same serotype (6B) for mixed-culture infection in time-kill experiments in vitro and in three different animal models, the mouse peritonitis, the mouse thigh, and the rabbit tissue cage models. Treatment regimens with penicillin were designed to give a wide range of T(>MIC)s, the amounts of time for which the drug concentrations in serum were above the MIC. The mixed culture of the three pneumococcal strains, 10(7) CFU of strain A (MIC of penicillin, 0.016 micro g/ml; erythromycin resistant)/ml, 10(6) CFU of strain B (MIC of penicillin, 0.25 micro g/ml)/ml, and 10(5) CFU of strain C (MIC of penicillin, 4 micro g/ml)/ml, was used in the two mouse models, and a mixture of 10(5) CFU of strain A/ml, 10(4) CFU of strain B/ml, and 10(3) CFU of strain C/ml was used in the rabbit tissue cage model. During the different treatment regimens, the differences in numbers of CFU between treated and control animals were calculated to measure the efficacies of the regimens. Selective media with erythromycin or different penicillin concentrations were used to quantify the strains separately. The efficacies of penicillin in vitro were similar when individual strains or mixed cultures were studied. The eradication of the bacteria, independent of the susceptibility of the strain or strains or the presence of the strains in a mixture or on their own, followed the well-known PK and PD rules for treatment with beta-lactams: a maximum efficacy was seen when the T(>MIC) was >40 to 50% of the observation time and the ratio of the maximum concentration of the drug in serum to the MIC was >10. It was possible in all three models to select for the less-susceptible strains by using insufficient treatments. In the rabbit tissue cage model, a regrowth of pneumococci was observed; in the mouse thigh model, the ratio between the different strains changed in

  20. Antiviral active peptide from oyster

    NASA Astrophysics Data System (ADS)

    Zeng, Mingyong; Cui, Wenxuan; Zhao, Yuanhui; Liu, Zunying; Dong, Shiyuan; Guo, Yao

    2008-08-01

    An active peptide against herpes virus was isolated from the enzymic hydrolysate of oyster ( Crassostrea gigas) and purified with the definite direction hydrolysis technique in the order of alcalase and bromelin. The hydrolysate was fractioned into four ranges of molecular weight (>10 kDa, 10 5 kDa, 5 1 kDa and <1 kDa) using ultrafiltration membranes and dialysis. The fraction of 10 5 kDa was purified using consecutive chromatographic methods including DEAE Sephadex A-25 column, Sephadex G-25 column, and high performance liquid chromatogram (HPLC) by activity-guided isolation. The antiviral effect of the obtained peptide on herpetic virus was investigated in Vero cells by observing cytopathic effect (CPE). The result shows that the peptide has high inhibitory activity on herpetic virus.

  1. Susceptibility to Polymyxin B of Penicillin G-induced Proteus mirabilis L Forms and Spheroplasts

    PubMed Central

    Teuber, Michael

    1969-01-01

    A polymyxin B-resistant strain of Proteus mirabilis was converted into L forms and spheroplasts in the presence of penicillin G. This treatment caused a 400-fold increase in polymyxin B susceptibility. The acquired susceptibility was in the range of the natural susceptibility reported for susceptible gram-negative bacteria (∼1 μg/ml). The high susceptibility to polymyxin B was lost as soon as the spheroplasts and L forms were allowed to reconvert into the bacillary form in penicillin-free media. This behavior is strong evidence that the natural resistance of Proteus strains to polymyxins is due to the impermeability of the outer cell wall structures to these antibiotic substances. PMID:4306537

  2. [Modelling a penicillin fed-batch fermentation using least squares support vector machines].

    PubMed

    Liu, Yi; Wang, Hai-Qing

    2006-01-01

    The biochemical processes are usually characterized as seriously time varying and nonlinear dynamic systems. Building their first-principle models are very costly and difficult due to the absence of inherent mechanism and efficient on-line sensors. Furthermore, these detailed and complicated models do not necessary guarantee a good performance in practice. An approach via least squares support vector machines (LS-SVM) based on Pensim simulator is proposed for modelling the penicillin fed-batch fermentation process, and the adjustment strategy for parameters of LS-SVM is presented. Based on the proposed modelling method, the predictive models of penicillin concentration, biomass concentration and substrate concentration are obtained by using very limited on-line measurements. The results show that the models established are more accurate and efficient, and suffice for the requirements of control and optimization for biochemical processes. PMID:16572855

  3. Recurrent cellulitis with benzathine penicillin prophylaxis is associated with diabetes and psoriasis.

    PubMed

    Karppelin, M; Siljander, T; Huhtala, H; Aromaa, A; Vuopio, J; Hannula-Jouppi, K; Kere, J; Syrjänen, J

    2013-03-01

    Risk factors for recurrent cellulitis were assessed in a case-control study including 398 patients receiving prophylactic treatment with benzathine penicillin and 8,005 controls derived from a national population-based health survey. In the multivariate analysis, psoriasis [odds ratio (OR) 3.69], other chronic dermatoses (OR 4.14), diabetes (OR 1.65), increasing body mass index (OR 1.17), increasing age (OR 1.06) and history of previous tonsillectomy (OR 6.82) were independently associated with recurrent cellulitis. Forty percent of the patients reported a cellulitis recurrence, despite ongoing benzathine penicillin prophylaxis. The role of previous tonsillectomy in recurrent cellulitis needs further evaluation. PMID:23007460

  4. Group A beta-hemolytic streptococcal bacteremia in a patient with sickle cell anemia on penicillin prophylaxis.

    PubMed Central

    LeBlanc, W.; Salah, H.; Khakoo, Y.

    1995-01-01

    Serious invasive bacterial infections, particularly those due to Streptococcus pneumoniae and Hemophilus influenzae, are a well-known complication in patients with sickle cell disease. Early penicillin prophylaxis has been shown to prevent these infections and also to improve survival. This article describes a child with sickle cell anemia who, while on penicillin prophylaxis, developed a group A streptococcal bacteremia, a pathogen not commonly associated with bacteremia in sickle cell disease. PMID:7783241

  5. Production, Extraction, and Qualitative Testing of Penicillin: A Biochemistry Experiment for Health Science Chemistry Courses

    NASA Astrophysics Data System (ADS)

    Stevens, Richard E.; Billingsley, Kara C.

    1998-10-01

    This laboratory procedure guides students through the growth of a submerged Penicillium chrysogenum culture. Subsequent steps include extraction of the penicillin by adsorption onto activated charcoal, extraction with acetone, and qualitative testing of the drug on a bacterial culture. The laboratory procedure is designed for freshman-level health science chemistry courses. This procedure produces minimal waste, which can be disposed of by the appropriate use of an autoclave.

  6. Kinetics and residues after intraperitoneal procaine penicillin G administration in lactating dairy cows.

    PubMed

    Chicoine, A L; Boison, J O; Parker, S; Clark, C; Dowling, P M

    2009-06-01

    This paper describes the pharmacokinetic profile of procaine penicillin G after intraperitoneal (IP) administration in eight lactating dairy cows. Procaine pencillin G (PPG, 21 000 IU/kg) was deposited into the abdominal cavity of each cow following an incision in the right paralumbar fossa. Blood and milk samples were taken over the following 10 days, at which point the cows were euthanized. Plasma, milk, muscle, liver, and kidney penicillin concentrations were determined by HPLC, with a limit of quantification of 5 ng/mL for plasma and milk and 40 ng/g for tissue samples. A noncompartmental method was used to analyze plasma kinetics. The mean pharmacokinetic parameters (+/-SD) were: C(max), 5.5 +/- 2.6 microg/mL; T(max), 0.75 +/- 0.27 h; AUC(0-infinity), 10.8 +/- 4.9 microg x h/mL; MRT, 2.2 +/- 0.9 h. All milk from treated cows contained detectable penicillin residues for a minimum of three milkings (31 h) and maximum of five milkings (52 h) after administration. Concentrations of penicillin in all muscle, liver, and kidney samples taken 10 days postadministration were below the limit of quantification. Necropsy examinations revealed foci of hemorrhage on the rumenal omentum of most cows but peritonitis was not observed. Systemic inflammation as determined by change in leukogram or plasma fibrinogen was noted in one cow. The results of this study demonstrate that IP PPG is absorbed and eliminated rapidly in lactating dairy cows. PMID:19646094

  7. Resolving phenylalanine metabolism sheds light on natural synthesis of penicillin G in Penicillium chrysogenum.

    PubMed

    Veiga, Tânia; Solis-Escalante, Daniel; Romagnoli, Gabriele; ten Pierick, Angela; Hanemaaijer, Mark; Deshmukh, Amit T; Deshmuhk, Amit; Wahl, Aljoscha; Pronk, Jack T; Daran, Jean-Marc

    2012-02-01

    The industrial production of penicillin G by Penicillium chrysogenum requires the supplementation of the growth medium with the side chain precursor phenylacetate. The growth of P. chrysogenum with phenylalanine as the sole nitrogen source resulted in the extracellular production of phenylacetate and penicillin G. To analyze this natural pathway for penicillin G production, chemostat cultures were switched to [U-(13)C]phenylalanine as the nitrogen source. The quantification and modeling of the dynamics of labeled metabolites indicated that phenylalanine was (i) incorporated in nascent protein, (ii) transaminated to phenylpyruvate and further converted by oxidation or by decarboxylation, and (iii) hydroxylated to tyrosine and subsequently metabolized via the homogentisate pathway. The involvement of the homogentisate pathway was supported by the comparative transcriptome analysis of P. chrysogenum cultures grown with phenylalanine and with (NH(4))(2)SO(4) as the nitrogen source. This transcriptome analysis also enabled the identification of two putative 2-oxo acid decarboxylase genes (Pc13g9300 and Pc18g01490). cDNAs of both genes were cloned and expressed in the 2-oxo-acid-decarboxylase-free Saccharomyces cerevisiae strain CEN.PK711-7C (pdc1 pdc5 pdc6Δ aro10Δ thi3Δ). The introduction of Pc13g09300 restored the growth of this S. cerevisiae mutant on glucose and phenylalanine, thereby demonstrating that Pc13g09300 encodes a dual-substrate pyruvate and phenylpyruvate decarboxylase, which plays a key role in an Ehrlich-type pathway for the production of phenylacetate in P. chrysogenum. These results provide a basis for the metabolic engineering of P. chrysogenum for the production of the penicillin G side chain precursor phenylacetate. PMID:22158714

  8. Resolving Phenylalanine Metabolism Sheds Light on Natural Synthesis of Penicillin G in Penicillium chrysogenum

    PubMed Central

    Veiga, Tânia; Solis-Escalante, Daniel; Romagnoli, Gabriele; ten Pierick, Angela; Hanemaaijer, Mark; Deshmuhk, Amit; Wahl, Aljoscha; Pronk, Jack T.

    2012-01-01

    The industrial production of penicillin G by Penicillium chrysogenum requires the supplementation of the growth medium with the side chain precursor phenylacetate. The growth of P. chrysogenum with phenylalanine as the sole nitrogen source resulted in the extracellular production of phenylacetate and penicillin G. To analyze this natural pathway for penicillin G production, chemostat cultures were switched to [U-13C]phenylalanine as the nitrogen source. The quantification and modeling of the dynamics of labeled metabolites indicated that phenylalanine was (i) incorporated in nascent protein, (ii) transaminated to phenylpyruvate and further converted by oxidation or by decarboxylation, and (iii) hydroxylated to tyrosine and subsequently metabolized via the homogentisate pathway. The involvement of the homogentisate pathway was supported by the comparative transcriptome analysis of P. chrysogenum cultures grown with phenylalanine and with (NH4)2SO4 as the nitrogen source. This transcriptome analysis also enabled the identification of two putative 2-oxo acid decarboxylase genes (Pc13g9300 and Pc18g01490). cDNAs of both genes were cloned and expressed in the 2-oxo-acid-decarboxylase-free Saccharomyces cerevisiae strain CEN.PK711-7C (pdc1 pdc5 pdc6Δ aro10Δ thi3Δ). The introduction of Pc13g09300 restored the growth of this S. cerevisiae mutant on glucose and phenylalanine, thereby demonstrating that Pc13g09300 encodes a dual-substrate pyruvate and phenylpyruvate decarboxylase, which plays a key role in an Ehrlich-type pathway for the production of phenylacetate in P. chrysogenum. These results provide a basis for the metabolic engineering of P. chrysogenum for the production of the penicillin G side chain precursor phenylacetate. PMID:22158714

  9. Influence of penicillin on microbial diversity of the cecal microbiota in broiler chickens.

    PubMed

    Singh, Pallavi; Karimi, Ahmad; Devendra, Kshitiz; Waldroup, Park W; Cho, Kwang Keun; Kwon, Young Min

    2013-01-01

    Antibiotic growth promoters have been used for growth promotion of chickens in poultry industry since 1940. Recently, concerns have been raised to the use of antibiotic growth promoters in livestock due to development of antibiotic resistance in bacteria. The objective of our study was to investigate the effect of penicillin supplementation in the feed on cecal microbiota of broiler chickens. Two groups (n = 30) of chickens were fed corn-soybean meal diets with and without supplementation of penicillin at the concentration of 55 mg/kg (ANT vs. CON, respectively). At 18 d of age, the ANT group had significantly (P ≤ 0.05) higher mean BW than the CON group (668.6 vs. 570.0 g). Cecal samples of 5 randomly selected birds were pooled from each group and used for genomic DNA isolation and PCR amplification of 16S rRNA gene; 454 pyrosequencing of the amplicons resulted in 7,881 and 11,214 sequence reads for ANT and CON groups, respectively. Phylogenetic analysis indicated that penicillin supplementation in the ANT group resulted in an elevated proportion of phylum Firmicutes from 58.15 to 91.5% and a decreased proportion of phylum Bacteroidetes from 31.1 to 2.96% compared with the CON group. Recent studies conducted in humans, pigs, and mice have shown a similar shift in gut microbiota in obese individuals compared with the lean ones, indicating that this microbial shift could be responsible for the increase in energy harvest and BW. The results of this study suggest that the growth-promoting effect of penicillin supplementation in broilers may be mediated by a similar microbial process. PMID:23243258

  10. Dendroaspis natriuretic peptide binds to the natriuretic peptide clearance receptor

    SciTech Connect

    Johns, Douglas G. . E-mail: Douglas.G.Johns@gsk.com; Ao, Zhaohui; Heidrich, Bradley J.; Hunsberger, Gerald E.; Graham, Taylor; Payne, Lisa; Elshourbagy, Nabil; Lu, Quinn; Aiyar, Nambi; Douglas, Stephen A.

    2007-06-22

    Dendroaspis natriuretic peptide (DNP) is a newly-described natriuretic peptide which lowers blood pressure via vasodilation. The natriuretic peptide clearance receptor (NPR-C) removes natriuretic peptides from the circulation, but whether DNP interacts with human NPR-C directly is unknown. The purpose of this study was to test the hypothesis that DNP binds to NPR-C. ANP, BNP, CNP, and the NPR-C ligands AP-811 and cANP(4-23) displaced [{sup 125}I]-ANP from NPR-C with pM-to-nM K {sub i} values. DNP displaced [{sup 125}I]-ANP from NPR-C with nM potency, which represents the first direct demonstration of binding of DNP to human NPR-C. DNP showed high pM affinity for the GC-A receptor and no affinity for GC-B (K {sub i} > 1000 nM). DNP was nearly 10-fold more potent than ANP at stimulating cGMP production in GC-A expressing cells. Blockade of NPR-C might represent a novel therapeutic approach in augmenting the known beneficial actions of DNP in cardiovascular diseases such as hypertension and heart failure.

  11. Molecular epidemiology of penicillin-non-susceptible Streptococcus pneumoniae isolates from children with invasive pneumococcal disease in Germany.

    PubMed

    Reinert, R R; van der Linden, M; Seegmüller, I; Al-Lahham, A; Siedler, A; Weissmann, B; Toschke, A M; von Kries, R

    2007-04-01

    A population-based nationwide surveillance of antibiotic resistance associated with invasive pneumococcal disease (IPD) in children and adolescents (aged<16 years) was performed in Germany between 1997 and 2004. In total, 1517 isolates were collected, of which 5.1% and 1.1% were intermediately- or fully-resistant, respectively, to penicillin G. During the 8-year study period, an increase in resistance to both penicillin G and erythromycin A was observed, and the frequency of isolates exhibiting reduced susceptibility to penicillin G or erythromycin A increased from 1.4% and 11.1%, respectively, in 1997, to 8.7% and 29.0%, respectively, in 2004. Among the penicillin non-susceptible pneumococcal isolates, serotypes 14 (24.5% of isolates), 23F (16.0%) and 6B (16.0%) were found most frequently. Multilocus sequence typing of 58 (62%) penicillin G non-susceptible isolates revealed that sequence type (ST) 156 (Spain9V-3 clone) and its single-locus variant ST 557 were widespread in Germany. Moreover, 17 new penicillin G non-susceptible STs were defined for the first time. The study illustrated the genetic heterogeneity of antibiotic-resistant pneumococcal isolates in Germany. PMID:17359319

  12. Ligand Replacement Approach to Raman-Responded Molecularly Imprinted Monolayer for Rapid Determination of Penicilloic Acid in Penicillin.

    PubMed

    Zhang, Liying; Jin, Yang; Huang, Xiaoyan; Zhou, Yujie; Du, Shuhu; Zhang, Zhongping

    2015-12-01

    Penicilloic acid (PA) is a degraded byproduct of penicillin and often causes fatal allergies to humans, but its rapid detection in penicillin drugs remains a challenge due to its similarity to the mother structure of penicillin. Here, we reported a ligand-replaced molecularly imprinted monolayer strategy on a surface-enhanced Raman scattering (SERS) substrate for the specific recognition and rapid detection of Raman-inactive PA in penicillin. The bis(phenylenediamine)-Cu(2+)-PA complex was first synthesized and stabilized onto the surface of silver nanoparticle film that was fabricated by a bromide ion-added silver mirror reaction. A molecularly imprinted monolayer was formed by the further modification of alkanethiol around the stabilized complex on the Ag film substrate, and the imprinted recognition site was then created by the replacement of the complex template with Raman-active probe molecule p-aminothiophenol. When PA rebound into the imprinted site in the alkanethiol monolayer, the SERS signal of p-aminothiophenol exhibited remarkable enhancement with a detection limit of 0.10 nM. The imprinted monolayer can efficiently exclude the interference of penicillin and thus provides a selective determination of 0.10‰ (w/w) PA in penicillin, which is about 1 order of magnitude lower than the prescribed residual amount of 1.0‰. The strategy reported here is simple, rapid and inexpensive compared to the traditional chromatography-based methods. PMID:26545037

  13. Effects of increasing levels of pharmaceutical penicillin G contamination on structure of free living nematode communities in experimental microcosms.

    PubMed

    Nasri, Ahmed; Jouili, Soufiane; Boufahja, Fehmi; Hedfi, Amor; Mahmoudi, Ezzeddine; Aïssa, Patricia; Essid, Naceur; Beyrem, Hamouda

    2015-07-01

    A microcosm experiment was conducted to examine the effects of the pharmaceutical (penicillin G) on free living nematode communities of a Tunisian coastal zone (South-Western Mediterranean Sea). Sediments were contaminated with five penicillin G dose [D1 (3 mgL(-1)), D2 (30 mgL(-1)), D3 (300 mgL(-1)), D4 (600 mgL(-1)), D5 (700 mgL(-1))], and effects were examined after 30 days. Results showed significant differences between nematode assemblages from undisturbed controls and those from penicillin G treatments. Most univariate measures, including diversity (H'), species richness (d), equitability (J) and number of species (S) decreased significantly with increasing level of the antibiotic contamination. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the penicillin treatments were varied: Kraspedonema octogoniata and Paracomesoma dubium were eliminated at all the antibiotic doses tested and seemed to be intolerant species to penicillin G contamination; Oncholaimus campylocercoides although survived even the highest dose D5, showed definite reduction in its abundance and may be classified as "opportunistic" species at this dose, whereas, Nannolaimoides decoratus which showed a positive response with an increase in density even at highest concentration of contaminant, seems to be "penicillin G resistant" species. PMID:26148743

  14. Human Chlamydia pneumoniae isolates demonstrate ability to recover infectivity following penicillin treatment whereas animal isolates do not.

    PubMed

    Chacko, Anu; Beagley, Kenneth W; Timms, Peter; Huston, Wilhelmina M

    2015-03-01

    Chlamydia pneumoniae strains have recently been demonstrated to have substantially different capacities to enter and recover from IFN-γ-induced persistence, depending on whether they are from human or animal host sources. Here, we examined the ability of two human and two animal strains to enter and be rescued from penicillin-induced persistence. The ability to form inclusions after the addition of penicillin was much reduced in the two animal isolates (koala LPCoLN, bandicoot B21) compared to the two human isolates (respiratory AR39 and heart A03). The penicillin treatment resulted in a dose-dependent loss of infectious progeny for all isolates, with the human strains failing to produce infectious progeny at lower doses of penicillin than the animal strains. The most remarkable finding however was the contrasting ability of the isolates to recover infectious progeny production after rescue by removal of the penicillin (at 72 h) and continued culture. The animal isolates both showed virtually no recovery from the penicillin treatment conditions. In contrast, the human isolates showed a significant ability to recovery infectivity, with the heart isolate (A03) showing the most marked recovery. Combined, these data further support the hypothesis that the ability to establish and recover from persistence appears to be enhanced in human C. pneumoniae strains compared to animal strains. PMID:25663156

  15. In vitro and in vivo effects of penicillin and clindamycin on expression of group A beta-hemolytic streptococcal capsule.

    PubMed Central

    Brook, I; Gober, A E; Leyva, F

    1995-01-01

    Encapsulation of group A beta-hemolytic streptococci (GABHS) is an important virulence factor. The changes that occur in the frequency of encapsulation of GABHS during pharyngotonsillitis, in 20 patients treated with penicillin and 20 treated with clindamycin, were investigated. The effects of subinhibitory concentrations of these agents were also evaluated in vitro. At day 4, 8 of 10 (80%) GABHS isolates recovered from children treated with penicillin were encapsulated, compared with 1 of 5 (20%) of those from children treated with clindamycin (P < 0.05). Two days following 10 days of therapy, GABHS was eliminated from 13 of the 20 (65%) children treated with penicillin and from all treated with clindamycin (P < 0.05). At that time, six of the seven GABHS isolates recovered in patients treated with penicillin were encapsulated. GABHS were not detected after 4 days of therapy in those treated with clindamycin. Incubation of GABHS isolates with one-half of the MIC of clindamycin reduced the frequency of encapsulation, compared with that after incubation with one-half of the MIC of penicillin (12.5 versus 67.5%). These data illustrate the superiority of clindamycin over penicillin in reducing the expression of a capsule by GABHS. PMID:7492105

  16. Pharmacokinetic detection of penicillin excreted in urine using a totally internally reflected resonance light scattering technique with cetyltrimethylammonium bromide.

    PubMed

    Huang, Cheng Zhi; Feng, Ping; Li, Yuan Fang; Tan, Ke Jun

    2005-05-01

    A quantitative analysis method for penicillins including ampicillin (AmP), benzyl penicillin (BP), oxacillin (OA) and amoxycillin (AmO) is proposed that makes use of the totally internally reflected resonance light scattering (TIR-RLS) signal from the penicillin at the H2O/CCl4 interface in the presence of cetyltrimethylammonium bromide (CTMAB), and enables the pharmacokinetics of penicillin taken orally and excreted through urine to be monitored. Penicillin is coadsorbed with CTMAB at the H2O/CCl4 interface in neutral solution, resulting in the formation of ion associates that display greatly enhanced TIR-RLS signals (maximum at 368-372 nm). This enhanced TIR-RLS intensity was found to be proportional to the penicillin concentration over the range 0.2 x 10(-6) to 2.2 x 10(-6) mol L(-1), with limits of determination (3sigma) of 5.0 x 10(-8) to 7.0 x 10(-8) mol L(-1). Pharmacokinetics studies performed using the present method show that the excretion of orally-taken ampicillin through urine has a half-time of 1.05 h and an excremental quantum over 8 h of 49.3%, respectively. PMID:15900456

  17. Comparison of the secondary metabolites in Penicillium chrysogenum between pilot and industrial penicillin G fermentations.

    PubMed

    Cao, Ying-Xiu; Qiao, Bin; Lu, Hua; Chen, Yao; Yuan, Ying-Jin

    2011-02-01

    The disparity of secondary metabolites in Penicillium chrysogenum between two scales of penicillin G fermentation (50 L as pilot process and 150,000 L as industrial one) was investigated by ion-pair reversed-phase liquid chromatography tandemed with hybrid quadrupole time-of-flight mass spectrometry. In industrial process, the pools of intracellular L-α-aminoadipyl-L-cysteinyl-D-valine (LLD-ACV) and isopenicillin N (IPN) were remarkably less than that in the pilot one, which indicated that the productivity of penicillin G might be higher in the large scale of fermentation. This conclusion was supported by the higher intracellular penicillin G concentration as well as its higher yield per unit biomass in industrial cultivation. The different changing tendencies of IPN, 6-aminopenicillanic acid and 6-oxopiperide-2-carboxylic acid between two processes also suggested the same conclusion. The higher content of intracellular LLD-ACV in pilot process lead to a similarly higher concentration of bis-δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine, which had an inhibitory effect on ACV synthetase and also subdued the activity of IPN synthetase. The interconversion of secondary metabolites and the influence they put on enzymes would intensify the discrepancy between two fermentations more largely. These findings provided new insight into the changes and regulation of secondary metabolites in P. chrysogenum under different fermentation sizes. PMID:20941491

  18. Serological Response to Treatment of Syphilis with Doxycycline Compared with Penicillin in HIV-infected Individuals.

    PubMed

    Salado-Rasmussen, Kirsten; Hoffmann, Steen; Cowan, Susan; Jensen, Jørgen Skov; Benfield, Thomas; Gerstoft, Jan; Katzenstein, Terese Lea

    2016-08-23

    Serological response to treatment of syphilis with orally administered doxycycline or intramuscularly administered penicillin was assessed in patients with concurrent HIV. All HIV-infected individuals diagnosed with syphilis attending 3 hospitals in Copenhagen, Denmark were included. Odds ratios (ORs) with 95% confidence intervals (CI) associated with serological outcome were modelled using propensity-score-adjusted logistic regression analysis. In total, 202 cases were treated with doxycycline or intramuscular penicillin. At 12 months, serological failure was observed in 12 cases (15%) treated with doxycycline and in 8 cases (17%) treated with penicillin (OR 0.78 (95% CI 0.16-3.88), p = 0.76). The serological cure rate at 12 months was highest in patients with primary syphilis (100%), followed by patients with secondary (89%), early latent (71%) and late latent (67%) syphilis (p = 0.006). In conclusion, this study provides evidence for the use of doxycycline as a treatment option when treating a HIV-infected population for syphilis. PMID:26568359

  19. Analysis of mutations in the pbp genes of penicillin-non-susceptible pneumococci from Turkey.

    PubMed

    Biçmen, M; Gülay, Z; Ramaswamy, S V; Musher, D M; Gür, D

    2006-02-01

    Sequence analysis of the pbp genes from 20 Streptococcus pneumoniae isolates from Turkey (eight with high-level penicillin-resistance, nine with low-level penicillin-resistance, and three that were penicillin-susceptible) was performed and phylogenetic trees were constructed. Most isolates clustered together within a single branch that was distinct from sequences deposited previously in GenBank, which suggests that these isolates have probably evolved following new recombination events. The most prominent active-site mutations, which have also been associated previously with resistance, were T371A in PBP1a, E481G followed by T451A in PBP2b, and T338A in PBP2x. All isolates also possessed a (570)SVES/TK(574) block in the PBP2b sequence, instead of the QLQPT sequence of R6, which is fairly uncommon in GenBank sequences. This is the first study to analyse alterations in the pbp sequences of pneumococci isolated in Turkey. PMID:16441453

  20. Penicillin resistance compromises Nod1-dependent proinflammatory activity and virulence fitness of neisseria meningitidis.

    PubMed

    Zarantonelli, Maria Leticia; Skoczynska, Anna; Antignac, Aude; El Ghachi, Meriem; Deghmane, Ala-Eddine; Szatanik, Marek; Mulet, Céline; Werts, Catherine; Peduto, Lucie; d'Andon, Martine Fanton; Thouron, Françoise; Nato, Faridabano; Lebourhis, Lionel; Philpott, Dana J; Girardin, Stephen E; Vives, Francina Langa; Sansonetti, Philippe; Eberl, Gérard; Pedron, Thierry; Taha, Muhamed-Kheir; Boneca, Ivo G

    2013-06-12

    Neisseria meningitidis is a life-threatening human bacterial pathogen responsible for pneumonia, sepsis, and meningitis. Meningococcal strains with reduced susceptibility to penicillin G (Pen(I)) carry a mutated penicillin-binding protein (PBP2) resulting in a modified peptidoglycan structure. Despite their antibiotic resistance, Pen(I) strains have failed to expand clonally. We analyzed the biological consequences of PBP2 alteration among clinical meningococcal strains and found that peptidoglycan modifications of the Pen(I) strain resulted in diminished in vitro Nod1-dependent proinflammatory activity. In an influenza virus-meningococcal sequential mouse model mimicking human disease, wild-type meningococci induced a Nod1-dependent inflammatory response, colonizing the lungs and surviving in the blood. In contrast, isogenic Pen(I) strains were attenuated for such response and were out-competed by meningococci sensitive to penicillin G. Our results suggest that antibiotic resistance imposes a cost to the success of the pathogen and may potentially explain the lack of clonal expansion of Pen(I) strains. PMID:23768497

  1. Thermodynamic study of the effect of ethanol on two amphiphilic penicillins.

    PubMed

    Barbosa, Silvia; Taboada, Pablo; Mosquera, Víctor

    2005-12-01

    The effect of ethanol on the thermodynamic properties on two anionic amphiphilic penicillins, cloxacillin and dicloxacillin, has been investigated. Cloxacillin and dicloxacillin are two molecules that are similar structurally, differing only by an additional chlorine atom on the phenyl ring of dicloxacillin. The penicillins can be considered as hydrotropes if we considered that the term comprises hydrophilic and hydrophobic moieties that form aggregates by a stacking mechanism as is the case of both penicillins. By means of ultrasound velocities and densities, we have calculated the apparent molar volumes and adiabatic compressibilities. The critical concentrations, cc, and partition coefficients, K, have been determined, the latter using an indirect method based on the pseudophase model with the help of apparent molar data. This method has the advantage of allowing one to calculate the distribution coefficients at concentrations of the solubilizate below the saturation. The standard molar energy of Gibbs change, DeltaG0, on transfer from the aqueous to the micelar phase was calculated from the partition coefficient. The effect of the alcohol involves a slight decrease of the critical concentration because of a headgroup repulsion decrease. The enthalpies of dilution of dicloxacillin in a mixture of water and 15% w/v of ethanol were calculated. The aggregation process is more exothermic in ethanol that in pure water. PMID:16853954

  2. Proteochemometric model for predicting the inhibition of penicillin-binding proteins.

    PubMed

    Nabu, Sunanta; Nantasenamat, Chanin; Owasirikul, Wiwat; Lawung, Ratana; Isarankura-Na-Ayudhya, Chartchalerm; Lapins, Maris; Wikberg, Jarl E S; Prachayasittikul, Virapong

    2015-02-01

    Neisseria gonorrhoeae infection threatens to become an untreatable sexually transmitted disease in the near future owing to the increasing emergence of N. gonorrhoeae strains with reduced susceptibility and resistance to the extended-spectrum cephalosporins (ESCs), i.e. ceftriaxone and cefixime, which are the last remaining option for first-line treatment of gonorrhea. Alteration of the penA gene, encoding penicillin-binding protein 2 (PBP2), is the main mechanism conferring penicillin resistance including reduced susceptibility and resistance to ESCs. To predict and investigate putative amino acid mutations causing β-lactam resistance particularly for ESCs, we applied proteochemometric modeling to generalize N. gonorrhoeae susceptibility data for predicting the interaction of PBP2 with therapeutic β-lactam antibiotics. This was afforded by correlating publicly available data on antimicrobial susceptibility of wild-type and mutant N. gonorrhoeae strains for penicillin-G, cefixime and ceftriaxone with 50 PBP2 protein sequence data using partial least-squares projections to latent structures. The generated model revealed excellent predictability (R2=0.91, Q2=0.77, QExt2=0.78). Moreover, our model identified amino acid mutations in PBP2 with the highest impact on antimicrobial susceptibility and provided information on physicochemical properties of amino acid mutations affecting antimicrobial susceptibility. Our model thus provided insight into the physicochemical basis for resistance development in PBP2 suggesting its use for predicting and monitoring novel PBP2 mutations that may emerge in the future. PMID:25344841

  3. No Resistance to Penicillin, Cefuroxime, Cefotaxime, or Vancomycin in Pneumococcal Pneumonia

    PubMed Central

    Yayan, Josef; Ghebremedhin, Beniam; Rasche, Kurt

    2015-01-01

    Objectives: Group B Streptococcus is a primary source of pneumonia, which is a leading cause of death worldwide. During the last few decades, there has been news of growing antibiotic resistance in group B streptococci to penicillin and different antibiotic agents. This clinical study retrospectively analyzes antimicrobial resistance in inpatients who were diagnosed with group B streptococcal pneumonia. Methods: All of the required information from inpatients who were identified to have group B streptococcal pneumonia was sourced from the database at the Department of Internal Medicine of HELIOS Clinic Wuppertal, Witten/Herdecke University, in Germany, from 2004-2014. Antimicrobial susceptibility testing was performed for the different antimicrobial agents that were regularly administered to these inpatients. Results: Sixty-six inpatients with a mean age of 63.3 ± 16.1 years (45 males [68.2%, 95% CI 60.0%-79.4%] and 21 females [31.8%, 95% CI 20.6%-43.0%]) were detected to have group B streptococcal pneumonia within the study period from January 1, 2004, to August 12, 2014. Group B Streptococcus had a high resistance rate to gentamicin (12.1%), erythromycin (12.1%), clindamycin (9.1%), and co-trimoxazole (3.0%), but it was not resistant to penicillin, cefuroxime, cefotaxime, or vancomycin (P < 0.0001). Conclusion: No resistance to penicillin, cefuroxime, cefotaxime, or vancomycin was detected among inpatients with pneumonia caused by group B streptococci. PMID:26664260

  4. No improvement in serological response among serofast latent patients retreated with benzathine penicillin.

    PubMed

    Ren, Rong-Xin; Wang, Lin-Na; Zheng, He-Yi; Li, Jun

    2016-01-01

    Persistent non-treponemal titres after treatment are common among patients with latent syphilis. Although retreatment is often done in clinical practice, optimal management remains uncertain due to the paucity of data regarding serological response to retreatment and long-term outcomes. We compared the serological responses of serofast latent syphilis patients retreated with 7.2 million units of benzathine penicillin with the responses of patients who did not receive retreatment (control group). We retrospectively analysed the serological response to therapy following retreatment of 35 serofast latent syphilis patients at 12 months with benzathine penicillin 2.4 million units weekly for 3 weeks. In all, 74.3% (26/35) of the cases with latent syphilis who failed to achieve serological cure at 12 months after initial therapy achieved serological cure after retreatment and after an additional 12 months of follow-up. However, statistically similar serological cure rate was observed in 80.0% (28/35) of the control group (p > .05). Our findings illustrate no improvement in serological response among serofast latent patients retreated with three doses of benzathine penicillin. PMID:25691394

  5. Action of Penicillin G on Endosymbiote Lambda Particles of Paramecium aurelia

    PubMed Central

    Soldo, Anthony T.; Musil, George; Godoy, Gustavo A.

    1970-01-01

    The kinetics of loss from the cytoplasm and changes in ultrastructure of symbiont lambda particles after treatment of axenically cultivated lambda-bearing Paramecium aurelia with penicillin G was investigated. Low concentrations (1 to 2 unit/ml) of the antibiotic caused many particles within the cell to become filamentous; high concentrations (2,000 unit/ml) caused lysis of the particles without noticeably affecting the protozoan. The ED50 value (2 to 3 unit/ml) was within the range of values found to cause lysis of many gram-negative bacteria. Rapidly dividing lambda were more vulnerable to the action of the antibiotic than slowly dividing particles. Nondividing particles were not affected by exposure to the antibiotic. Ultrastructural changes observed in lambda during lysis by penicillin G were consistent with the view that penicillin interferes with the synthesis of a vital component of the cell envelope of the particle, possibly a peptidoglycan similar to that found in the cell walls of bacteria. The deoxyribonucleic acid of lambda was dispersed throughout the particle as electron dense fibers enclosed within electron transparent areas. The cell envelope appeared to consist of at least two morphologically distinguishable layers, an inner layer homologous to the plasma membrane of bacteria and an outer layer homologous to the bacterial cell wall. Lambda may be regarded as a randomly distributed population of bacteria growing and dividing synchronously within the collective cytoplasm of its protozoan host. Images PMID:4099102

  6. Effect of penicillin on fatty acid synthesis and excretion in Streptococcus mutans BHT

    SciTech Connect

    Brissette, J.L.; Pieringer, R.A.

    1985-03-01

    Treatment of exponentially growing cultures of Streptococcus mutans BHT with growth-inhibitory concentrations (0.2 microgram/ml) of benzylpenicillin stimulates the incorporation of (2-/sup 14/C) acetate into lipids excreted by the cells by as much as 69-fold, but does not change the amount of /sup 14/C incorporated into intracellular lipids. At this concentration of penicillin cellular lysis does not occur. The radioactive label is incorporated exclusively into the fatty acid moieties of the glycerolipids. During a 4-hr incubation in the presence of penicillin, the extracellular fatty acid ester concentration increases 1.5 fold, even though there is no growth or cellular lysis. An indication of the relative rate of fatty acid synthesis was most readily obtained by placing S. mutans BHT in a buffer containing /sup 14/C-acetate. Under these nongrowing conditions free fatty acids are the only lipids labeled, a factor which simplifies the assay. The addition of glycerol to the buffer causes all of the nonesterified fatty acids to be incorporated into glycerolipid. The cells excrete much of the lipid whether glycerol is present or not. Addition of penicillin to the nongrowth supporting buffer system does not stimulate the incorporation of (/sup 14/C)-acetate into fatty acids.

  7. Supramolecular Nanofibers of Peptide Amphiphiles for Medicine

    PubMed Central

    Webber, Matthew J.; Berns, Eric J.; Stupp, Samuel I.

    2014-01-01

    Peptide nanostructures are an exciting class of supramolecular systems that can be designed for novel therapies with great potential in advanced medicine. This paper reviews progress on nanostructures based on peptide amphiphiles capable of forming one-dimensional assemblies that emulate in structure the nanofibers present in extracellular matrices. These systems are highly tunable using supramolecular chemistry, and can be designed to signal cells directly with bioactive peptides. Peptide amphiphile nanofibers can also be used to multiplex functions through co-assembly and designed to deliver proteins, nucleic acids, drugs, or cells. We illustrate here the functionality of these systems describing their use in regenerative medicine of bone, cartilage, the nervous system, the cardiovascular system, and other tissues. In addition, we highlight recent work on the use of peptide amphiphile assemblies to create hierarchical biomimetic structures with order beyond the nanoscale, and also discuss the future prospects of these supramolecular systems. PMID:24532851

  8. Brain natriutetic peptide test

    MedlinePlus

    ... medlineplus.gov/ency/article/007509.htm Brain natriuretic peptide test To use the sharing features on this page, please enable JavaScript. Brain natriuretic peptide (BNP) test is a blood test that measures ...

  9. Vasoactive intestinal peptide test

    MedlinePlus

    ... medlineplus.gov/ency/article/003508.htm Vasoactive intestinal peptide test To use the sharing features on this page, please enable JavaScript. Vasoactive intestinal peptide (VIP) is a test that measures the amount ...

  10. [SYNTHETIC PEPTIDE VACCINES].

    PubMed

    Sergeyev, O V; Barinsky, I F

    2016-01-01

    An update on the development and trials of synthetic peptide vaccines is reviewed. The review considers the successful examples of specific protection as a result of immunization with synthetic peptides using various protocols. The importance of conformation for the immunogenicity of the peptide is pointed out. An alternative strategy of the protection of the organism against the infection using synthetic peptides is suggested. PMID:27145593

  11. Peptides and the blood-brain barrier.

    PubMed

    Banks, William A

    2015-10-01

    The demonstration that peptides and regulatory proteins can cross the blood-brain barrier (BBB) is one of the major contributions of Dr. Abba J. Kastin. He was the first to propose that peptides could cross the BBB, the first to show that an endogenous peptide did so, and the first to describe a saturable transport system at the BBB for peptides. His work shows that in crossing the BBB, peptides and regulatory proteins act as informational molecules, informing the brain of peripheral events. Brain-to-blood passage helps to control levels of peptides with the brain and can deliver information in the brain-to-blood direction. He showed that the transporters for peptides and proteins are not static, but respond to developmental and physiological changes and are affected by disease states. As such, the BBB is adaptive to the needs of the CNS, but when that adaption goes awry, the BBB can be a cause of disease. The mechanisms by which peptides and proteins cross the BBB offer opportunities for drug delivery of these substances or their analogs to the brain in the treatment of diseases of the central nervous system. PMID:25805003

  12. PH dependent adhesive peptides

    DOEpatents

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  13. Antimicrobial Peptides in 2014

    PubMed Central

    Wang, Guangshun; Mishra, Biswajit; Lau, Kyle; Lushnikova, Tamara; Golla, Radha; Wang, Xiuqing

    2015-01-01

    This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms. PMID:25806720

  14. Antimicrobial peptides in 2014.

    PubMed

    Wang, Guangshun; Mishra, Biswajit; Lau, Kyle; Lushnikova, Tamara; Golla, Radha; Wang, Xiuqing

    2015-01-01

    This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms. PMID:25806720

  15. Potent and rapid antigonococcal activity of the venom peptide BmKn2 and its derivatives against different Maldi biotype of multidrug-resistant Neisseria gonorrhoeae.

    PubMed

    Arpornsuwan, Teerakul; Buasakul, Brisana; Jaresitthikunchai, Janthima; Roytrakul, Sittiruk

    2014-03-01

    The emergence of multidrug-resistant strains of Neisseria gonorrhoeae constitutes a serious threat to public health and necessitates the discovery of new types of antimicrobial agents. Among the 18 clinical isolates of N. gonorrhoeae with susceptible to spectinomycin, ceftriaxone and cefixime, 14 isolates were resistance to penicillin, tetracycline and ciprofloxacin, while 2 isolates were susceptible to tetracycline and another was penicillin intermediate isolate. Significant differences between laboratory strain and multidrug resistant strains were revealed by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry profiling and bioinformatics examination using the MALDI BioTyper software. However, Maldi Biotyper was not successfully separated ciprofloxacin-penicillin resistance and ciprofloxacin-tetracycline resistance from ciprofloxacin-penicillin-tetracycline resistant N. gonorrhoeae isolates. BmKn2 is a basic, alpha-helical peptide with no disulfide-bridge venom peptides that was first isolated from Buthus martensii Kasch. A panel of BmKn2 scorpion venom peptide and its derivatives of varying length and characteristics were synthesized chemically and evaluated for their ability to inhibit the growth of clinical N. gonorrhoeae isolates. Synthetic BmKn2 displayed potent activity against 18 clinical isolates of N. gonorrhoeae with MIC50 values of 6.9-27.6 μM. BmKn2 exerted its antibacterial activity via a bactericidal mechanism. Cyclic BmKn1 did not show antigonococcal activity. Decreasing the cationicity and helix percentage at the C-terminus of BmKn2 reduced the potency against N. gonorrhoeae. Taken together, the BmKn1 peptide can be developed as a topical therapeutic agent for treating multidrug-resistant strains of N. gonorrhoeae infections. PMID:24184420

  16. Observations on the effect of penicillin on the reaction between phage and staphylococci.

    PubMed

    KRUEGER, A P; COHN, T

    1948-07-20

    The essential facts relating to the reaction between phage, sodium penicillin G, and the K race of Staphylococcus aureus are: 1. Except when [P] is very high, massive lysis of the cellular substrate occurs considerably sooner in the P-PN-B mixture than in preparations containing P alone or PN alone. 2. The accelerative effect is present in concentrations of PN varying from 0.1 to 1 x 10(4) units/ml. 3. Acceleration of lysis can be secured by exposing staphylococci to PN prior to treatment with P. 4. In certain concentrations of P and B in tryptose-phosphate broth, P formation apparently takes place without bacterial reproduction. The extent to which P is produced is influenced very little by [PN](0) but is markedly dependent upon [P](0). With low P/B ratios the [P] curve shows a lag followed by a rapid rise to a peak of 25 to 30 times [P](0). When the P/B ratio approaches unity there is a considerable primary drop in [P] and later an increase which, however, fails to bring the total P produced above [P](0). When P/B is still higher, the [P] curve drops profoundly as the bacteria lyse and never enters into a productive phase. 5. In Locke's solution mixtures of P-PN-B, containing 5 to 10 per cent broth, P formation occurs in the absence of detectable cellular reproduction to the extent of a four- to sixfold increase over [P](0). 6. Direct microscopic examination of wet preparations removed during the P-PN-B reaction has disclosed swelling of the staphylococci. The swollen cells are three times the diameter of normal S. aureus secured from an 18 hour culture. Cellular swelling apparently accounts for the experimental observation that the curve for lysis plotted from [B](K) lags considerably behind the [B](D) curve. Increase in the size of individual cells would tend to keep the photoelectric colorimeter measurements high even while the direct count was diminishing. 7. When the P-PN-B reaction is carried out in broth, attainment of the peak in P production is followed

  17. From a pro-apoptotic peptide to a lytic peptide: One single residue mutation.

    PubMed

    Zhou, Xi-Rui; Zhang, Qiang; Tian, Xi-Bo; Cao, Yi-Meng; Liu, Zhu-Qing; Fan, Ruru; Ding, Xiu-Fang; Zhu, Zhentai; Chen, Long; Luo, Shi-Zhong

    2016-08-01

    Further discovery and design of new anticancer peptides are important for the development of anticancer therapeutics, and study on the detailed acting mechanism and structure-function relationship of peptides is critical for anticancer peptide design and application. In this study, a novel anticancer peptide ZXR-1 (FKIGGFIKKLWRSKLA) derived from a known anticancer peptide mauriporin was developed, and a mutant ZXR-2 (FKIGGFIKKLWRSLLA) with only one residue difference at the 14th position (Lys→Leu) was also engineered. Replacement of the lysine with leucine made ZXR-2 more potent than ZXR-1 in general. Even with only one residue mutation, the two peptides displayed distinct anticancer modes of action. ZXR-1 could translocate into cells, target on the mitochondria and induce cell apoptosis, while ZXR-2 directly targeted on the cell membranes and caused membrane lysis. The variance in their acting mechanisms might be due to the different amphipathicity and positive charge distribution. In addition, the two Ile-Leu pairs (3-10 and 7-14) in ZXR-2 might also play a role in improving its cytotoxicity. Further study on the structure-function relationship of the two peptides may be beneficial for the design of novel anticancer peptides and peptide based therapeutics. PMID:27207743

  18. The Allosteric Site for the Nascent Cell Wall in Penicillin-Binding Protein 2a: An Achilles' Heel of Methicillin-Resistant Staphylococcus aureus.

    PubMed

    Acebrón, Iván; Chang, Mayland; Mobashery, Shahriar; Hermoso, Juan A

    2015-01-01

    The ability to resist the effect of a wide range of antibiotics makes methicillin-resistant Staphylococcus aureus (MRSA) a leading global human pathogen. A key determinant of resistance to β-lactam antibiotics in this organism is penicillin-binding protein 2a (PBP2a), an enzyme that catalyzes the crosslinking reaction between two adjacent peptide stems during the peptidoglycan biosynthesis. The recently published crystal structure of the complex of PBP2a with ceftaroline, a cephalosporin antibiotic that shows efficacy against MRSA, has revealed the allosteric site at 60-Å distance from the transpeptidase domain. Binding of ceftaroline to the allosteric site of PBP2a triggers conformational changes that lead to the opening of the active site from a closed conformation, where a second molecule of ceftaroline binds to give inhibition of the enzyme. The discovery of allostery in MRSA remains the only known example of such regulation of cellwall biosynthesis and represents a new paradigm in fighting MRSA. This review summarizes the present knowledge of the allosteric mechanism, the conformational changes allowing PBP2a catalysis and the means by which some clinical strains have acquired resistance to ceftaroline by disrupting the allosteric mechanism. PMID:25760091

  19. Fast HPLC-MS/MS Method for Determining Penicillin Antibiotics in Infant Formulas Using Molecularly Imprinted Solid-Phase Extraction

    PubMed Central

    Díaz-Bao, Mónica; Barreiro, Rocío; Miranda, José Manuel; Cepeda, Alberto; Regal, Patricia

    2015-01-01

    The dairy cattle may suffer from different infections relatively often, but the inflammation of the mammary gland is very important to the farmer. These infections are frequently treated with penicillin antimicrobial drugs. However, their use may result in the presence of residues in animal products, such as milk powder and/or infant formulas, and it represents a potential risk for consumers. To monitor this, the EU has defined safe maximum residue limits (MRLs) through Commission Regulation (EU) number 37/2010. Although LC-MS is a trustful option for confirmation and quantification of antibiotics, the analysis of real samples with complex matrices frequently implies previous clean-up steps. In this work, precipitation polymerization has been used and different molecularly imprinted polymer (MIP) sorbents were tested and optimized for the fast and simultaneous solid-phase extraction (MISPE) of eight common penicillins (ampicillin, amoxicillin, oxacillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, and nafcillin). The extracts were analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and the applicability of these polymers as sorbents for the extraction of penicillins at MRL levels in milk powder (infant formulas) was proved. The limits of detection and quantification were below the legal tolerances, except for LOQ for oxacillin and cloxacillin. PMID:25785233

  20. Fast HPLC-MS/MS Method for Determining Penicillin Antibiotics in Infant Formulas Using Molecularly Imprinted Solid-Phase Extraction.

    PubMed

    Díaz-Bao, Mónica; Barreiro, Rocío; Miranda, José Manuel; Cepeda, Alberto; Regal, Patricia

    2015-01-01

    The dairy cattle may suffer from different infections relatively often, but the inflammation of the mammary gland is very important to the farmer. These infections are frequently treated with penicillin antimicrobial drugs. However, their use may result in the presence of residues in animal products, such as milk powder and/or infant formulas, and it represents a potential risk for consumers. To monitor this, the EU has defined safe maximum residue limits (MRLs) through Commission Regulation (EU) number 37/2010. Although LC-MS is a trustful option for confirmation and quantification of antibiotics, the analysis of real samples with complex matrices frequently implies previous clean-up steps. In this work, precipitation polymerization has been used and different molecularly imprinted polymer (MIP) sorbents were tested and optimized for the fast and simultaneous solid-phase extraction (MISPE) of eight common penicillins (ampicillin, amoxicillin, oxacillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, and nafcillin). The extracts were analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and the applicability of these polymers as sorbents for the extraction of penicillins at MRL levels in milk powder (infant formulas) was proved. The limits of detection and quantification were below the legal tolerances, except for LOQ for oxacillin and cloxacillin. PMID:25785233

  1. Synthesis of novel hapten and production of generic monoclonal antibody for immunoassay of penicillins residues in milk.

    PubMed

    Jiao, Sai N; Wang, Ping; Zhao, Guo X; Zhang, Huui C; Liu, Jing; Wang, Jian P

    2013-01-01

    The objective of this study was to produce a generic monoclonal antibody for determination of penicillins residues in milk. The compound 6-aminopenicillanic acid was used as the template to synthesize two novel generic haptens that were used to produce the monoclonal antibodies. The obtained monoclonal antibodies simultaneously recognized 11 penicillin drugs (amoxicillin, ampicillin, penicillin G, penicillin V, sulbenicillin, carbencillin, methicillin, cloxacillin, dicloxacillin, oxacillin, and nafcillin). After evaluation of different reagent combinations, a heterologous indirect competitive enzyme immunoassay was developed to multi-determine the 11 drugs in milk. The crossreactivities to the 11 drugs were in a range of 16%-117% and the limits of detection were in a range of 0.7-9.3 ng/mL depending on the drug. The recoveries from the fortified blank milk were in a range of 77.6%-99.4% with coefficients of variation lower than 13.5%. This method could be used as a rapid screen tool for routine monitoring the residues of the 11 penicillin drugs in animal derived foods. PMID:23452214

  2. Interaction of Zwitterionic Penicillins with the OmpF Channel Facilitates Their Translocation

    PubMed Central

    Danelon, Christophe; Nestorovich, Ekaterina M.; Winterhalter, Mathias; Ceccarelli, Matteo; Bezrukov, Sergey M.

    2006-01-01

    To study translocation of β-lactam antibiotics of different size and charge across the outer bacterial membrane, we combine an analysis of ion currents through single trimeric outer membrane protein F (OmpF) porins in planar lipid bilayers with molecular dynamics simulations. Because the size of penicillin molecules is close to the size of the narrowest part of the OmpF pore, penicillins occlude the pore during their translocation. Favorably interacting penicillins cause time-resolvable transient blockages of the small-ion current through the channel and thereby provide information about their dynamics within the pore. Analyzing these random fluctuations, we find that ampicillin and amoxicillin have a relatively high affinity for OmpF. In contrast, no or only a weak interaction is detected for carbenicillin, azlocillin, and piperacillin. Molecular dynamics simulations suggest a possible pathway of these drugs through the OmpF channel and rationalize our experimental findings. For zwitterionic ampicillin and amoxicillin, we identify a region of binding sites near the narrowest part of the channel pore. Interactions with these sites partially compensate for the entropic cost of drug confinement by the channel. Whereas azlocillin and piperacillin are clearly too big to pass through the channel constriction, dianionic carbenicillin does not find an efficient binding region in the constriction zone. Carbenicillin's favorable interactions are limited to the extracellular vestibule. These observations confirm our earlier suggestion that a set of high-affinity sites at the narrowest part of the OmpF channel improves a drug's ability to cross the membrane via the pore. PMID:16339889

  3. CTX-M-93, a CTX-M Variant Lacking Penicillin Hydrolytic Activity▿

    PubMed Central

    Djamdjian, Laura; Naas, Thierry; Tandé, Didier; Cuzon, Gaelle; Hanrotel-Saliou, Catherine; Nordmann, Patrice

    2011-01-01

    Extended-spectrum β-lactamases (ESBLs) of the CTX-M type are increasingly being reported worldwide, with more than 90 known variants. Clinical Escherichia coli isolate Bre-1 was isolated in 2009 and displayed an unusual ESBL phenotype, made of a synergy image between expanded cephalosporins and clavulanic acid discs and susceptibility to penicillins. E. coli Bre-1 harbored a novel CTX-M-encoding gene, designated blaCTX-M-93. CTX-M-93 differed from CTX-M-27 by only a single L169Q substitution. Compared to CTX-M-27, CTX-M-93 conferred higher MICs of ceftazidime for E. coli (MIC of 8 versus 1.5 μg/ml) and decreased MICs of other expanded-cephalosporins (MIC of cefotaxime of 1 versus 32 μg/ml) and penicillins (MIC of ticarcillin of 0.5 versus >256 μg/ml). A comparison of enzymatic properties revealed that the L169Q substitution led to a decreased Km for ceftazidime (25.5 versus 330 μM) but decreased hydrolytic activity against good substrates, such as cefotaxime (kcat of 0.6 versus 113 s−1), probably owing to the alteration of the omega loop positioning during the catalytic process. The blaCTX-M-93 gene was surrounded by the ISEcp1 and IS903 elements and inserted onto a 150-kb non-self-transferrable IncF-type plasmid. E. coli Bre-1 belongs to phylogroup D and is of multilocus sequence type (MLST) 624, a sequence type found only in rare Spanish CTX-M-14-producing E. coli isolates. We have characterized a novel CTX-M variant, CTX-M-93, lacking significant penicillin hydrolysis but with increased ceftazidime hydrolysis. PMID:21343457

  4. 4D-QSAR analysis and pharmacophore modeling: electron conformational-genetic algorithm approach for penicillins.

    PubMed

    Yanmaz, Ersin; Sarıpınar, Emin; Şahin, Kader; Geçen, Nazmiye; Çopur, Fatih

    2011-04-01

    4D-QSAR studies were performed on a series of 87 penicillin analogues using the electron conformational-genetic algorithm (EC-GA) method. In this EC-based method, each conformation of the molecular system is described by a matrix (ECMC) with both electron structural parameters and interatomic distances as matrix elements. Multiple comparisons of these matrices within given tolerances for high active and low active penicillin compounds allow one to separate a smaller number of matrix elements (ECSA) which represent the pharmacophore groups. The effect of conformations was investigated building model 1 and 2 based on ensemble of conformers and single conformer, respectively. GA was used to select the most important descriptors and to predict the theoretical activity of the training (74 compounds) and test (13 compounds, commercial penicillins) sets. The model 1 for training and test sets obtained by optimum 12 parameters gave more satisfactory results (R(training)(2)=0.861, SE(training)=0.044, R(test)(2)=0.892, SE(test)=0.099, q(2)=0.702, q(ext1)(2)=0.777 and q(ext2)(2)=0.733) than model 2 (R(training)(2)=0.774, SE(training)=0.056, R(test)(2)=0.840, SE(test)=0.121, q(2)=0.514, q(ext1)(2)=0.641 and q(ext2)(2)=0.570). To estimate the individual influence of each of the molecular descriptors on biological activity, the E statistics technique was applied to the derived EC-GA model. PMID:21419636

  5. Penicillin-binding proteins from Erwinia amylovora: mutants lacking PBP2 are avirulent.

    PubMed Central

    Milner, J S; Dymock, D; Cooper, R M; Roberts, I S

    1993-01-01

    Radiolabelled penicillin G was used to examine penicillin-binding proteins (PBPs) from Erwinia amylovora (OT1). This procedure identified seven PBPs with molecular masses ranging from 22 to 83 kDa. E. amylovora PBPs were compared with those from Escherichia coli (JM101) and from two spherical, avirulent TnphoA mutants derived from OT1. Radiolabelled penicillin G bound to only six proteins from the spherical mutants which lacked a 69-kDa PBP. The spherical mutants could be complemented by the cloned E. coli pbpA-rodA operon, which restored both cell shape and virulence to apple seedlings. This suggested that the E. amylovora 69-kDa PBP is probably the functional equivalent of the E. coli PBP2 protein. Southern blot analysis using the E. coli rodA and pbpA genes as radiolabelled probes showed that TnphoA had inserted into the E. amylovora equivalent of the E. coli rodA-pbpA operon. Southern blots to chromosomal DNAs of the two spherical mutants, using the cloned hrp and dsp genes from E. amylovora as radiolabelled probes, confirmed that the TnphoA insertions were not located in the region of the E. amylovora chromosome postulated to encode known virulence factors. Both of the spherical TnphoA mutants synthesized amounts of extracellular polysaccharide equivalent to those synthesized by the wild-type strain (OT1), were resistant to lysis in distilled water and to lysozyme, and elicited the hypersensitive response on nonhost plants. These results indicate a possible role for cell shape in the virulence of this plant pathogen. Images PMID:8407779

  6. Profiling of β-Lactam Selectivity for Penicillin-Binding Proteins in Streptococcus pneumoniae D39

    PubMed Central

    Kocaoglu, Ozden; Tsui, Ho-Ching T.; Winkler, Malcolm E.

    2015-01-01

    Selective fluorescent β-lactam chemical probes enable the visualization of the transpeptidase activity of penicillin-binding proteins (PBPs) at different stages of bacterial cell division. To facilitate the development of new fluorescent probes for PBP imaging, we evaluated 20 commercially available β-lactams for selective PBP inhibition in an unencapsulated derivative of the D39 strain of Streptococcus pneumoniae. Live cells were treated with β-lactam antibiotics at different concentrations and subsequently incubated with Bocillin FL (Boc-FL; fluorescent penicillin) to saturate uninhibited PBPs. Fluorophore-labeled PBPs were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorescence scanning. Among 20 compounds tested, carbapenems (doripenem and meropenem) were coselective for PBP1a, PBP2x, and PBP3, while six of the nine penicillin compounds were coselective for PBP2x and PBP3. In contrast, the seven cephalosporin compounds tested display variability in their PBP-binding profiles. Three cephalosporin compounds (cefoxitin, cephalexin, and cefsulodin) and the monobactam aztreonam exhibited selectivity for PBP3, while only cefuroxime (a cephalosporin) was selective for PBP2x. Treatment of S. pneumoniae cultures with a sublethal concentration of cefuroxime that inhibited 60% of PBP2x activity and less than 20% of the activity of other PBPs resulted in formation of elongated cells. In contrast, treatment of S. pneumoniae cultures with concentrations of aztreonam and cefoxitin that inhibited up to 70% of PBP3 activity and less than 30% of other PBPs resulted in no discernible morphological changes. Additionally, correlation of the MIC and IC50s for each PBP, with the exception of faropenem, amdinocillin (mecillinam), and 6-APA, suggests that pneumococcal growth inhibition is primarily due to the inhibition of PBP2x. PMID:25845878

  7. Profiling of β-lactam selectivity for penicillin-binding proteins in Streptococcus pneumoniae D39.

    PubMed

    Kocaoglu, Ozden; Tsui, Ho-Ching T; Winkler, Malcolm E; Carlson, Erin E

    2015-01-01

    Selective fluorescent β-lactam chemical probes enable the visualization of the transpeptidase activity of penicillin-binding proteins (PBPs) at different stages of bacterial cell division. To facilitate the development of new fluorescent probes for PBP imaging, we evaluated 20 commercially available β-lactams for selective PBP inhibition in an unencapsulated derivative of the D39 strain of Streptococcus pneumoniae. Live cells were treated with β-lactam antibiotics at different concentrations and subsequently incubated with Bocillin FL (Boc-FL; fluorescent penicillin) to saturate uninhibited PBPs. Fluorophore-labeled PBPs were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorescence scanning. Among 20 compounds tested, carbapenems (doripenem and meropenem) were coselective for PBP1a, PBP2x, and PBP3, while six of the nine penicillin compounds were coselective for PBP2x and PBP3. In contrast, the seven cephalosporin compounds tested display variability in their PBP-binding profiles. Three cephalosporin compounds (cefoxitin, cephalexin, and cefsulodin) and the monobactam aztreonam exhibited selectivity for PBP3, while only cefuroxime (a cephalosporin) was selective for PBP2x. Treatment of S. pneumoniae cultures with a sublethal concentration of cefuroxime that inhibited 60% of PBP2x activity and less than 20% of the activity of other PBPs resulted in formation of elongated cells. In contrast, treatment of S. pneumoniae cultures with concentrations of aztreonam and cefoxitin that inhibited up to 70% of PBP3 activity and less than 30% of other PBPs resulted in no discernible morphological changes. Additionally, correlation of the MIC and IC50s for each PBP, with the exception of faropenem, amdinocillin (mecillinam), and 6-APA, suggests that pneumococcal growth inhibition is primarily due to the inhibition of PBP2x. PMID:25845878

  8. Effects of new penicillin susceptibility breakpoints for Streptococcus pneumoniae--United States, 2006-2007.

    PubMed

    2008-12-19

    Streptococcus pneumoniae (pneumococcus) is a common cause of pneumonia and meningitis in the United States. Antimicrobial resistance, which can result in pneumococcal infection treatment failure, is identified by measuring the minimum inhibitory concentration (MIC) of an antimicrobial that will inhibit pneumococcal growth. Breakpoints are MICs that define infections as susceptible (treatable), intermediate (possibly treatable with higher doses), and resistant (not treatable) to certain antimicrobials. In January 2008, after a reevaluation that included more recent clinical studies, the Clinical and Laboratory Standards Institute (CLSI) published new S. pneumoniae breakpoints for penicillin (the preferred antimicrobial for susceptible S. pneumoniae infections). To assess the potential effects of the new breakpoints on susceptibility categorization, CDC applied them to MICs of invasive pneumococcal disease (IPD) isolates collected by the Active Bacterial Core surveillance (ABCs) system at sites in 10 states during 2006-2007. This report summarizes the results of that analysis, which found that the percentage of IPD nonmeningitis S. pneumoniae isolates categorized as susceptible, intermediate, and resistant to penicillin changed from 74.7%, 15.0%, and 10.3% under the former breakpoints to 93.2%, 5.6%, and 1.2%, respectively, under the new breakpoints. Microbiology laboratories should be aware of the new breakpoints to interpret pneumococcal susceptibility accurately, and clinicians should be aware of the breakpoints to prescribe antimicrobials appropriately for pneumococcal infections. State and local health departments also should be aware of the new breakpoints because they might result in a decrease in the number of reported cases of penicillin-resistant pneumococcus. PMID:19092758

  9. 2D NMR Methods for Structural Delineation of Copper(II) Complexes of Penicillin and Pilocarpine

    PubMed Central

    Gaggelli, Elena; Gaggelli, Nicola

    1994-01-01

    A method was developed for delineating the structure of paramagnetic metal complexes. The selective disappearance of cross-peaks in proton-carbon shift correlated 2D NMR maps was shown to uniquely depend upon the scalar and/or dipolar interaction between ligand nuclei and the unpaired electron(s), thus providing a means of identifying binding sites. Copper(II) was shown to form metal complexes with both Penicillin (PNC) and Pilocarpine (PLC) and the structure of the two 1:2 complexes in water solution at physiological pH were determined. PMID:18476239

  10. Beta-lactamase genes of the penicillin-susceptible Bacillus anthracis Sterne strain.

    PubMed

    Chen, Yahua; Succi, Janice; Tenover, Fred C; Koehler, Theresa M

    2003-02-01

    Susceptibility to penicillin and other beta-lactam-containing compounds is a common trait of Bacillus anthracis. Beta-lactam agents, particularly penicillin, have been used worldwide to treat anthrax in humans. Nonetheless, surveys of clinical and soil-derived strains reveal penicillin G resistance in 2 to 16% of isolates tested. Bacterial resistance to beta-lactam agents is often mediated by production of one or more types of beta-lactamases that hydrolyze the beta-lactam ring, inactivating the antimicrobial agent. Here, we report the presence of two beta-lactamase (bla) genes in the penicillin-susceptible Sterne strain of B. anthracis. We identified bla1 by functional cloning with Escherichia coli. bla1 is a 927-nucleotide (nt) gene predicted to encode a protein with 93.8% identity to the type I beta-lactamase gene of Bacillus cereus. A second gene, bla2, was identified by searching the unfinished B. anthracis chromosome sequence database of The Institute for Genome Research for open reading frames (ORFs) predicted to encode beta-lactamases. We found a partial ORF predicted to encode a protein with significant similarity to the carboxy-terminal end of the type II beta-lactamase of B. cereus. DNA adjacent to the 5' end of the partial ORF was cloned using inverse PCR. bla2 is a 768-nt gene predicted to encode a protein with 92% identity to the B. cereus type II enzyme. The bla1 and bla2 genes confer ampicillin resistance to E. coli and Bacillus subtilis when cloned individually in these species. The MICs of various antimicrobial agents for the E. coli clones indicate that the two beta-lactamase genes confer different susceptibility profiles to E. coli; bla1 is a penicillinase, while bla2 appears to be a cephalosporinase. The beta-galactosidase activities of B. cereus group species harboring bla promoter-lacZ transcriptional fusions indicate that bla1 is poorly transcribed in B. anthracis, B. cereus, and B. thuringiensis. The bla2 gene is strongly expressed in B

  11. [Plant signaling peptides. Cysteine-rich peptides].

    PubMed

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation. PMID:26281357

  12. Cell Penetrating Peptides and Cationic Antibacterial Peptides

    PubMed Central

    Rodriguez Plaza, Jonathan G.; Morales-Nava, Rosmarbel; Diener, Christian; Schreiber, Gabriele; Gonzalez, Zyanya D.; Lara Ortiz, Maria Teresa; Ortega Blake, Ivan; Pantoja, Omar; Volkmer, Rudolf; Klipp, Edda; Herrmann, Andreas; Del Rio, Gabriel

    2014-01-01

    Cell penetrating peptides (CPP) and cationic antibacterial peptides (CAP) have similar physicochemical properties and yet it is not understood how such similar peptides display different activities. To address this question, we used Iztli peptide 1 (IP-1) because it has both CPP and CAP activities. Combining experimental and computational modeling of the internalization of IP-1, we show it is not internalized by receptor-mediated endocytosis, yet it permeates into many different cell types, including fungi and human cells. We also show that IP-1 makes pores in the presence of high electrical potential at the membrane, such as those found in bacteria and mitochondria. These results provide the basis to understand the functional redundancy of CPPs and CAPs. PMID:24706763

  13. Test battery with the human cell line activation test, direct peptide reactivity assay and DEREK based on a 139 chemical data set for predicting skin sensitizing potential and potency of chemicals.

    PubMed

    Takenouchi, Osamu; Fukui, Shiho; Okamoto, Kenji; Kurotani, Satoru; Imai, Noriyasu; Fujishiro, Miyuki; Kyotani, Daiki; Kato, Yoshinao; Kasahara, Toshihiko; Fujita, Masaharu; Toyoda, Akemi; Sekiya, Daisuke; Watanabe, Shinichi; Seto, Hirokazu; Hirota, Morihiko; Ashikaga, Takao; Miyazawa, Masaaki

    2015-11-01

    To develop a testing strategy incorporating the human cell line activation test (h-CLAT), direct peptide reactivity assay (DPRA) and DEREK, we created an expanded data set of 139 chemicals (102 sensitizers and 37 non-sensitizers) by combining the existing data set of 101 chemicals through the collaborative projects of Japan Cosmetic Industry Association. Of the additional 38 chemicals, 15 chemicals with relatively low water solubility (log Kow > 3.5) were selected to clarify the limitation of testing strategies regarding the lipophilic chemicals. Predictivities of the h-CLAT, DPRA and DEREK, and the combinations thereof were evaluated by comparison to results of the local lymph node assay. When evaluating 139 chemicals using combinations of three methods based on integrated testing strategy (ITS) concept (ITS-based test battery) and a sequential testing strategy (STS) weighing the predictive performance of the h-CLAT and DPRA, overall similar predictivities were found as before on the 101 chemical data set. An analysis of false negative chemicals suggested a major limitation of our strategies was the testing of low water-soluble chemicals. When excluded the negative results for chemicals with log Kow > 3.5, the sensitivity and accuracy of ITS improved to 97% (91 of 94 chemicals) and 89% (114 of 128). Likewise, the sensitivity and accuracy of STS to 98% (92 of 94) and 85% (111 of 129). Moreover, the ITS and STS also showed good correlation with local lymph node assay on three potency classifications, yielding accuracies of 74% (ITS) and 73% (STS). Thus, the inclusion of log Kow in analysis could give both strategies a higher predictive performance. PMID:25820183

  14. Plant peptide hormone signalling.

    PubMed

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions. PMID:26374891

  15. Susceptibility of Recently Collected Spanish Pneumococci Nonsusceptible to Oral Penicillin from Serotypes Not Included in the 7-Valent Conjugate Vaccine▿

    PubMed Central

    Fenoll, Asunción; Aguilar, Lorenzo; Giménez, María-José; Vicioso, María-Dolores; Robledo, Olga; Granizo, Juan-José; Coronel, Pilar

    2010-01-01

    The susceptibilities of pneumococci recently collected (up to June 2009) in Spain (500 isolates nonsusceptible to oral penicillin and 150 susceptible isolates) from serotypes not included in the conjugate vaccine were determined. Most nonsusceptible isolates (53.6%) belonged to serotype 19A. Susceptibility rates in serotype 19A penicillin-intermediate (n = 201)/penicillin-resistant (n = 67) isolates were <33%/≤6.0% (erythromycin and oral cephalosporins with defined breakpoints), 85.1%/11.9% (amoxicillin), and 96.0%/52.2% (cefotaxime), respectively. Low susceptibility to common oral β-lactams was also found in serotypes 11A (95.5% susceptibility to cefotaxime and erythromycin) and 35B. PMID:20308373

  16. Multifunctional nanoparticles composite for MALDI-MS: Cd2+-doped carbon nanotubes with CdS nanoparticles as the matrix, preconcentrating and accelerating probes of microwave enzymatic digestion of peptides and proteins for direct MALDI-MS analysis.

    PubMed

    Shrivas, Kamlesh; Wu, Hui-Fen

    2010-12-01

    For the first time, we utilized multifunctional nanoparticles composite (NPs composite) for matrix-assisted laser desorption/ionization mass spectrometric (MALDI-MS) analysis of peptides and proteins. Multiwalled carbon nanotubes doped with Cd(2+) ions and modified with cadmium sulfide NPs were synthesized by a chemical reduction method at room temperature. The multifunctional NPs composite applied for the analysis of peptides and microwave-digested proteins in the atmospheric pressure matrix-assisted laser desorption/ionization ion-trap and MALDI time-of-flight (TOF) mass spectrometry (MS) was successfully demonstrated. The maximum detection sensitivity for peptides in MALDI-MS was achieved by the adsorption of negatively charged peptides onto the surfaces of NP composite through electrostatic interactions. The optimal conditions of peptide mixtures were obtained at 20 min of incubation time using 1 mg of NPs composite when the pH of the sample solution was kept higher than the pI values of peptides. The potentiality of the NP composite in the preconcentration of peptides was compared with that of the individual NP by calculating the preconcentration factors (PF) and found that the NPs composite showed a 4-6 times of PF than the other NPs. In addition, the NPs composite was also applied as heat-absorbing materials for efficient microwave tryptic digestion of cytochrome c and lysozyme from milk protein in MALDI-TOF-MS analysis. We believe that the use of NPs composite technique would be an efficient and powerful preconcentrating tool for MALDI-MS for the study of proteome research. PMID:21053343

  17. Seasonal Variation in Penicillin Use in Mexico and Brazil: Analysis of the Impact of Over-the-Counter Restrictions

    PubMed Central

    Santa-Ana-Tellez, Yared; Mantel-Teeuwisse, Aukje K.; Leufkens, Hubert G. M.

    2014-01-01

    During 2010, Mexico and Brazil implemented policies to enforce existing laws of restricting over-the-counter sales of antibiotics. We determined if the enforcement led to more appropriate antibiotic use by measuring changes in seasonal variation of penicillin use. We used retail quarterly sales data in defined daily doses per 1,000 inhabitant-days (DDD/TID) from IMS Health from the private sector in Mexico and Brazil from the first quarter of 2007 to the first quarter of 2013. This database contains information on volume of antibiotics sold in retail pharmacies using information from wholesalers. We used interrupted time-series models controlling for external factors with the use of antihypertensives with interaction terms to assess changes in trend, level, and variation in use between quarters for total penicillin use and by active substance. The most used penicillin was amoxicillin, followed by amoxicillin-clavulanic acid and ampicillin (minimal use in Brazil). Before the restrictions, the seasonal variation in penicillin use was 1.1 DDD/TID in Mexico and 0.8 DDD/TID in Brazil. In Mexico, we estimated a significant decrease in the seasonal variation of 0.4 DDD/TID after the restriction, mainly due to changes in seasonal variation of amoxicillin and ampicillin. In Brazil, the seasonal variation did not change significantly, overall and in the breakdown by individual active substances. For Mexico, inappropriate penicillin use may have diminished after the restrictions were enforced. For Brazil, increasing use and no change in seasonal variation suggest that further efforts are needed to reduce inappropriate penicillin use. PMID:25313222

  18. Peptide Binding for Bio-Based Nanomaterials.

    PubMed

    Bedford, N M; Munro, C J; Knecht, M R

    2016-01-01

    Peptide-based strategies represent transformative approaches to fabricate functional inorganic materials under sustainable conditions by modeling the methods exploited in biology. In general, peptides with inorganic affinity and specificity have been isolated from organisms and through biocombinatorial selection techniques (ie, phage and cell surface display). These peptides recognize and bind the inorganic surface through a series of noncovalent interactions, driven by both enthalpic and entropic contributions, wherein the biomolecules wrap the metallic nanoparticle structure. Through these interactions, modification of the inorganic surface can be accessed to drive the incorporation of significantly disordered surface metal atoms, which have been found to be highly catalytically active for a variety of chemical transformations. We have employed synthetic, site-directed mutagenesis studies to reveal localized binding effects of the peptide at the metallic nanoparticle structure to begin to identify the biological basis of control over biomimetic nanoparticle catalytic activity. The protocols described herein were used to fabricate and characterize peptide-capped nanoparticles in atomic resolution to identify peptide sequence effects on the surface structure of the materials, which can then be directly correlated to the catalytic activity to identify structure/function relationships. PMID:27586350

  19. Efficient enzymatic synthesis of ampicillin by mutant Alcaligenes faecalis penicillin G acylase.

    PubMed

    Deng, Senwen; Su, Erzheng; Ma, Xiaoqiang; Yang, Shengli; Wei, Dongzhi

    2015-04-10

    Semi-synthetic β-lactam antibiotics (SSBAs) are one of the most important antibiotic families in the world market. Their enzymatic synthesis can be catalyzed by penicillin G acylases (PGAs). In this study, to improve enzymatic synthesis of ampicillin, site-saturating mutagenesis was performed on three conserved amino acid residues: βF24, αR146, and αF147 of thermo-stable penicillin G acylase from Alcaligenes faecalis (Af PGA). Four mutants βF24G, βF24A, βF24S, and βF24P were recovered by screening the mutant bank. Kinetic analysis of them showed up to 800-fold increased kcat/Km value for activated acyl donor D-phenylglycine methyl ester (D-PGME). When βF24G was used for ampicillin synthesis under kinetic control at industrially relevant conditions, 95% of nucleophile 6-aminopenicillanic acid (6-APA) was converted to ampicillin in aqueous medium at room temperature while 12% process time is needed to reach maximum product accumulation at 25% enzyme concentration compared with the wild-type Af PGA. Consequently, process productivity of enzymatic synthesis of ampicillin catalyzed by Af PGA was improved by more than 130 times, which indicated an enzyme viable for efficient SSBAs synthesis. PMID:25681630

  20. Growth of soil bacteria, on penicillin and neomycin, not previously exposed to these antibiotics.

    PubMed

    Zhang, Qichun; Dick, Warren A

    2014-09-15

    There is growing evidence that bacteria, in the natural environment (e.g. the soil), can exhibit naturally occurring resistance/degradation against synthetic antibiotics. Our aim was to assess whether soils, not previously exposed to synthetic antibiotics, contained bacterial strains that were not only antibiotic resistant, but could actually utilize the antibiotics for energy and nutrients. We isolated 19 bacteria from four diverse soils that had the capability of growing on penicillin and neomycin as sole carbon sources up to concentrations of 1000 mg L(-1). The 19 bacterial isolates represent a diverse set of species in the phyla Proteobacteria (84%) and Bacteroidetes (16%). Nine antibiotic resistant genes were detected in the four soils but some of these genes (i.e. tetM, ermB, and sulI) were not detected in the soil isolates indicating the presence of unculturable antibiotic resistant bacteria. Most isolates that could subsist on penicillin or neomycin as sole carbon sources were also resistant to the presence of these two antibiotics and six other antibiotics at concentrations of either 20 or 1000 mg L(-1). The potentially large and diverse pool of antibiotic resistant and degradation genes implies ecological and health impacts yet to be explored and fully understood. PMID:24956077

  1. New penicillin-producing Penicillium species and an overview of section Chrysogena.

    PubMed

    Houbraken, J; Frisvad, J C; Seifert, K A; Overy, D P; Tuthill, D M; Valdez, J G; Samson, R A

    2012-12-01

    Species classified in Penicillium sect. Chrysogena are primary soil-borne and the most well-known members are P. chrysogenum and P. nalgiovense. Penicillium chrysogenum has received much attention because of its role in the production on penicillin and as a contaminant of indoor environments and various food and feedstuffs. Another biotechnologically important species is P. nalgiovense, which is used as a fungal starter culture for the production of fermented meat products. Previous taxonomic studies often had conflicting species circumscriptions. Here, we present a multigene analysis, combined with phenotypic characters and extrolite data, demonstrating that sect. Chrysogena consists of 18 species. Six of these are newly described here (P. allii-sativi, P. desertorum, P. goetzii, P. halotolerans, P. tardochrysogenum, P. vanluykii) and P. lanoscoeruleum was found to be an older name for P. aethiopicum. Each species produces a unique extrolite profile. The species share phenotypic characters, such as good growth on CYA supplemented with 5 % NaCl, ter- or quarterverticillate branched conidiophores and short, ampulliform phialides (< 9 μm). Conidial colours, production of ascomata and ascospores, shape and ornamentation of conidia and growth rates on other agar media are valuable for species identification. Eight species (P. allii-sativi, P. chrysogenum, P. dipodomyis, P. flavigenum, P. nalgiovense, P. rubens, P. tardochrysogenum and P. vanluykii) produce penicillin in culture. PMID:23606767

  2. Heat-labile enterotoxin of Escherichia coli and its site-directed mutant LTK63 enhance the proliferative and cytotoxic T-cell responses to intranasally co-immunized synthetic peptides.

    PubMed

    Partidos, C D; Salani, B F; Pizza, M; Rappuoli, R

    1999-04-15

    The adjuvanticity of heat-labile enterotoxin (LT) of Escherichia coli and its non-toxic mutant LTK63 was assessed and compared for intranasal immunization of synthetic peptides. Mice immunized intranasally with LT, or its mutant LTK63, generated strong systemic proliferative and cytotoxic T-cell responses to co-administered synthetic peptides. The wild LT toxin promoted higher peptide-specific proliferative and cytotoxic T-cell responses than the LTK63 mutant. Moreover, the wild-type LT toxin was shown to promote peptide-specific memory CTL responses which were detectable 1 year after intranasal priming. Both LT and LTK63 molecules were shown to be immunogenic, with serum antibody subclasses being predominantly IgG1 and to a lesser extent IgG2a. These findings demonstrate that cellular immune responses to small synthetic peptide antigens administered by the intranasal route can be potentiated with the use of mucosal adjuvants. Moreover, the ability of LT and LTK63 to promote both CD4+ and CD8+ T-cell responses will have relevance to the design and production of future mucosal vaccines. PMID:10369128

  3. Neisseria meningitidis C:2b:P1.2,5 with Intermediate Resistance to Penicillin, Portugal

    PubMed Central

    Dias, Ricardo; Ferreira, Eugénia

    2004-01-01

    For 1 year, serogroup, serotype, serosubtype, and penicillin susceptibility of meningococci circulating in various regions in Portugal were evaluated. Most frequent phenotypes were B:4:P1.15 (13.4%) and C:2b:P1.2,5 (75.9%), which are also common in Spain. Overall, 27.5% of C:2b:P1.2,5 strains showed intermediate resistance to penicillin. Laboratory-based surveillance of meningococcal infection in Portugal provides important information to assess the adequacy of public health measures. PMID:15109429

  4. Simulation of Peptides at Aqueous Interfaces

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Wilson, M.; Chipot, C.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Behavior of peptides at water-membrane interfaces is of great interest in studies on cellular transport and signaling, membrane fusion, and the action of toxins and antibiotics. Many peptides, which exist in water only as random coils, can form sequence-dependent, ordered structures at aqueous interfaces, incorporate into membranes and self-assembly into functional units, such as simple ion channels. Multi -nanosecond molecular dynamics simulations have been carried out to study the mechanism and energetics of interfacial folding of both non-polar and amphiphilic peptides, their insertion into membranes and association into higher-order structures. The simulations indicate that peptides fold non-sequentially, often through a series of amphiphilic intermediates. They further incorporate into the membrane in a preferred direction as folded monomers, and only then aggregate into dimers and, possibly, further into "dimers of dimers".

  5. Cell-penetrating peptides transport therapeutics into cells.

    PubMed

    Ramsey, Joshua D; Flynn, Nicholas H

    2015-10-01

    Nearly 30years ago, certain small, relatively nontoxic peptides were discovered to be capable of traversing the cell membrane. These cell-penetrating peptides, as they are now called, have been shown to not only be capable of crossing the cell membrane themselves but can also carry many different therapeutic agents into cells, including small molecules, plasmid DNA, siRNA, therapeutic proteins, viruses, imaging agents, and other various nanoparticles. Many cell-penetrating peptides have been derived from natural proteins, but several other cell-penetrating peptides have been developed that are either chimeric or completely synthetic. How cell-penetrating peptides are internalized into cells has been a topic of debate, with some peptides seemingly entering cells through an endocytic mechanism and others by directly penetrating the cell membrane. Although the entry mechanism is still not entirely understood, it seems to be dependent on the peptide type, the peptide concentration, the cargo the peptide transports, and the cell type tested. With new intracellular disease targets being discovered, cell-penetrating peptides offer an exciting approach for delivering drugs to these intracellular targets. There are hundreds of cell-penetrating peptides being studied for drug delivery, and ongoing studies are demonstrating their success both in vitro and in vivo. PMID:26210404

  6. Synthesis of gold nanoparticles on the surface of pyrolytic graphite using penicillin as a stabilizing reagent and the catalytic oxidation of α-naphthylamine

    NASA Astrophysics Data System (ADS)

    Song, Y. Z.; Song, Y.; Cheng, Z. P.; Zhou, J. F.; Wei, C.

    2013-01-01

    Electrochemical synthesis of gold nanoparticles on the surface of pyrolytic graphite using penicillin as a stabilizing reagent was proposed. The gold nanoparticles were characterized by scanning electron microscopy, cyclic voltammetry, IR spectra, UV spectra, and powder X-ray diffraction spectra. The electro-chemical catalysis of penicillin for α-naphthylamine was demonstrated.

  7. Application of kidney inhibition swab tests to evaluate penicillin-G residues in sow tissues and body fluids following intramuscular injection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Kidney inhibition swab (KIS) tests, recently adapted by the US FSIS for antibiotics on-site screening, were employed to evaluate the depletion of penicillin-G residues from kidney, liver, muscle, serum, and urine of sows after intramuscular (IM) penicillin-G procaine administration. Sows (n=130; 22...

  8. Antihypertensive peptides from curd

    PubMed Central

    Dabarera, Melani Chathurika; Athiththan, Lohini V.; Perera, Rasika P.

    2015-01-01

    Introduction: Curd (Dadhi) peptides reduce hypertension by inhibiting angiotensin converting enzyme (ACE) and serum cholesterol. Peptides vary with bacterial species and milk type used during fermentation. Aim: To isolate and assay the antihypertensive peptides, before and after digestion, in two commercially available curd brands in Sri Lanka. Materials and Methods: Whey (Dadhi Mastu) separated by high-speed centrifugation was isolated using reverse-phase-high- performance liquid chromatography (HPLC). Eluted fractions were analyzed for ACE inhibitory activity using modified Cushman and Cheung method. Curd samples were subjected to enzymatic digestion with pepsin, trypsin, and carboxypeptidase-A at their optimum pH and temperature. Peptides isolated using reverse-phase-HPLC was assayed for ACE inhibitory activity. Results: Whey peptides of both brands gave similar patterns (seven major and five minor peaks) in HPLC elution profile. Smaller peptides concentration was higher in brand 1 and penta-octapeptides in brand 2. Pentapeptide had the highest ACE inhibitory activity (brand 2–90% and brand 1–73%). After digestion, di and tri peptides with similar inhibitory patterns were obtained in both which were higher than before digestion. Thirteen fractions were obtained, where nine fractions showed more than 70% inhibition in both brands with 96% ACE inhibition for a di-peptide. Conclusion: Curd has ACE inhibitory peptides and activity increases after digestion. PMID:27011726

  9. Antimicrobial Peptides in Reptiles

    PubMed Central

    van Hoek, Monique L.

    2014-01-01

    Reptiles are among the oldest known amniotes and are highly diverse in their morphology and ecological niches. These animals have an evolutionarily ancient innate-immune system that is of great interest to scientists trying to identify new and useful antimicrobial peptides. Significant work in the last decade in the fields of biochemistry, proteomics and genomics has begun to reveal the complexity of reptilian antimicrobial peptides. Here, the current knowledge about antimicrobial peptides in reptiles is reviewed, with specific examples in each of the four orders: Testudines (turtles and tortosises), Sphenodontia (tuataras), Squamata (snakes and lizards), and Crocodilia (crocodilans). Examples are presented of the major classes of antimicrobial peptides expressed by reptiles including defensins, cathelicidins, liver-expressed peptides (hepcidin and LEAP-2), lysozyme, crotamine, and others. Some of these peptides have been identified and tested for their antibacterial or antiviral activity; others are only predicted as possible genes from genomic sequencing. Bioinformatic analysis of the reptile genomes is presented, revealing many predicted candidate antimicrobial peptides genes across this diverse class. The study of how these ancient creatures use antimicrobial peptides within their innate immune systems may reveal new understandings of our mammalian innate immune system and may also provide new and powerful antimicrobial peptides as scaffolds for potential therapeutic development. PMID:24918867

  10. Peptide binding to a bacterial signal peptidase visualized by peptide tethering and carrier-driven crystallization

    PubMed Central

    Ting, Yi Tian; Harris, Paul W. R.; Batot, Gaelle; Brimble, Margaret A.; Baker, Edward N.; Young, Paul G.

    2016-01-01

    Bacterial type I signal peptidases (SPases) are membrane-anchored serine proteases that process the signal peptides of proteins exported via the Sec and Tat secretion systems. Despite their crucial importance for bacterial virulence and their attractiveness as drug targets, only one such enzyme, LepB from Escherichia coli, has been structurally characterized, and the transient nature of peptide binding has stymied attempts to directly visualize SPase–substrate complexes. Here, the crystal structure of SpsB, the type I signal peptidase from the Gram-positive pathogen Staphylococcus aureus, is reported, and a peptide-tethering strategy that exploits the use of carrier-driven crystallization is described. This enabled the determination of the crystal structures of three SpsB–peptide complexes, both with cleavable substrates and with an inhibitory peptide. SpsB–peptide interactions in these complexes are almost exclusively limited to the canonical signal-peptide motif Ala-X-Ala, for which clear specificity pockets are found. Minimal contacts are made outside this core, with the variable side chains of the peptides accommodated in shallow grooves or exposed faces. These results illustrate how high fidelity is retained despite broad sequence diversity, in a process that is vital for cell survival. PMID:26870377

  11. In silico analysis of different generation β lactams antibiotics with penicillin binding protein-2 of Neisseria meningitidis for curing meningococcal disease.

    PubMed

    Tripathi, Vijay; Tripathi, Pooja; Srivastava, Navita; Gupta, Dwijendra

    2014-12-01

    Neisseria meningitidis is a gram negative, diplococcic pathogen responsible for the meningococcal disease and fulminant septicemia. Penicillin-binding proteins-2 (PBPs) is crucial for the cell wall biosynthesis during cell proliferation of N. meningitidis and these are the target for β-lactam antibiotics. For many years penicillin has been recognized as the antibiotic for meningococcal disease but the meningococcus has seemed to be antibiotic resistance. In the present work we have verified the molecular interaction of Penicillin binding protein-2 N. meningitidis to different generation of β-lactam antibiotics and concluded that the third generation of β-lactam antibiotics shows efficient binding with Penicillin binding protein-2 of N. meningitidis. On the basis of binding efficiency and inhibition constant, ceftazidime emerged as the most efficient antibiotic amongst the other advanced β-lactam antibiotics against Penicillin-binding protein-2 of N. meningitidis. PMID:25118647

  12. Insulin C-peptide test

    MedlinePlus

    C-peptide ... the test depends on the reason for the C-peptide measurement. Ask your health care provider if ... C-peptide is measured to tell the difference between insulin produced by the body and insulin injected ...

  13. Bacteriocin Inducer Peptides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel peptides produced by bacteriocin-producing bacteria stimulate the production of bacteriocins in vitro. The producer bacteria are cultured in the presence of a novel inducer bacteria and a peptide having a carboxy terminal sequence of VKGLT in order to achieve an increase in bacteriocin produc...

  14. In Vitro Activity of Tebipenem, a New Oral Carbapenem Antibiotic, against Penicillin-Nonsusceptible Streptococcus pneumoniae

    PubMed Central

    Kobayashi, Reiko; Konomi, Mami; Hasegawa, Keiko; Morozumi, Miyuki; Sunakawa, Keisuke; Ubukata, Kimiko

    2005-01-01

    The in vitro activity of tebipenem (TBM), a new oral carbapenem antibiotic, against Streptococcus pneumoniae clinical isolates (n = 202) was compared with those of 15 reference agents. The isolates were classified into five genotypic classes after PCR identification of abnormal pbp1a, pbp2x, and pbp2b genes: (i) penicillin-susceptible S. pneumoniae (PSSP) isolates with no abnormal pbp genes (n = 34; 16.8%), (ii) genotypic penicillin-intermediate S. pneumoniae (gPISP) isolates with only an abnormal pbp2x gene [gPISP (2x)] (n = 48; 23.8%), (iii) gPISP isolates with abnormal pbp1a and pbp2x genes (n = 32; 15.8%), (iv) gPISP isolates with abnormal pbp2x and pbp2b genes (n = 16; 7.9%), and (v) genotypic penicillin-resistant S. pneumoniae (gPRSP) isolates with three abnormal pbp genes (n = 72; 35.6%). The majority of the strains tested had mefA (n = 59; 29.2%) or ermB (n = 91; 45%) gene-mediating macrolide resistance. For these isolates the MIC at which 90% of isolates are inhibited was significantly lower for TBM than for the reference oral antibiotics, as follows: 0.002 μg/ml for PSSP, 0.004 μg/ml for gPISP (2x), 0.016 μg/ml for gPISP (isolates with abnormal pbp1a and pbp2x genes and isolates with abnormal pbp2x and pbp2b genes), and 0.063 μg/ml for gPRSP. In addition, TBM showed excellent bactericidal activity against gPRSP isolates, which exhibited a 3-log10 decrease within 2 h when they were incubated with a concentration greater than or equal to the MIC. Inhibition of cell wall synthesis toward the long axis and subsequent cell lysis were observed by scanning electron microscopy after a short-term exposure to TBM, unlike the effects seen with cephalosporins. These data suggest that TBM has potent activity against multidrug-resistant S. pneumoniae, the causative pathogen of community-acquired respiratory tract infections. PMID:15728880

  15. Antimicrobial Peptides from Fish

    PubMed Central

    Masso-Silva, Jorge A.; Diamond, Gill

    2014-01-01

    Antimicrobial peptides (AMPs) are found widely distributed through Nature, and participate in the innate host defense of each species. Fish are a great source of these peptides, as they express all of the major classes of AMPs, including defensins, cathelicidins, hepcidins, histone-derived peptides, and a fish-specific class of the cecropin family, called piscidins. As with other species, the fish peptides exhibit broad-spectrum antimicrobial activity, killing both fish and human pathogens. They are also immunomodulatory, and their genes are highly responsive to microbes and innate immuno-stimulatory molecules. Recent research has demonstrated that some of the unique properties of fish peptides, including their ability to act even in very high salt concentrations, make them good potential targets for development as therapeutic antimicrobials. Further, the stimulation of their gene expression by exogenous factors could be useful in preventing pathogenic microbes in aquaculture. PMID:24594555

  16. Mechanism and kinetics of peptide partitioning into membranes

    SciTech Connect

    Ulmschneider, Martin; Killian, J Antoinette; Doux, Jacques P. F.; Smith, Jeremy C; Ulmschneider, Jakob

    2010-02-01

    Partitioning properties of transmembrane (TM) polypeptide segments directly determine membrane protein folding, stability, and function, and their understanding is vital for rational design of membrane active peptides. However, direct determination of water-to-bilayer transfer of TM peptides has proved difficult. Experimentally, sufficiently hydrophobic peptides tend to aggregate, while atomistic computer simulations at physiological temperatures cannot yet reach the long time scales required to capture partitioning. Elevating temperatures to accelerate the dynamics has been avoided, as this was thought to lead to rapid denaturing. However, we show here that model TM peptides (WALP) are exceptionally thermostable. Circular dichroism experiments reveal that the peptides remain inserted into the lipid bilayer and are fully helical, even at 90 C. At these temperatures, sampling is 50 500 times faster, sufficient to directly simulate spontaneous partitioning at atomic resolution. A folded insertion pathway is observed, consistent with three-stage partitioning theory. Elevated temperature simulation ensembles further allow the direct calculation of the insertion kinetics, which is found to be first-order for all systems. Insertion barriers are Hin = 15 kcal/mol for a general hydrophobic peptide and 23 kcal/mol for the tryptophan-flanked WALP peptides. The corresponding insertion times at room temperature range from 8.5 s to 163 ms. High-temperature simulations of experimentally validated thermostable systems suggest a new avenue for systematic exploration of peptide partitioning properties.

  17. Depletion of intramuscularly and subcutaneously injected procaine penicillin G from tissues and plasma of yearling beef steers.

    PubMed Central

    Korsrud, G O; Boison, J O; Papich, M G; Yates, W D; MacNeil, J D; Janzen, E D; Cohen, R D; Landry, D A; Lambert, G; Yong, M S

    1993-01-01

    Withdrawal periods required when doses of 24,000 IU and 66,000 IU of procaine penicillin G/kg body weight were administered to yearling beef steers by intramuscular injection daily for five consecutive days were investigated. These dosages are in excess of product label recommendations, but are in the range of procaine penicillin G dosages that have been administered for the treatment of some feedlot bacterial diseases. The approved dose in Canada is 7,500 IU/kg body weight intramuscularly, once daily, with a withdrawal period of five days. Based on the tissue residue data from this study, the appropriate withdrawal period is ten days for the 24,000 IU/kg body weight dose and 21 days for the 66,000 IU/kg body weight dose when administered intramuscularly to yearling beef steers. In a related study, 18 yearling beef steers received 66,000 IU of procaine penicillin G/kg body weight administered by subcutaneous injection, an extra-label treatment in terms of both dose and route of administration, typical of current practice in some circumstances. Deposits of the drug were visible at subcutaneous injection sites up to ten days after injection, with more inflammation and hemorrhage observed than for intramuscular injections of the same dose. These results suggest that procaine penicillin G should not be administered subcutaneously at high doses; and therefore a withdrawal period was not established for subcutaneous injection. Images Fig. 3. Fig. 4. PMID:8269359

  18. Depletion of penicillin G residues in heavy sows after intramuscular injection. Part II: Application of kidney inhibition swab tests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sows (n = 126; 228 ± 30.1 kg) were administered daily IM doses of penicillin G procaine (33 000 IU/kg bw; 5× the label dose) for 3 consecutive days using three different administration patterns. Within treatment, six sows each were slaughtered on withdrawal day 5, 10, 15, 20, 25, 32, and 39. Tissues...

  19. Evaluation of penicillin G residues by kidney inhibition swab tests in sow body fluids and tissues following intramuscular injection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2011, the USDA-Food Safety and Inspection Service (FSIS) changed the method used for screening swine tissues for antimicrobial residues to the Kidney Inhibition Swab (KIS(TM)) from the Fast Antimicrobial Screen Test. A high dose of penicillin G procaine relative to a label dose is commonly used ...

  20. Development of the radiation-resistant strain of Moraxella osloensis and effect of penicillin G on its growth

    NASA Astrophysics Data System (ADS)

    Lim, Sangyong; Yun, Hyejeong; Joe, Minho; Kim, Dongho

    2009-07-01

    A series of repeated exposures to γ-radiation with intervening outgrowth of survivors was used to develop radioresistant cultures of Moraxella osloensis that have been recognized as potential pathogenic microorganism. The D10 value of the radiation-resistant strain, 5.903±0.006 kGy, was increased by four-fold compared to the parent wild-type strain, 1.637±0.004 kGy. Since most strains of M. osloensis are sensitive to penicillin, we have surveyed the sensitivity of radiation-resistant strain to this antibiotic. When the optical density was monitored after the addition of penicillin G, the radioresistant strain appeared to be more resistant to only a low concentration of penicillin G (0.5 U/ml) than the parent strain. Interestingly, however, there was no apparent difference in the number of viable cells between both strains. Scanning electron microscope data showed that the resistance cells were generally larger than the parent cells, suggesting that this increase in size may cause a higher optical density of radioresistant cells. In conclusion, radiation mutation does not affect the penicillin resistance of M. osloensis.

  1. Evaluation of penicillin G residues by kidney inhibition swab tests in sow body fluids and tissues following intramuscular injection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2011, the USDA-Food Safety and Inspection Service (FSIS) changed the method used for screening swine tissues for antimicrobial residues from the Fast Antimicrobial Screen Test to the Kidney Inhibition Swab (KIS(TM)). Here, we describe the use of KIS(TM) test for the detection of penicillin G res...

  2. A class IIa peptide from Enterococcus mundtii inhibits bacteria associated with otitis media.

    PubMed

    Knoetze, H; Todorov, S D; Dicks, L M T

    2008-03-01

    Peptide ST4SA, produced by Enterococcus mundtii ST4SA, inhibits the growth of Acinetobacter baumannii, Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, Streptococcus pneumoniae and Gram-positive bacteria isolated from patients diagnosed with middle ear infections. The peptide adsorbed at a level of 94% to S. pneumoniae 40, Pseudomonas aeruginosa 25 and E. faecium HKLHS. Low concentrations of peptide ST4SA (51200 arbitrary units (AU)/mL) caused DNA and enzyme leakage from target cells, whilst 1638400AU/mL caused cell lysis. No decrease in antimicrobial activity was observed when tested on solid medium with human blood as base. Peptide ST4SA revealed a similar level of activity compared with tetracycline (30 microg), but much higher activity compared with nasal sprays, aminoglycosides, cephalosporins, fluoroquinolones, lincosamides, macrolides, nitroimidazole, penicillin, quinolones, sulphonamides, chloramphenicol, furazolidone, fusidic acid, rifampicin, trimethoprim, trimethoprim/sulfamethoxazole and vancomycin when tested in vitro. Peptide ST4SA dissipates the proton-motive force and may be used in the treatment of multidrug-resistant strains where antibiotics are excluded from cells by efflux pumps dependent on the membrane proton gradient. PMID:18155886

  3. The Impact of Reporting a Prior Penicillin Allergy on the Treatment of Methicillin-Sensitive Staphylococcus aureus Bacteremia

    PubMed Central

    Shenoy, Erica S.; Huang, Mingshu; Kuhlen, James L.; Ware, Winston A.; Parker, Robert A.; Walensky, Rochelle P.

    2016-01-01

    Background Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy. Objective To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia. Design Retrospective cohort. Participants Adult inpatients with MSSA bacteremia, January 2009 through October 2013. Main Measures The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes. Key Results Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]). Conclusions Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the

  4. Jarisch-Herxheimer reaction among HIV-positive patients with early syphilis: azithromycin versus benzathine penicillin G therapy

    PubMed Central

    Tsai, Mao-Song; Yang, Chia-Jui; Lee, Nan-Yao; Hsieh, Szu-Min; Lin, Yu-Hui; Sun, Hsin-Yun; Sheng, Wang-Huei; Lee, Kuan-Yeh; Yang, Shan-Ping; Liu, Wen-Chun; Wu, Pei-Ying; Ko, Wen-Chien; Hung, Chien-Ching

    2014-01-01

    Introduction The Jarisch-Herxheimer reaction, a febrile inflammatory reaction that often occurs after the first dose of chemotherapy in spirochetal diseases, may result in deleterious effects to patients with neurosyphilis and to pregnant women. A single 2-g oral dose of azithromycin is an alternative treatment to benzathine penicillin G for early syphilis in areas with low macrolide resistance. With its potential anti-inflammatory activity, the impact of azithromycin on the incidence of the Jarisch-Herxheimer reaction in HIV-positive patients with early syphilis has rarely been investigated. Methods In HIV-positive patients with early syphilis, the Jarisch-Herxheimer reaction was prospectively investigated using the same data collection form in 119 patients who received benzathine penicillin G between 2007 and 2009 and 198 who received azithromycin between 2012 and 2013, when shortage of benzathine penicillin G occurred in Taiwan. Between 2012 and 2013, polymerase chain reaction (PCR) assay was performed to detect Treponema pallidum DNA in clinical specimens, and PCR restriction fragment length polymorphism of the 23S ribosomal RNA was performed to detect point mutations (2058G or A2059G) that are associated with macrolide resistance. Results The overall incidence of the Jarisch-Herxheimer reaction was significantly lower in patients receiving azithromycin than those receiving benzathine penicillin G (14.1% vs. 56.3%, p<0.001). The risk increased with higher rapid plasma reagin (RPR) titres (adjusted odds ratio [AOR] per 1-log2 increase, 1.21; confidence interval [CI], 1.04–1.41), but decreased with prior penicillin therapy for syphilis (AOR, 0.37; 95% CI, 0.19–0.71) and azithromycin treatment (AOR, 0.15; 95% CI, 0.08–0.29). During the study period, 310 specimens were obtained from 198 patients with syphilis for PCR assays, from whom T. pallidum was identified in 76 patients, one of whom (1.3%) was found to be infected with T. pallidum harbouring the

  5. Antimicrobial Cyclic Peptides for Plant Disease Control

    PubMed Central

    Lee, Dong Wan; Kim, Beom Seok

    2015-01-01

    Antimicrobial cyclic peptides derived from microbes bind stably with target sites, have a tolerance to hydrolysis by proteases, and a favorable degradability under field conditions, which make them an attractive proposition for use as agricultural fungicides. Antimicrobial cyclic peptides are classified according to the types of bonds within the ring structure; homodetic, heterodetic, and complex cyclic peptides, which in turn reflect diverse physicochemical features. Most antimicrobial cyclic peptides affect the integrity of the cell envelope. This is achieved through direct interaction with the cell membrane or disturbance of the cell wall and membrane component biosynthesis such as chitin, glucan, and sphingolipid. These are specific and selective targets providing reliable activity and safety for non-target organisms. Synthetic cyclic peptides produced through combinatorial chemistry offer an alternative approach to develop antimicrobials for agricultural uses. Those synthesized so far have been studied for antibacterial activity, however, the recent advancements in powerful technologies now promise to provide novel antimicrobial cyclic peptides that are yet to be discovered from natural resources. PMID:25774105

  6. Antimicrobial and Immunomodulatory Activities of PR-39 Derived Peptides

    PubMed Central

    Veldhuizen, Edwin J. A.; Schneider, Viktoria A. F.; Agustiandari, Herfita; van Dijk, Albert; Tjeerdsma-van Bokhoven, Johanna L. M.; Bikker, Floris J.; Haagsman, Henk P.

    2014-01-01

    The porcine cathelicidin PR-39 is a host defence peptide that plays a pivotal role in the innate immune defence of the pig against infections. Besides direct antimicrobial activity, it is involved in immunomodulation, wound healing and several other biological processes. In this study, the antimicrobial- and immunomodulatory activity of PR-39, and N- and C-terminal derivatives of PR-39 were tested. PR-39 exhibited an unexpected broad antimicrobial spectrum including several Gram positive strains such as Bacillus globigii and Enterococcus faecalis. Of organisms tested, only Staphylococcus aureus was insensitive to PR-39. Truncation of PR-39 down to 15 (N-terminal) amino acids did not lead to major loss of activity, while peptides corresponding to the C-terminal part of PR-39 were hampered in their antimicrobial activity. However, shorter peptides were all much more sensitive to inhibition by salt. Active peptides induced ATP leakage and loss of membrane potential in Bacillus globigii and Escherichia coli, indicating a lytic mechanism of action for these peptides. Finally, only the mature peptide was able to induce IL-8 production in porcine macrophages, but some shorter peptides also had an effect on TNF-α production showing differential regulation of cytokine induction by PR-39 derived peptides. None of the active peptides showed high cytotoxicity highlighting the potential of these peptides for use as an alternative to antibiotics. PMID:24755622

  7. Structural modelling of substrate binding and inhibition in penicillin V acylase from Pectobacterium atrosepticum.

    PubMed

    Avinash, V S; Panigrahi, Priyabrata; Suresh, C G; Pundle, Archana V; Ramasamy, Sureshkumar

    2013-08-01

    Penicillin V acylases (PVAs) and bile salt hydrolases (BSHs) have considerable sequence and structural similarity; however, they vary significantly in their substrate specificity. We have identified a PVA from a Gram-negative organism, Pectobacterium atrosepticum (PaPVA) that turned out to be a remote homolog of the PVAs and BSHs reported earlier. Even though the active site residues were conserved in PaPVA it showed high specificity towards penV and interestingly the penV acylase activity was inhibited by bile salts. Comparative modelling and docking studies were carried out to understand the structural differences of the binding site that confer this characteristic property. We show that PaPVA exhibits significant differences in structure, which are in contrast to those of known PVAs and such enzymes from Gram-negative bacteria require further investigation. PMID:23850621

  8. Production of penicillin acylase by a recombinant Escherichia coli using cheese whey as substrate and inducer.

    PubMed

    De León-Rodríguez, Antonio; Rivera-Pastrana, Dulce; Medina-Rivero, Emilio; Flores-Flores, José Luis; Estrada-Baltazar, Alejandro; Ordóñez-Acevedo, Leandro G; de la Rosa, Ana P Barba

    2006-12-01

    Cheese whey (CW) is the major subproduct from cheese manufacturing and it is considered as a waste pollutant since its high content of lactose. In this work a fermentation process for the production of penicillin acylase (PA) by a recombinant Escherichia coli and using CW as unique carbon source and inducer was developed. A design factorial 3(2) was used to evaluate the influence of independent variables (dissolved oxygen and CW concentration) on the ability of E. coli W3110/pPA102 to produce PA. Maximum specific PA activity of 781 U g(-1) was attained at 5 g L(-1) of CW and 3% dissolved oxygen. The results showed that CW can be used successfully as unique carbon source and inducer for the production of recombinant proteins using constructions driven by the lac promoter and this way reducing the discharges of that pollutant to the environment. PMID:17097344

  9. Separation of penicillin G from phenylacetic acid in a supported liquid membrane system.

    PubMed

    Lee, C J; Yeh, H J; Yang, W Y; Kan, C R

    1994-02-20

    The separation of penicillin G (Pen G) from phenylacetic acid (PAA) by use of a supported liquid membrane (SLM) system with Amberlite LA-2 dissolved in 1-decanol, supported on a microporous polypropylene membrane, was studied. The results show that the individual permeability of each component in mixture was lower than that in a single compartment system and, it suggests a strong transport competition between Pen G and PAA. The SLM system in this study proved to be a promising process for the selective separation of Pen G from PAA. The maximum separation factor was found to be 1.8 under a liquid membrane resistance controlled mechanism. (c) 1994 John Wiley & Sons, Inc. PMID:18615694

  10. Inhibition of proliferation of cervical and leukemic cancer cells by penicillin G.

    PubMed

    Banerjee, Aditya; Dahiya, Meetu; Anand, M T; Kumar, Sudhir

    2013-01-01

    Cancer, despite all the efforts, still causes one in five deaths worldwide. Surgery, chemotherapy and radiotherapy provide inadequate protection and instead affect normal cells along with cancer cells. The search for cancer cures from natural products (plants and animals) has been practice for over a decade and the use of purified chemical to treat cancer still continues. Several studies have been undertaken during last three decades to find the anti-cancerous property of various plant extract and toxins secreted by animals and micro-organism. These lead to the discovery of several promising molecule having anticancer activity, some of which are in clinical trial and may emerged to be a potential future drug in cancer therapy. In this study we have used penicillin to evaluate its anti-cancer activity. It shown significant effects at cellular and molecular levels against growth of HeLa and K562 cell lines. PMID:23679330

  11. Effects of Carbon dioxide on the Rheological behavior and oxygen transfer in submerged penicillin fermentations.

    PubMed

    Ju, L K; Ho, C S; Shanahan, J F

    1991-12-01

    Fermentations of Penicillium chrysogenum have been made with different CO(2) contents in the influent gas streams. The rheological behavior of the culture broth was found to be significantly changed by exposure to high levels of CO(2). This is attributed to the wide variation in the morphology of P. chrysogenum, from normal mycelia with long hyphae to roughly spherical pellets when subjected to high levels of CO(2). A correlation has been developed relating volumetric O(2) transfer coefficients, k(L)a, with the effective O(2) diffusion coefficients, D(e), and the apparent viscosities, micro(app), based on the results obtained in this study. The use of CO(2) as a potent means for altering the rheological properties of culture broths and consequently improving the O(2) transfer capabilities in penicillin fermentations was clearly demonstrated. PMID:18600719

  12. [Comparison between penicillin and amoxicillin-clavulanic acid for the treatment of recurrent tonsillopharyngitis in childhood].

    PubMed

    Asensi, F; López-Hontangas, J L; Otero, M; Santos, M; Román, J; Pérez-Tamarit, D

    1999-09-01

    Fifty-one children aged 2-14 years with recurrent tonsillopharyngitis, presenting dysphagia, fever and lymphadenitis, with more than two similar episodes in the last three years and showing a beta-hemolytic group A streptococci in the pharyngeal smear, were studied. They underwent random treatment for ten days with phenoxymethylpenicillin (40-60 mg/kg/day) (n = 28) or amoxicillin-clavulanic acid (20-40 mg/kg/day) (n = 23) taken orally three times a day. Clinical and bacteriological tests were carried out at 10 days and 2, 6 and 12 months post-treatment. The clinical and bacteriological results showed the superiority of the amoxicillin-clavulanic acid treatment both in the short term (disappearance of symptoms) and in the long term (decrease in recurrence). These results support the idea that betalactamases produced by the pharyngeal flora play an important role in the failures of penicillin. PMID:10878510

  13. Spherulitic assembly of peptide nanowires via spontaneous crystallization.

    PubMed

    Han, Tae Hee

    2014-11-01

    In this work, the hierarchal arrangement of peptide nanowires was achieved via the spontaneous crystallization of peptide molecules. Peptide molecules, which are structural motifs associated with Alzheimer's disease, assembled into one-dimensional nanowires and spontaneously formed two-dimensional peptide spherulites during crystallization of the peptide melt. The assembly behavior of the peptides could be directed by physically confining the soft mold. Furthermore, a hybrid assembly of small functional molecules, such as photoluminescent Alq3, was also achieved. Our approach offers a simple method for achieving spontaneous long-range crystalline order of building blocks approaching macroscopic dimensions and also a facile hybridization strategy to conjugate biomolecules and functional small molecules. PMID:25958606

  14. Removal of penicillin G from aqueous phase by Fe+3-TiO2/UV-A process

    PubMed Central

    2014-01-01

    Background Anomalous use of antibiotics and their entrance into the environment have increased concerns around the world. These compounds enter the environment through an incomplete metabolism and a considerable amount of them cannot be removed using conventional wastewater treatment. Therefore, the main objectives of this research are evaluation of the feasibility of using ultraviolet radiation (UV-A) and fortified nanoparticles of titanium dioxide (TiO2) doped with Fe+3 to remove penicillin G (PENG) from aqueous phase and determining the optimum conditions for maximum removal efficiency. Results The results showed that the maximum removal rate of penicillin G occurred in acidic pH (pH = 3) in the presence of 90 mg/L Fe+3-TiO2 catalyst. In addition, an increase in pH caused a decrease in penicillin G removal rate. As the initial concentration of penicillin G increased, the removal rate of antibiotic decreased. Moreover, due to the effect of UV on catalyst activation in Fe+3-TiO2/UV-A process, a significant increase was observed in the rate of antibiotic removal. All of the variables in the process had a statistically significant effect (p < 0.001). Conclusion The findings demonstrated that the antibiotic removal rate increased by decreasing pH and increasing the amount of catalyst and contact time. In conclusion, Fe+3-TiO2/UV-A process is an appropriate method for reducing penicillin G in polluted water resources. PMID:24598354

  15. Influence of prepartum pirlimycin hydrochloride or penicillin-novobiocin therapy on mastitis in heifers during early lactation.

    PubMed

    Oliver, S P; Gillespie, B E; Ivey, S J; Lewis, M J; Johnson, D L; Lamar, K C; Moorehead, H; Dowlen, H H; Chester, S T; Hallberg, J W

    2004-06-01

    A study was conducted in 2 dairy research herds to determine whether prepartum therapy of heifer mammary glands with penicillin-novobiocin or pirlimycin hydrochloride was effective for reducing the percentage of heifers and mammary quarters infected with mastitis pathogens during early lactation. Almost 96% of Jersey heifers (67 of 70) and 71.3% of quarters (199 of 279) were infected 14 d before expected calving. Of the quarters infected at 14 d before expected parturition, 75% (54 of 72) were uninfected following treatment with penicillin-novobiocin; 87% (61 of 70) were uninfected following treatment with pirlimycin, and 56% (32 of 57) were uninfected in the untreated negative control group. The majority of intramammary infections in Jersey heifers were due to coagulase-negative staphylococci (61%), Streptococcus species, primarily Streptococcus uberis (19%), and Staphylococcus aureus (8%). Almost 73% of Holstein heifers (40 of 55) and 34.3% of mammary quarters (73 of 213) were infected 14 d before expected calving. Of the quarters infected at 14 d before expected parturition, 76% (19 of 25) were uninfected following treatment with penicillin-novobiocin; 59% (17 of 29) were uninfected following treatment with pirlimycin, and 26% (5 of 19) were uninfected in the untreated negative control group. The majority of intramammary infections in Holstein heifers were due to coagulase-negative staphylococci (44%) and Staph. aureus (30%). In both herds, the bacteriological cure rate was significantly higher in heifer mammary glands treated with penicillin-novobiocin or pirlimycin hydrochloride than in untreated controls. Prepartum therapy of heifer mammary glands with penicillin-novobiocin or pirlimycin hydrochloride significantly reduced the percentage of heifers and quarters infected with mastitis pathogens during early lactation. PMID:15453485

  16. From Penicillin-Streptomycin to Amikacin-Vancomycin: Antibiotic Decontamination of Cardiovascular Homografts in Singapore

    PubMed Central

    Heng, Wee Ling; Lim, Chong Hee; Tan, Ban Hock; Chlebicki, Maciej Piotr; Lee, Winnie Hui Ling; Seck, Tracy; Lim, Yeong Phang

    2012-01-01

    Background In February 2012, the National Cardiovascular Homograft Bank (NCHB) became the first tissue bank outside of North America to receive accreditation from the American Association of Tissue Banks. From 2008 to 2009, NCHB had been decontaminating its cardiovascular homografts with penicillin and streptomycin. The antibiotic decontamination protocol was changed in January 2010 as amikacin and vancomycin were recommended, in order to cover bacteria isolated from post-recovery and post- antibiotic incubation tissue cultures. Aim The objective of this study is to determine the optimal incubation conditions for decontamination of homografts by evaluating the potencies of amikacin and vancomycin in different incubation conditions. Retrospective reviews of microbiological results were also performed for homografts recovered from 2008 to 2012, to compare the effectiveness of penicillin-streptomycin versus the amikacin-vancomycin regimens. Methods Based on microbiological assays stated in United States Pharmacopeia 31, potency of amikacin was evaluated by turbidimetric assay using Staphylococcus aureus, while vancomycin was by diffusion assay using Bacillus subtilis sporulate. Experiments were performed to investigate the potencies of individual antibiotic 6-hours post incubation at 4°C and 37°C and 4°C for 24 hours, after the results suggested that amikacin was more potent at lower temperature. Findings Tissue incubation at 4°C for 24 hours is optimal for both antibiotics, especially for amikacin, as its potency falls drastically at 37°C. Conclusion The decontamination regimen of amikacin-vancomycin at 4°C for 24 hours is effective. Nevertheless, it is imperative to monitor microbiological trends closely and evaluate the efficacy of current antibiotics regimen against emerging strains of micro-organisms. PMID:23251592

  17. The thioredoxin system of Penicillium chrysogenum and its possible role in penicillin biosynthesis.

    PubMed Central

    Cohen, G; Argaman, A; Schreiber, R; Mislovati, M; Aharonowitz, Y

    1994-01-01

    Penicillium chrysogenum is an important producer of penicillin antibiotics. A key step in their biosynthesis is the oxidative cyclization of delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) to isopenicillin N by the enzyme isopenicillin N synthase (IPNS). bis-ACV, the oxidized disulfide form of ACV is, however, not a substrate for IPNS. We report here the characterization of a broad-range disulfide reductase from P. chrysogenum that efficiently reduces bis-ACV to the thiol monomer. When coupled in vitro with IPNS, it converts bis-ACV to isopenicillin N and may therefore play a role in penicillin biosynthesis. The disulfide reductase consists of two protein components, a 72-kDa NADPH-dependent reductase, containing two identical subunits, and a 12-kDa general disulfide reductant. The latter reduces disulfide bonds in low-molecular-weight compounds and in proteins. The genes coding for the reductase system were cloned and sequenced. Both possess introns. A comparative analysis of their predicted amino acid sequences showed that the 12-kDa protein shares 26 to 60% sequence identity with thioredoxins and that the 36-kDa protein subunit shares 44 to 49% sequence identity with the two known bacterial thioredoxin reductases. In addition, the P. chrysogenum NADPH-dependent reductase is able to accept thioredoxin as a substrate. These results establish that the P. chrysogenum broad-range disulfide reductase is a member of the thioredoxin family of oxidoreductases. This is the first example of the cloning of a eucaryotic thioredoxin reductase gene. Images PMID:8106340

  18. Improved penicillin amidase production using a genetically engineered mutant of escherichia coli ATCC 11105

    SciTech Connect

    Robas, N.; Zouheiry, H.; Branlant, G.; Branlant, C. )

    1993-01-05

    Penicillin G amidase (PGA) is a key enzyme for the industrial production of penicillin G derivatives used in therapeutics. Escherichia coli ATCC 11105 is the more commonly used strain for PGA production. To improve enzyme yield, the authors constructed various recombinant E. coli HB 101 and ATCC 11105 strains. For each strain, PGA production was determined for various concentrations of glucose and phenylacetic acid (PAA) in the medium. The E. coli strain, G271, was identified as the best performer (800 U NIPAB/L). This strain was obtained as follows: an E. coli ATCC 11105 mutant (E. coli G133) was first selected based on a low negative effect of glucose on PGA production. This mutant was then transformed with a pBR322 derivative containing the PGA gene. Various experiments were made to try to understand the reason for the high productivity of E. coli G271. The host strain, E. coli G133, was found to be mutated in one (or more) gene(s) whose product(s) act(s) in trans on the PGA gene expression. Its growth is not inhibited by high glucose concentration in the medium. Interestingly, whereas glucose still exerts some negative effect on the PGA production by E. coli G133, PGA production by its transformant (E. coli G271) is stimulated by glucose. The reason for this stimulation is discussed. Transformation of E. coli G133 with a pBR322 derivative containing the HindIII fragment of the PGA gene, showed that the performance of E. coli G271 depends both upon the host strain properties and the plasmid structure. Study of the production by the less efficient E. coli HB101 derivatives brought some light on the mechanism of regulation of the PGA gene.

  19. Recent Advances Toward the Discovery of Drug-Like Peptides De novo

    PubMed Central

    Goldflam, Michael; Ullman, Christopher G.

    2015-01-01

    Peptides are important natural molecules that possess functions as diverse as antibiotics, toxins, venoms and hormones, for example. However, whilst these peptides have useful properties, there are many targets and pathways that are not addressed through the activities of natural peptidic compounds. In these circumstances, directed evolution techniques, such as phage display, have been developed to sample the diverse chemical and structural repertoire of small peptides for useful means. In this review, we consider recent concepts that relate peptide structure to drug-like attributes and how these are incorporated within display technologies to deliver peptides de novo with valuable pharmaceutical properties. PMID:26734602

  20. Peptide self-assembly for nanomaterials: the old new kid on the block.

    PubMed

    De Santis, Emiliana; Ryadnov, Maxim G

    2015-11-21

    Peptide self-assembly is an increasingly attractive tool for nanomaterials. Perfected in biology peptide self-assembling systems have impacted on nearly any conceivable nanomaterial type. However, with all the information available to us commercialisation of peptide materials remains in its infancy. In an attempt to better understand the reasons behind this shortcoming we categorise peptide self-assembled materials in relation to their non-peptide counterparts. A particular emphasis is placed on the versatility of peptide self-assembly in terms of modularity, responsiveness and functional diversity, which enables direct comparisons with more traditional material chemistries. PMID:26272066