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Sample records for nonspecific peptidases

  1. Evolutionary families of peptidases.

    PubMed Central

    Rawlings, N D; Barrett, A J

    1993-01-01

    The available amino acid sequences of peptidases have been examined, and the enzymes have been allocated to evolutionary families. Some of the families can be grouped together in 'clans' that show signs of distant relationship, but nevertheless, it appears that there may be as many as 60 evolutionary lines of peptidases with separate origins. Some of these contain members with quite diverse peptidase activities, and yet there are some striking examples of convergence. We suggest that the classification by families could be used as an extension of the current classification by catalytic type. PMID:8439290

  2. MEROPS: the peptidase database

    PubMed Central

    Rawlings, Neil D.; Barrett, Alan J.

    2000-01-01

    Important additions have been made to the MEROPS database (http://www.bi.bbsrc.ac.uk/Merops/Merops.htm ). These include sequence alignments and cladograms for many of the families of peptidases, and these have proved very helpful in the difficult task of distinguishing the sequences of peptidases that are simply species variants of already known enzymes from those that represent novel enzymes. PMID:10592261

  3. Localization of Peptidases in Lactococci

    PubMed Central

    Tan, Paris S. T.; Chapot-Chartier, Marie-Pierre; Pos, Klaas M.; Rousseau, Micheline; Boquien, Clair-Yves; Gripon, Jean-Claude; Konings, Wil N.

    1992-01-01

    The localization of two aminopeptidases, an X-prolyl-dipeptidyl aminopeptidase, an endopeptidase, and a tripeptidase in Lactococcus lactis was studied. Polyclonal antibodies raised against each purified peptidase are specific and do not cross-react with other peptidases. Experiments were performed by immunoblotting after cell fractionation and by electron microscopy of immunogold-labeled peptidases. All peptidases were found to be intracellular. However, immunogold studies showed a peripheral labeling of the X-prolyl-dipeptidyl aminopeptidase, the tripeptidase, and the endopeptidase. This peripheral location was further supported by the detection of these three enzymes in cell membrane fractions in which none of the two aminopeptidases was present. Images PMID:16348629

  4. Evolutionary lines of cysteine peptidases.

    PubMed

    Barrett, A J; Rawlings, N D

    2001-05-01

    The proteolytic enzymes that depend upon a cysteine residue for activity have come from at least seven different evolutionary origins, each of which has produced a group of cysteine peptidases with distinctive structures and properties. We show here that the characteristic molecular topologies of the peptidases in each evolutionary line can be seen not only in their three-dimensional structures, but commonly also in the two-dimensional structures. Clan CA contains the families of papain (C1), calpain (C2), streptopain (C10) and the ubiquitin-specific peptidases (C12, C19), as well as many families of viral cysteine endopeptidases. Clan CD contains the families of clostripain (C11), gingipain R (C25), legumain (C13), caspase-1 (C14) and separin (C50). These enzymes have specificities dominated by the interactions of the S1 subsite. Clan CE contains the families of adenain (C5) from adenoviruses, the eukaryotic Ulp1 protease (C48) and the bacterial YopJ proteases (C55). Clan CF contains only pyroglutamyl peptidase I (C15). The picornains (C3) in clan PA have probably evolved from serine peptidases, which still form the majority of enzymes in the clan. The cysteine peptidase activities in clans PB and CH are autolytic only. In conclusion, we suggest that although almost all the cysteine peptidases depend for activity on catalytic dyads of cysteine and histidine, it is worth noting some important differences that they have inherited from their distant ancestral peptidases. PMID:11517925

  5. Peptidase activities in Saccharomyces cerevisiae.

    PubMed Central

    Rose, B; Becker, J M; Naider, F

    1979-01-01

    At least four distinct aminopeptidase activities and a single dipeptidase activity were found in cell extracts of a leucine-lysine auxotroph of Saccharomyces cerevisiae. The assay for peptidase activity involved polyacrylamide gel electrophoresis followed by an enzyme-coupled activity staining procedure. The aminopeptidases had largely overlapping specificities but could be distinguished from one another by their electrophoretic mobilities and activities toward different peptide substrates. Substrates tested included both free and blocked di- and tripeptides and amino acid derivatives. Images PMID:378955

  6. HOW IMMUNE PEPTIDASES CHANGE SPECIFICITY

    PubMed Central

    Raymond, Wilfred W.; Trivedi, Neil N.; Makarova, Anastasia; Ray, Manisha; Craik, Charles S.; Caughey, George H.

    2014-01-01

    Cathepsin G is a major secreted serine peptidase of neutrophils and mast cells. Studies in Ctsg-null mice suggest that cathepsin G supports antimicrobial defenses but can injure host tissues. The human enzyme has unusual “Janus-faced” ability to cleave peptides at basic (tryptic) as well as aromatic (chymotryptic) sites. Tryptic activity has been attributed to acidic Glu226 in the primary specificity pocket and underlies proposed important functions such as activation of pro-urokinase. However, most mammals, including mice, substitute Ala for Glu226, suggesting that human tryptic activity may be anomalous. To test this hypothesis, human cathepsin G was compared with mouse wild type and humanized active site mutants, revealing that mouse primary specificity is markedly narrower than that of human cathepsin G, with much greater Tyr activity and selectivity and near absence of tryptic activity. It also differs from human in resisting tryptic peptidase inhibitors (e.g., aprotinin), while favoring angiotensin destruction at Tyr4 over activation at Phe8. Ala226Glu mutants of mouse cathepsin G acquire tryptic activity and human ability to activate pro-urokinase. Phylogenetic analysis reveals that the Ala226Glu missense mutation appearing in primates 31–43 million years ago represented an apparently unprecedented way to create tryptic activity in a serine peptidase. We propose that tryptic activity is not an attribute of ancestral mammalian cathepsin G, which was primarily chymotryptic, and that primate-selective broadening of specificity opposed the general trend of increased specialization by immune peptidases and allowed acquisition of new functions. PMID:20889553

  7. Evolutionary families of peptidase inhibitors.

    PubMed Central

    Rawlings, Neil D; Tolle, Dominic P; Barrett, Alan J

    2004-01-01

    The proteins that inhibit peptidases are of great importance in medicine and biotechnology, but there has never been a comprehensive system of classification for them. Some of the terminology currently in use is potentially confusing. In the hope of facilitating the exchange, storage and retrieval of information about this important group of proteins, we now describe a system wherein the inhibitor units of the peptidase inhibitors are assigned to 48 families on the basis of similarities detectable at the level of amino acid sequence. Then, on the basis of three-dimensional structures, 31 of the families are assigned to 26 clans. A simple system of nomenclature is introduced for reference to each clan, family and inhibitor. We briefly discuss the specificities and mechanisms of the interactions of the inhibitors in the various families with their target enzymes. The system of families and clans of inhibitors described has been implemented in the MEROPS peptidase database (http://merops.sanger.ac.uk/), and this will provide a mechanism for updating it as new information becomes available. PMID:14705960

  8. Extracellular peptidases from Deinococcus radiodurans.

    PubMed

    Dalmaso, Gabriel Z L; Lage, Claudia A S; Mazotto, Ana Maria; Dias, Edilma Paraguai de Souza; Caldas, Lucio Ayres; Ferreira, Davis; Vermelho, Alane B

    2015-09-01

    The extremophile Deinococcus radiodurans wild type R1 produces peptidases (metallo- and serine-) in TGY medium and in the media supplemented with human hair (HMY) and chicken feathers (FMY). Enzymatic screening on agar plates revealed peptidase activity. In TGY medium metallopeptidases were detected corresponding to a molecular mass range of 300-85 kDa (gelatinases); 280-130 (caseinases) and a 300 and a 170 kDa (keratinases); and a gelatinolytic serine peptidase (75 kDa). In HMY medium after 144 h, D. radiodurans produced keratinase (290 U/ml), gelatinase (619 U/ml) and sulfite (26 µg/ml). TGY medium produced higher proteolytic activity: 950 U/ml of gelatinolytic (24 h); 470 U/ml of keratinolytic (24 h) and 110 U/ml of caseinolytic (72 h). In the FMY medium, we found gelatinolytic (317 U/ml), keratinolytic (43 U/ml) and caseinolytic (85 U/ml) activities. The sulfite had a maximum release at 48 h (8.1 µg/ml). Enzymography analysis revealed that the keratinases degraded keratin after 24 h of reaction. The addition of sodium sulfite (1.0 %) improved the keratin degradation. Environmental Scanning Electron microscopy revealed alterations such as damage and holes in the hair fiber cuticle after D. radiodurans growth. This work presents for the first time D. radiodurans as a new keratinolytic microorganism. PMID:26216108

  9. Nonspecific Arm Pain

    PubMed Central

    Moradi, Ali; Ebrahimzadeh, Mohammad H; Ring, David

    2013-01-01

    Nonspecific activity-related arm pain is characterized by an absence of objective physical findings and symptoms that do not correspond with objective pathophysiology. Arm pain without strict diagnosis is often related to activity, work-related activity in particular, and is often seen in patients with physically demanding work. Psychological factors such as catastrophic thinking, symptoms of depression, and heightened illness concern determine a substantial percentage of the disability associated with puzzling hand and arm pains. Ergonomic modifications can help to control symptoms, but optimal health may require collaborative management incorporating psychosocial and psychological elements of illness. PMID:25207288

  10. An Essential Signal Peptide Peptidase Identified in an RNAi Screen of Serine Peptidases of Trypanosoma brucei

    PubMed Central

    Moss, Catherine X.; Brown, Elaine; Hamilton, Alana; Van der Veken, Pieter; Augustyns, Koen; Mottram, Jeremy C.

    2015-01-01

    The serine peptidases of Trypanosoma brucei have been viewed as potential drug targets. In particular, the S9 prolyl oligopeptidase subfamily is thought to be a good avenue for drug discovery. This is based on the finding that some S9 peptidases are secreted and active in the mammalian bloodstream, and that they are a class of enzyme against which drugs have successfully been developed. We collated a list of all serine peptidases in T. brucei, identifying 20 serine peptidase genes, of which nine are S9 peptidases. We screened all 20 serine peptidases by RNAi to determine which, if any, are essential for bloodstream form T. brucei survival. All S9 serine peptidases were dispensable for parasite survival in vitro, even when pairs of similar genes, coding for oligopeptidase B or prolyl oligopeptidase, were targeted simultaneously. We also found no effect on parasite survival in an animal host when the S9 peptidases oligopeptidase B, prolyl oligopeptidase or dipeptidyl peptidase 8 were targeted. The only serine peptidase to emerge from the RNAi screen as essential was a putative type-I signal peptide peptidase (SPP1). This gene was essential for parasite survival both in vitro and in vivo. The growth defect conferred by RNAi depletion of SPP1 was rescued by expression of a functional peptidase from an RNAi resistant SPP1 gene. However, expression of catalytically inactive SPP1 was unable to rescue cells from the SPP1 depleted phenotype, demonstrating that SPP1 serine peptidase activity is necessary for T. brucei survival. PMID:25816352

  11. Dipeptidyl peptidase 4 – an important digestive peptidase in Tenebrio molitor larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dipeptidyl peptidase 4 (DPP 4) is a proline specific serine peptidase that plays an important role in different regulatory processes in mammals. In this report, we isolated and characterized a unique secreted digestive DPP 4 from the anterior midgut of a stored product pest, Tenebrio molitor larvae ...

  12. Peptidases and peptidase inhibitors in gut of caterpillars and in the latex of their host plants.

    PubMed

    Ramos, Márcio V; Pereira, Danielle A; Souza, Diego P; Silva, Maria-Lídia S; Alencar, Luciana M R; Sousa, Jeanlex S; Queiroz, Juliany-Fátima N; Freitas, Cleverson D T

    2015-01-01

    Studies investigating the resistance-susceptibility of crop insects to proteins found in latex fluids have been reported. However, latex-bearing plants also host insects. In this study, the gut proteolytic system of Pseudosphinx tetrio, which feeds on Plumeria rubra leaves, was characterized and further challenged against the latex proteolytic system of its own host plant and those of other latex-bearing plants. The gut proteolytic system of Danaus plexippus (monarch) and the latex proteolytic system of its host plant (Calotropis procera) were also studied. The latex proteins underwent extensive hydrolysis when mixed with the corresponding gut homogenates of the hosted insects. The gut homogenates partially digested the latex proteins of foreign plants. The fifth instar of D. plexippus that were fed diets containing foreign latex developed as well as those individuals who were fed diets containing latex proteins from their host plant. In vitro assays detected serine and cysteine peptidase inhibitors in both the gut homogenates and the latex fluids. Curiously, the peptidase inhibitors of caterpillars did not inhibit the latex peptidases of their host plants. However, the peptidase inhibitors of laticifer origin inhibited the proteolysis of gut homogenates. In vivo analyses of the peritrophic membrane proteins of D. plexippus demonstrate resistance against latex peptidases. Only discrete changes were observed when the peritrophic membrane was directly treated with purified latex peptidases in vitro. This study concludes that peptidase inhibitors are involved in the defensive systems of both caterpillars and their host plants. Although latex peptidase inhibitors inhibit gut peptidases (in vitro), the ability of gut peptidases to digest latex proteins (in vivo) regardless of their origin seems to be important in governing the resistance-susceptibility of caterpillars. PMID:25246317

  13. Peptidase activity of beta-lactamases.

    PubMed Central

    Rhazi, N; Galleni, M; Page, M I; Frère, J M

    1999-01-01

    Although beta-lactamases have generally been considered as being devoid of peptidase activity, a low but significant hydrolysis of various N-acylated dipeptides was observed with representatives of each class of beta-lactamases. The kcat/Km values were below 0.1 M(-1). s(-1), but the enzyme rate enhancement factors were in the range 5000-20000 for the best substrates. Not unexpectedly, the best 'peptidase' was the class C beta-lactamase of Enterobacter cloacae P99, but, more surprisingly, the activity was always higher with the phenylacetyl- and benzoyl-d-Ala-d-Ala dipeptides than with the diacetyl- and alpha-acetyl-l-Lys-d-Ala-d-Ala tripeptides, which are the preferred substrates of the low-molecular-mass, soluble dd-peptidases. A comparison between the beta-lactamases and dd-peptidases showed that it might be as difficult for a dd-peptidase to open the beta-lactam ring as it is for the beta-lactamases to hydrolyse the peptides, an observation which can be explained by geometric and stereoelectronic considerations. PMID:10393100

  14. On the substrate specificity of bacterial DD-peptidases: evidence from two series of peptidoglycan-mimetic peptides.

    PubMed Central

    Anderson, John W; Adediran, Suara A; Charlier, Paulette; Nguyen-Distèche, Martine; Frère, Jean-Marie; Nicholas, Robert A; Pratt, Rex F

    2003-01-01

    The reactions between bacterial DD-peptidases and beta-lactam antibiotics have been studied for many years. Less well understood are the interactions between these enzymes and their natural substrates, presumably the peptide moieties of peptidoglycan. In general, remarkably little activity has previously been demonstrated in vitro against potential peptide substrates, although in many cases the peptides employed were non-specific and not homologous with the relevant peptidoglycan. In this paper, the specificity of a panel of DD-peptidases against elements of species-specific D-alanyl-D-alanine peptides has been assessed. In two cases, those of soluble, low-molecular-mass DD-peptidases, high activity against the relevant peptides has been demonstrated. In these cases, the high specificity is towards the free N-terminus of the peptidoglycan fragment. With a number of other enzymes, particularly high-molecular-mass DD-peptidases, little or no activity against these peptides was observed. In separate experiments, the reactivity of the enzymes against the central, largely invariant, peptide stem was examined. None of the enzymes surveyed showed high activity against this structural element although weak specificity in the expected direction towards the one structural variable (D-gammaGln versus D-gammaGlu) was observed. The current state of understanding of the activity of these enzymes in vitro is discussed. PMID:12723972

  15. Sugarcane Serine Peptidase Inhibitors, Serine Peptidases, and Clp Protease System Subunits Associated with Sugarcane Borer (Diatraea saccharalis) Herbivory and Wounding.

    PubMed

    Medeiros, Ane H; Mingossi, Fabiana B; Dias, Renata O; Franco, Flávia P; Vicentini, Renato; Mello, Marcia O; Moura, Daniel S; Silva-Filho, Marcio C

    2016-01-01

    Sugarcane's (Saccharum spp.) response to Diatraea saccharalis (F.) (Lepidoptera: (Crambidae) herbivory was investigated using a macroarray spotted with 248 sugarcane Expressed Sequence Tags (ESTs) encoding serine peptidase inhibitors, serine peptidases. and Clp protease system subunits. Our results showed that after nine hours of herbivory, 13 sugarcane genes were upregulated and nine were downregulated. Among the upregulated genes, nine were similar to serine peptidase inhibitors and four were similar to Bowman-Birk Inhibitors (BBIs). Phylogenetic analysis revealed that these sequences belong to a phylogenetic group of sugarcane BBIs that are potentially involved in plant defense against insect predation. The remaining four upregulated genes included serine peptidases and one homolog to the Arabidopsis AAA+ chaperone subunit ClpD, which is a member of the Clp protease system. Among the downregulated genes, five were homologous to serine peptidases and four were homologous to Arabidopsis Clp subunits (three homologous to Clp AAA+ chaperones and one to a ClpP-related ClpR subunit). Although the roles of serine peptidase inhibitors in plant defenses against herbivory have been extensively investigated, the roles of plant serine peptidases and the Clp protease system represent a new and underexplored field of study. The up- and downregulated D. saccharalis genes presented in this study may be candidate genes for the further investigation of the sugarcane response to herbivory. PMID:27598134

  16. Assaying nonspecific phospholipase C activity.

    PubMed

    Pejchar, Přemysl; Scherer, Günther F E; Martinec, Jan

    2013-01-01

    Plant nonspecific phospholipase C (NPC) is a recently described enzyme which plays a role in membrane rearrangement during phosphate starvation. It is also involved in responses of plants to brassinolide, abscisic acid (ABA), elicitors, and salt. The NPC activity is decreased in cells treated with aluminum. In the case of salt stress, the molecular mechanism of NPC action is based on accumulation of diacylglycerol (DAG) by hydrolysis of phospholipids and conversion of DAG, the product of NPC activity, to phosphatidic acid (PA) that participates in ABA signaling pathways. Here we describe a step-by-step protocol, which can be used to determine in situ or in vitro NPC activity. Determination is based on quantification of fluorescently labeled DAG as a product of cleavage of the fluorescently labeled substrate lipid, phosphatidylcholine. High-performance thin-layer chromatography is used for separation of fluorescent DAG. The spot is visualized with a laser scanner and the relative amounts of fluorescent DAG are quantified using imaging software. PMID:23681535

  17. Evolution of the Thermopsin Peptidase Family (A5)

    PubMed Central

    Rawlings, Neil D.

    2013-01-01

    Thermopsin is a peptidase from Sulfolobus acidocaldarius that is active at low pH and high temperature. From reversible inhibition with pepstatin, thermopsin is thought to be an aspartic peptidase. It is a member of the only family of peptidases to be restricted entirely to the archaea, namely peptidase family A5. Evolution within this family has been mapped, using a taxonomic tree based on the known classification of archaea. Homologues are found only in archaeans that are both hyperthermophiles and acidophiles, and this implies lateral transfer of genes between archaea, because species with homologues are not necessarily closely related. Despite the remarkable stability and activity in extreme conditions, no tertiary structure has been solved for any member of the family, and the catalytic mechanism is unknown. Putative catalytic residues have been predicted here by examination of aligned sequences. PMID:24312173

  18. Cysteine peptidases from Phytomonas serpens: biochemical and immunological approaches.

    PubMed

    Elias, Camila G R; Aor, Ana Carolina; Valle, Roberta S; d'Avila-Levy, Claudia M; Branquinha, Marta H; Santos, André L S

    2009-12-01

    Phytomonas serpens, a phytoflagellate trypanosomatid, shares common antigens with Trypanosoma cruzi. In the present work, we compared the hydrolytic capability of cysteine peptidases in both trypanosomatids. Trypanosoma cruzi epimastigotes presented a 10-fold higher efficiency in hydrolyzing the cysteine peptidase substrate Z-Phe-Arg-AMC than P. serpens promastigotes. Moreover, two weak cysteine-type gelatinolytic activities were detected in P. serpens, while a strong 50-kDa cysteine peptidase was observed in T. cruzi. Cysteine peptidase activities were detected at twofold higher levels in the cytoplasmic fraction when compared with the membrane-rich or the content released from P. serpens. The cysteine peptidase secreted by P. serpens cleaved several proteinaceous substrates. Corroborating these findings, the cellular distribution of the cruzipain-like molecules in P. serpens was attested through immunocytochemistry analysis. Gold particles were observed in all cellular compartments, including the cytoplasm, plasma membrane, flagellum, flagellar membrane and flagellar pocket. Interestingly, some gold particles were visualized free in the flagellar pocket, suggesting the release of the cruzipain-like molecule. The antigenic properties of the cruzipain-like molecules of P. serpens were also analyzed. Interestingly, sera from chagasic patients recognized both cellular and extracellular antigens of P. serpens, including the cruzipain-like molecule. These results point to the use of P. serpens antigens, especially the cruzipain-like cysteine-peptidases, as an alternative vaccination approach to T. cruzi infection. PMID:19780820

  19. Cardiovascular effects of dipeptidyl peptidase-4 inhibitors

    PubMed Central

    Papagianni, M; Tziomalos, K

    2015-01-01

    Dipeptidyl peptidase-4 (DPP-4) inhibitors are effective glucose-lowering agents that do not increase body weight and are associated with a low risk for hypoglycemia. Also, they appear to exert beneficial effects on other established cardiovascular risk factors, including dyslipidemia and hypertension. Moreover, DPP-4 inhibitors exert antiinflammatory and antioxidant actions, improve endothelial function and reduce urinary albumin excretion. In contrast to these favorable cardiovascular effects, three recent large, randomized, placebo-controlled trials in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease or multiple cardiovascular risk factors showed that DPP-4 inhibitors do not affect the risk of myocardial infarction or ischemic stroke and might increase the risk of heart failure. The findings of the former randomized studies highlight the limitations of surrogate markers and show that beneficial effects on cardiovascular risk factors do not necessarily translate into reductions in hard clinical endpoints. Ongoing trials will shed more light on the safety profile of DPP-4 inhibitors and will clarify whether they will improve the cardiovascular outcomes of patients with T2DM. Hippokratia 2015; 19 (3): 195-199. PMID:27418775

  20. Cathepsin K: a unique collagenolytic cysteine peptidase.

    PubMed

    Novinec, Marko; Lenarčič, Brigita

    2013-09-01

    Cathepsin K has emerged as a promising target for the treatment of osteoporosis in recent years. Initially identified as a papain-like cysteine peptidase expressed in high levels in osteoclasts, the important role of this enzyme in bone metabolism was highlighted by the finding that mutations in the CTSK gene cause the rare recessive disorder pycnodysostosis, which is characterized by severe bone anomalies. At the molecular level, the physiological role of cathepsin K is reflected by its unique cleavage pattern of type I collagen molecules, which is fundamentally different from that of other endogenous collagenases. Several cathepsin K inhibitors have been developed to reduce the excessive bone matrix degradation associated with osteoporosis, with the frontrunner odanacatib about to successfully conclude Phase 3 clinical trials. Apart from osteoclasts, cathepsin K is expressed in different cell types throughout the body and is involved in processes of adipogenesis, thyroxine liberation and peptide hormone regulation. Elevated activity of cathepsin K has been associated with arthritis, atherosclerosis, obesity, schizophrenia, and tumor metastasis. Accordingly, its activity is tightly regulated via multiple mechanisms, including competitive inhibition by endogenous macromolecular inhibitors and allosteric regulation by glycosaminoglycans. This review provides a state-of-the-art description of the activity of cathepsin K at the molecular level, its biological functions and the mechanisms involved in its regulation. PMID:23629523

  1. Structure and Catalysis of Acylaminoacyl Peptidase

    PubMed Central

    Harmat, Veronika; Domokos, Klarissza; Menyhárd, Dóra K.; Palló, Anna; Szeltner, Zoltán; Szamosi, Ilona; Beke-Somfai, Tamás; Náray-Szabó, Gábor; Polgár, László

    2011-01-01

    Acylaminoacyl peptidase from Aeropyrum pernix is a homodimer that belongs to the prolyl oligopeptidase family. The monomer subunit is composed of one hydrolase and one propeller domain. Previous crystal structure determinations revealed that the propeller domain obstructed the access of substrate to the active site of both subunits. Here we investigated the structure and the kinetics of two mutant enzymes in which the aspartic acid of the catalytic triad was changed to alanine or asparagine. Using different substrates, we have determined the pH dependence of specificity rate constants, the rate-limiting step of catalysis, and the binding of substrates and inhibitors. The catalysis considerably depended both on the kind of mutation and on the nature of the substrate. The results were interpreted in terms of alterations in the position of the catalytic histidine side chain as demonstrated with crystal structure determination of the native and two mutant structures (D524N and D524A). Unexpectedly, in the homodimeric structures, only one subunit displayed the closed form of the enzyme. The other subunit exhibited an open gate to the catalytic site, thus revealing the structural basis that controls the oligopeptidase activity. The open form of the native enzyme displayed the catalytic triad in a distorted, inactive state. The mutations affected the closed, active form of the enzyme, disrupting its catalytic triad. We concluded that the two forms are at equilibrium and the substrates bind by the conformational selection mechanism. PMID:21084296

  2. Trypanosoma brucei has a canonical mitochondrial processing peptidase.

    PubMed

    Desy, Silvia; Schneider, André; Mani, Jan

    2012-10-01

    Most mitochondrial matrix and inner membrane proteins have N-terminal presequences which serve as import signals. After import these presequences are cleaved by the heterodimeric mitochondrial processing peptidase. In the parasitic protozoa Trypanosoma brucei mitochondrial protein import relies on presequences that are much shorter than in other eukaryotes. How they are processed is unknown. The trypansomal genome encodes four open reading frames that are annotated as mitochondrial processing peptidase. Here we show that RNAi-mediated ablation of two of these proteins leads to a growth arrest and a concomitant accumulation of mitochondrial precursor proteins inside mitochondria. Import experiments using isolated mitochondria from RNAi cell lines reveals that both proteins are required for efficient import and processing of the tested precursor protein. Reciprocal immunoprecipitation demonstrates that the proteins interact with each other. In summary these results show that we have identified the two subunits of the trypanosomal mitochondrial processing peptidase. PMID:22841752

  3. Molecular cloning and expression analysis of peptidase genes in the fish-pathogenic scuticociliate Miamiensis avidus

    PubMed Central

    2013-01-01

    Background Parasite peptidases have been actively studied as vaccine candidates or drug targets for prevention or treatment of parasitic diseases because of their important roles for survival and/or invasion in the host. Like other parasites, the facultative histophagous ciliate Miamiensis avidus would possess peptidases that are closely associated with the invasion into the host tissue and survival in the host. Results The 17 genes encoding peptidases, including seven cathepsin-like cysteine peptidases, four serine carboxypeptidases, a eukaryotic aspartyl protease family protein, an ATP-dependent metalloprotease FtsH family protein, three leishmanolysin family proteins and a peptidase family M49 protein were identified from a Miamiensis avidus cDNA library by BLAST X search. Expression of genes encoding two cysteine peptidases, three leishmanolysin-like peptidases and a peptidase family M49 protein was up-regulated in the cell-fed ciliates compared to the starved ciliates. Especially, one cysteine peptidase (MaPro 4) and one leishmanolysin-like peptidase (MaPro 14) were transcribed more than 100-folds in the cell-fed ciliates. Conclusions The genetic information and transcriptional characteristics of the peptidases in the present results would be helpful to elucidate the role of peptidases in the invasion of scuticociliates into their hosts. PMID:23311870

  4. Dipeptidyl peptidase-4: A key player in chronic liver disease

    PubMed Central

    Itou, Minoru; Kawaguchi, Takumi; Taniguchi, Eitaro; Sata, Michio

    2013-01-01

    Dipeptidyl peptidase-4 (DPP-4) is a membrane-associated peptidase, also known as CD26. DPP-4 has widespread organ distribution throughout the body and exerts pleiotropic effects via its peptidase activity. A representative target peptide is glucagon-like peptide-1, and inactivation of glucagon-like peptide-1 results in the development of glucose intolerance/diabetes mellitus and hepatic steatosis. In addition to its peptidase activity, DPP-4 is known to be associated with immune stimulation, binding to and degradation of extracellular matrix, resistance to anti-cancer agents, and lipid accumulation. The liver expresses DPP-4 to a high degree, and recent accumulating data suggest that DPP-4 is involved in the development of various chronic liver diseases such as hepatitis C virus infection, non-alcoholic fatty liver disease, and hepatocellular carcinoma. Furthermore, DPP-4 occurs in hepatic stem cells and plays a crucial role in hepatic regeneration. In this review, we described the tissue distribution and various biological effects of DPP-4. Then, we discussed the impact of DPP-4 in chronic liver disease and the possible therapeutic effects of a DPP-4 inhibitor. PMID:23613622

  5. Non-Specific Immunotherapies and Adjuvants

    MedlinePlus

    ... and spinal cord. Other drugs that boost the immune system Some other drugs boost the immune system in a non-specific way, similar to cytokines. ... and CTLA-4, which normally help keep the immune system in check. While these checkpoint proteins are important ...

  6. Stretching DNA to quantify nonspecific protein binding

    NASA Astrophysics Data System (ADS)

    Goyal, Sachin; Fountain, Chandler; Dunlap, David; Family, Fereydoon; Finzi, Laura

    2012-07-01

    Nonspecific binding of regulatory proteins to DNA can be an important mechanism for target search and storage. This seems to be the case for the lambda repressor protein (CI), which maintains lysogeny after infection of E. coli. CI binds specifically at two distant regions along the viral genome and induces the formation of a repressive DNA loop. However, single-molecule imaging as well as thermodynamic and kinetic measurements of CI-mediated looping show that CI also binds to DNA nonspecifically and that this mode of binding may play an important role in maintaining lysogeny. This paper presents a robust phenomenological approach using a recently developed method based on the partition function, which allows calculation of the number of proteins bound nonspecific to DNA from measurements of the DNA extension as a function of applied force. This approach was used to analyze several cycles of extension and relaxation of λ DNA performed at several CI concentrations to measure the dissociation constant for nonspecific binding of CI (˜100 nM), and to obtain a measurement of the induced DNA compaction (˜10%) by CI.

  7. Bunyamwera orthobunyavirus glycoprotein precursor is processed by cellular signal peptidase and signal peptide peptidase

    PubMed Central

    Shi, Xiaohong; Botting, Catherine H.; Li, Ping; Niglas, Mark; Brennan, Benjamin; Shirran, Sally L.; Szemiel, Agnieszka M.; Elliott, Richard M.

    2016-01-01

    The M genome segment of Bunyamwera virus (BUNV)—the prototype of both the Bunyaviridae family and the Orthobunyavirus genus—encodes the glycoprotein precursor (GPC) that is proteolytically cleaved to yield two viral structural glycoproteins, Gn and Gc, and a nonstructural protein, NSm. The cleavage mechanism of orthobunyavirus GPCs and the host proteases involved have not been clarified. In this study, we investigated the processing of BUNV GPC and found that both NSm and Gc proteins were cleaved at their own internal signal peptides (SPs), in which NSm domain I functions as SPNSm and NSm domain V as SPGc. Moreover, the domain I was further processed by a host intramembrane-cleaving protease, signal peptide peptidase, and is required for cell fusion activities. Meanwhile, the NSm domain V (SPGc) remains integral to NSm, rendering the NSm topology as a two-membrane-spanning integral membrane protein. We defined the cleavage sites and boundaries between the processed proteins as follows: Gn, from residue 17–312 or nearby residues; NSm, 332–477; and Gc, 478–1433. Our data clarified the mechanism of the precursor cleavage process, which is important for our understanding of viral glycoprotein biogenesis in the genus Orthobunyavirus and thus presents a useful target for intervention strategies. PMID:27439867

  8. The first crystal structure of the peptidase domain of the U32 peptidase family.

    PubMed

    Schacherl, Magdalena; Montada, Angelika A M; Brunstein, Elena; Baumann, Ulrich

    2015-12-01

    The U32 family is a collection of over 2500 annotated peptidases in the MEROPS database with unknown catalytic mechanism. They mainly occur in bacteria and archaea, but a few representatives have also been identified in eukarya. Many of the U32 members have been linked to pathogenicity, such as proteins from Helicobacter and Salmonella. The first crystal structure analysis of a U32 catalytic domain from Methanopyrus kandleri (gene mk0906) reveals a modified (βα)8 TIM-barrel fold with some unique features. The connecting segment between strands β7 and β8 is extended and helix α7 is located on top of the C-terminal end of the barrel body. The protein exhibits a dimeric quaternary structure in which a zinc ion is symmetrically bound by histidine and cysteine side chains from both monomers. These residues reside in conserved sequence motifs. No typical proteolytic motifs are discernible in the three-dimensional structure, and biochemical assays failed to demonstrate proteolytic activity. A tunnel in which an acetate ion is bound is located in the C-terminal part of the β-barrel. Two hydrophobic grooves lead to a tunnel at the C-terminal end of the barrel in which an acetate ion is bound. One of the grooves binds to a Strep-Tag II of another dimer in the crystal lattice. Thus, these grooves may be binding sites for hydrophobic peptides or other ligands. PMID:26627657

  9. Identification of peptidases in highly pathogenic vs. weakly pathogenic Naegleria fowleri amebae.

    PubMed

    Vyas, Ishan K; Jamerson, Melissa; Cabral, Guy A; Marciano-Cabral, Francine

    2015-01-01

    Naegleria fowleri, a free-living ameba, is the causative agent of Primary Amebic Meningoencephalitis. Highly pathogenic mouse-passaged amebae (Mp) and weakly pathogenic axenically grown (Ax) N. fowleri were examined for peptidase activity. Zymography and azocasein peptidase activity assays demonstrated that Mp and Ax N. fowleri exhibited a similar peptidase pattern. Prominent for whole cell lysates, membranes and conditioned medium (CM) from Mp and Ax amebae was the presence of an activity band of approximately 58 kDa that was sensitive to E64, a cysteine peptidase inhibitor. However, axenically grown N. fowleri demonstrated a high level of this peptidase activity in membrane preparations. The inhibitor E64 also reduced peptidase activity in ameba-CM consistent with the presence of secreted cysteine peptidases. Exposure of Mp amebae to E64 reduced their migration through matrigel that was used as an extracellular matrix, suggesting a role for cysteine peptidases in invasion of the central nervous system (CNS). The collective results suggest that the profile of peptidases is not a discriminative marker for distinguishing Mp from Ax N. fowleri. However, the presence of a prominent level of activity for cysteine peptidases in N. fowleri membranes and CM, suggests that these enzymes may serve to facilitate passage of the amebae into the CNS. PMID:25066578

  10. Regulation of the Epithelial Na+ Channel by Peptidases

    PubMed Central

    Planès, Carole; Caughey, George H.

    2008-01-01

    Recent investigations point to an important role for peptidases in regulating transcellular ion transport by the epithelial Na+ channel, ENaC. Several peptidases, including furins and proteasomal hydrolases, modulate ENaC maturation and disposal. More idiosyncratically, apical Na+ transport by ENaC in polarized epithelia of kidney, airway, and gut is stimulated constitutively by one or more trypsin-family serine peptidases, as revealed by inhibition of amiloride-sensitive Na+ transport by broad-spectrum antipeptidases, including aprotinin and bikunin/SPINT2. In vitro, the transporting activity of aprotinin-suppressed ENaC can be restored by exposure to trypsin. The prototypical channel-activating peptidase (CAP) is a type 1 membrane-anchored tryptic peptidase first identified in Xenopus kidney cells. Frog CAP1 strongly upregulates Na+ transport when coexpressed with ENaC in oocytes. The amphibian enzyme's apparent mammalian orthologue is prostasin, otherwise known as CAP1, which is coexpressed with ENaC in a variety of epithelia. In airway cells, prostasin is the major basal regulator of ENaC activity, as suggested by inhibition and knockdown experiments. Other candidate regulators of mature ENaC include CAP2/TMPRSS4 and CAP3/matriptase (also known as membrane-type serine protease 1/ST14). Mammalian CAPs are potential targets for treatment of ENaC-mediated Na+ hyperabsorption by the airway in cystic fibrosis (CF) and by the kidney in hypertension. CAPs can be important for mammalian development, as indicated by embryonic lethality in mice with null mutations of CAP1/prostasin. Mice with selectively knocked out expression of CAP1/prostasin in the epidermis and mice with globally knocked out expression of CAP3/matriptase exhibit phenotypically similar defects in skin barrier function and neonatal death from dehydration. In rats, transgenic overexpression of human prostasin disturbs salt balance and causes hypertension. Thus, several converging lines of evidence

  11. Nonspecific cleavage of proteins using graphene oxide.

    PubMed

    Lee, Heeyoung; Tran, Minh-Hai; Jeong, Hae Kyung; Han, Jinwoo; Jang, Sei-Heon; Lee, ChangWoo

    2014-04-15

    In this article, we report the intrinsic catalytic activity of graphene oxide (GO) for the nonspecific cleavage of proteins. We used bovine serum albumin (BSA) and a recombinant esterase (rEstKp) from the cold-adapted bacterium Pseudomonas mandelii as test proteins. Cleavage of BSA and rEstKp was nonspecific regarding amino acid sequence, but it exhibited dependence on temperature, time, and the amount of GO. However, cleavage of the proteins did not result in complete hydrolysis into their constituent amino acids. GO also invoked hydrolysis of p-nitrophenyl esters at moderate temperatures lower than those required for peptide hydrolysis regardless of chain length of the fatty acyl esters. Based on the results, the functional groups of GO, including alcohols, phenols, and carboxylates, can be considered as crucial roles in the GO-mediated hydrolysis of peptides and esters via general acid-base catalysis. Our findings provide novel insights into the role of GO as a carbocatalyst with nonspecific endopeptidase activity in biochemical reactions. PMID:24508487

  12. Cysteine Peptidases as Schistosomiasis Vaccines with Inbuilt Adjuvanticity

    PubMed Central

    El Ridi, Rashika; Tallima, Hatem; Selim, Sahar; Donnelly, Sheila; Cotton, Sophie; Gonzales Santana, Bibiana; Dalton, John P.

    2014-01-01

    Schistosomiasis is caused by several worm species of the genus Schistosoma and afflicts up to 600 million people in 74 tropical and sub-tropical countries in the developing world. Present disease control depends on treatment with the only available drug praziquantel. No vaccine exists despite the intense search for molecular candidates and adjuvant formulations over the last three decades. Cysteine peptidases such as papain and Der p 1 are well known environmental allergens that sensitize the immune system driving potent Th2-responses. Recently, we showed that the administration of active papain to mice induced significant protection (P<0.02, 50%) against an experimental challenge infection with Schistosoma mansoni. Since schistosomes express and secrete papain-like cysteine peptidases we reasoned that these could be employed as vaccines with inbuilt adjuvanticity to protect against these parasites. Here we demonstrate that sub-cutaneous injection of functionally active S. mansoni cathepsin B1 (SmCB1), or a cathepsin L from a related parasite Fasciola hepatica (FhCL1), elicits highly significant (P<0.0001) protection (up to 73%) against an experimental challenge worm infection. Protection and reduction in worm egg burden were further increased (up to 83%) when the cysteine peptidases were combined with other S. mansoni vaccine candidates, glyceraldehyde 3-phosphate dehydrogenase (SG3PDH) and peroxiredoxin (PRX-MAP), without the need to add chemical adjuvants. These studies demonstrate the capacity of helminth cysteine peptidases to behave simultaneously as immunogens and adjuvants, and offer an innovative approach towards developing schistosomiasis vaccines PMID:24465551

  13. Dipeptidyl peptidase-4 inhibitor for steroid-induced diabetes

    PubMed Central

    Yanai, Hidekatsu; Masui, Yoshinori; Yoshikawa, Reo; Kunimatsu, Junwa; Kaneko, Hiroshi

    2010-01-01

    The addition of the dipeptidyl peptidase-4 (DDP-4) inhibitor has been reported to achieve greater improvements in glucose metabolism with fewer adverse events compared to increasing the metformin dose in type 2 diabetic patients. We present a patient with steroid-induced diabetes whose blood glucose levels were ameliorated by the use of the DPP-4 inhibitor, showing that the DPP-4 inhibitors may be an effective and safe oral anti-diabetic drug for steroid-induced diabetes. PMID:21537433

  14. NAAG peptidase inhibitors and deletion of NAAG peptidase gene enhance memory in novel object recognition test.

    PubMed

    Janczura, Karolina J; Olszewski, Rafal T; Bzdega, Tomasz; Bacich, Dean J; Heston, Warren D; Neale, Joseph H

    2013-02-15

    The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) is inactivated by the extracellular enzyme glutamate carboxypeptidase II. Inhibitors of this enzyme reverse dizocilpine (MK-801)-induced impairment of short-term memory in the novel object recognition test. The objective of this study was to test the hypothesis that NAAG peptidase inhibition enhances long-term (24h delay) memory of C57BL mice. These mice and mice in which glutamate carboxypeptidase II had been knocked out were presented with two identical objects to explore for 10min on day 1 and tested with one of these familiar objects and one novel object on day 2. Memory was assessed as the degree to which the mice recalled the familiar object and explored the novel object to a greater extent on day 2. Uninjected mice or mice injected with saline prior to the acquisition session on day 1 demonstrated a lack of memory of the acquisition experience by exploring the familiar and novel objects to the same extent on day 2. Mice treated with glutamate carboxypeptidase II inhibitors ZJ43 or 2-PMPA prior to the acquisition trial explored the novel object significantly more time than the familiar object on day 2. Consistent with these results, mice in which glutamate carboxypeptidase II had been knocked out distinguished the novel from the familiar object on day 2 while their heterozygous colony mates did not. Inhibition of glutamate carboxypeptidase II enhances recognition memory, a therapeutic action that might be useful in treatment of memory deficits related to age and neurological disorders. PMID:23200894

  15. Extracellular peptidases of the cereal pathogen Fusarium graminearum

    PubMed Central

    Lowe, Rohan G. T.; McCorkelle, Owen; Bleackley, Mark; Collins, Christine; Faou, Pierre; Mathivanan, Suresh; Anderson, Marilyn

    2015-01-01

    The plant pathogenic fungus Fusarium graminearum (Fgr) creates economic and health risks in cereals agriculture. Fgr causes head blight (or scab) of wheat and stalk rot of corn, reducing yield, degrading grain quality, and polluting downstream food products with mycotoxins. Fungal plant pathogens must secrete proteases to access nutrition and to breakdown the structural protein component of the plant cell wall. Research into the proteolytic activity of Fgr is hindered by the complex nature of the suite of proteases secreted. We used a systems biology approach comprising genome analysis, transcriptomics and label-free quantitative proteomics to characterize the peptidases deployed by Fgr during growth. A combined analysis of published microarray transcriptome datasets revealed seven transcriptional groupings of peptidases based on in vitro growth, in planta growth, and sporulation behaviors. A high resolution mass spectrometry-based proteomics analysis defined the extracellular proteases secreted by F. graminearum. A meta-classification based on sequence characters and transcriptional/translational activity in planta and in vitro provides a platform to develop control strategies that target Fgr peptidases. PMID:26635820

  16. Streptococcal C5a peptidase is a highly specific endopeptidase.

    PubMed Central

    Cleary, P P; Prahbu, U; Dale, J B; Wexler, D E; Handley, J

    1992-01-01

    Compositional analysis of streptococcal C5a peptidase (SCPA) cleavage products from a synthetic peptide corresponding to the 20 C-terminal residues of C5a demonstrated that the target cleavage site is His-Lys rather than Lys-Asp, as previously suggested. A C5a peptide analog with Lys replaced by Gln was also subject to cleavage by SCPA. This confirmed that His-Lys rather than Lys-Asp is the scissile bond. Cleavage at histidine is unusual but is the same as that suggested for a peptidase produced by group B streptococci. Native C5 protein was also resistant to SCPA, suggesting that the His-Lys bond is inaccessible prior to proteolytic cleavage by C5 convertase. These experiments showed that the streptococcal C5a peptidase is highly specific for C5a and suggest that its function is not merely to process protein for metabolic consumption but to act primarily to eliminate this chemotactic signal from inflammatory foci. Images PMID:1452354

  17. Selective chromogenic and fluorogenic peptide substrates for the assay of cysteine peptidases in complex mixtures.

    PubMed

    Semashko, Tatiana A; Vorotnikova, Elena A; Sharikova, Valeriya F; Vinokurov, Konstantin S; Smirnova, Yulia A; Dunaevsky, Yakov E; Belozersky, Mikhail A; Oppert, Brenda; Elpidina, Elena N; Filippova, Irina Y

    2014-03-15

    This study describes the design, synthesis, and use of selective peptide substrates for cysteine peptidases of the C1 papain family, important in many biological processes. The structure of the newly synthesized substrates is Glp-Xaa-Ala-Y (where Glp=pyroglutamyl; Xaa=Phe or Val; and Y=pNA [p-nitroanilide], AMC [4-amino-7-methylcoumaride], or AFC [4-amino-7-trifluoromethyl-coumaride]). Substrates were synthesized enzymatically to guarantee selectivity of the reaction and optical purity of the target compounds, simplifying the scheme of synthesis and isolation of products. The hydrolysis of the synthesized substrates was evaluated by C1 cysteine peptidases from different organisms and with different functions, including plant enzymes papain, bromelain, ficin, and mammalian lysosomal cathepsins B and L. The new substrates were selective for C1 cysteine peptidases and were not hydrolyzed by serine, aspartic, or metallo peptidases. We demonstrated an application of the selectivity of the synthesized substrates during the chromatographic separation of a multicomponent set of digestive peptidases from a beetle, Tenebrio molitor. Used in combination with the cysteine peptidase inhibitor E-64, these substrates were able to differentiate cysteine peptidases from peptidases of other classes in midgut extracts from T. molitor larvae and larvae of the genus Tribolium; thus, they are useful in the analysis of complex mixtures containing peptidases from different classes. PMID:24388866

  18. Campylobacter jejuni gene cj0511 encodes a serine peptidase essential for colonisation

    PubMed Central

    Karlyshev, A.V.; Thacker, G.; Jones, M.A.; Clements, M.O.; Wren, B.W.

    2014-01-01

    According to MEROPS peptidase database, Campylobacter species encode 64 predicted peptidases. However, proteolytic properties of only a few of these proteins have been confirmed experimentally. In this study we identified and characterised a Campylobacter jejuni gene cj0511 encoding a novel peptidase. The proteolytic activity associated with this enzyme was demonstrated in cell lysates. Moreover, enzymatic studies conducted with a purified protein confirmed a prediction of it being a serine peptidase. Furthermore, cj0511 mutant was found to be severely attenuated in chicken colonisation model, suggesting a role of the Cj0511 protein in infection. PMID:24918062

  19. Identification of dipeptidyl peptidase 3 as the Angiotensin-(1-7) degrading peptidase in human HK-2 renal epithelial cells.

    PubMed

    Cruz-Diaz, Nildris; Wilson, Bryan A; Pirro, Nancy T; Brosnihan, K Bridget; Marshall, Allyson C; Chappell, Mark C

    2016-09-01

    Angiotensin-(1-7) (Ang-(1-7)) is expressed within the kidney and exhibits renoprotective actions that antagonize the inflammatory, fibrotic and pro-oxidant effects of the Ang II-AT1 receptor axis. We previously identified a peptidase activity from sheep brain, proximal tubules and human HK-2 proximal tubule cells that metabolized Ang-(1-7); thus, the present study isolated and identified the Ang-(1-7) peptidase. Utilizing ion exchange and hydrophobic interaction chromatography, a single 80kDa protein band on SDS-PAGE was purified from HK-2 cells. The 80kDa band was excised, the tryptic digest peptides analyzed by LC-MS and a protein was identified as the enzyme dipeptidyl peptidase 3 (DPP 3, EC: 3.4.14.4). A human DPP 3 antibody identified a single 80kDa band in the purified enzyme preparation identical to recombinant human DPP 3. Both the purified Ang-(1-7) peptidase and DPP 3 exhibited an identical hydrolysis profile of Ang-(1-7) and both activities were abolished by the metallopeptidase inhibitor JMV-390. DPP 3 sequentially hydrolyzed Ang-(1-7) to Ang-(3-7) and rapidly converted Ang-(3-7) to Ang-(5-7). Kinetic analysis revealed that Ang-(3-7) was hydrolyzed at a greater rate than Ang-(1-7) [17.9 vs. 5.5 nmol/min/μg protein], and the Km for Ang-(3-7) was lower than Ang-(1-7) [3 vs. 12μM]. Finally, chronic treatment of the HK-2 cells with 20nM JMV-390 reduced intracellular DPP 3 activity and tended to augment the cellular levels of Ang-(1-7). We conclude that DPP 3 may influence the cellular expression of Ang-(1-7) and potentially reflect a therapeutic target to augment the actions of the peptide. PMID:27315786

  20. THE CURRENT PROBLEMS OF NONSPECIFIC BACK PAIN.

    PubMed

    Seleznova, S; Zabara, A; Mamuladze, D

    2016-01-01

    The article deals with various aspects of pain in degenerative diseases of the spine and with the actual problems of non-specific back pain. The data on the mechanisms of pain and analgesic treatment algorithms of the patients with radicular syndrome, and pharmacological and non-pharmacological therapies is provided. The effect of structural-modifying drugs in relief of nonspecific back pain was investigated and compared with a traditional nonsteroidal anti-inflammatory drug (NSAID) therapy in combination with B vitamins, without chondroprotectors. The study population was composed of 85 patients (42 men and 43 women) aged 38 to 68 years (mean age - (46,3±2,6) years) with chronic vertebral pain syndromes (VPS). For objectification assessment of pain, severity of pain, and evaluate the effectiveness of therapy we used the visual analog scale (VAS).The majority (88%) of the patients included in the study, complained of a moderately severe pain (from 40 to 70 mm on the VAS). Patients were divided into two groups. The first (primary) group consisted of 55 patients (30 men and 25 women). The following treatment was applied: all patients of the first group, in addition to the NSAID administered with hondroprotektror arbitrarily - Struktum 1000 mg twice a day or 300 mg Piaskledin once a day for 40-60 days.The second (control) group consisted of 30 patients (14 men, 16 women). Patients in the control group administered with a traditional NSAID therapy in combination with B vitamins, without chondroprotectors. The results of the study on the influence of drugs Piaskledin 300, Struktum for the relief of nonspecific back pain revealed that in the treatment of vertebral pain, a combination of non-steroidal anti-inflammatory drugs with structure-modifying agents could achieve rapid rehabilitation of patients with locomotor activity and improve quality of life in general. PMID:26870977

  1. Impaired nonspecific cellular immunity in experimental cholestasis.

    PubMed

    Roughneen, P T; Drath, D B; Kulkarni, A D; Rowlands, B J

    1987-11-01

    The abilities of polymorphonuclear leukocytes (PMN) and pulmonary alveolar macrophages (PAM), to demonstrate chemotaxis, phagocytosis, and superoxide release after bile duct ligation in the rat were investigated to determine the effect of cholestasis on nonspecific cellular immune mechanisms. Chemotactic response to C5a and FMLP, phagocytosis of 14C labeled Staphylococcus aureus, and zymosan-induced superoxide release were evaluated 21 days after bile duct ligation (BDL), sham operation, or in normal controls. Serum total bilirubin level was elevated after BDL (p less than 0.01). Chemotactic ability was similar to each group. PMN phagocytic uptake of 14C labeled Staphylococcus aureus was depressed in BDL (p less than 0.05). BDL rats exhibited impaired PAM phagocytic indices and improved PMN superoxide release (p less than 0.03). PAM superoxide release was similar in each study group. Alterations in phagocytic function with cholestasis are important deficits in nonspecific cellular immunity that may contribute to the high incidence of infective complications associated with obstructive jaundice. PMID:2823730

  2. Impaired nonspecific cellular immunity in experimental cholestasis.

    PubMed Central

    Roughneen, P T; Drath, D B; Kulkarni, A D; Rowlands, B J

    1987-01-01

    The abilities of polymorphonuclear leukocytes (PMN) and pulmonary alveolar macrophages (PAM), to demonstrate chemotaxis, phagocytosis, and superoxide release after bile duct ligation in the rat were investigated to determine the effect of cholestasis on nonspecific cellular immune mechanisms. Chemotactic response to C5a and FMLP, phagocytosis of 14C labeled Staphylococcus aureus, and zymosan-induced superoxide release were evaluated 21 days after bile duct ligation (BDL), sham operation, or in normal controls. Serum total bilirubin level was elevated after BDL (p less than 0.01). Chemotactic ability was similar to each group. PMN phagocytic uptake of 14C labeled Staphylococcus aureus was depressed in BDL (p less than 0.05). BDL rats exhibited impaired PAM phagocytic indices and improved PMN superoxide release (p less than 0.03). PAM superoxide release was similar in each study group. Alterations in phagocytic function with cholestasis are important deficits in nonspecific cellular immunity that may contribute to the high incidence of infective complications associated with obstructive jaundice. PMID:2823730

  3. Selective chromogenic and fluorogenic peptide substrates for the assay of cysteine peptidases in complex mixtures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cysteine peptidases are important in many biological processes. In this study, we describe the design, synthesis and use of selective peptide substrates for cysteine peptidases of the C1 papain family. The structure of the proposed substrates can be expressed by the general formula Glp-Xaa-Ala-Y, wh...

  4. Excretion/secretion products from Schistosoma mansoni adults, eggs and schistosomula have unique peptidase specificity profiles.

    PubMed

    Dvořák, Jan; Fajtová, Pavla; Ulrychová, Lenka; Leontovyč, Adrian; Rojo-Arreola, Liliana; Suzuki, Brian M; Horn, Martin; Mareš, Michael; Craik, Charles S; Caffrey, Conor R; O'Donoghue, Anthony J

    2016-03-01

    Schistosomiasis is one of a number of chronic helminth diseases of poverty that severely impact personal and societal well-being and productivity. Peptidases (proteases) are vital to successful parasitism, and can modulate host physiology and immunology. Interference of peptidase action by specific drugs or vaccines can be therapeutically beneficial. To date, research on peptidases in the schistosome parasite has focused on either the functional characterization of individual peptidases or their annotation as part of global genome or transcriptome studies. We were interested in functionally characterizing the complexity of peptidase activity operating at the host-parasite interface, therefore the excretory-secretory products of key developmental stages of Schistosoma mansoni that parasitize the human were examined. Using class specific peptidase inhibitors in combination with a multiplex substrate profiling assay, a number of unique activities derived from endo- and exo-peptidases were revealed in the excretory-secretory products of schistosomula (larval migratory worms), adults and eggs. The data highlight the complexity of the functional degradome for each developmental stage of this parasite and facilitate further enquiry to establish peptidase identity, physiological and immunological function, and utility as drug or vaccine candidates. PMID:26409899

  5. Localization of two post-proline cleaving peptidases in the midgut of Tenebrio molitor larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two soluble post-proline cleaving peptidase activities, PPCP1 and PPCP2, were demonstrated in the midgut of Tenebrio molitor larvae with the substrate benzyloxycarbonyl-L-alanyl-L-proline p-nitroanilide. Both activities were serine peptidases. PPCP1 was active in acidic buffers, with maximum activit...

  6. Pulmonary Vein Stenosis Mimicking Nonspecific Interstitial Pneumonia

    PubMed Central

    Linga, Karthika R.; Khoor, Andras; Phelan, Jonathan A.; Mira-Avendano, Isabel

    2015-01-01

    Pulmonary vein stenosis (PVS) is a known complication after catheter ablation of arrhythmias. Surprisingly, little information is available on its manifestations in the lung. We describe the case of a 39-year-old woman who presented from an outside hospital with worsening shortness of breath after catheter ablation of pulmonary veins for atrial fibrillation. After an initial diagnosis of pneumonia and its nonimprovement with antibiotics, a surgical lung biopsy was done and interpreted as nonspecific interstitial pneumonia (NSIP) with vascular changes consistent with pulmonary arterial hypertension. Later, she was admitted to our institution where a transthoracic echocardiogram (TTE) and subsequent computed tomography (CT) angiogram of the heart showed severe stenosis of all four pulmonary veins. The previous lung biopsy was rereviewed and reinterpreted as severe parenchymal congestion mimicking NSIP. Our case demonstrates that PVS is an underrecognized complication of catheter ablation, and increased awareness among both clinicians and pathologists is necessary to avoid misdiagnosis. PMID:26779359

  7. Regulatory signals for intestinal amino acid transporters and peptidases

    SciTech Connect

    Ferraris, R.P.; Kwan, W.W.; Diamond, J. )

    1988-08-01

    Dietary protein ultimately regulates many processes involved in protein digestion, but it is often unclear whether proteins themselves, peptides, or amino acids (AAs) are the proximate regulatory signal. Hence the authors compared several processes involved in protein digestion in mice adapted to one of three rations, identical except for containing 54% of either casein, a partial hydrolysate of casein, or a free AA mixture simulating a complete hydrolysate of casein. The authors measured brush-border uptakes of seven AAs that variously serve as substrates for four AA transporters, and brush-border and cytosolic activities of four peptidases. The three rations yielded essentially the same AA uptake rates. Peptidase activities tended to be lower on the AA ration than on the protein ration. In other studies, all three rations yielded the same rates of brush-border peptide uptake; protein is only modestly more effective than AAs at inducing synthesis of pancreatic proteases; and, depending on the animal species, protein is either much less or much more effective than AAs at stimulating release of cholecystokinin and hence of pancreatic enzymes. Thus the regulators of each process involved in protein digestion are not necessarily that process's substrate.

  8. Sequential processing of hepatitis C virus core protein by host cell signal peptidase and signal peptide peptidase: a reassessment.

    PubMed

    Pène, V; Hernandez, C; Vauloup-Fellous, C; Garaud-Aunis, J; Rosenberg, A R

    2009-10-01

    Hepatitis C virus (HCV) core protein is believed to play critical roles in the virus morphogenesis and pathogenesis. In HCV polyprotein, core protein terminates with a signal peptide followed by E1 envelope protein. It has remained unclear whether cleavage by host cell signal peptidase (SP) at the core-E1 junction to generate the complete form of core protein, which is anchored in the endoplasmic reticulum membrane, is absolutely required for cleavage within the signal peptide by host cell signal peptide peptidase (SPP) to liberate the mature form of core protein, which is then free for trafficking to lipid droplets. In this study, the possible sources of disagreement in published reports have been examined, and we conclude that a product generated upon inhibition of SP-catalysed cleavage at the core-E1 junction in heterologous expression systems was incorrectly identified as mature core protein. Moreover, inhibition of this cleavage in the most relevant model of human hepatoma cells replicating a full-length HCV genome was shown to abolish interaction of core protein with lipid droplets and production of infectious progeny virus. These results firmly establish that SPP-catalysed liberation of mature core protein is absolutely dependent on prior cleavage by SP at the correct core-E1 site to generate the complete form of core protein, consistent with this obligatory order of processing playing a role in HCV infectious cycle. PMID:19281487

  9. Heterogeneous production of metallo-type peptidases in parasites belonging to the family Trypanosomatidae.

    PubMed

    dos Santos, André Luis Souza; Soares, Rosangela Maria de Araújo; Alviano, Celuta Sales; Kneipp, Lucimar Ferreira

    2008-05-01

    Proteolytic enzymes play a central role in the physiology of all living organisms, participating in several metabolic pathways and in different phases of parasite-host interactions. We have identified cell-associated peptidase activities in 33 distinct flagellates, including representatives of almost all known trypanosomatid genera parasitizing insects (Herpetomonas, Crithidia, Leishmania, Trypanosoma, Leptomonas, Phytomonas, Blastocrithidia and Endotrypanum) as well as the biflagellate kinetoplastid Bodo, by using SDS-PAGE containing gelatin as co-polymerized substrate and proteolytic inhibitors. Under the alkaline pH (9.0) conditions employed, all the flagellates presented at least one peptidase, with the exception of Crithidia acanthocephali and Phytomonas serpens, which did not display any detectable proteolytic enzyme activity. All the proteolytic activities were completely inhibited by 1,10-phenanthroline, a zinc-chelating agent, putatively identifying these activities as metallo-type peptidases. EDTA and EGTA, two other metallopeptidase inhibitors, E-64 (a cysteine peptidase inhibitor), pepstatin A (an aspartyl peptidase inhibitor) and PMSF (a serine peptidase inhibitor) did not interfere with the metallopeptidase activities detected in the studied trypanosomatids. Conversely, Bodo-derived peptidases were resistant to 1,10-phenanthroline and only partially inhibited by EDTA, showing a distinct inhibition profile. Together, our data demonstrated great heterogeneity of expression of metallopeptidases in a wide range of parasites belonging to the family Trypanosomatidae. PMID:17942292

  10. Astacin Family Metallopeptidases and Serine Peptidase Inhibitors in Spider Digestive Fluid

    PubMed Central

    Foradori, Matthew J.; Tillinghast, Edward K.; Smith, J. Stephen; Townley, Mark A.; Mooney, Robert E.

    2006-01-01

    Digestive fluid of the araneid spider Argiope aurantia is known to contain zinc metallopeptidases. Using anion-exchange chromatography, size-exclusion chromatography, sucrose density gradient centrifugation, and gel electrophoresis, we isolated two lower-molecular-mass peptidases, designated p16 and p18. The N-terminal amino acid sequences of p16 (37 residues) and p18 (20 residues) are 85% identical over the first 20 residues and are most similar to the N-terminal sequences of the fully active form of meprin (β subunits) from several vertebrates (47–52% and 50–60% identical, respectively). Meprin is a peptidase in the astacin (M12A) subfamily of the astacin (M12) family. Additionally, a 66-residue internal sequence obtained from p16 aligns with the conserved astacin subfamily domain. Thus, at least some spider digestive peptidases appear related to astacin of decapod crustaceans. However, important differences between spider and crustacean metallopeptidases with regard to isoelectric point and their susceptibility to hemolymph-borne inhibitors are demonstrated. Anomalous behavior of the lower-molecular-mass Argiope peptidases during certain fractionation procedures indicates that these peptidases may take part in reversible associations with each other or with other proteins. A. aurantia digestive fluid also contains inhibitory activity effective against insect digestive peptidases. Here we present evidence for at least thirteen, heat-stable serine peptidase inhibitors ranging in molecular mass from about 15 to 32 kDa. PMID:16458560

  11. Problems with nonspecific binding in radioimmunoassay for fibrinogen fragment D

    SciTech Connect

    Thornton, R.D.; Kulkarni, P.; Wilson, J.E.

    1982-07-01

    Because of problems associated with non-specific binding in the competetive inhibition radioimmunoassay, the author, in a letter, recommends running a blank (without the first antibody) for each dilution of the antigen. He adds, further, that normal human plasma can be used a diluent when preparing standard curves if non-specific binding is found. (JMT)

  12. Conditional tonic stimulus control of nonspecific arousal.

    PubMed

    Kimmel, H D; Birbaumer, N; Elbert, T; Lutzenberger, W; Rockstroh, B

    1983-01-01

    Subjects performed a reaction time (RT) task in the presence of colored indirect lighting which had previously been associated with either sporadic electric shock (Unsafe context) or no shock (Safe context). Autonomic and cortical processes were influenced by the visual context in two ways. Nonspecific arousal was elevated in the Unsafe context as compared with the Safe context (larger SCR and more accelerative HR change elicited by the RT warning stimulus, and retarded habituation of the middle component of the slow cortical potential during the warning stimulus). In addition, information processing may have been impaired in the Unsafe as compared to the Safe context, since the earliest component of the SCR and the N100 component of the auditory evoked potential were both reduced. Higher frequency of unelicited SCR was observed following changes from a Safe to an Unsafe context than with reverse changes, during the association of these contexts with shock, but this was the only evidence of direct tonic conditioning. In general, the results demonstrate the degree to which psychophysiological processes may be influenced by tonic environmental conditions. PMID:6622070

  13. Characterization of papaya peptidase A as an enzyme of extreme basicity.

    PubMed

    Kaarsholm, N C; Schack, P

    1983-01-01

    Papaya peptidase A, a papain-like enzyme, has formerly been shown to contain a larger excess of basic amino acids and to have a higher isoelectric point than any of the other enzymes in the papaya latex. Determinations of the free electrophoretic mobility as a function of pH now establishes the isoelectric point of papaya peptidase A as 11.7 and that of succinylated papaya peptidase A as 3.8. Although the specific activity of the enzyme appears only slightly affected by the succinylation, the accompanying change in the charge/mobility ratio seems to indicate a relatively large conformational change upon succinylation. PMID:6362305

  14. NAAG peptidase inhibitors and their potential for diagnosis and therapy.

    PubMed

    Zhou, Jia; Neale, Joseph H; Pomper, Martin G; Kozikowski, Alan P

    2005-12-01

    Modulation of N-acetyl-L-aspartyl-L-glutamate peptidase activity with small-molecule inhibitors holds promise for a wide variety of diseases that involve glutamatergic transmission, and has implications for the diagnosis and therapy of cancer. This new class of compounds, of which at least one has entered clinical trials and proven to be well tolerated, has demonstrated efficacy in experimental models of pain, schizophrenia, amyotrophic lateral sclerosis, traumatic brain injury and, when appropriately functionalized, can image prostate cancer. Further investigation of these promising drug candidates will be needed to bring them to the marketplace. The recent publication of the X-ray crystal structure for the enzymatic target of these compounds should facilitate the development of other new agents with enhanced activity that could improve both the diagnosis and treatment of neurological disorders. PMID:16341066

  15. Kallikrein-related peptidases (KLKs) and the hallmarks of cancer.

    PubMed

    Filippou, Panagiota S; Karagiannis, George S; Musrap, Natasha; Diamandis, Eleftherios P

    2016-08-01

    The kallikrein-related peptidases (KLKs) represent the largest family of serine proteases within the human genome and are expressed in various tissues. Although they regulate several important physiological functions, KLKs have also been implicated in numerous pathophysiological processes, including cancer. Growing evidence describing the deregulation of KLK expression and secretion, as well as activation in various malignancies, has uncovered their potential as mediators of cancer progression, biomarkers of disease and as candidate therapeutic targets. The diversity of signalling pathways and proteolytic cascades involving KLKs and their downstream targets appears to affect cancer biology through multiple mechanisms, including those related to the hallmarks of cancer. The aim of this review is to provide an update on the importance of KLK-driven molecular pathways in relation to cancer cell traits associated with the hallmarks of cancer and to highlight their potential in personalized therapeutics. PMID:26886390

  16. Lipoprotein effects of incretin analogs and dipeptidyl peptidase 4 inhibitors

    PubMed Central

    Zhong, Jixin; Maiseyeu, Andrei; Rajagopalan, Sanjay

    2015-01-01

    Elevated post-prandial lipoprotein levels are common in patients with type 2 diabetes. Post-prandial lipoprotein alterations in type 2 diabetics are widely believed to drive inflammation and are considered a major risk factor for cardiovascular disease in diabetic patients. The incretins glucagon like peptide-1 (GLP-1) and glucose insulinotropic peptide (GIP) modulate post-prandial lipoproteins through a multitude of pathways that are independent of insulin and weight loss. Evidence from both animal models and humans seems to suggest an important effect on triglyceride rich lipoproteins (Apo48 containing) with little to no effects on other lipoproteins at least in humans. Dipeptidyl peptidase-4 (DPP4) inhibitors also appear to share these effects suggesting an important role for incretins in these effects. In this review, we will summarize lipid modulating effects of incretin analogs and DPP-4 inhibitors in both animal models and human studies and provide an overview of mechanisms responsible for these effects. PMID:26005496

  17. Nonspecific plasma proteins during sublingual immunotherapy.

    PubMed

    Reich, M; Zwacka, G; Markert, U R

    2003-01-01

    Usually, specific allergy-related plasma proteins such as immunoglobulin E (IgE) and immunoglobulin G (IgG) are used for estimating the grade of sensitization and follow-up of immunotherapy. In recent years, several nonspecific inflammatory markers, such as sICAM-1 and sIL-2R, have been shown as being suitable for therapy control in allergy. In our investigation of patients under sublingual immunotherapy (SLIT), plasma from 42 healthy controls and 133 children with single inhalation allergies to grass pollen, birch pollen or house dust mites was obtained during the symptom-free period. Patients showed symptoms including allergic rhinitis, dermatitis and allergic asthma with one single RAST class 3 or higher. Plasma concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), soluble interleukin-2 receptor (sIL-2R), sE-selectin, interleukin-12 (IL-12) and specific IgG4 were analyzed with the ELISA technique. After 1 year of SLIT, concentrations of sICAM-1, sIL-2R and sE-selectin declined significantly when results from all patients were taken as one group. Regarding the single allergen groups, the sICAM-1 and sIL-2R decrease was significant in the grass and mite group, but not in the birch group, while the sE-selectin decline was only significant in the birch group after 1 year of SLIT, but not in the grass and the mite group. No difference was observed in IL-12 and IgG4 expression. In two groups of controls with a mean age of 9.5 versus 17.5 years, the analyzed parameters were not age-dependent. The increased proteins may be useful as additional markers for the evaluation of immunological effects and follow-up investigations of allergy therapies. PMID:12947996

  18. Elevated nonspecific plasma proteins in allergic patients.

    PubMed

    Reich, M; Niess, J H; Bär, C; Zwacka, G; Markert, U R

    2003-01-01

    Several allergen-specific plasma proteins, such as IgE and IgG subclasses, are commonly used for the evaluation of grade of allergy. In the present investigation, we compared the concentration of various nonspecific plasma proteins, mostly known as inflammation markers, in an allergic and a healthy population. Plasma from 130 children with single inhalation allergies to grass pollen, birch pollen, or house dust mites as well as from 42 healthy children was obtained during the symptom-free period. Patients showed symptoms including allergic rhinitis, dermatitis, and asthma with one single radioallergosorbent test (RAST) class 3 or higher. Plasma concentrations of soluble intercellular adhesion molecule-1(sICAM-1), soluble interleukin-2 receptor(sIL-2R), sE-selectin, and soluble vascular cell adhesion molecule-1 (1sVCAM-1) were analyzed by enzyme linked immunosorbent assay (ELISA) technique. Concentrations of sICAM-1 and sE-selectin were significantly increased in all patients compared to controls. In the single allergen groups, sICAM-1 elevation was significant in the grass and mite groups, but not in the birch group; while sE-selection increase was significant in the birch and mite groups, but not in the grass group. The elevation of sIL-2R in the allergic patients was obvious in each single allergen group, but not significant. No difference was observed in sVCAM-1 expression. In two groups of patients with mean age of 9.5 years versus 17.5 years, the analyzed parameters were not age dependent. The increased proteins may be useful as additional markers for efficacy and follow-up investigations of allergy therapies. PMID:12861853

  19. Idiopathic non-specific interstitial pneumonia.

    PubMed

    Belloli, Elizabeth A; Beckford, Rosemarie; Hadley, Ryan; Flaherty, Kevin R

    2016-02-01

    Non-specific interstitial pneumonia (NSIP) is an interstitial lung disease that may be idiopathic or secondary to connective tissue disease, toxins or numerous other causes. Idiopathic NSIP is a rare diagnosis and requires exclusion of these other possible causes. Patients typically present in mid-adulthood with dyspnoea, cough and often constitutional symptoms including fever and fatigue. The disease has a female predominance, and more than 50% of patients have never smoked. Physical exam features mild hypoxaemia and inspiratory rales. Pulmonary function tests demonstrate restriction and a low diffusing capacity for carbon monoxide. High-resolution computed tomography abnormalities include predominantly lower lobe subpleural reticular changes, traction bronchiectasis and ground-glass opacities; honeycombing is rarely seen. An evaluation of the underlying pathology is necessary for a firm diagnosis. Histologically, alveolar and interstitial mononuclear cell inflammation and fibrosis are seen in a temporally uniform pattern with preserved underlying alveolar architecture. NSIP must be differentiated from other parenchymal lung diseases including idiopathic pulmonary fibrosis and hypersensitivity pneumonitis. A thorough exposure history and assessment for underlying connective tissue diseases are highly important, as positive findings in these categories would likely denote a case of secondary NSIP. A multi-disciplinary discussion that includes pulmonologist(s), radiologist(s) and pathologist(s) assists in reaching a consensus diagnosis and improves diagnostic accuracy. Treatment of idiopathic NSIP, although not well proven, is generally instituted in the form of immunosuppression. Prognosis is favourable compared with idiopathic pulmonary fibrosis, although the diagnosis still carries an attributable mortality. Herein we will summarize the clinical characteristics and management of idiopathic NSIP. PMID:26564810

  20. Type III procollagen peptide and PZ-peptidase serum levels in pre-cirrhotic liver diseases.

    PubMed

    Morelli, A; Vedovelli, A; Fiorucci, S; Angelini, G P; Fini, C; Palmerini, C A; Floridi, A

    1985-05-30

    To obtain a dynamic and non-invasive picture of hepatic fibrosis in pre-cirrhotic liver diseases we measured both the concentration of the N-terminal peptide of procollagen III, as a marker of collagen synthesis, and the activity of PZ-peptidase, an enzyme involved in collagen degradation, in the serum of alcoholic or chronic viral hepatitis patients. Peptide serum levels were similar in chronic persistent hepatitis and controls, but significantly higher in chronic active hepatitis. Chronic persistent hepatitis patients had PZ-peptidase levels higher than controls, but similar to chronic active hepatitis. The increase in collagen synthesis without a parallel increase in collagen degradation seen in chronic active hepatitis could be regarded as a sign of impending cirrhosis, whereas the unbalanced rise in PZ-peptidase observed in chronic persistent hepatitis is consistent with the non-progressive character of this disorder. In alcoholic hepatitis both peptide concentration and PZ-peptidase activity were elevated, thus suggesting that both collagen synthesis and degradation are activated. However, the greater increase in PZ-peptidase than in peptide serum levels seen in some patients seems to indicate a minor tendency to progressive fibrosis or a trend towards resolution. Unlike liver disease patients, normal peptide and PZ-peptidase levels were found in patients with pancreatic fibrosis. Since circulating inhibitors and activators of the PZ-peptidase activity can be excluded, as proved by this study, joint peptide and PZ-peptidase serum measurements would seem to offer a simple reliable non-invasive method for differentiating and monitoring progressive and non-progressive forms of hepatic fibrosis. PMID:3888456

  1. Biochemical and antigenic characterization of a new dipeptidyl-peptidase isolated from Aspergillus fumigatus.

    PubMed

    Beauvais, A; Monod, M; Debeaupuis, J P; Diaquin, M; Kobayashi, H; Latgé, J P

    1997-03-01

    A novel dipeptidyl-peptidase (DPP V) was purified from the culture medium of Aspergillus fumigatus. This is the first report of a secreted dipeptidyl-peptidase. The enzyme had a molecular mass of 88 kDa and contained approximately 9 kDa of N-linked carbohydrate. The expression and secretion of dipeptidyl-peptidase varied with the growth conditions; maximal intra- and extracellular levels were detected when the culture medium contained only proteins or protein hydrolysates in the absence of sugars. The gene of DPP V was cloned and showed significant sequence homology to other eukaryotic dipeptidyl-peptidase genes. Unlike the other dipeptidyl-peptidases, which are all intracellular, DPP V contained a signal peptide. Like the genes of other dipeptidyl-peptidases, that of DPP V displayed the consensus sequences of the catalytic site of the nonclassical serine proteases. The biochemical properties of native and recombinant DPP V obtained in Pichia pastoris were unique and were characterized by a substrate specificity limited to the hydrolysis of X-Ala, His-Ser, and Ser-Tyr dipeptides at a neutral pH optimum. In addition, we showed that DPP V is identical to one of the two major antigens used for the diagnosis of aspergillosis. PMID:9045640

  2. Comparison of cysteine peptidase activities in Trichobilharzia regenti and Schistosoma mansoni cercariae.

    PubMed

    Kasný, M; Mikes, L; Dalton, J P; Mountford, A P; Horák, P

    2007-10-01

    Cercariae of the bird schistosome Trichobilharzia regenti and of the human schistosome Schistosoma mansoni employ proteases to invade the skin of their definitive hosts. To investigate whether a similar proteolytic mechanism is used by both species, cercarial extracts of T. regenti and S. mansoni were biochemically characterized, with the primary focus on cysteine peptidases. A similar pattern of cysteine peptidase activities was detected by zymography of cercarial extracts and their chromatographic fractions from T. regenti and S. mansoni. The greatest peptidase activity was recorded in both species against the fluorogenic peptide substrate Z-Phe-Arg-AMC, commonly used to detect cathepsins B and L, and was markedly inhibited (> 96%) by Z-Phe-Ala-CHN2 at pH 4.5. Cysteine peptidases of 33 kDa and 33-34 kDa were identified in extracts of T. regenti and S. mansoni cercariae employing a biotinylated Clan CA cysteine peptidase-specific inhibitor (DCG-04). Finally, cercarial extracts from both T. regenti and S. mansoni were able to degrade native substrates present in skin (collagen II and IV, keratin) at physiological pH suggesting that cysteine peptidases are important in the pentration of host skin. PMID:17517170

  3. Nonspecific side effects of oral contraceptives: nocebo or noise?

    PubMed

    Grimes, David A; Schulz, Kenneth F

    2011-01-01

    Side effects of combined oral contraceptives are the most common reason why women discontinue them. Over the past half century, an elaborate mythology about these ill effects has evolved, fueled by rumor, gossip and poor-quality research. In contrast, placebo-controlled randomized trials document that nonspecific side effects are not significantly more common with combined oral contraceptives than with inert pills. These reported nonspecific side effects may reflect the nocebo phenomenon (the inverse of a placebo): if women are told to expect noxious side effects, these complaints occur because of the power of suggestion. Alternatively, nonspecific complaints may simply reflect their background prevalence in the population. Because Level I evidence documents no important increase in nonspecific side effects with oral contraceptives, counseling about these side effects or including them in package labeling is unwarranted and probably unethical. When in doubt, clinicians should err on the side of optimism. PMID:21134497

  4. [Description of an acidic peptidase, insensitive to classical inhibitors, in protein extracts of Trypanosoma cruzi, from a rural area of Venezuela, where Chagas disease is endemic].

    PubMed

    Zambrano, Edgar Armando; de la Cruz, Henry Samuel; Coita, Blanca Elena

    2013-09-01

    Through two peptidase assay methods, one in liquid-phase and another, in gel-phase (gel zymography), an acid peptidase was detected in protein crude extracts of epimastigotes of Trypanosoma cruzi, from a rural area of Venezuela where Chagas disease is endemic. The peptidase shows activity at a pH range between 2.0 and 2.9. Under the experimental conditions described, the acid peptidase was insensitive to usual concentrations of peptidase inhibitors of the types: serine, cysteine, aspartic and metallopeptidases. Nevertheless, like porcine pepsin at pH 2.9, the peptidase was inhibited in the presence of 5mM DTT. PMID:24354241

  5. Aspartic Peptidases of Human Pathogenic Trypanosomatids: Perspectives and Trends for Chemotherapy

    PubMed Central

    Santos, L.O.; Garcia-Gomes, A.S.; Catanho, M.; Sodré, C.L.; Santos, A.L.S.; Branquinha, M.H.; d’Avila-Levy, C.M.

    2013-01-01

    Aspartic peptidases are proteolytic enzymes present in many organisms like vertebrates, plants, fungi, protozoa and in some retroviruses such as human immunodeficiency virus (HIV). These enzymes are involved in important metabolic processes in microorganisms/virus and play major roles in infectious diseases. Although few studies have been performed in order to identify and characterize aspartic peptidase in trypanosomatids, which include the etiologic agents of leishmaniasis, Chagas’ disease and sleeping sickness, some beneficial properties of aspartic peptidase inhibitors have been described on fundamental biological events of these pathogenic agents. In this context, aspartic peptidase inhibitors (PIs) used in the current chemotherapy against HIV (e.g., amprenavir, indinavir, lopinavir, nelfinavir, ritonavir and saquinavir) were able to inhibit the aspartic peptidase activity produced by different species of Leishmania. Moreover, the treatment of Leishmania promastigotes with HIV PIs induced several perturbations on the parasite homeostasis, including loss of the motility and arrest of proliferation/growth. The HIV PIs also induced an increase in the level of reactive oxygen species and the appearance of irreversible morphological alterations, triggering parasite death pathways such as programed cell death (apoptosis) and uncontrolled autophagy. The blockage of physiological parasite events as well as the induction of death pathways culminated in its incapacity to adhere, survive and escape of phagocytic cells. Collectively, these results support the data showing that parasites treated with HIV PIs have a significant reduction in the ability to cause in vivo infection. Similarly, the treatment of Trypanosoma cruzi cells with pepstatin A showed a significant inhibition on both aspartic peptidase activity and growth as well as promoted several and irreversible morphological changes. These studies indicate that aspartic peptidases can be promising targets in

  6. Comparative review of dipeptidyl peptidase-4 inhibitors and sulphonylureas.

    PubMed

    Deacon, C F; Lebovitz, H E

    2016-04-01

    Type 2 diabetes (T2DM) is a progressive disease, and pharmacotherapy with a single agent does not generally provide durable glycaemic control over the long term. Sulphonylurea (SU) drugs have a history stretching back over 60 years, and have traditionally been the mainstay choice as second-line agents to be added to metformin once glycaemic control with metformin monotherapy deteriorates; however, they are associated with undesirable side effects, including increased hypoglycaemia risk and weight gain. Dipeptidyl peptidase (DPP)-4 inhibitors are, by comparison, more recent, with the first compound being launched in 2006, but the class now globally encompasses at least 11 different compounds. DPP-4 inhibitors improve glycaemic control with similar efficacy to SUs, but do not usually provoke hypoglycaemia or weight gain, are relatively free from adverse side effects, and have recently been shown not to increase cardiovascular risk in large prospective safety trials. Because of these factors, DPP-4 inhibitors have become an established therapy for T2DM and are increasingly being positioned earlier in treatment algorithms. The present article reviews these two classes of oral antidiabetic drugs (DPP-4 inhibitors and SUs), highlighting differences and similarities between members of the same class, as well as discussing the potential advantages and disadvantages of the two drug classes. While both classes have their merits, the choice of which to use depends on the characteristics of each individual patient; however, for the majority of patients, DPP-4 inhibitors are now the preferred choice. PMID:26597596

  7. Inhibition of dipeptidyl peptidase 8/9 impairs preadipocyte differentiation

    PubMed Central

    Han, Ruijun; Wang, Xinying; Bachovchin, William; Zukowska, Zofia; Osborn, John W.

    2015-01-01

    Adipocytes are the primary cells in adipose tissue, and adipocyte dysfunction causes lipodystrophy, obesity and diabetes. The dipeptidyl peptidase (DPP) 4 family includes four enzymes, DPP4, DPP8, DPP9 and fibroblast activation protein (FAP). DPP4 family inhibitors have been used for the treatment of type 2 diabetes patients, but their role in adipocyte formation are poorly understood. Here we demonstrate that the DPP8/9 selective inhibitor 1G244 blocks adipogenesis in preadipocyte 3T3-L1 and 3T3-F422A, while DPP4 and FAP inhibitors have no effect. In addition, knockdown of DPP8 or DPP9 significantly impairs adipocyte differentiation in preadipocytes. We further uncovered that blocking the expression or activities of DPP8 and DPP9 attenuates PPARγ2 induction during preadipocyte differentiation. Addition of PPARγ agonist thiazolidinediones (TZDs), or ectopic expression of PPARγ2, is able to rescue the adipogenic defect caused by DPP8/9 inhibition in preadipocytes. These results indicate the importance of DPP8 and DPP9 on adipogenesis. PMID:26242871

  8. Inhibition of dipeptidyl peptidase 8/9 impairs preadipocyte differentiation.

    PubMed

    Han, Ruijun; Wang, Xinying; Bachovchin, William; Zukowska, Zofia; Osborn, John W

    2015-01-01

    Adipocytes are the primary cells in adipose tissue, and adipocyte dysfunction causes lipodystrophy, obesity and diabetes. The dipeptidyl peptidase (DPP) 4 family includes four enzymes, DPP4, DPP8, DPP9 and fibroblast activation protein (FAP). DPP4 family inhibitors have been used for the treatment of type 2 diabetes patients, but their role in adipocyte formation are poorly understood. Here we demonstrate that the DPP8/9 selective inhibitor 1G244 blocks adipogenesis in preadipocyte 3T3-L1 and 3T3-F422A, while DPP4 and FAP inhibitors have no effect. In addition, knockdown of DPP8 or DPP9 significantly impairs adipocyte differentiation in preadipocytes. We further uncovered that blocking the expression or activities of DPP8 and DPP9 attenuates PPARγ2 induction during preadipocyte differentiation. Addition of PPARγ agonist thiazolidinediones (TZDs), or ectopic expression of PPARγ2, is able to rescue the adipogenic defect caused by DPP8/9 inhibition in preadipocytes. These results indicate the importance of DPP8 and DPP9 on adipogenesis. PMID:26242871

  9. Identification of dipeptidyl peptidase III in human neutrophils.

    PubMed

    Hashimoto, J; Yamamoto, Y; Kurosawa, H; Nishimura, K; Hazato, T

    2000-07-01

    We have found activity of dipeptidyl peptidase (DPP) III, one of the most important enkephalin-degrading enzymes in the central nervous system, in human neutrophils. HPLC analysis of the peptide fragments produced by treatment of leucine-enkephalin with isolated neutrophils in the presence of inhibitors of other enkephalin-degrading enzymes revealed that the enzyme in human neutrophils cleaved dipeptides from the NH(2) terminus of leucine-enkephalin, suggesting the presence of DPPIII activity in human neutrophils. Using a specific synthesized substrate and proteinase inhibitors, it was found that the neutrophils have 19.2 +/- 3.6 microM/h/5 x 10(6) cells of beta-naphthylamine for the enzyme. It was also confirmed that spinorphin and tynorphin, both reported to inhibit the activities of enkephalin-degrading enzymes, had potent inhibitory activities (IC(50): 4.0 and 0.029 microg/ml, respectively) against the enzyme. The presence of DPPIII activity in human neutrophils suggests that the biologically active peptides which are associated with enkephalin play a physiological role in regulating enkephalin or inflammatory mechanisms in peripheral tissues. PMID:10873616

  10. Prolyl-specific peptidases for applications in food protein hydrolysis.

    PubMed

    Mika, Nicole; Zorn, Holger; Rühl, Martin

    2015-10-01

    Various food proteins including, e.g. gluten, collagen and casein are rich in L-proline residues. Due to the cyclic structure of proline, these proteins are well protected from enzymatic degradation by typical digestive enzymes. Proline-specific peptidases (PsP) belong to different families of hydrolases acting on peptide bonds (EC 3.4.x.x). They occur in various organisms including bacteria, fungi, plants and insects. Based on their biochemical characteristics, PsP type enzymes are further grouped into different subclasses of which prolyl aminopeptidases (EC 3.4.11.5, PAP), prolyl carboxypeptidases (EC 3.4.17.16, PCP) and prolyl oligopeptidases/prolyl endopeptidases (EC 3.4.21.26, POP/PEP) are of major interest for applications in food biotechnology. This mini review summarises the biochemical assays employed for these subclasses of PsP and their structural properties and the reaction mechanisms. A special focus was set on PsP derived from fungi and insects and important industrial applications in the field of food biotechnology. The degradation of gluten and collagen as well as the hydrolysis of bitter peptides are discussed. PMID:26239067

  11. Kinetics of Extracellular Peptidases in Sediments of the White Oak River, NC, USA

    NASA Astrophysics Data System (ADS)

    Steen, A. D.; Kevorkian, R. T.; Alperin, M. J.; Lloyd, K. G.

    2013-12-01

    Recent molecular work has shed light on the mechanisms underlying organoheterotrophy in the marine subsurface, including production of extracellular peptidases by deeply-branching Archaea. Here we present measurements of the potential activity (Vmax) and half-saturation constants (Km) for six extracellular peptidase substrates in sediments from 0 to 83 cm deep in the White Oak River estuary, NC, USA. Potential activities at 83 cm were on average 12% of the values at the surface, but because surface Vmax values were several orders of magnitude greater than comparable values from surface seawater, the deep activities were still substantial. Km values did not display a clear trend with depth. Activities consistent with leucyl aminopeptidase were higher than any other extracellular peptidase, but there was no clear division in activities between endopeptidases (which cleave bonds in the interior of proteins) versus aminopeptidases (which cleave N-terminal amino acids). Competitive inhibition experiments will reveal the extent to which the activities we measured reflect the distinct enzymes. We will also present model-based estimates of organic carbon mineralization rates based on methane and sulfate profiles in order to assess the relative importance of extracellular peptidases as a means to acquire organic carbon in the subsurface. Saturation curves for 5 peptidase substrates at the surface and 83 cm in the White Oak River.

  12. S46 Peptidases are the First Exopeptidases to be Members of Clan PA

    PubMed Central

    Sakamoto, Yasumitsu; Suzuki, Yoshiyuki; Iizuka, Ippei; Tateoka, Chika; Roppongi, Saori; Fujimoto, Mayu; Inaka, Koji; Tanaka, Hiroaki; Masaki, Mika; Ohta, Kazunori; Okada, Hirofumi; Nonaka, Takamasa; Morikawa, Yasushi; Nakamura, Kazuo T.; Ogasawara, Wataru; Tanaka, Nobutada

    2014-01-01

    The dipeptidyl aminopeptidase BII (DAP BII) belongs to a serine peptidase family, S46. The amino acid sequence of the catalytic unit of DAP BII exhibits significant similarity to those of clan PA endopeptidases, such as chymotrypsin. However, the molecular mechanism of the exopeptidase activity of family S46 peptidase is unknown. Here, we report crystal structures of DAP BII. DAP BII contains a peptidase domain including a typical double β-barrel fold and previously unreported α-helical domain. The structures of peptide complexes revealed that the α-helical domain covers the active-site cleft and the side chain of Asn330 in the domain forms hydrogen bonds with the N-terminus of the bound peptide. These observations indicate that the α-helical domain regulates the exopeptidase activity of DAP BII. Because S46 peptidases are not found in mammals, we expect that our study will be useful for the design of specific inhibitors of S46 peptidases from pathogens. PMID:24827749

  13. Identification of dipeptidyl peptidase IV inhibitors: virtual screening, synthesis and biological evaluation.

    PubMed

    Xing, Junhao; Li, Qing; Zhang, Shengping; Liu, Haomiao; Zhao, Leilei; Cheng, Haibo; Zhang, Yuan; Zhou, Jinpei; Zhang, Huibin

    2014-09-01

    Inhibition of dipeptidyl peptidase IV is an important approach for the treatment of type-2 diabetes. In this study, we reported a multistage virtual screening workflow that integrated 3D pharmacophore models, structural consensus docking, and molecular mechanics/generalized Born surface area binding energy calculation to identify novel dipeptidyl peptidase IV inhibitors. After screening our in-house database, two hit compounds, HWL-405 and HWL-892, having persistent high performance in all stages of virtual screening were identified. These two hit compounds together with several analogs were synthesized and evaluated for in vitro inhibition of dipeptidyl peptidase IV. The experimental data indicated that most designed compounds exhibited significant dipeptidyl peptidase IV inhibitory activity. Among them, compounds 35f displayed the greatest potency against dipeptidyl peptidase IV in vitro with the IC50 value of 78 nm. In an oral glucose tolerance test in normal male Kunming mice, compound 35f reduced blood glucose excursion in a dose-dependent manner. PMID:24674599

  14. Processing, stability, and kinetic parameters of C5a peptidase from Streptococcus pyogenes.

    PubMed

    Anderson, Elizabeth T; Wetherell, Michael G; Winter, Laurie A; Olmsted, Stephen B; Cleary, Patrick P; Matsuka, Yury V

    2002-10-01

    A recombinant streptococcal C5a peptidase was expressed in Escherichia coli and its catalytic properties and thermal stability were subjected to examination. It was shown that the NH2-terminal region of C5a peptidase (Asn32-Asp79/Lys90) forms the pro-sequence segment. Upon maturation the propeptide is hydrolyzed either via an autocatalytic intramolecular cleavage or by exogenous protease streptopain. At pH 7.4 the enzyme exhibited maximum activity in the narrow range of temperatures between 40 and 43 degrees C. The process of heat denaturation of C5a peptidase investigated by fluorescence and circular dichroism spectroscopy revealed that the protein undergoes biphasic unfolding transition with Tm of 50 and 70 degrees C suggesting melting of different parts of the molecule with different stability. Unfolding of the less stable structures was accompanied by the loss of proteolytic activity. Using synthetic peptides corresponding to the COOH-terminus of human complement C5a we demonstrated that in vitro peptidase catalyzes hydrolysis of two His67-Lys68 and Ala58-Ser59 peptide bonds. The high catalytic efficiency obtained for the SQLRANISHKDMQLGR extended peptide compared to the poor hydrolysis of its derivative Ac-SQLRANISH-pNA that lacks residues at P2'-P7' positions, suggest the importance of C5a peptidase interactions with the P' side of the substrate. PMID:12354115

  15. Simulation of non-specific protein–mRNA interactions

    PubMed Central

    Magee, James; Warwicker, Jim

    2005-01-01

    Protein–nucleic acid interactions exhibit varying degrees of specificity. Relatively high affinity, sequence-specific interactions, can be studied with structure determination, but lower affinity, non-specific interactions are also of biological importance. We report simulations that predict the population of nucleic acid paths around protein surfaces, and give binding constant differences for changes in the protein scaffold. The method is applied to the non-specific component of interactions between eIF4Es and messenger RNAs that are bound tightly at the cap site. Adding a fragment of eIF4G to the system changes both the population of mRNA paths and the protein–mRNA binding affinity, suggesting a potential role for non-specific interactions in modulating translational properties. Generally, the free energy simulation technique could work in harness with characterized tethering points to extend analysis of nucleic acid conformation, and its modulation by protein scaffolds. PMID:16314302

  16. Heparin reduces nonspecific eosinophil staining artifacts in mass cytometry experiments.

    PubMed

    Rahman, Adeeb H; Tordesillas, Leticia; Berin, M Cecilia

    2016-06-01

    The analysis of heterogeneous cell samples by mass cytometry (CyTOF) relies on the assumption that metal labeled antibodies accurately bind to their target antigens. We report a previously unappreciated experimental artifact of non-specific antibody binding by eosinophils during intracellular CyTOF analysis of human whole blood samples. We hypothesized that this non-specific binding results from a charge-based interaction between the metal-labeled antibodies and highly cationic proteins found in eosinophillic granules and found that this non-specific staining artifact could be reduced to background levels with a simple blocking protocol using heparin as a competing anionic protein. This protocol eliminates a potential source of erroneous data interpretation in all experiments involving intracellular staining of human whole blood samples, and allows accurate assessment of dynamic changes in intracellular proteins in eosinophils by CyTOF. © 2016 International Society for Advancement of Cytometry. PMID:27061608

  17. Specificity and non-specificity in RNA–protein interactions

    PubMed Central

    Jankowsky, Eckhard; Harris, Michael E.

    2016-01-01

    Gene expression is regulated by complex networks of interactions between RNAs and proteins. Proteins that interact with RNA have been traditionally viewed as either specific or non-specific; specific proteins interact preferentially with defined RNA sequence or structure motifs, whereas non-specific proteins interact with RNA sites devoid of such characteristics. Recent studies indicate that the binary “specific vs. non-specific” classification is insufficient to describe the full spectrum of RNA–protein interactions. Here, we review new methods that enable quantitative measurements of protein binding to large numbers of RNA variants, and the concepts aimed as describing resulting binding spectra: affinity distributions, comprehensive binding models and free energy landscapes. We discuss how these new methodologies and associated concepts enable work towards inclusive, quantitative models for specific and non-specific RNA–protein interactions. PMID:26285679

  18. Natural and synthetic inhibitors of kallikrein-related peptidases (KLKs).

    PubMed

    Goettig, Peter; Magdolen, Viktor; Brandstetter, Hans

    2010-11-01

    Including the true tissue kallikrein KLK1, kallikrein-related peptidases (KLKs) represent a family of fifteen mammalian serine proteases. While the physiological roles of several KLKs have been at least partially elucidated, their activation and regulation remain largely unclear. This obscurity may be related to the fact that a given KLK fulfills many different tasks in diverse fetal and adult tissues, and consequently, the timescale of some of their physiological actions varies significantly. To date, a variety of endogenous inhibitors that target distinct KLKs have been identified. Among them are the attenuating Zn(2+) ions, active site-directed proteinaceous inhibitors, such as serpins and the Kazal-type inhibitors, or the huge, unspecific compartment forming α(2)-macroglobulin. Failure of these inhibitory systems can lead to certain pathophysiological conditions. One of the most prominent examples is the Netherton syndrome, which is caused by dysfunctional domains of the Kazal-type inhibitor LEKTI-1 which fail to appropriately regulate KLKs in the skin. Small synthetic inhibitory compounds and natural polypeptidic exogenous inhibitors have been widely employed to characterize the activity and substrate specificity of KLKs and to further investigate their structures and biophysical properties. Overall, this knowledge leads not only to a better understanding of the physiological tasks of KLKs, but is also a strong fundament for the synthesis of small compound drugs and engineered biomolecules for pharmaceutical approaches. In several types of cancer, KLKs have been found to be overexpressed, which makes them clinically relevant biomarkers for prognosis and monitoring. Thus, down regulation of excessive KLK activity in cancer and in skin diseases by small inhibitor compounds may represent attractive therapeutical approaches. PMID:20615447

  19. Navigating the chemical space of dipeptidyl peptidase-4 inhibitors

    PubMed Central

    Shoombuatong, Watshara; Prachayasittikul, Veda; Anuwongcharoen, Nuttapat; Songtawee, Napat; Monnor, Teerawat; Prachayasittikul, Supaluk; Prachayasittikul, Virapong; Nantasenamat, Chanin

    2015-01-01

    This study represents the first large-scale study on the chemical space of inhibitors of dipeptidyl peptidase-4 (DPP4), which is a potential therapeutic protein target for the treatment of diabetes mellitus. Herein, a large set of 2,937 compounds evaluated for their ability to inhibit DPP4 was compiled from the literature. Molecular descriptors were generated from the geometrically optimized low-energy conformers of these compounds at the semiempirical AM1 level. The origins of DPP4 inhibitory activity were elucidated from computed molecular descriptors that accounted for the unique physicochemical properties inherently present in the active and inactive sets of compounds as defined by their respective half maximal inhibitory concentration values of less than 1 μM and greater than 10 μM, respectively. Decision tree analysis revealed the importance of molecular weight, total energy of a molecule, topological polar surface area, lowest unoccupied molecular orbital, and number of hydrogen-bond donors, which correspond to molecular size, energy, surface polarity, electron acceptors, and hydrogen bond donors, respectively. The prediction model was subjected to rigorous independent testing via three external sets. Scaffold and chemical fragment analysis was also performed on these active and inactive sets of compounds to shed light on the distinguishing features of the functional moieties. Docking of representative active DPP4 inhibitors was also performed to unravel key interacting residues. The results of this study are anticipated to be useful in guiding the rational design of novel and robust DPP4 inhibitors for the treatment of diabetes. PMID:26309399

  20. Bacillus thuringiensis Cry3Aa protoxin intoxication of Tenebrio molitor induces widespread changes in the expression of serine peptidase transcripts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yellow mealworm, Tenebrio molitor, is a pest of stored grain products and is sensitive to the coleopteran-specific Cry3Aa toxin from Bacillus thuringiensis (Bt). Larvae digest protein initially with cysteine peptidases in the anterior midgut and further with serine peptidases in middle and poste...

  1. Fluorometric assay using naphthylamide substrates for assessing novel venom peptidase activities.

    PubMed

    Gasparello-Clemente, Elaine; Silveira, Paulo Flávio

    2002-11-01

    In the present study we examined the feasibility of using the fluorometry of naphthylamine derivatives for revealing peptidase activities in venoms of the snakes Bothrops jararaca, Bothrops alternatus, Bothrops atrox, Bothrops moojeni, Bothrops insularis, Crotalus durissus terrificus and Bitis arietans, of the scorpions Tityus serrulatus and Tityus bahiensis, and of the spiders Phoneutria nigriventer and Loxosceles intermedia. Neutral aminopeptidase (APN) and prolyl-dipeptidyl aminopeptidase IV (DPP IV) activities were presented in all snake venoms, with the highest levels in B. alternatus. Although all examined peptidase activities showed relatively low levels in arthropod venoms, basic aminopeptidase (APB) activity from P. nigriventer venom was the exception. Compared to the other peptidase activities, relatively high levels of acid aminopeptidase (APA) activity were restricted to B. arietans venom. B. arietans also exhibited a prominent content of APB activity which was lower in other venoms. Relatively low prolyl endopeptidase and proline iminopeptidase activities were, respectively, detectable only in T. bahiensis and B. insularis. Pyroglutamate aminopeptidase activity was undetectable in all venoms. All examined peptidase activities were undetectable in T. serrulatus venom. In this study, the specificities of a diverse array of peptidase activities from representative venoms were demonstrated for the first time, with a description of their distribution which may contribute to guiding further investigations. The expressive difference between snake and arthropod venoms was indicated by APN and DPP IV activities while APA and APB activities distinguished the venom of B. arietans from those of Brazilian snakes. The data reflected the relatively uniform qualitative distribution of the peptidase activities investigated, together with their unequal quantitative distribution, indicating the evolutionary divergence in the processing of peptides in these different

  2. Phytomonas serpens: cysteine peptidase inhibitors interfere with growth, ultrastructure and host adhesion.

    PubMed

    Santos, André L S; d'Avila-Levy, Claudia M; Dias, Felipe A; Ribeiro, Rachel O; Pereira, Fernanda M; Elias, Camila G R; Souto-Padrón, Thaïs; Lopes, Angela H C S; Alviano, Celuta S; Branquinha, Marta H; Soares, Rosangela M A

    2006-01-01

    In this study, we report the ultrastructural and growth alterations caused by cysteine peptidase inhibitors on the plant trypanosomatid Phytomonas serpens. We showed that the cysteine peptidase inhibitors at 10 microM were able to arrest cellular growth as well as promote alterations in the cell morphology, including the parasites becoming short and round. Additionally, iodoacetamide induced ultrastructural alterations, such as disintegration of cytoplasmic organelles, swelling of the nucleus and kinetoplast-mitochondrion complex, which culminated in parasite death. Leupeptin and antipain induced the appearance of microvillar extensions and blebs on the cytoplasmic membrane, resembling a shedding process. A 40 kDa cysteine peptidase was detected in hydrophobic and hydrophilic phases of P. serpens cells after Triton X-114 extraction. Additionally, we have shown through immunoblotting that anti-cruzipain polyclonal antibodies recognised two major polypeptides in P. serpens, including a 40 kDa component. Flow cytometry analysis confirmed that this cruzipain-like protein has a location on the cell surface. Ultrastructural immunocytochemical analysis demonstrated the presence of the cruzipain-like protein on the surface and in small membrane fragments released from leupeptin-treated parasites. Furthermore, the involvement of cysteine peptidases of P. serpens in the interaction with explanted salivary glands of the phytophagous insect Oncopeltus fasciatus was also investigated. When P. serpens cells were pre-treated with either cysteine peptidase inhibitors or anti-cruzipain antibody, a significant reduction of the interaction process was observed. Collectively, these results suggest that cysteine peptidases participate in several biological processes in P. serpens including cell growth and interaction with the invertebrate vector. PMID:16310789

  3. Structural Basis for Specificity of Propeptide-Enzyme Interaction in Barley C1A Cysteine Peptidases

    PubMed Central

    Cambra, Inés; Hernández, David; Diaz, Isabel; Martinez, Manuel

    2012-01-01

    C1A cysteine peptidases are synthesized as inactive proenzymes. Activation takes place by proteolysis cleaving off the inhibitory propeptide. The inhibitory capacity of propeptides from barley cathepsin L and B-like peptidases towards commercial and barley cathepsins has been characterized. Differences in selectivity have been found for propeptides from L-cathepsins against their cognate and non cognate enzymes. Besides, the propeptide from barley cathepsin B was not able to inhibit bovine cathepsin B. Modelling of their three-dimensional structures suggests that most propeptide inhibitory properties can be explained from the interaction between the propeptide and the mature cathepsin structures. Their potential use as biotechnological tools is discussed. PMID:22615948

  4. Dipeptidyl peptidase with strict substrate specificity of an anaerobic periodontopathogen Porphyromonas gingivalis.

    PubMed

    Fujimura, Setsuo; Hirai, Kaname; Shibata, Yukinaga

    2002-03-19

    A dipeptidyl peptidase which hydrolyzed Xaa-Ala-p-nitroanilide was purified to homogeneity by sequential procedures including ammonium sulfate precipitation, ion-exchange chromatography, hydrophobic interaction chromatography, gel filtration and isoelectric focusing from the cell extract of Porphyromonas gingivalis. The purified enzyme hydrolyzed p-nitroanilide derivatives of Lys-Ala, Ala-Ala, and Val-Ala, but not Xaa-Pro. Enzyme activity was maximum at neutral pHs. Its molecular mass was 64 kDa with an isoelectric point of 5.7. The enzyme belonged to the family of serine peptidases. PMID:12007665

  5. Non-Specific Microbicide Product Development: Then and Now

    PubMed Central

    Romano, Joseph W.; Robbiani, Melissa; Doncel, Gustavo F.; Moench, Thomas

    2015-01-01

    Despite the identification of HIV-1 as the etiological agent responsible for AIDS nearly 30 years ago, a sterilizing vaccine capable of preventing transmission of the virus remains elusive. In response to struggles on the vaccine development front, significant effort has been devoted to preventing the transmission of HIV with alternative products, technologies, and strategies. One of the early alternative HIV prevention strategies was microbicides, which are topical products that can be used to prevent sexual transmission of HIV either vaginally or rectally. First generation microbicide products were designed to be simple gel formulations comprised of readily available active agents that were inexpensive and broadly active (i.e., non-specific). Unfortunately, despite the clinical investigation of multiple product concepts satisfying these requirements, none were shown to be efficacious in pivotal trials. More recently, microbicide and oral prevention strategies involving highly specific and potent anti-retroviral (ARV) drugs have shown to be efficacious in trials. Although building on these successes continues, these products have a number of issues including potential toxicity with long term use, selection of HIV resistance, and cost. Further, all of the original justifications for non-specific microbicide products remain valid. This review provides a brief history of non-specific microbicide development, outlines the evolution to, and limitations of, ARV based microbicides, and summarizes the current activity on non-specific microbicide product development. PMID:22264041

  6. Nonspecific Verbal Cues Alleviate Forgetting by Young Children

    ERIC Educational Resources Information Center

    Morgan, Kirstie; Hayne, Harlene

    2007-01-01

    Verbal reminders play a pervasive role in memory retrieval by human adults. In fact, relatively nonspecific verbal information (e.g. "Remember the last time we ate at that restaurant?") will often cue vivid recollections of a past event even when presented outside the original encoding context. Although research has shown that memory retrieval by…

  7. Challenges in urine bioanalytical assays: overcoming nonspecific binding.

    PubMed

    Ji, Allena Ji; Jiang, Zhiping; Livson, Yuliya; Davis, Jennifer Ann; Chu, Jasper Xuegong; Weng, Naidong

    2010-09-01

    Dr Allena Ji is the Director of Bioanalytical Services, XenoBiotic Laboratories, Inc., NJ, USA. She has worked in the bioanalytical field for many years and accumulated rich experience in LC-MS/MS method development, method validation and sample analysis under GLP compliance in large pharmaceutical company and contract laboratory settings. In the past 10 years, Allena worked at Pfizer (Legacy of Wyeth) and investigated many small-molecule drug candidates for their nonspecific binding in urine assays. Nonspecific binding of compounds results in a severe underestimation of the compounds' concentrations and poor precision and accuracy in urine bioanalytical assays. To overcome nonspecific binding in urine assays, Allena and her colleagues developed a series of practical approaches for urine method development. By adding an appropriate anti-adsorptive agent at its optimum concentration to the urine collection containers, the nonspecific binding can be blocked. Urine assays have much higher hurdles than plasma assays due to nonspecific binding and variability of urine pH, salt concentration, volume and solubility of drug(s) in urine. A simple and systematic approach for urine method development is emphasized in this paper. Nonspecific binding is a very serious issue in bioanalytical urine assays where a compound(s) adsorbs to the container wall. The adsorption happens frequently in urine assays because urine lacks proteins and lipids that can bind to the analytes or solubilize lipophilic analytes. Therefore, urine bioanalytical assays tend to suffer from analyte losses more often than plasma assays. In the past decade, there have been many methods described to overcome nonspecific adsorption in urine assays based on individual analyte characteristics. However, a common and simple method development approach for various analytes has not been discussed and summarized. In this article we demonstrate, discuss and summarize a common approach to urine method development with

  8. Discrete Pathophysiology is Uncommon in Patients with Nonspecific Arm Pain

    PubMed Central

    Kortlever, Joost T.P.; Janssen, Stein J.; Molleman, Jeroen; Hageman, Michiel G.J.S.; Ring, David

    2016-01-01

    Background: Nonspecific symptoms are common in all areas of medicine. Patients and caregivers can be frustrated when an illness cannot be reduced to a discrete pathophysiological process that corresponds with the symptoms. We therefore asked the following questions: 1) Which demographic factors and psychological comorbidities are associated with change from an initial diagnosis of nonspecific arm pain to eventual identification of discrete pathophysiology that corresponds with symptoms? 2) What is the percentage of patients eventually diagnosed with discrete pathophysiology, what are those pathologies, and do they account for the symptoms? Methods: We evaluated 634 patients with an isolated diagnosis of nonspecific upper extremity pain to see if discrete pathophysiology was diagnosed on subsequent visits to the same hand surgeon, a different hand surgeon, or any physician within our health system for the same pain. Results: There were too few patients with discrete pathophysiology at follow-up to address the primary study question. Definite discrete pathophysiology that corresponded with the symptoms was identified in subsequent evaluations by the index surgeon in one patient (0.16% of all patients) and cured with surgery (nodular fasciitis). Subsequent doctors identified possible discrete pathophysiology in one patient and speculative pathophysiology in four patients and the index surgeon identified possible discrete pathophysiology in four patients, but the five discrete diagnoses accounted for only a fraction of the symptoms. Conclusion: Nonspecific diagnoses are not harmful. Prospective randomized research is merited to determine if nonspecific, descriptive diagnoses are better for patients than specific diagnoses that imply pathophysiology in the absence of discrete verifiable pathophysiology. PMID:27517064

  9. Trelagliptin (SYR-472, Zafatek), Novel Once-Weekly Treatment for Type 2 Diabetes, Inhibits Dipeptidyl Peptidase-4 (DPP-4) via a Non-Covalent Mechanism

    PubMed Central

    Jennings, Andy; Kamran, Ruhi; Ueno, Hikaru; Nishigaki, Nobuhiro; Kosaka, Takuo; Tani, Akiyoshi; Sano, Hiroki; Kinugawa, Yoshinobu; Koumura, Emiko; Shi, Lihong; Takeuchi, Koji

    2016-01-01

    Trelagliptin (SYR-472), a novel dipeptidyl peptidase-4 inhibitor, shows sustained efficacy by once-weekly dosing in type 2 diabetes patients. In this study, we characterized in vitro properties of trelagliptin, which exhibited approximately 4- and 12-fold more potent inhibition against human dipeptidyl peptidase-4 than alogliptin and sitagliptin, respectively, and >10,000-fold selectivity over related proteases including dipeptidyl peptidase-8 and dipeptidyl peptidase-9. Kinetic analysis revealed reversible, competitive and slow-binding inhibition of dipeptidyl peptidase-4 by trelagliptin (t1/2 for dissociation ≈ 30 minutes). X-ray diffraction data indicated a non-covalent interaction between dipeptidyl peptidase and trelagliptin. Taken together, potent dipeptidyl peptidase inhibition may partially contribute to sustained efficacy of trelagliptin. PMID:27328054

  10. Trelagliptin (SYR-472, Zafatek), Novel Once-Weekly Treatment for Type 2 Diabetes, Inhibits Dipeptidyl Peptidase-4 (DPP-4) via a Non-Covalent Mechanism.

    PubMed

    Grimshaw, Charles E; Jennings, Andy; Kamran, Ruhi; Ueno, Hikaru; Nishigaki, Nobuhiro; Kosaka, Takuo; Tani, Akiyoshi; Sano, Hiroki; Kinugawa, Yoshinobu; Koumura, Emiko; Shi, Lihong; Takeuchi, Koji

    2016-01-01

    Trelagliptin (SYR-472), a novel dipeptidyl peptidase-4 inhibitor, shows sustained efficacy by once-weekly dosing in type 2 diabetes patients. In this study, we characterized in vitro properties of trelagliptin, which exhibited approximately 4- and 12-fold more potent inhibition against human dipeptidyl peptidase-4 than alogliptin and sitagliptin, respectively, and >10,000-fold selectivity over related proteases including dipeptidyl peptidase-8 and dipeptidyl peptidase-9. Kinetic analysis revealed reversible, competitive and slow-binding inhibition of dipeptidyl peptidase-4 by trelagliptin (t1/2 for dissociation ≈ 30 minutes). X-ray diffraction data indicated a non-covalent interaction between dipeptidyl peptidase and trelagliptin. Taken together, potent dipeptidyl peptidase inhibition may partially contribute to sustained efficacy of trelagliptin. PMID:27328054

  11. Trelagliptin (SYR-472, Zafatek), novel once-weekly treatment for type 2 diabetes, inhibits dipeptidyl peptidase-4 (DPP-4) via a non-covalent mechanism

    DOE PAGESBeta

    Grimshaw, Charles E.; Jennings, Andy; Kamran, Ruhi; Ueno, Hikaru; Nishigaki, Nobuhiro; Kosaka, Takuo; Tani, Akiyoshi; Sano, Hiroki; Kinugawa, Yoshinobu; Koumura, Emiko; et al

    2016-06-21

    Trelagliptin (SYR-472), a novel dipeptidyl peptidase-4 inhibitor, shows sustained efficacy by once-weekly dosing in type 2 diabetes patients. In this study, we characterized in vitro properties of trelagliptin, which exhibited approximately 4-and 12-fold more potent inhibition against human dipeptidyl peptidase-4 than alogliptin and sitagliptin, respectively, and >10,000-fold selectivity over related proteases including dipeptidyl peptidase-8 and dipeptidyl peptidase-9. Kinetic analysis revealed reversible, competitive and slow-binding inhibition of dipeptidyl peptidase-4 by trelagliptin (t1/2 for dissociation ≈ 30 minutes). X-ray diffraction data indicated a non-covalent interaction between dipeptidyl peptidase and trelagliptin. Altogether, potent dipeptidyl peptidase inhibitionmay partially contribute to sustained efficacy of trelagliptin.

  12. Chymotrypsin-like peptidases from Tribolium castaneum: A role in molting revealed by RNA interference

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chymotrypsin-like peptidases (CTLPs) of insects are primarily secreted into the gut lumen where they act as digestive enzymes. We studied the gene family encoding CTLPs in the genome of the red flour beetle, Tribolium castaneum. Using an extended search pattern, we identified 14 TcCTLP genes that e...

  13. Intestinal peptidases form functional complexes with the neutral amino acid transporter B0AT1

    PubMed Central

    Fairweather, Stephen J.; Bröer, Angelika; O'Mara, Megan L.; Bröer, Stefan

    2012-01-01

    The brush-border membrane of the small intestine and kidney proximal tubule are the major sites for the absorption and re-absorption of nutrients in the body respectively. Transport of amino acids is mediated through the action of numerous secondary active transporters. In the mouse, neutral amino acids are transported by B0AT1 [broad neutral (0) amino acid transporter 1; SLC6A19 (solute carrier family 6 member 19)] in the intestine and by B0AT1 and B0AT3 (SLC6A18) in the kidney. Immunoprecipitation and Blue native electrophoresis of intestinal brush-border membrane proteins revealed that B0AT1 forms complexes with two peptidases, APN (aminopeptidase N/CD13) and ACE2 (angiotensin-converting enzyme 2). Physiological characterization of B0AT1 expressed together with these peptidases in Xenopus laevis oocytes revealed that APN increased the substrate affinity of the transporter up to 2.5-fold and also increased its surface expression (Vmax). Peptide competition experiments, in silico modelling and site-directed mutagenesis of APN suggest that the catalytic site of the peptidase is involved in the observed changes of B0AT1 apparent substrate affinity, possibly by increasing the local substrate concentration. These results provide evidence for the existence of B0AT1-containing digestive complexes in the brush-border membrane, interacting differentially with various peptidases, and responding to the dynamic needs of nutrient absorption in the intestine and kidney. PMID:22677001

  14. Lack of relevance of kinetic parameters for exocellular DD-peptidases to cephalosporin MICs.

    PubMed Central

    Boyd, D B; Ott, J L

    1986-01-01

    MICs of a set of cephalosporins against a variety of gram-positive and gram-negative pathogens showed no strong correlations with the rate at which these inhibitors acylate or are deacylated by beta-lactam-sensitive DD-peptidases excreted by Streptomyces sp. strain R61 and Actinomadura sp. strain R39. PMID:3729340

  15. Hydrolysis of wheat gluten by combining peptidases of Flammulina velutipes and electrodialysis.

    PubMed

    Giesler, Lucienne; Linke, Diana; Rabe, Swen; Appel, Daniel; Berger, Ralf Günter

    2013-09-11

    Wheat gluten hydrolysis, used to generate seasonings, was studied using peptidases from Flammulina velutipes or commercial Flavourzyme. L-amino acids were added in a range from 0.5 to 75.0 mM, and L-isoleucine, L-leucine, L-valine, and L-phenylalanine were identified as the strongest inhibitors for both enzyme mixtures. L-serine inhibited Flammulina velutipes peptidases only, while L-histidine and L-glutamine inhibited Flavourzyme peptidases only. To reduce product inhibition by released L-amino acids, electrodialysis was explored. An increase of the degree of hydrolysis of up to 60% for Flammulina velutipes peptidases and 31% for Flavourzyme compared to that for the best control batch was observed after applying an electrodialysis unit equipped with an ultrafiltration membrane for two times 1 h during the 20 h of hydrolysis. The total transfer of free L-amino acids into the concentrate reached 25-30% per hour. Peptides passed the membrane less easily, although the nominal cutoff was 4 kDa. PMID:23947566

  16. Purification and biochemical characterization of an extracellular serine peptidase from Aspergillus terreus.

    PubMed

    Biaggio, Rafael Tage; Silva, Ronivaldo Rodrigues da; Rosa, Nathalia Gonsales da; Leite, Rodrigo Simões Ribeiro; Arantes, Eliane Candiani; Cabral, Tatiana Pereira de Freitas; Juliano, Maria A; Juliano, Luiz; Cabral, Hamilton

    2016-04-01

    Peptidases are important because they play a central role in pharmaceutical, food, environmental, and other industrial processes. A serine peptidase from Aspergillus terreus was isolated after two chromatography steps that showed a yield of 15.5%. Its molecular mass was determined to be 43 kD, by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). This peptidase was active between pH 5.0 to 8.0 and had maximum activity at pH 7.0, at 45°C. When exposited with 1 M of urea, the enzyme maintained 100% activity and used azocasein as substrate. The N-terminal (first 15 residues) showed 33% identity with the serine peptidase of Aspergillus clavatus ES1. The kinetics assays showed that subsite S2 did not bind polar basic amino acids (His and Arg) nonpolar acidic amino acids (Asp and Glu). The subsite S1 showed higher catalytic efficiency than the S2 and S3 subsites. PMID:25830777

  17. PsoP1, a milk-clotting aspartic peptidase from the basidiomycete fungus Piptoporus soloniensis.

    PubMed

    El-Baky, Hassan Abd; Linke, Diana; Nimtz, Manfred; Berger, Ralf Günter

    2011-09-28

    The first enzyme of the basidiomycete Piptoporus soloniensis, a peptidase (PsoP1), was characterized after isolation from submerged cultures, purification by fractional precipitation, and preparative native-polyarylamide gel electrophoresis (PAGE). The native molecular mass of PsoP1 was 38 kDa with an isoelectric point of 3.9. Similar to chymosin from milk calves, PsoP1 showed a maximum milk-clotting activity (MCA) at 35-40 °C and was most stable at pH 6 and below 40 °C. The complete inhibition by pepstatin A identified this enzyme as an aspartic peptidase. Electrospray ionization-tandem MS showed an amino acid partial sequence that was more homologous to mammalian milk clotting peptidases than to the chymosin substitute from a fungal species, such as the Zygomycete Mucor miehei. According to sodium dodecyl sulfate-PAGE patterns, the peptidase cleaved κ-casein in a way similar to chymosin and hydrolyzed β-casein slowly, as it would be expected from an efficient chymosin substitute. PMID:21888369

  18. Cysteine digestive peptidases function as post-glutamine cleaving enzymes in tenebrionid stored product pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereals have storage proteins with high amounts of the amino acids glutamine and proline. Therefore, storage pests need to have digestive enzymes that are efficient in hydrolyzing these types of proteins. Post-glutamine cleaving peptidases (PGP) were isolated from the midgut of the stored product pe...

  19. Evaluation of the catalytic specificity, biochemical properties, and milk clotting abilities of an aspartic peptidase from Rhizomucor miehei.

    PubMed

    da Silva, Ronivaldo Rodrigues; Souto, Tatiane Beltramini; de Oliveira, Tássio Brito; de Oliveira, Lilian Caroline Gonçalves; Karcher, Daniel; Juliano, Maria Aparecida; Juliano, Luiz; de Oliveira, Arthur H C; Rodrigues, André; Rosa, Jose C; Cabral, Hamilton

    2016-08-01

    In this study, we detail the specificity of an aspartic peptidase from Rhizomucor miehei and evaluate the effects of this peptidase on clotting milk using the peptide sequence of k-casein (Abz-LSFMAIQ-EDDnp) and milk powder. Molecular mass of the peptidase was estimated at 37 kDa, and optimum activity was achieved at pH 5.5 and 55 °C. The peptidase was stable at pH values ranging from 3 to 5 and temperatures of up 45 °C for 60 min. Dramatic reductions in proteolytic activity were observed with exposure to sodium dodecyl sulfate, and aluminum and copper (II) chloride. Peptidase was inhibited by pepstatin A, and mass spectrometry analysis identified four peptide fragments (TWSISYGDGSSASGILAK, ASNGGGGEYIFGGYDSTK, GSLTTVPIDNSR, and GWWGITVDRA), similar to rhizopuspepsin. The analysis of catalytic specificity showed that the coagulant activity of the peptidase was higher than the proteolytic activity and that there was a preference for aromatic, basic, and nonpolar amino acids, particularly methionine, with specific cleavage of the peptide bond between phenylalanine and methionine. Thus, this peptidase may function as an important alternative enzyme in milk clotting during the preparation of cheese. PMID:27165660

  20. The midgut of Aedes albopictus females expresses active trypsin-like serine peptidases

    PubMed Central

    2014-01-01

    Background Aedes albopictus is widely distributed across tropical and sub-tropical regions and is associated with the transmission of several arboviruses. Although this species is increasingly relevant to public health due its ability to successfully colonize both urban and rural habitats, favoring the dispersion of viral infections, little is known about its biochemical traits, with all assumptions made based on studies of A. aegypti. In previous studies we characterized the peptidase profile of pre-imaginal stages of A. albopictus and we reported the first proteomic analysis of the midgut from sugar-fed females of this insect species. Methods In the present work, we further analyzed the peptidase expression in the midgut of sugar-fed females using 1DE-substrate gel zymography, two-dimensional electrophoresis (2DE), mass spectrometry (MS), and protein identification based on similarity. Results The combination of zymography, in solution assays using fluorescent substrates and 2DE-MS/MS allowed us to identify the active serine peptidase “fingerprint” in the midgut of A. albopictus females. Zymographic analysis revealed a proteolytic profile composed of at least 13 bands ranging from ~25 to 250 kDa, which were identified as trypsin-like serine peptidases by using specific inhibitors of this class of enzymes. Concomitant use of the fluorogenic substrate Z-Phe-Arg-AMC and trypsin-like serine protease inhibitors corroborated the zymographic findings. Our proteomic approach allowed the identification of two different trypsin-like serine peptidases and one chymotrypsin in protein spots of the alkaline region in 2DE map of the A. albopictus female midgut. Identification of these protein coding genes was achieved by similarity to the A. aegypti genome sequences using Mascot and OMSSA search engines. Conclusion These results allowed us to detect, identify and characterize the expression of active trypsin-like serine peptidases in the midgut of sugar-fed A. albopictus

  1. Prokaryote-derived protein inhibitors of peptidases: a sketchy occurrence and mostly unknown function

    PubMed Central

    Kantyka, Tomasz; Rawlings, Neil D.; Potempa, Jan

    2010-01-01

    In metazoan organisms protein inhibitors of peptidases are important factors essential for regulation of proteolytic activity. In vertebrates genes encoding peptidase inhibitors constitute up to 1% of genes reflecting a need for tight and specific control of proteolysis especially in extracellular body fluids. In stark contrast unicellular organisms, both prokaryotic and eukaryotic consistently contain only few, if any, genes coding for putative peptidase inhibitors. This may seem perplexing in the light of the fact that these organisms produce large numbers of proteases of different catalytic classes with the genes constituting up to 6% of the total gene count with the average being about 3%. Apparently, however, a unicellular life-style is fully compatible with other mechanisms of regulation of proteolysis and does not require protein inhibitors to control their intracellular and extracellular proteolytic activity. So in prokaryotes occurrence of genes encoding different types of peptidase inhibitors is infrequent and often scattered among phylogenetically distinct orders or even phyla of microbiota. Genes encoding proteins homologous to alpha-2-macroglobulin (family I39), serine carboxypeptidase Y inhibitor (family I51), alpha-1-peptidase inhibitor (family I4) and ecotin (family I11) are the most frequently represented in Bacteria. Although several of these gene products were shown to possess inhibitory activity, with an exception of ecotin and staphostatins, the biological function of microbial inhibitors is unclear. In this review we present distribution of protein inhibitors from different families among prokaryotes, describe their mode of action and hypothesize on their role in microbial physiology and interactions with hosts and environment. PMID:20558234

  2. Local administration of N-acetylaspartylglutamate (NAAG) peptidase inhibitors is analgesic in peripheral pain in rats.

    PubMed

    Yamamoto, Tatsuo; Saito, Osamu; Aoe, Tomohiko; Bartolozzi, Alessandra; Sarva, Jayaprakash; Zhou, Jia; Kozikowski, Alan; Wroblewska, Barbara; Bzdega, Tomasz; Neale, Joseph H

    2007-01-01

    The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) selectively activates group II metabotropic glutamate receptors (mGluRs). Systemic administration of inhibitors of the enzymes that inactivate NAAG results in decreased pain responses in rat models of inflammatory and neuropathic pain. These effects are blocked by a group II mGluR antagonist. This research tested the hypothesis that some analgesic effects of NAAG peptidase inhibition are mediated by NAAG acting on sensory neurite mGluRs at the site of inflammation. Group II mGluR agonists, SLx-3095-1, NAAG and APDC, or NAAG peptidase inhibitors, ZJ-43 and 2-PMPA, injected into the rat footpad reduced pain responses in carrageenan or formalin models. The analgesic effects of SLx-3095-1, APDC, ZJ-43, 2-PMPA and NAAG were blocked by co-injection of LY341495, a selective group II mGluR antagonist. Injection of group II mGluR agonists, NAAG or the peptidase inhibitors into the contralateral rat footpad had no effect on pain perception in the injected paw. At 10-100 microm ZJ-43 and 2-PMPA demonstrated no consistent agonist activity at mGluR2 or mGluR3. Consistent with the conclusion that peripherally administered NAAG peptidase inhibitors increase the activation of mGluR3 by NAAG that is released from peripheral sensory neurites, we found that the tissue average concentration of NAAG in the unstimulated rat hind paw was about 6 microm. These data extend our understanding of the role of this peptide in sensory neurons and reveal the potential for treatment of inflammatory pain via local application of NAAG peptidase inhibitors at doses that may have little or no central nervous system effects. PMID:17241276

  3. The astrocyte surface NAAG receptor and NAAG peptidase signaling complex as a therapeutic target.

    PubMed

    Baslow, Morris H

    2008-06-01

    There is evidence that schizophrenia and other neuropathies may involve malfunction of a unique N-acetylaspartylglutamate (NAAG) receptor and its associated NAAG peptidase, a receptor and enzyme found together on the astrocyte surface. NAAG is a peptide neurotransmitter released by stimulated neurons and specifically targeted to the group II metabotropic glutamate receptor 3 (mGlu(3)), activation of which initiates astrocyte Ca(2+) waves responsible for astrocyte-astrocyte and astrocyte-vascular system signaling and induction of vascular hyperemic responses that increase energy supplies to stimulated neurons. In this review, it is hypothesized that the receptor and enzyme exist as a cytostructural unit on the astrocyte surface, and the nature of this proposed mGlu(3)-NAAG peptidase complex is considered in terms of its physiological signaling role, and of the effect of drugs on this role. The mGlu(3) receptor has been the target of extrinsic antagonists and agonists that mimic NAAG structure and compete with natural NAAG for the receptor site. NAAG metabolism has also been the target of extrinsic NAAG-like substances that inhibit NAAG peptidase, competing with NAAG for the enzyme active site. Several drugs that affect the mGlu(3) receptor or NAAG peptidase have reached a stage of human testing. Two are agonists of the mGlu(3) receptor, and another is an NAAG peptidase inhibitor. These substances appear to have potential for treating schizophrenia and other cognitive neuropathies by interfering with a homeostatic NAAG activated neuron-astrocyte-vascular energy supply system. PMID:18596989

  4. Extracellular peptidase hunting for improvement of protein production in plant cells and roots

    PubMed Central

    Lallemand, Jérôme; Bouché, Frédéric; Desiron, Carole; Stautemas, Jennifer; de Lemos Esteves, Frédéric; Périlleux, Claire; Tocquin, Pierre

    2015-01-01

    Plant-based recombinant protein production systems have gained an extensive interest over the past few years, because of their reduced cost and relative safety. Although the first products are now reaching the market, progress are still needed to improve plant hosts and strategies for biopharming. Targeting recombinant proteins toward the extracellular space offers several advantages in terms of protein folding and purification, but degradation events are observed, due to endogenous peptidases. This paper focuses on the analysis of extracellular proteolytic activities in two production systems: cell cultures and root-secretion (rhizosecretion), in Arabidopsis thaliana and Nicotiana tabacum. Proteolytic activities of extracellular proteomes (secretomes) were evaluated in vitro against two substrate proteins: bovine serum albumin (BSA) and human serum immunoglobulins G (hIgGs). Both targets were found to be degraded by the secretomes, BSA being more prone to proteolysis than hIgGs. The analysis of the proteolysis pH-dependence showed that target degradation was mainly dependent upon the production system: rhizosecretomes contained more peptidase activity than extracellular medium of cell suspensions, whereas variations due to plant species were smaller. Using class-specific peptidase inhibitors, serine, and metallopeptidases were found to be responsible for degradation of both substrates. An in-depth in silico analysis of genomic and transcriptomic data from Arabidopsis was then performed and led to the identification of a limited number of serine and metallo-peptidases that are consistently expressed in both production systems. These peptidases should be prime candidates for further improvement of plant hosts by targeted silencing. PMID:25705212

  5. Zwitteration: Coating Surfaces with Zwitterionic Functionality to Reduce Nonspecific Adsorption

    PubMed Central

    2015-01-01

    Coating surfaces with thin or thick films of zwitterionic material is an effective way to reduce or eliminate nonspecific adsorption to the solid/liquid interface. This review tracks the various approaches to zwitteration, such as monolayer assemblies and polymeric brush coatings, on micro- to macroscopic surfaces. A critical summary of the mechanisms responsible for antifouling shows how zwitterions are ideally suited to this task. PMID:24754399

  6. Phase separation in solutions with specific and nonspecific interactions

    SciTech Connect

    Jacobs, William M.; Frenkel, Daan; Oxtoby, David W.

    2014-05-28

    Protein solutions, which tend to be thermodynamically stable under physiological conditions, can demix into protein-enriched and protein-depleted phases when stressed. Using a lattice-gas model of proteins with both isotropic and specific, directional interactions, we calculate the critical conditions for phase separation for model proteins with up to four patches via Monte Carlo simulations and statistical associating fluid theory. Given a fixed specific interaction strength, the critical value of the isotropic energy, which accounts for dispersion forces and nonspecific interactions, measures the stability of the solution with respect to nonspecific interactions. Phase separation is suppressed by the formation of protein complexes, which effectively passivate the strongly associating sites on the monomers. Nevertheless, we find that protein models with three or more patches can form extended aggregates that phase separate despite the assembly of passivated complexes, even in the absence of nonspecific interactions. We present a unified view of the critical behavior of model fluids with anisotropic interactions, and we discuss the implications of these results for the thermodynamic stability of protein solutions.

  7. Controllable Nonspecific Protein Adsorption by Charged Hyperbranched Polyglycerol Thin Films.

    PubMed

    Yu, Yaming; Frey, Holger

    2015-12-01

    Antifouling thin films derived from charged hyperbranched polyglycerol (hbPG) layers were fabricated and evaluated. The anionic hbPG (a-hbPG) monolayers and cationic hbPG/anionic hbPG (c/a-hbPG) bilayers were adsorbed on the underlying self-assembled monolayers (SAMs) of cysteamine and 3-mercaptopropionic acid (3-MPA) by electrostatic interaction, respectively, and their procession was monitored by surface plasmon resonance spectroscopy (SPR). The adsorption of bovine serum albumin (BSA) and fibrinogen on the premade a-hbPG and c/a-hbPG thin films was measured and the capability of these thin films to resist nonspecific protein adsorption was evaluated by SPR as well. It is observed that the c/a-hbPG bilayer films possessed good antifouling properties. With c/a-hbPG bilayers consisting of higher molecular weight a-hbPG, the adsorption of BSA and fibrinogen were as low as 0.015 ng/mm(-2) and 0.0076 ng/mm(-2), respectively, comparable to the traditionally ultralow antifouling surfaces (<0.05 ng/mm(-2) of nonspecific protein adsorption). This work proved that the charged hbPG thin films can strongly reduce the nonspecific protein adsorption and have the promise for the antifouling coatings with improved performance. PMID:26562213

  8. Functional analysis of C1 family cysteine peptidases in the larval gut of Tenebrio molitor and Tribolium castaneum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied protein digestion the tenebrionids Tenebrio molitor and Tribolium castaneum, pests of stored grains and grain products, to identify potential targets for biopesticide development. Tenebrionid larvae have highly compartmentalized guts, with primarily cysteine peptidases in the acidic anter...

  9. Use of phoA fusions to study the topology of the Escherichia coli inner membrane protein leader peptidase.

    PubMed Central

    San Millan, J L; Boyd, D; Dalbey, R; Wickner, W; Beckwith, J

    1989-01-01

    A topology of the Escherichia coli leader peptidase has been previously proposed on the basis of proteolytic studies. Here, a collection of alkaline phosphatase fusions to leader peptidase is described. Fusions to the periplasmic domain of this protein exhibit high alkaline phosphatase activity, while fusions to the cytoplasmic domain exhibit low activity. Elements within the cytoplasmic domain are necessary to stably anchor alkaline phosphatase in the cytoplasm. The amino-terminal hydrophobic segment of leader peptidase acts as a weak export signal for alkaline phosphatase. However, when this segment is preceded by four lysines, it acts as a highly efficient export signal. The coherence of in vitro studies with alkaline phosphatase fusion analysis of the topology of leader peptidase further indicates the utility of this genetic approach to membrane protein structure and insertion. Images PMID:2551889

  10. Expression patterns of cysteine peptidase genes across the Tribolium castaneum life cycle provide clues to biological function

    PubMed Central

    Elpidina, Elena N.; Oppert, Brenda

    2016-01-01

    The red flour beetle, Tribolium castaneum, is a major agricultural pest responsible for considerable loss of stored grain and cereal products worldwide. T. castaneum larvae have a highly compartmentalized gut, with cysteine peptidases mostly in the acidic anterior part of the midgut that are critical to the early stages of food digestion. In previous studies, we described 26 putative cysteine peptidase genes in T. castaneum (types B, L, O, F, and K) located mostly on chromosomes 3, 7, 8, and 10. In the present study, we hypothesized that specific cysteine peptidase genes could be associated with digestive functions for food processing based on comparison of gene expression profiles in different developmental stages, feeding and non-feeding. RNA-Seq was used to determine the relative expression of cysteine peptidase genes among four major developmental stages (egg, larvae, pupae, and adult) of T. castaneum. We also compared cysteine peptidase genes in T. castaneum to those in other model insects and coleopteran pests. By combining transcriptome expression, phylogenetic comparisons, response to dietary inhibitors, and other existing data, we identified key cysteine peptidases that T. castaneum larvae and adults use for food digestion, and thus new potential targets for biologically-based control products. PMID:26819843

  11. A novel allosteric mechanism in the cysteine peptidase cathepsin K discovered by computational methods

    NASA Astrophysics Data System (ADS)

    Novinec, Marko; Korenč, Matevž; Caflisch, Amedeo; Ranganathan, Rama; Lenarčič, Brigita; Baici, Antonio

    2014-02-01

    Allosteric modifiers have the potential to fine-tune enzyme activity. Therefore, targeting allosteric sites is gaining increasing recognition as a strategy in drug design. Here we report the use of computational methods for the discovery of the first small-molecule allosteric inhibitor of the collagenolytic cysteine peptidase cathepsin K, a major target for the treatment of osteoporosis. The molecule NSC13345 is identified by high-throughput docking of compound libraries to surface sites on the peptidase that are connected to the active site by an evolutionarily conserved network of residues (protein sector). The crystal structure of the complex shows that NSC13345 binds to a novel allosteric site on cathepsin K. The compound acts as a hyperbolic mixed modifier in the presence of a synthetic substrate, it completely inhibits collagen degradation and has good selectivity for cathepsin K over related enzymes. Altogether, these properties qualify our methodology and NSC13345 as promising candidates for allosteric drug design.

  12. Involvement of Kallikrein-Related Peptidases in Normal and Pathologic Processes

    PubMed Central

    Stefanini, Ana Carolina B.; da Cunha, Bianca Rodrigues; Henrique, Tiago; Tajara, Eloiza H.

    2015-01-01

    Human kallikrein-related peptidases (KLKs) are a subgroup of serine proteases that participate in proteolytic pathways and control protein levels in normal physiology as well as in several pathological conditions. Their complex network of stimulatory and inhibitory interactions may induce inflammatory and immune responses and contribute to the neoplastic phenotype through the regulation of several cellular processes, such as proliferation, survival, migration, and invasion. This family of proteases, which includes one of the most useful cancer biomarkers, kallikrein-related peptidase 3 or PSA, also has a protective effect against cancer promoting apoptosis or counteracting angiogenesis and cell proliferation. Therefore, they represent attractive therapeutic targets and may have important applications in clinical oncology. Despite being intensively studied, many gaps in our knowledge on several molecular aspects of KLK functions still exist. This review aims to summarize recent data on their involvement in different processes related to health and disease, in particular those directly or indirectly linked to the neoplastic process. PMID:26783378

  13. Predicting Nonspecific Ion Binding Using DelPhi

    PubMed Central

    Petukh, Marharyta; Zhenirovskyy, Maxim; Li, Chuan; Li, Lin; Wang, Lin; Alexov, Emil

    2012-01-01

    Ions are an important component of the cell and affect the corresponding biological macromolecules either via direct binding or as a screening ion cloud. Although some ion binding is highly specific and frequently associated with the function of the macromolecule, other ions bind to the protein surface nonspecifically, presumably because the electrostatic attraction is strong enough to immobilize them. Here, we test such a scenario and demonstrate that experimentally identified surface-bound ions are located at a potential that facilitates binding, which indicates that the major driving force is the electrostatics. Without taking into consideration geometrical factors and structural fluctuations, we show that ions tend to be bound onto the protein surface at positions with strong potential but with polarity opposite to that of the ion. This observation is used to develop a method that uses a DelPhi-calculated potential map in conjunction with an in-house-developed clustering algorithm to predict nonspecific ion-binding sites. Although this approach distinguishes only the polarity of the ions, and not their chemical nature, it can predict nonspecific binding of positively or negatively charged ions with acceptable accuracy. One can use the predictions in the Poisson-Boltzmann approach by placing explicit ions in the predicted positions, which in turn will reduce the magnitude of the local potential and extend the limits of the Poisson-Boltzmann equation. In addition, one can use this approach to place the desired number of ions before conducting molecular-dynamics simulations to neutralize the net charge of the protein, because it was shown to perform better than standard screened Coulomb canned routines, or to predict ion-binding sites in proteins. This latter is especially true for proteins that are involved in ion transport, because such ions are loosely bound and very difficult to detect experimentally. PMID:22735539

  14. Recombinant Rp1 genes confer necrotic or nonspecific resistance phenotypes.

    PubMed

    Smith, Shavannor M; Steinau, Martin; Trick, Harold N; Hulbert, Scot H

    2010-06-01

    Genes at the Rp1 rust resistance locus of maize confer race-specific resistance to the common rust fungus Puccinia sorghi. Three variant genes with nonspecific effects (HRp1 -Kr1N, -D*21 and -MD*19) were found to be generated by intragenic crossing over within the LRR region. The LRR region of most NBS-LRR encoding genes is quite variable and codes for one of the regions in resistance gene proteins that controls specificity. Sequence comparisons demonstrated that the Rp1-Kr1N recombinant gene was identical to the N-terminus of the rp1-kp2 gene and C-terminus of another gene from its HRp1-K grandparent. The Rp1-D*21 recombinant gene consists of the N-terminus of the rp1-dp2 gene and C-terminus of the Rp1-D gene from the parental haplotype. Similarly, a recombinant gene from the Rp1-MD*19 haplotype has the N-terminus of an rp1 gene from the HRp1-M parent and C-terminus of the rp1-D19 gene from the HRp1-D parent. The recombinant Rp1 -Kr1N, -D*21 and -MD*19 genes activated defense responses in the absence of their AVR proteins triggering HR (hypersensitive response) in the absence of the pathogen. The results indicate that the frequent intragenic recombination events that occur in the Rp1 gene cluster not only recombine the genes into novel haplotypes, but also create genes with nonspecific effects. Some of these may contribute to nonspecific quantitative resistance but others have severe consequences for the fitness of the plant. PMID:20443026

  15. DNA topology confers sequence specificity to nonspecific architectural proteins.

    PubMed

    Wei, Juan; Czapla, Luke; Grosner, Michael A; Swigon, David; Olson, Wilma K

    2014-11-25

    Topological constraints placed on short fragments of DNA change the disorder found in chain molecules randomly decorated by nonspecific, architectural proteins into tightly organized 3D structures. The bacterial heat-unstable (HU) protein builds up, counter to expectations, in greater quantities and at particular sites along simulated DNA minicircles and loops. Moreover, the placement of HU along loops with the "wild-type" spacing found in the Escherichia coli lactose (lac) and galactose (gal) operons precludes access to key recognition elements on DNA. The HU protein introduces a unique spatial pathway in the DNA upon closure. The many ways in which the protein induces nearly the same closed circular configuration point to the statistical advantage of its nonspecificity. The rotational settings imposed on DNA by the repressor proteins, by contrast, introduce sequential specificity in HU placement, with the nonspecific protein accumulating at particular loci on the constrained duplex. Thus, an architectural protein with no discernible DNA sequence-recognizing features becomes site-specific and potentially assumes a functional role upon loop formation. The locations of HU on the closed DNA reflect long-range mechanical correlations. The protein responds to DNA shape and deformability—the stiff, naturally straight double-helical structure—rather than to the unique features of the constituent base pairs. The structures of the simulated loops suggest that HU architecture, like nucleosomal architecture, which modulates the ability of regulatory proteins to recognize their binding sites in the context of chromatin, may influence repressor-operator interactions in the context of the bacterial nucleoid. PMID:25385626

  16. Vapor Trace Recognition Using a Single Nonspecific Chemiresistor

    PubMed Central

    Dobrokhotov, Vladimir; Larin, Alexander; Sowell, Dewayne

    2013-01-01

    An application of spectral analysis to the transient response signals of ALD-fabricated conductometric sensors (chemiresistors) upon exposure to short vapor pulses is discussed. It is based on the representation of a response curve in the frequency domain, followed by the multi-dimensional Quadratic Discriminant Analysis (QDA) for analyte identification. Compared to the standard steady-state amplitude analysis, this technique does not depend on a short-term sensor drift, does not have limitations for the number of extracted features and has a strict physical validation. Effective recognition of some relatively simple combustible analytes (acetone, toluene, ethanol) was demonstrated using a single nonspecific chemiresistor. PMID:23857265

  17. Retained strabismus suture material masquerading as nonspecific orbital inflammation.

    PubMed

    Callahan, Alison B; Scofield, Stacy M; Gallin, Pamela F; Kazim, Michael

    2016-06-01

    We report a case of orbital myositis of the superior rectus muscle-levator complex masquerading as nonspecific orbital inflammation but corresponding in location to a known braided polyester "chicken suture" placed 20 years earlier during strabismus surgery. The orbital inflammation was refractory to oral steroids but resolved promptly on surgical removal of the suture material. Although suture material is known to cause foreign body granulomatous reactions, to our knowledge this is the first reported case of a deep, diffuse orbital inflammation attributable to chicken suture placed during strabismus surgery. PMID:27112911

  18. Effects of NAAG peptidase inhibitor 2-PMPA in model chronic pain - relation to brain concentration.

    PubMed

    Nagel, Jens; Belozertseva, Irina; Greco, Sergio; Kashkin, Vladimir; Malyshkin, Andrey; Jirgensons, Aigars; Shekunova, Elena; Eilbacher, Bernd; Bespalov, Anton; Danysz, Wojciech

    2006-12-01

    N-acetylated-alpha-linked-acidic peptidase (NAAG peptidase) converts N-acetyl-aspartyl-glutamate (NAAG, mGluR3 agonist) into N-acetyl-aspartate and glutamate. The NAAG peptidase inhibitor 2-PMPA (2-(phosphonomethyl)pentanedioic acid) had neuroprotective activity in an animal model of stroke and anti-allodynic activity in CCI model despite its uncertain ability to penetrate the blood-brain barrier. The NAAG concentration in brain ECF under basal conditions and its alteration in relation to the brain ECF concentration of 2-PMPA is unclear. We therefore assessed those brain concentrations after i.p. administration of 2-PMPA, using in vivo microdialysis combined with LC/MS/MS analysis. Administration of 2-PMPA (50mg/kg) produced a mean peak concentration of 2-PMPA of 29.66+/-8.1microM. This concentration is about 100,000 fold more than is needed for inhibition of NAAG peptidase, and indicates very good penetration to the brain. Application of 2-PMPA was followed by a linear increase of NAAG-concentration reaching a maximum of 2.89+/-0.42microM at the end of microdialysis. However, during the time the anti-allodynic effects of 2-PMPA were observed, the NAAG concentration in the ECF did not reach levels which are likely to have an impact on any known target. It appears therefore that the observed behavioural effects of 2-PMPA may not be mediated by NAAG nor, in turn, by mGluR3 receptors. PMID:16926034

  19. Antibacterial Activity of and Resistance to Small Molecule Inhibitors of the ClpP Peptidase

    PubMed Central

    Compton, Corey L.; Schmitz, Karl R.; Sauer, Robert T.; Sello, Jason K.

    2014-01-01

    There is rapidly mounting evidence that intracellular proteases in bacteria are compelling targets for antibacterial drugs. Multiple reports suggest that the human pathogen Mycobacterium tuberculosis and other actinobacteria may be particularly sensitive to small molecules that perturb the activities of self-compartmentalized peptidases, which catalyze intracellular protein turnover as components of ATP-dependent proteolytic machines. Here, we report chemical syntheses and evaluations of structurally diverse β-lactones, which have a privileged structure for selective, suicide inhibition of the self-compartmentalized ClpP peptidase. β-lactones with certain substituents on the α- and β-carbons were found to be toxic to M. tuberculosis. Using an affinity-labeled analog of a bioactive β-lactone in a series of chemical proteomic experiments, we selectively captured the ClpP1P2 peptidase from live cultures of two different actinobacteria that are related to M. tuberculosis. Importantly, we found that the growth inhibitory β-lactones also inactivate the M. tuberculosis ClpP1P2 peptidase in vitro via formation of a covalent adduct at the ClpP2 catalytic serine. Given the potent antibacterial activity of these compounds and their medicinal potential, we sought to identify innate mechanisms of resistance. Using a genome mining strategy, we identified a genetic determinant of β-lactone resistance in Streptomyces coelicolor, a non-pathogenic relative of M. tuberculosis. Collectively, these findings validate the potential of ClpP inhibition as a strategy in antibacterial drug development and define a mechanism by which bacteria could resist the toxic effects of ClpP inhibitors. PMID:24047344

  20. Generation of dipeptidyl peptidase-IV-inhibiting peptides from β-lactoglobulin secreted by Lactococcus lactis.

    PubMed

    Shigemori, Suguru; Oshiro, Kazushi; Wang, Pengfei; Yamamoto, Yoshinari; Wang, Yeqin; Sato, Takashi; Uyeno, Yutaka; Shimosato, Takeshi

    2014-01-01

    Previous studies showed that hydrolysates of β-lactoglobulin (BLG) prepared using gastrointestinal proteases strongly inhibit dipeptidyl peptidase-IV (DPP-IV) activity in vitro. In this study, we developed a BLG-secreting Lactococcus lactis strain as a delivery vehicle and in situ expression system. Interestingly, trypsin-digested recombinant BLG from L. lactis inhibited DPP-IV activity, suggesting that BLG-secreting L. lactis may be useful in the treatment of type 2 diabetes mellitus. PMID:25157356

  1. Identification of peptidase substrates in human plasma by FTMS based differential mass spectrometry

    NASA Astrophysics Data System (ADS)

    Yates, Nathan A.; Deyanova, Ekaterina G.; Geissler, Wayne; Wiener, Matthew C.; Sachs, Jeffrey R.; Wong, Kenny K.; Thornberry, Nancy A.; Sinha Roy, Ranabir; Settlage, Robert E.; Hendrickson, Ronald C.

    2007-01-01

    Approximately 2% of the human genome encodes for proteases. Unfortunately, however, the biological roles of most of these enzymes remain poorly defined, since the physiological substrates are typically unknown and are difficult to identify using traditional methods. We have developed a proteomics experiment based on FTMS profiling and differential mass spectrometry (dMS) to identify candidate endogenous substrates of proteases using fractionated human plasma as the candidate substrate pool. Here we report proof-of-concept experiments for identifying in vitro substrates of aminopeptidase P2, (APP2) and dipeptidyl peptidase 4 (DPP-4), a peptidase of therapeutic interest for the treatment of type 2 diabetes. For both proteases, previously validated peptide substrates spiked into the human plasma pool were identified. Of note, the differential mass spectrometry experiments also identified novel substrates for each peptidase in the subfraction of human plasma. Targeted MS/MS analysis of these peptides in the complex human plasma pool and manual confirmation of the amino acid sequences led to the identification of these substrates. The novel DPP-4 substrate EPLGRQLTSGP was chemically synthesized and cleavage kinetics were determined in an in vitro DPP-4 enzyme assay. The apparent second order rate constant (kcat/KM) for DPP-4-mediated cleavage was determined to be 2.3 x 105 M-1 s-1 confirming that this peptide is efficiently processed by the peptidase in vitro. Collectively, these results demonstrate that differential mass spectrometry has the potential to identify candidate endogenous substrates of target proteases from a human plasma pool. Importantly, knowledge of the endogenous substrates can provide useful insight into the biology of these enzymes and provides useful biomarkers for monitoring their activity in vivo.

  2. Three extracellular dipeptidyl peptidases found in Aspergillus oryzae show varying substrate specificities.

    PubMed

    Maeda, Hiroshi; Sakai, Daisuke; Kobayashi, Takuji; Morita, Hiroto; Okamoto, Ayako; Takeuchi, Michio; Kusumoto, Ken-Ichi; Amano, Hitoshi; Ishida, Hiroki; Yamagata, Youhei

    2016-06-01

    Three extracellular dipeptidyl peptidase genes, dppB, dppE, and dppF, were unveiled by sequence analysis of the Aspergillus oryzae genome. We investigated their differential enzymatic profiles, in order to gain an understanding of the diversity of these genes. The three dipeptidyl peptidases were expressed using Aspergillus nidulans as the host. Each recombinant enzyme was purified and subsequently characterized. The enzymes displayed similar optimum pH values, but optimum temperatures, pH stabilities, and substrate specificities varied. DppB was identified as a Xaa-Prolyl dipeptidyl peptidase, while DppE scissile substrates were similar to the substrates for Aspergillus fumigatus DPPV (AfDPPV). DppF was found to be a novel enzyme that could digest both substrates for A. fumigatus DPPIV and AfDPPV. Semi-quantitative PCR revealed that the transcription of dppB in A. oryzae was induced by protein substrates and repressed by the addition of an inorganic nitrogen source, despite the presence of protein substrates. The transcription of dppE depended on its growth time, while the transcription of dppF was not affected by the type of the nitrogen source in the medium, and it started during the early stage of the fungal growth. Based on these results, we conclude that these enzymes may represent the nutrition acquisition enzymes. Additionally, DppF may be one of the sensor peptidases responsible for the detection of the protein substrates in A. oryzae environment. DppB may be involved in nitrogen assimilation control, since the transcription of dppB was repressed by NaNO3, despite the presence of protein substrates. PMID:26846741

  3. Posttranslational signal peptidase cleavage at the flavivirus C-prM junction in vitro.

    PubMed Central

    Stocks, C E; Lobigs, M

    1995-01-01

    We have investigated the cleavages at the flavivirus capsid-prM protein junction in vitro. When expressed in the absence of the flavivirus proteinase, capsid and prM, which are separated by an internal signal sequence, exist as a membrane-spanning precursor protein. Here we show the induction of posttranslational signal peptidase cleavage of prM by trypsin cleavage of a cytoplasmic region of this precursor protein. PMID:7494334

  4. Blockade of N-acetylaspartylglutamate peptidases: a novel protective strategy for brain injuries and neurological disorders.

    PubMed

    Zhong, Chunlong; Luo, Qizhong; Jiang, Jiyao

    2014-12-01

    The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) is reported to suppress glutamate release mainly through selective activation of presynaptic Group II metabotropic glutamate receptor subtype 3 (mGluR3). Therefore, strategies of inhibition of NAAG peptidases and subsequent NAAG hydrolysis to elevate levels of NAAG could reduce glutamate release under pathological conditions and be neuroprotective by attenuating excitotoxic cell injury. A series of potent inhibitors of NAAG peptidases has been synthesized and demonstrated efficacy in experimental models of ischemic-hypoxic brain injury, traumatic brain injury, inflammatory pain, diabetic neuropathy, amyotrophic lateral sclerosis and phencyclidine-induced schizophrenia-like behaviors. The excessive glutamatergic transmission has been implicated in all of these neurological disorders. Thus, blockade of NAAG peptidases may augment an endogenous protective mechanism and afford neuroprotection in the brain. This review aims to summarize and provide insight into the current understanding of the novel neuroprotective strategy based on limiting glutamate excitotoxicity for a wide variety of brain injuries and neurological disorders. PMID:24494725

  5. Peptidases released by necrotic cells control CD8+ T cell cross-priming

    PubMed Central

    Gamrekelashvili, Jaba; Kapanadze, Tamar; Han, Miaojun; Wissing, Josef; Ma, Chi; Jaensch, Lothar; Manns, Michael P.; Armstrong, Todd; Jaffee, Elizabeth; White, Ayla O.; Citrin, Deborah E.; Korangy, Firouzeh; Greten, Tim F.

    2013-01-01

    Cross-priming of CD8+ T cells and generation of effector immune responses is pivotal for tumor immunity as well as for successful anticancer vaccination and therapy. Dead and dying cells produce signals that can influence Ag processing and presentation; however, there is conflicting evidence regarding the immunogenicity of necrotic cell death. We used a mouse model of sterile necrosis, in which mice were injected with sterile primary necrotic cells, to investigate a role of these cells in priming of CD8+ T cells. We discovered a molecular mechanism operating in Ag donor cells that regulates cross-priming of CD8+ T cells during primary sterile necrosis and thereby controls adaptive immune responses. We found that the cellular peptidases dipeptidyl peptidase 3 (DPP-3) and thimet oligopeptidase 1 (TOP-1), both of which are present in nonimmunogenic necrotic cells, eliminated proteasomal degradation products and blocked Ag cross-presentation. While sterile necrotic tumor cells failed to induce CD8+ T cell responses, their nonimmunogenicity could be reversed in vitro and in vivo by inactivation of DPP-3 and TOP-1. These results indicate that control of cross-priming and thereby immunogenicity of primary sterile necrosis relies on proteasome-dependent oligopeptide generation and functional status of peptidases in Ag donor cells. PMID:24216478

  6. Tripeptidyl Peptidase II Mediates Levels of Nuclear Phosphorylated ERK1 and ERK2*

    PubMed Central

    Wiemhoefer, Anne; Stargardt, Anita; van der Linden, Wouter A.; Renner, Maria C.; van Kesteren, Ronald E.; Stap, Jan; Raspe, Marcel A.; Tomkinson, Birgitta; Kessels, Helmut W.; Ovaa, Huib; Overkleeft, Herman S.; Florea, Bogdan; Reits, Eric A.

    2015-01-01

    Tripeptidyl peptidase II (TPP2) is a serine peptidase involved in various biological processes, including antigen processing, cell growth, DNA repair, and neuropeptide mediated signaling. The underlying mechanisms of how a peptidase can influence this multitude of processes still remain unknown. We identified rapid proteomic changes in neuroblastoma cells following selective TPP2 inhibition using the known reversible inhibitor butabindide, as well as a new, more potent, and irreversible peptide phosphonate inhibitor. Our data show that TPP2 inhibition indirectly but rapidly decreases the levels of active, di-phosphorylated extracellular signal-regulated kinase 1 (ERK1) and ERK2 in the nucleus, thereby down-regulating signal transduction downstream of growth factors and mitogenic stimuli. We conclude that TPP2 mediates many important cellular functions by controlling ERK1 and ERK2 phosphorylation. For instance, we show that TPP2 inhibition of neurons in the hippocampus leads to an excessive strengthening of synapses, indicating that TPP2 activity is crucial for normal brain function. PMID:26041847

  7. Comparative structural analysis of the caspase family with other clan CD cysteine peptidases

    PubMed Central

    McLuskey, Karen; Mottram, Jeremy C.

    2015-01-01

    Clan CD forms a structural group of cysteine peptidases, containing seven individual families and two subfamilies of structurally related enzymes. Historically, it is most notable for containing the mammalian caspases, on which the structures of the clan were founded. Interestingly, the caspase family is split into two subfamilies: the caspases, and a second subfamily containing both the paracaspases and the metacaspases. Structural data are now available for both the paracaspases and the metacaspases, allowing a comprehensive structural analysis of the entire caspase family. In addition, a relative plethora of structural data has recently become available for many of the other families in the clan, allowing both the structures and the structure–function relationships of clan CD to be fully explored. The present review compares the enzymes in the caspase subfamilies with each other, together with a comprehensive comparison of all the structural families in clan CD. This reveals a diverse group of structures with highly conserved structural elements that provide the peptidases with a variety of substrate specificities and activation mechanisms. It also reveals conserved structural elements involved in substrate binding, and potential autoinhibitory functions, throughout the clan, and confirms that the metacaspases are structurally diverse from the caspases (and paracaspases), suggesting that they should form a distinct family of clan CD peptidases. PMID:25697094

  8. The effects of dipeptidyl peptidase-4 inhibition on microvascular diabetes complications.

    PubMed

    Avogaro, Angelo; Fadini, Gian Paolo

    2014-10-01

    We performed a review of the literature to determine whether the dipeptidyl peptidase-4 inhibitors (DPP4-I) may have the capability to directly and positively influence diabetic microvascular complications. The literature was scanned to identify experimental and clinical evidence that DPP4-I can ameliorate diabetic microangiopathy. We retrieved articles published between 1 January 1980 and 1 March 2014 in English-language peer-reviewed journals using the following terms: ("diabetes" OR "diabetic") AND ("retinopathy" OR "retinal" OR "nephropathy" OR "renal" OR "albuminuria" OR "microalbuminuria" OR "neuropathy" OR "ulcer" OR "wound" OR "bone marrow"); ("dipeptidyl peptidase-4" OR "dipeptidyl peptidase-IV" OR "DPP-4" OR "DPP-IV"); and ("inhibition" OR "inhibitor"). Experimentally, DPP4-I appears to improve inflammation, endothelial function, blood pressure, lipid metabolism, and bone marrow function. Several experimental studies report direct potential beneficial effects of DPP4-I on all microvascular diabetes-related complications. These drugs have the ability to act either directly or indirectly via improved glucose control, GLP-1 bioavailability, and modifying nonincretin substrates. Although preliminary clinical data support that DPP4-I therapy can protect from microangiopathy, insufficient evidence is available to conclude that this class of drugs directly prevents or decreases microangiopathy in humans independently from improved glucose control. Experimental findings and preliminary clinical data suggest that DPP4-I, in addition to improving metabolic control, have the potential to interfere with the onset and progression of diabetic microangiopathy. Further evidence is needed to confirm these effects in patients with diabetes. PMID:25249673

  9. Interactions of “Bora-Penicilloates” with Serine β-Lactamases and DD-Peptidases

    PubMed Central

    2015-01-01

    Specific boronic acids are generally powerful tetrahedral intermediate/transition state analogue inhibitors of serine amidohydrolases. This group of enzymes includes bacterial β-lactamases and DD-peptidases where there has been considerable development of boronic acid inhibitors. This paper describes the synthesis, determination of the inhibitory activity, and analysis of the results from two α-(2-thiazolidinyl) boronic acids that are closer analogues of particular tetrahedral intermediates involved in β-lactamase and DD-peptidase catalysis than those previously described. One of them, 2-[1-(dihydroxyboranyl)(2-phenylacetamido)methyl]-5,5-dimethyl-1,3-thiazolidine-4-carboxylic acid, is a direct analogue of the deacylation tetrahedral intermediates of these enzymes. These compounds are micromolar inhibitors of class C β-lactamases but, very unexpectedly, not inhibitors of class A β-lactamases. We rationalize the latter result on the basis of a new mechanism of boronic acid inhibition of the class A enzymes. A stable inhibitory complex is not accessible because of the instability of an intermediate on its pathway of formation. The new boronic acids also do not inhibit bacterial DD-peptidases (penicillin-binding proteins). This result strongly supports a central feature of a previously proposed mechanism of action of β-lactam antibiotics, where deacylation of β-lactam-derived acyl-enzymes is not possible because of unfavorable steric interactions. PMID:25302576

  10. Acid, basic, and neutral peptidases present different profiles in chromophobe renal cell carcinoma and in oncocytoma.

    PubMed

    Blanco, Lorena; Larrinaga, Gorka; Pérez, Itxaro; López, José I; Gil, Javier; Agirregoitia, Ekaitz; Varona, Adolfo

    2008-04-01

    Renal cell carcinomas (RCCs) are neoplasias with high prevalence and mortality. We previously reported that several peptidases may be involved in the pathophysiology of clear cell renal cell carcinoma (CCRCC). Now, to gain insight into the reasons that lead the various RCC types to behave very differently with regard to aggressiveness and response to anticancer treatments, we analyzed subsets of chromophobe renal cell carcinoma (ChRCC), and renal oncocytoma (RO), a benign tumor; as well as different grades and stages of CCRCCs. Particulate APN, APB, and APA activities were decreased in both ChRCC and RO (tumor vs. nontumor tissues). Interestingly, activities were downregulated in a tumor-type specific way and the intensities of the decreases were stronger in the benign tumor than in the malignant type. Moreover, when two key histopathological parameters for tumor prognosis (high vs. low stage and grade) were analyzed, increases of activity were also observed in several of these cell surface peptidases (APN, APB). Some soluble activities (APB, Asp-AP) were also downregulated in the RCCs. With respect to genetic expression, PSA and APN were in a positive correlation related to their activities in both ChRCC and RO; but not APB, Asp-AP, APA, and PGI. These results may suggest an involvement of several peptidases in the pathophysiology of renal cancer, since they presented different patterns of activity and expression in tumors with different behaviors. PMID:18216146

  11. A phytopathogenic cysteine peptidase from latex of wild rubber vine Cryptostegia grandiflora.

    PubMed

    Ramos, M V; Souza, D P; Gomes, M T R; Freitas, C D T; Carvalho, C P S; Júnior, P A V R; Salas, C E

    2014-04-01

    A 24,118 Da (MALDI-TOF) cysteine peptidase (EC 3.4.22.16) was purified from the latex extract of Cryptostegia grandiflora by two chromatographic steps involving ion exchange and Reverse-phase HPLC. The purified protein (Cg24-I) exhibits a single band profile following reduced SDS-PAGE and a unique amino terminal sequence, 1VPASIDWREKGTVL14, that is similar to other plant cysteine peptidases. Cg24-I displayed optimal proteolytic activity at pH 8.0 with 25 mM phosphate buffer. The proteolytic activity was inhibited with 0.2 mM E-64 and 1 mM iodoacetamide and was stimulated with 1 mM DTT. Cg24-I fully inhibited spore germination of phytopathogenic fungi Fusarium solani at a dose of 28.1 μg/mL. Its toxicity involves the membrane permeabilization of spores as probed by propidium iodide uptake. These results show that latex peptidases are part of the plant's defensive strategy against phytopathogens and that they most likely act synergistically with other recognized defensive proteins. PMID:24596120

  12. Structural and kinetic contributions of the oxyanion binding site to the catalytic activity of acylaminoacyl peptidase.

    PubMed

    Kiss, András L; Palló, Anna; Náray-Szabó, Gábor; Harmat, Veronika; Polgár, László

    2008-05-01

    It is widely accepted that the catalytic activity of serine proteases depends primarily on the Asp-His-Ser catalytic triad and other residues within the vicinity of this motif. Some of these residues form the oxyanion binding site that stabilizes the tetrahedral intermediate by hydrogen bonding to the negatively charged oxyanion. In acylaminoacyl peptidase from the thermophile Aeropyrum pernix, the main chain NH group of Gly369 is one of the hydrogen bond donors forming the oxyanion binding site. The side chain of His367, a conserved residue in acylaminoacyl peptidases across all species, fastens the loop holding Gly369. Determination of the crystal structure of the H367A mutant revealed that this loop, including Gly369, moves away considerably, accounting for the observed three orders of magnitude decrease in the specificity rate constant. For the wild-type enzyme ln(k(cat)/K(m)) vs. 1/T deviates from linearity indicating greater rate enhancement with increasing temperature for the dissociation of the enzyme-substrate complex compared with its decomposition to product. In contrast, the H367A variant provided a linear Arrhenius plot, and its reaction was associated with unfavourable entropy of activation. These results show that a residue relatively distant from the active site can significantly affect the catalytic activity of acylaminoacyl peptidase without changing the overall structure of the enzyme. PMID:18325786

  13. Substrate specificity of mitochondrial intermediate peptidase analysed by a support-bound peptide library

    PubMed Central

    Marcondes, M.F.M.; Alves, F.M.; Assis, D.M.; Hirata, I.Y.; Juliano, L.; Oliveira, V.; Juliano, M.A.

    2015-01-01

    The substrate specificity of recombinant human mitochondrial intermediate peptidase (hMIP) using a synthetic support-bound FRET peptide library is presented. The collected fluorescent beads, which contained the hydrolysed peptides generated by hMIP, were sequenced by Edman degradation. The results showed that this peptidase presents a remarkable preference for polar uncharged residues at P1 and P1′ substrate positions: Ser = Gln > Thr at P1 and Ser > Thr at P1′. Non-polar residues were frequent at the substrate P3, P2, P2′ and P3′ positions. Analysis of the predicted MIP processing sites in imported mitochondrial matrix proteins shows these cleavages indeed occur between polar uncharged residues. Previous analysis of these processing sites indicated the importance of positions far from the MIP cleavage site, namely the presence of a hydrophobic residue (Phe or Leu) at P8 and a polar uncharged residue (Ser or Thr) at P5. To evaluate this, additional kinetic analyses were carried out, using fluorogenic substrates synthesized based on the processing sites attributed to MIP. The results described here underscore the importance of the P1 and P1′ substrate positions for the hydrolytic activity of hMIP. The information presented in this work will help in the design of new substrate-based inhibitors for this peptidase. PMID:26082885

  14. Substrate specificity of mitochondrial intermediate peptidase analysed by a support-bound peptide library.

    PubMed

    Marcondes, M F M; Alves, F M; Assis, D M; Hirata, I Y; Juliano, L; Oliveira, V; Juliano, M A

    2015-01-01

    The substrate specificity of recombinant human mitochondrial intermediate peptidase (hMIP) using a synthetic support-bound FRET peptide library is presented. The collected fluorescent beads, which contained the hydrolysed peptides generated by hMIP, were sequenced by Edman degradation. The results showed that this peptidase presents a remarkable preference for polar uncharged residues at P1 and P1' substrate positions: Ser = Gln > Thr at P1 and Ser > Thr at P1'. Non-polar residues were frequent at the substrate P3, P2, P2' and P3' positions. Analysis of the predicted MIP processing sites in imported mitochondrial matrix proteins shows these cleavages indeed occur between polar uncharged residues. Previous analysis of these processing sites indicated the importance of positions far from the MIP cleavage site, namely the presence of a hydrophobic residue (Phe or Leu) at P8 and a polar uncharged residue (Ser or Thr) at P5. To evaluate this, additional kinetic analyses were carried out, using fluorogenic substrates synthesized based on the processing sites attributed to MIP. The results described here underscore the importance of the P1 and P1' substrate positions for the hydrolytic activity of hMIP. The information presented in this work will help in the design of new substrate-based inhibitors for this peptidase. PMID:26082885

  15. Heterologous production of the stain solving peptidase PPP1 from Pleurotus pulmonarius.

    PubMed

    Leonhardt, Robin-Hagen; Krings, Ulrich; Berger, Ralf G; Linke, Diana

    2016-05-01

    A novel stain solving subtilisin-like peptidase (PPP1) was identified from the culture supernatant of the agaricomycete Pleurotus pulmonarius. It was purified to homogeneity using a sequence of preparative isoelectric focusing, anion exchange and size exclusion chromatography. Peptides were identified by ab initio sequencing (nLC-ESI-QTOF-MS/MS), characterizing the enzyme as a member of the subtilase family (EC 3.4.21.X). An expression system was established featuring the pPIC9K vector, an alternative Kozak sequence, the codon optimized gene ppp1 gene without the native signal sequence with C-terminal hexa-histidine tag, and Pichia pastoris GS115 as expression host. Intracellular active enzyme was obtained from cultivations in shake flasks and in a five liter bioreactor. With reaction optima of 40 °C and a pH > 8.5, considerable bleaching of pre-stained fabrics (blood, milk and India ink), and the possibility of larger-scale production, the heterologous enzyme is well suitable for detergent applications, especially at lower temperatures as part of a more energy- and cost-efficient washing process. Showing little sequence similarity to other subtilases, this unique peptidase is the first subtilisin-like peptidase from Basidiomycota, which has been functionally produced in Pichia pastoris. PMID:26873705

  16. Analysis of heterogeneity in nonspecific PEGylation reactions of biomolecules.

    PubMed

    Hakem, Ilhem F; Leech, Anna M; Bohn, Justin; Walker, Jeremy P; Bockstaller, Michael R

    2013-07-01

    The compositional heterogeneity associated with polymer conjugation reactions of biomolecules is analyzed for the particular case of nonspecific PEGylation reactions. It is shown that the distribution of the number of PEG moieties grafted to biomolecules such as proteins is a binomial-type function of two parameters-the reaction efficiency as well as the number of binding sites per biomolecule. The nature of this distribution implies that uniform compositions are favored for increasing number of coupling sites per biomolecule as well as for increasing efficiency of the modification process. Therefore, the binomial distribution provides a rationale for the pronounced heterogeneity that is observed for PEGylated small enzyme systems even at high coupling efficiencies. For the particular case of PEGylated trypsin it is shown that the heterogeneity results in a broad distribution of deactivation times that is captured by a stretched exponential decay model. The presented analysis is expected to apply to general modification processes of compounds in which partial functionalization of a fixed number of reactive sites is achieved by means of a nonspecific coupling reaction. PMID:23616211

  17. Peptidase specificity from the substrate cleavage collection in the MEROPS database and a tool to measure cleavage site conservation

    PubMed Central

    Rawlings, Neil D.

    2016-01-01

    One peptidase can usually be distinguished from another biochemically by its action on proteins, peptides and synthetic substrates. Since 1996, the MEROPS database (http://merops.sanger.ac.uk) has accumulated a collection of cleavages in substrates that now amounts to 66,615 cleavages. The total number of peptidases for which at least one cleavage is known is 1700 out of a total of 2457 different peptidases. This paper describes how the cleavages are obtained from the scientific literature, how they are annotated and how cleavages in peptides and proteins are cross-referenced to entries in the UniProt protein sequence database. The specificity profiles of 556 peptidases are shown for which ten or more substrate cleavages are known. However, it has been proposed that at least 40 cleavages in disparate proteins are required for specificity analysis to be meaningful, and only 163 peptidases (6.6%) fulfil this criterion. Also described are the various displays shown on the website to aid with the understanding of peptidase specificity, which are derived from the substrate cleavage collection. These displays include a logo, distribution matrix, and tables to summarize which amino acids or groups of amino acids are acceptable (or not acceptable) in each substrate binding pocket. For each protein substrate, there is a display to show how it is processed and degraded. Also described are tools on the website to help with the assessment of the physiological relevance of cleavages in a substrate. These tools rely on the hypothesis that a cleavage site that is conserved in orthologues is likely to be physiologically relevant, and alignments of substrate protein sequences are made utilizing the UniRef50 database, in which in each entry sequences are 50% or more identical. Conservation in this case means substitutions are permitted only if the amino acid is known to occupy the same substrate binding pocket from at least one other substrate cleaved by the same peptidase. PMID

  18. Production and partial characterization of serine and metallo peptidases secreted by Aspergillus fumigatus Fresenius in submerged and solid state fermentation.

    PubMed

    da Silva, Ronivaldo Rodrigues; de Freitas Cabral, Tatiana Pereira; Rodrigues, André; Cabral, Hamilton

    2013-01-01

    Enzyme production varies in different fermentation systems. Enzyme expression in different fermentation systems yields important information for improving our understanding of enzymatic production induction. Comparative studies between solid-state fermentation (SSF) using agro-industrial waste wheat bran and submerged fermentation (SmF) using synthetic media were carried out to determinate the best parameters for peptidase production by the fungus Aspergillus fumigatus Fresen. Variables tested include: the concentration of carbon and protein nitrogen sources, the size of the inoculum, the pH of the media, temperature, and the length of the fermentation process. The best peptidase production during SSF was obtained after 96 hours using wheat bran at 30 °C with an inoculum of 1 × 10(6) spores and yielded 1500 active units (U/mL). The best peptidase production using SmF was obtained after periods of 72 and 96 hours of fermentation in media containing 0.5% and 0.25% of casein, respectively, at a pH of 6.0 and at 30 °C and yielded 40 U/mL. We also found examples of catabolite repression of peptidase production under SmF conditions. Biochemical characterization of the peptidases produced by both fermentative processes showed optimum activity at pH 8.0 and 50 °C, and also showed that their proteolytic activity is modulated by surfactants. The enzymatic inhibition profile using phenylmethylsulfonyl fluoride (PMSF) in SmF and SSF indicated that both fermentative processes produced a serine peptidase. Additionally, the inhibitory effect of the ethylene-diaminetetraacetic acid (EDTA) chelating agent on the peptidase produced by SmF indicated that this fermentative process also produced a metallopeptidase. PMID:24159310

  19. Cysteine peptidases in the tomato trypanosomatid Phytomonas serpens: influence of growth conditions, similarities with cruzipain and secretion to the extracellular environment.

    PubMed

    Elias, Camila G R; Pereira, Fernanda M; Dias, Felipe A; Silva, Thiago L A; Lopes, Angela H C S; d'Avila-Levy, Claudia M; Branquinha, Marta H; Santos, André L S

    2008-12-01

    We have characterized the cysteine peptidase production by Phytomonas serpens, a tomato trypanosomatid. The parasites were cultivated in four distinct media, since growth conditions could modulate the synthesis of bioactive molecules. The proteolytic profile has not changed qualitatively regardless the media, showing two peptidases of 38 and 40kDa; however, few quantitative changes were observed including a drastic reduction (around 70%) on the 40 and 38kDa peptidase activities when parasites were grown in yeast extract and liver infusion trypticase medium, respectively, in comparison with parasites cultured in Warren medium. The time-span of growth did not significantly alter the protein and peptidase expression. The proteolytic activities were blocked by classical cysteine peptidase inhibitors (E-64, leupeptin, and cystatin), being more active at pH 5.0 and showing complete dependence to reducing agents (dithiothreitol and l-cysteine) for full activity. The cysteine peptidases were able to hydrolyze several proteinaceous substrates, including salivary gland proteins from Oncopeltus fasciatus, suggesting broad substrate utilization. By means of agglutination, fluorescence microscopy, flow cytometry and Western blotting analyses we showed that both cysteine peptidases produced by P. serpens share common epitopes with cruzipain, the major cysteine peptidase of Trypanosoma cruzi. Moreover, our data suggest that the 40kDa cysteine peptidase was located at the P. serpens cell surface, attached to membrane domains via a glycosylphosphatidylinositol anchor. The 40kDa peptidase was also detected in the cell-free culture supernatant, in an active form, which suggests secretion of this peptidase to the extracellular environment. PMID:18793639

  20. Hermansky-Pudlak syndrome with nonspecific interstitial pneumonia.

    PubMed

    Furuhashi, Kazuki; Enomoto, Noriyuki; Fujisawa, Tomoyuki; Hashimoto, Dai; Inui, Naoki; Nakamura, Yutaro; Suda, Takafumi

    2014-01-01

    We herein report a case of Hermansky-Pudlak syndrome (HPS) with nonspecific interstitial pneumonia (NSIP). A 58-year-old Japanese woman presented with oculocutaneous albinism and dyspnea on exertion. A high resolution computed tomography scan showed areas of reticular and ground glass opacity in the lungs, and a surgical lung biopsy revealed fibrotic NSIP. Foamy type 2 pneumocytes and the absence of dense granules in platelets were also observed, consistent with a diagnosis of HPS. Ultimately, a genetic analysis revealed a mutation in the HPS1 gene. The interstitial pneumonia progressed despite treatment with prednisolone, cyclosporine A and pirfenidone. In this report, we discuss the pathological lung features and treatment of HPS associated with interstitial pneumonia. PMID:24583434

  1. Improvement in idiopathic nonspecific interstitial pneumonia after smoking cessation.

    PubMed

    Shinohara, Tsutomu; Kadota, Naoki; Hino, Hiroyuki; Naruse, Keishi; Ohtsuki, Yuji; Ogushi, Fumitaka

    2015-01-01

    Although cigarette smoking has been recognized as a risk factor for the development of several interstitial lung diseases, the relationship between smoking and nonspecific interstitial pneumonia (NSIP) has not yet been fully elucidated. We here present a case of fibrotic NSIP with mild emphysema in an elderly male with normal pulmonary function, whose symptoms, serum KL-6 level, and high-resolution computed tomography findings of interstitial changes markedly improved without medication following the cessation of smoking. Our case suggests that smoking may be an etiological factor in some patients with NSIP and that early smoking cessation before a clinically detectable decline in pulmonary function may be critical for smokers with idiopathic NSIP. PMID:26029566

  2. Preventing biosensor non-specific adsorption: Static to dynamic interfaces

    NASA Astrophysics Data System (ADS)

    Harwood, Lucy; Hopkins, Neal

    2012-02-01

    Biosensors are currently being developed for the detection of a wide range of analytes in a variety of scenarios. One such area is that of environmental monitoring for the presence of biological threats, from toxins through to viruses and bacteria. Environmental samples will contain a wide variety of contaminants, dependent on the location and prevalent environmental conditions. The sensing surfaces employed by biosensor instruments must be capable of resisting non-specific adsorption (NSA) of the contaminants whilst specifically capturing targets of interest. The ability to do so reduces the incidence of false positives and negatives increasing confidence in the system. We have assessed a range of biosensor surface chemistries of both two and three dimensional topography using a commercial BIAcore platform, for ability to prevent NSA of soluble materials of medical and military significance. This has highlighted that future solutions may benefit from dynamic interfaces as opposed to the conventional static interface often employed.

  3. Improvement in idiopathic nonspecific interstitial pneumonia after smoking cessation

    PubMed Central

    Shinohara, Tsutomu; Kadota, Naoki; Hino, Hiroyuki; Naruse, Keishi; Ohtsuki, Yuji; Ogushi, Fumitaka

    2014-01-01

    Although cigarette smoking has been recognized as a risk factor for the development of several interstitial lung diseases, the relationship between smoking and nonspecific interstitial pneumonia (NSIP) has not yet been fully elucidated. We here present a case of fibrotic NSIP with mild emphysema in an elderly male with normal pulmonary function, whose symptoms, serum KL-6 level, and high-resolution computed tomography findings of interstitial changes markedly improved without medication following the cessation of smoking. Our case suggests that smoking may be an etiological factor in some patients with NSIP and that early smoking cessation before a clinically detectable decline in pulmonary function may be critical for smokers with idiopathic NSIP. PMID:26029566

  4. Nonspecific cell-mediated immunity in patients with epidermodysplasia verruciformis.

    PubMed

    Pereira de Oliveira, Walmar Roncalli; Carrasco, Solange; Neto, Cyro Festa; Rady, Peter; Tyring, Stephen K

    2003-03-01

    Epidermodysplasia verruciformis (EV) is a rare disease that usually begins in childhood and is characterized by a generalized infection by human papilloma virus (HPV), frequent associations with cutaneous carcinomas, and abnormalities of cell-mediated immunity (CMI). We studied nonspecific CMI in 13 patients with EV by bacterial skin tests, allergic reactions to dinitrochlorobenzene (DNCB), measurement of responses to phytohemagglutinin (PHA), and quantification of T lymphocytes and T lymphocytes subsets in peripheral blood. Impairment of CMI was manifested by the cutaneous anergy to a variety of common skin antigens and, by the reduction of the lymphocyte transformation to PHA. There were no correlation between the severity of cases and abnormalities of CMI in our patients, however; the impairment of CMI was lower in cases of short duration, suggesting that the impairment of CMI in EV might reflect a long period of disease. PMID:12692356

  5. Crystal Structure and Activity Studies of the C11 Cysteine Peptidase from Parabacteroides merdae in the Human Gut Microbiome.

    PubMed

    McLuskey, Karen; Grewal, Jaspreet S; Das, Debanu; Godzik, Adam; Lesley, Scott A; Deacon, Ashley M; Coombs, Graham H; Elsliger, Marc-André; Wilson, Ian A; Mottram, Jeremy C

    2016-04-29

    Clan CD cysteine peptidases, a structurally related group of peptidases that include mammalian caspases, exhibit a wide range of important functions, along with a variety of specificities and activation mechanisms. However, for the clostripain family (denoted C11), little is currently known. Here, we describe the first crystal structure of a C11 protein from the human gut bacterium, Parabacteroides merdae (PmC11), determined to 1.7-Å resolution. PmC11 is a monomeric cysteine peptidase that comprises an extended caspase-like α/β/α sandwich and an unusual C-terminal domain. It shares core structural elements with clan CD cysteine peptidases but otherwise structurally differs from the other families in the clan. These studies also revealed a well ordered break in the polypeptide chain at Lys(147), resulting in a large conformational rearrangement close to the active site. Biochemical and kinetic analysis revealed Lys(147) to be an intramolecular processing site at which cleavage is required for full activation of the enzyme, suggesting an autoinhibitory mechanism for self-preservation. PmC11 has an acidic binding pocket and a preference for basic substrates, and accepts substrates with Arg and Lys in P1 and does not require Ca(2+) for activity. Collectively, these data provide insights into the mechanism and activity of PmC11 and a detailed framework for studies on C11 peptidases from other phylogenetic kingdoms. PMID:26940874

  6. Crystal structure and activity studies of the C11 cysteine peptidase from Parabacteroides merdae in the human gut microbiome

    DOE PAGESBeta

    McLuskey, Karen; Grewal, Jaspreet S.; Das, Debanu; Godzik, Adam; Lesley, Scott A.; Deacon, Ashley M.; Coombs, Graham H.; Elsliger, Marc-André; Wilson, Ian A.; Mottram, Jeremy C.

    2016-03-03

    Clan CD cysteine peptidases, a structurally related group of peptidases that include mammalian caspases, exhibit a wide range of important functions, along with a variety of specificities and activation mechanisms. However, for the clostripain family (denoted C11), little is currently known. Here, we describe the first crystal structure of a C11 protein from the human gut bacterium, Parabacteroides merdae (PmC11), determined to 1.7-Å resolution. PmC11 is a monomeric cysteine peptidase that comprises an extended caspase-like α/β/α sandwich and an unusual C-terminal domain. It shares core structural elements with clan CD cysteine peptidases but otherwise structurally differs from the other familiesmore » in the clan. These studies also revealed a well ordered break in the polypeptide chain at Lys147, resulting in a large conformational rearrangement close to the active site. Biochemical and kinetic analysis revealed Lys147 to be an intramolecular processing site at which cleavage is required for full activation of the enzyme, suggesting an autoinhibitory mechanism for self-preservation. PmC11 has an acidic binding pocket and a preference for basic substrates, and accepts substrates with Arg and Lys in P1 and does not require Ca2+ for activity. Altogether, these data provide insights into the mechanism and activity of PmC11 and a detailed framework for studies on C11 peptidases from other phylogenetic kingdoms.« less

  7. Crystal Structure and Activity Studies of the C11 Cysteine Peptidase from Parabacteroides merdae in the Human Gut Microbiome*

    PubMed Central

    Das, Debanu; Godzik, Adam; Lesley, Scott A.; Deacon, Ashley M.; Coombs, Graham H.; Elsliger, Marc-André; Wilson, Ian A.

    2016-01-01

    Clan CD cysteine peptidases, a structurally related group of peptidases that include mammalian caspases, exhibit a wide range of important functions, along with a variety of specificities and activation mechanisms. However, for the clostripain family (denoted C11), little is currently known. Here, we describe the first crystal structure of a C11 protein from the human gut bacterium, Parabacteroides merdae (PmC11), determined to 1.7-Å resolution. PmC11 is a monomeric cysteine peptidase that comprises an extended caspase-like α/β/α sandwich and an unusual C-terminal domain. It shares core structural elements with clan CD cysteine peptidases but otherwise structurally differs from the other families in the clan. These studies also revealed a well ordered break in the polypeptide chain at Lys147, resulting in a large conformational rearrangement close to the active site. Biochemical and kinetic analysis revealed Lys147 to be an intramolecular processing site at which cleavage is required for full activation of the enzyme, suggesting an autoinhibitory mechanism for self-preservation. PmC11 has an acidic binding pocket and a preference for basic substrates, and accepts substrates with Arg and Lys in P1 and does not require Ca2+ for activity. Collectively, these data provide insights into the mechanism and activity of PmC11 and a detailed framework for studies on C11 peptidases from other phylogenetic kingdoms. PMID:26940874

  8. Differential Effects of Deep Sedation with Propofol on the Specific and Nonspecific Thalamocortical Systems

    PubMed Central

    Liu, Xiaolin; Lauer, Kathryn K.; Ward, Douglas; Li, Shi-Jiang; Hudetz, Anthony G.

    2014-01-01

    Background Current state of knowledge suggests that disruption of neuronal information integration may be a unitary mechanism of anesthetic-induced unconsciousness. A neural system central for information integration is the thalamocortical system whose specific and nonspecific divisions may play the roles for representing and integrating information; respectively. How anesthetics affect the function of these systems individually is not completely understood. We studied the effect of propofol on thalamocortical functional connectivity in the specific and nonspecific systems using functional magnetic resonance imaging. Methods Eight healthy volunteers were instructed to listen to and encode 40 English words during wakeful baseline, light sedation, deep sedation, and recovery in the scanner. Functional connectivity was determined as the temporal correlation of blood oxygen level-dependent signals with seed regions defined within the specific and nonspecific thalamic nuclei. Results Thalamocortical connectivity at baseline was dominantly medial and bilateral frontal and temporal for the specific system and medial frontal and medial parietal for the nonspecific system. During deep sedation, propofol reduced functional connectivity by 43% (specific) and 79% (nonspecific), a significantly greater reduction of connections in the nonspecific than in the specific system and in the left hemisphere than in the right. Upon regaining consciousness, functional connectivity increased by 58% (specific) and 123% (nonspecific) during recovery, exceeding their values at baseline. Conclusions Propofol conferred differential changes in functional connectivity of the specific and nonspecific thalamocortical systems. The changes in nonspecific thalamocortical connectivity may correlate with loss and return of consciousness. PMID:23221862

  9. Nonspecific Binding of Complement by Digestion Fragments from Antiviral Gamma Globulin.

    PubMed

    Cremer, N E; Riggs, J L; Lennette, E H; Jensen, F W

    1965-07-01

    The nonspecificity of rabbit gamma-globulin (antibody) to western equine encephalitis virus and the non-specificity of normal rabbit gamma-globulin in complement-fixation tests with anti-gens prepared from chick-embryo cells infected with this virus and normal chick-embryo cells resided primarily in Porter's fragment III. Addition of complement to fragment III from the anti-body globulin, followed by inactivation of the added complement, abolished the complement-fixing ability of fragment III with both specific and nonspecific antigens. Similar treatment of the undigested antibody abolished its complement-fixing ability with nonspecific antigen only. PMID:17737800

  10. The cloning and characterization of a second brain enzyme with NAAG peptidase activity.

    PubMed

    Bzdega, Tomasz; Crowe, Samantha L; Ramadan, Epolia R; Sciarretta, Kathryn H; Olszewski, Rafal T; Ojeifo, Olumide A; Rafalski, Victoria A; Wroblewska, Barbara; Neale, Joseph H

    2004-05-01

    The peptide neurotransmitter N-acetylaspartylglutamate is inactivated by extracellular peptidase activity following synaptic release. It is speculated that the enzyme, glutamate carboxypeptidase II (GCPII, EC 3.14.17.21), participates in this inactivation. However, CGCPII knockout mice appear normal in standard neurological tests. We report here the cloning and characterization of a mouse enzyme (tentatively identified as glutamate carboxypeptidase III or GCPIII) that is homologous to an enzyme identified in a human lung carcinoma. The mouse peptidase was cloned from two non-overlapping EST clones and mouse brain cDNA using PCR. The sequence (GenBank, AY243507) is 85% identical to the human carcinoma enzyme and 70% homologous to mouse GCPII. GCPIII sequence analysis suggests that it too is a zinc metallopeptidase. Northern blots revealed message in mouse ovary, testes and lung, but not brain. Mouse cortical and cerebellar neurons in culture expressed GCPIII message in contrast to the glial specific expression of GCPII. Message levels of GCPIII were similar in brains obtained from wild-type mice and mice that are null mutants for GCPII. Chinese hamster ovary (CHO) cells transfected with rat GCPII or mouse GCPIII expressed membrane bound peptidase activity with similar V(max) and K(m) values (1.4 micro m and 54 pmol/min/mg; 3.5 micro m and 71 pmol/min/mg, respectively). Both enzymes are activated by a similar profile of metal ions and their activities are blocked by EDTA. GCPIII message was detected in brain and spinal cord by RT-PCR with highest levels in the cerebellum and hippocampus. These data are consistent with the hypothesis that nervous system cells express at least two differentially distributed homologous enzymes with similar pharmacological properties and affinity for NAAG. PMID:15086519

  11. Porphyromonas gingivalis Virulence Factor Gingipain RgpB Shows a Unique Zymogenic Mechanism for Cysteine Peptidases*

    PubMed Central

    de Diego, Iñaki; Veillard, Florian T.; Guevara, Tibisay; Potempa, Barbara; Sztukowska, Maryta; Potempa, Jan; Gomis-Rüth, F. Xavier

    2013-01-01

    Zymogenicity is a regulatory mechanism that prevents inadequate catalytic activity in the wrong context. It plays a central role in maintaining microbial virulence factors in an inactive form inside the pathogen until secretion. Among these virulence factors is the cysteine peptidase gingipain B (RgpB), which is the major virulence factor secreted by the periodontopathogen Porphyromonas gingivalis that attacks host vasculature and defense proteins. The structure of the complex between soluble mature RgpB, consisting of a catalytic domain and an immunoglobulin superfamily domain, and its 205-residue N-terminal prodomain, the largest structurally characterized to date for a cysteine peptidase, reveals a novel fold for the prodomain that is distantly related to sugar-binding lectins. It attaches laterally to the catalytic domain through a large concave surface. The main determinant for latency is a surface “inhibitory loop,” which approaches the active-site cleft of the enzyme on its non-primed side in a substrate-like manner. It inserts an arginine (Arg126) into the S1 pocket, thus matching the substrate specificity of the enzyme. Downstream of Arg126, the polypeptide leaves the cleft, thereby preventing cleavage. Moreover, the carbonyl group of Arg126 establishes a very strong hydrogen bond with the co-catalytic histidine, His440, pulling it away from the catalytic cysteine, Cys473, and toward Glu381, which probably plays a role in orienting the side chain of His440 during catalysis. The present results provide the structural determinants of zymogenic inhibition of RgpB by way of a novel inhibitory mechanism for peptidases in general and open the field for the design of novel inhibitory strategies in the treatment of human periodontal disease. PMID:23558682

  12. Serpin peptidase inhibitor clade A member 1 is a biomarker of poor prognosis in gastric cancer

    PubMed Central

    Kwon, C H; Park, H J; Lee, J R; Kim, H K; Jeon, T Y; Jo, H-J; Kim, D H; Kim, G H; Park, D Y

    2014-01-01

    Background: In a previous study, we reported that serpin peptidase inhibitor clade A member 1 (serpinA1) is upregulated in Snail-overexpressing gastric cancer. Although serpinA1 has been studied in several types of cancer, little is known about its roles and mechanisms of action. In this study, we examined the role of serpinA1 in the migration and invasion of gastric cancers and determined its underlying mechanism. Methods: Expression levels were assessed by western blot analyses and real-time PCR. Snail binding to serpinA1 promoter was analysed by chromatin immunoprecipitation (ChIP) assays. The roles of serpinA1 were studied using cell invasion and migration assays. In addition, the clinicopathologic and prognostic significance of serpinA1 expression were validated in 400 gastric cancer patients using immunohistochemical analysis. Results: Overexpression of Snail resulted in upregulation of serpinA1 in gastric cancer cell lines, AGS and MKN45, whereas knockdown of Snail inhibited serpinA1 expression. Chromatin immunoprecipitation analysis showed that overexpression of Snail increased Snail recruitment to the serpinA1 promoter. Overexpression of serpinA1 increased the migration and invasion of gastric cancer cells, whereas knockdown of serpinA1 decreased invasion and migration. Moreover, serpinA1 increased mRNA levels and release of metalloproteinase-8 in gastric cancer cells. Serpin peptidase inhibitor clade A member 1 was observed in the cytoplasm of tumour cells and the stroma by immunohistochemistry. Enhanced serpinA1 expression was significantly associated with increased tumour size, advanced T stage, perineural invasion, lymphovascular invasion, lymph node metastases, and shorter overall survival. Conclusions: Serpin peptidase inhibitor clade A member 1 induces the invasion and migration of gastric cancer cells and its expression is associated with the progression of gastric cancer. These results may provide a potential target to prevent invasion and

  13. PNT1 is a C11 cysteine peptidase essential for replication of the Trypanosome Kinetoplast

    DOE PAGESBeta

    Grewal, Jaspreet S.; McLuskey, Karen; Das, Debanu; Myburgh, Elmarie; Wilkes, Jonathan; Brown, Elaine; Lemgruber, Leandro; Gould, Matthew K.; Burchmore, Richard J.; Coombs, Graham H.; et al

    2016-03-03

    The structure of a C11 peptidase PmC11 from the gut bacterium, Parabacteroides merdae, has recently been determined, enabling the identification and characterization of a C11 orthologue, PNT1, in the parasitic protozoon Trypanosoma brucei. A phylogenetic analysis identified PmC11 orthologues in bacteria, archaea, Chromerids, Coccidia, and Kinetoplastida, the latter being the most divergent. A primary sequence alignment of PNT1 with clostripain and PmC11 revealed the position of the characteristic His-Cys catalytic dyad (His99 and Cys136), and an Asp (Asp134) in the potential S1 binding site. Immunofluorescence and cryoelectron microscopy revealed that PNT1 localizes to the kinetoplast, an organelle containing the mitochondrialmore » genome of the parasite (kDNA), with an accumulation of the protein at or near the antipodal sites. Depletion of PNT1 by RNAi in the T. brucei bloodstream form was lethal both in in vitro culture and in vivo in mice and the induced population accumulated cells lacking a kinetoplast. In contrast, overexpression of PNT1 led to cells having mislocated kinetoplasts. RNAi depletion of PNT1 in a kDNA independent cell line resulted in kinetoplast loss but was viable, indicating that PNT1 is required exclusively for kinetoplast maintenance. Expression of a recoded wild-type PNT1 allele, but not of an active site mutant restored parasite viability after induction in vitro and in vivo confirming that the peptidase activity of PNT1 is essential for parasite survival. Furthermore, these data provide evidence that PNT1 is a cysteine peptidase that is required exclusively for maintenance of the trypanosome kinetoplast.« less

  14. PNT1 Is a C11 Cysteine Peptidase Essential for Replication of the Trypanosome Kinetoplast.

    PubMed

    Grewal, Jaspreet S; McLuskey, Karen; Das, Debanu; Myburgh, Elmarie; Wilkes, Jonathan; Brown, Elaine; Lemgruber, Leandro; Gould, Matthew K; Burchmore, Richard J; Coombs, Graham H; Schnaufer, Achim; Mottram, Jeremy C

    2016-04-29

    The structure of a C11 peptidase PmC11 from the gut bacterium, Parabacteroides merdae, has recently been determined, enabling the identification and characterization of a C11 orthologue, PNT1, in the parasitic protozoon Trypanosoma brucei. A phylogenetic analysis identified PmC11 orthologues in bacteria, archaea, Chromerids, Coccidia, and Kinetoplastida, the latter being the most divergent. A primary sequence alignment of PNT1 with clostripain and PmC11 revealed the position of the characteristic His-Cys catalytic dyad (His(99) and Cys(136)), and an Asp (Asp(134)) in the potential S1 binding site. Immunofluorescence and cryoelectron microscopy revealed that PNT1 localizes to the kinetoplast, an organelle containing the mitochondrial genome of the parasite (kDNA), with an accumulation of the protein at or near the antipodal sites. Depletion of PNT1 by RNAi in the T. brucei bloodstream form was lethal both in in vitro culture and in vivo in mice and the induced population accumulated cells lacking a kinetoplast. In contrast, overexpression of PNT1 led to cells having mislocated kinetoplasts. RNAi depletion of PNT1 in a kDNA independent cell line resulted in kinetoplast loss but was viable, indicating that PNT1 is required exclusively for kinetoplast maintenance. Expression of a recoded wild-type PNT1 allele, but not of an active site mutant restored parasite viability after induction in vitro and in vivo confirming that the peptidase activity of PNT1 is essential for parasite survival. These data provide evidence that PNT1 is a cysteine peptidase that is required exclusively for maintenance of the trypanosome kinetoplast. PMID:26940875

  15. PNT1 Is a C11 Cysteine Peptidase Essential for Replication of the Trypanosome Kinetoplast*

    PubMed Central

    Das, Debanu; Myburgh, Elmarie; Wilkes, Jonathan; Brown, Elaine; Lemgruber, Leandro; Gould, Matthew K.; Burchmore, Richard J.; Coombs, Graham H.; Schnaufer, Achim

    2016-01-01

    The structure of a C11 peptidase PmC11 from the gut bacterium, Parabacteroides merdae, has recently been determined, enabling the identification and characterization of a C11 orthologue, PNT1, in the parasitic protozoon Trypanosoma brucei. A phylogenetic analysis identified PmC11 orthologues in bacteria, archaea, Chromerids, Coccidia, and Kinetoplastida, the latter being the most divergent. A primary sequence alignment of PNT1 with clostripain and PmC11 revealed the position of the characteristic His-Cys catalytic dyad (His99 and Cys136), and an Asp (Asp134) in the potential S1 binding site. Immunofluorescence and cryoelectron microscopy revealed that PNT1 localizes to the kinetoplast, an organelle containing the mitochondrial genome of the parasite (kDNA), with an accumulation of the protein at or near the antipodal sites. Depletion of PNT1 by RNAi in the T. brucei bloodstream form was lethal both in in vitro culture and in vivo in mice and the induced population accumulated cells lacking a kinetoplast. In contrast, overexpression of PNT1 led to cells having mislocated kinetoplasts. RNAi depletion of PNT1 in a kDNA independent cell line resulted in kinetoplast loss but was viable, indicating that PNT1 is required exclusively for kinetoplast maintenance. Expression of a recoded wild-type PNT1 allele, but not of an active site mutant restored parasite viability after induction in vitro and in vivo confirming that the peptidase activity of PNT1 is essential for parasite survival. These data provide evidence that PNT1 is a cysteine peptidase that is required exclusively for maintenance of the trypanosome kinetoplast. PMID:26940875

  16. The acylaminoacyl peptidase from Aeropyrum pernix K1 thought to be an exopeptidase displays endopeptidase activity.

    PubMed

    Kiss, András L; Hornung, Balázs; Rádi, Krisztina; Gengeliczki, Zsolt; Sztáray, Bálint; Juhász, Tünde; Szeltner, Zoltán; Harmat, Veronika; Polgár, László

    2007-04-27

    Mammalian acylaminoacyl peptidase, a member of the prolyl oligopeptidase family of serine peptidases, is an exopeptidase, which removes acylated amino acid residues from the N terminus of oligopeptides. We have investigated the kinetics and inhibitor binding of the orthologous acylaminoacyl peptidase from the thermophile Aeropyrum pernix K1 (ApAAP). Complex pH-rate profiles were found with charged substrates, indicating a strong electrostatic effect in the surroundings of the active site. Unexpectedly, we have found that oligopeptides can be hydrolysed beyond the N-terminal peptide bond, demonstrating that ApAAP exhibits endopeptidase activity. It was thought that the enzyme is specific for hydrophobic amino acids, in particular phenylalanine, in accord with the non-polar S1 subsite of ApAAP. However, cleavage after an Ala residue contradicted this notion and demonstrated that P1 residues of different nature may bind to the S1 subsite depending on the remaining peptide residues. The crystal structures of the complexes formed between the enzyme and product-like inhibitors identified the oxyanion-binding site unambiguously and demonstrated that the phenylalanine ring of the P1 peptide residue assumes a position different from that established in a previous study, using 4-nitrophenylphosphate. We have found that the substrate-binding site extends beyond the S2 subsite, being capable of binding peptides with a longer N terminus. The S2 subsite displays a non-polar character, which is unique among the enzymes of this family. The S3 site was identified as a hydrophobic region that does not form hydrogen bonds with the inhibitor P3 residue. The enzyme-inhibitor complexes revealed that, upon ligand-binding, the S1 subsite undergoes significant conformational changes, demonstrating the plasticity of the specificity site. PMID:17350041

  17. The Dipeptidyl Peptidase Family, Prolyl Oligopeptidase, and Prolyl Carboxypeptidase in the Immune System and Inflammatory Disease, Including Atherosclerosis

    PubMed Central

    Waumans, Yannick; Baerts, Lesley; Kehoe, Kaat; Lambeir, Anne-Marie; De Meester, Ingrid

    2015-01-01

    Research from over the past 20 years has implicated dipeptidyl peptidase (DPP) IV and its family members in many processes and different pathologies of the immune system. Most research has been focused on either DPPIV or just a few of its family members. It is, however, essential to consider the entire DPP family when discussing any one of its members. There is a substantial overlap between family members in their substrate specificity, inhibitors, and functions. In this review, we provide a comprehensive discussion on the role of prolyl-specific peptidases DPPIV, FAP, DPP8, DPP9, dipeptidyl peptidase II, prolyl carboxypeptidase, and prolyl oligopeptidase in the immune system and its diseases. We highlight possible therapeutic targets for the prevention and treatment of atherosclerosis, a condition that lies at the frontier between inflammation and cardiovascular disease. PMID:26300881

  18. In Vivo Effects of Bradykinin B2 Receptor Agonists with Varying Susceptibility to Peptidases

    PubMed Central

    Jean, Mélissa; Gera, Lajos; Charest-Morin, Xavier; Marceau, François; Bachelard, Hélène

    2016-01-01

    We reported evidence of bradykinin (BK) regeneration from C-terminal extended BK sequences that behave as peptidase-activated B2 receptor (B2R) agonists. Further to these in vitro studies, we carried out in vivo experiments to verify hemodynamic effects of BK analogs exhibiting variable susceptibility toward vascular and blood plasma peptidases. Rats were anesthetized and instrumented to record blood pressure and heart rate responses to bolus intravenous (i.v.) injection of increasing doses of BK, B-9972 (D-Arg-[Hyp3,Igl5,Oic7,Igl8]-BK), BK-Arg, BK-His-Leu or BK-Ala-Pro, in the absence or presence of specific inhibitors. In some experiments, pulsed Doppler flow probes measured hindquarter Doppler shift in response to i.v. injections of kinins. BK caused rapid, transient and dose-related hypotensive effects. These effects were potentiated ∼15-fold by the angiotensin converting enzyme (ACE) inhibitor, enalaprilat, but extensively inhibited by icatibant (a B2R antagonist) and not influenced by the Arg-carboxypeptidase (CP) inhibitor (Plummer’s inhibitor). The hypotensive responses elicited by the peptidase-resistant B2R agonist, B-9972, were not affected by enalaprilat, but were inhibited by icatibant. The hypotensive responses to BK-Arg were abolished by pre-treatment with either the Arg-CP inhibitor or icatibant, pharmacologically evidencing BK regeneration. The hypotensive effects of BK-His-Leu and BK-Ala-Pro, previously reported as ACE-activated substrates, were abolished by icatibant, but not by enalaprilat. In vivo regeneration of BK from these two C-terminally extended analogs with no affinity for the B2R must follow alternative cleavage rules involving unidentified carboxypeptidase(s) when ACE is blocked. The transient hypotensive responses to BK and three tested analogs coincided with concomitant vasodilation (increased Doppler shift signal). Together, these results provide in vivo evidence that interesting hypotensive and vasodilator effects can be

  19. Whey proteins as source of dipeptidyl dipeptidase IV (dipeptidyl peptidase-4) inhibitors.

    PubMed

    Tulipano, Giovanni; Sibilia, Valeria; Caroli, Anna Maria; Cocchi, Daniela

    2011-04-01

    Preclinical and clinical studies suggest that whey proteins can reduce postprandial glucose levels and stimulate insulin release in healthy subjects and in subjects with type 2 diabetes by reducing dipeptidyl peptidase-4 (DPP-4) activity in the proximal bowel and hence increasing intact incretin levels. Our aim was to identify DPP-4 inhibitors among short peptides occurring in hydrolysates of β-lactoglobulin, the major whey protein found in the milk of ruminants. We proved that the bioactive peptide Ile-Pro-Ala can be regarded as a moderate DPP-4 inhibitor. PMID:21256171

  20. Some properties and possible biological role of peptidase inhibitors from the entomopathogenic fungus Tolypocladium cylindrosporum.

    PubMed

    Popova, V V; Dunaevsky, Y E; Domash, V I; Semenova, T A; Beliakova, G A; Belozersky, M A

    2015-10-01

    The activities of secreted and mycelial inhibitors of proteolytic enzymes from fungi of the order Hypocreales have been investigated. Inhibitors of bromelain, papain, and trypsin of low molecular mass (about 1 kDa) and a subtilisin proteinaceous inhibitor with molecular mass of 45 kDa were revealed in the culture liquid of the fungus Tolypocladium cylindrosporum. The subtilisin inhibitor from T. cylindrosporum has antibiotic properties, significantly decreased the activity of purified bacterial enzymes, and prevented the growth of the bacterium Pseudomonas sp. Data suggesting the existence in fungi of the Hypocreales order of two pools of peptidase inhibitors have been obtained. PMID:26210235

  1. Decoding the Anti-Trypanosoma cruzi Action of HIV Peptidase Inhibitors Using Epimastigotes as a Model

    PubMed Central

    Sangenito, Leandro S.; Menna-Barreto, Rubem F. S.; d′Avila-Levy, Claudia M.; Branquinha, Marta H.

    2014-01-01

    Background Aspartic peptidase inhibitors have shown antimicrobial action against distinct microorganisms. Due to an increase in the occurrence of Chagas' disease/AIDS co-infection, we decided to explore the effects of HIV aspartic peptidase inhibitors (HIV-PIs) on Trypanosoma cruzi, the etiologic agent of Chagas' disease. Methodology and Principal Findings HIV-PIs presented an anti-proliferative action on epimastigotes of T. cruzi clone Dm28c, with IC50 values ranging from 0.6 to 14 µM. The most effective inhibitors, ritonavir, lopinavir and nelfinavir, also had an anti-proliferative effect against different phylogenetic T. cruzi strains. The HIV-PIs induced some morphological alterations in clone Dm28c epimastigotes, as reduced cell size and swollen of the cellular body. Transmission electron microscopy revealed that the flagellar membrane, mitochondrion and reservosomes are the main targets of HIV-PIs in T. cruzi epimastigotes. Curiously, an increase in the epimastigote-into-trypomastigote differentiation process of clone Dm28c was observed, with many of these parasites presenting morphological alterations including the detachment of flagellum from the cell body. The pre-treatment with the most effective HIV-PIs drastically reduced the interaction process between epimastigotes and the invertebrate vector Rhodnius prolixus. It was also noted that HIV-PIs induced an increase in the expression of gp63-like and calpain-related molecules, and decreased the cruzipain expression in epimastigotes as judged by flow cytometry and immunoblotting assays. The hydrolysis of a cathepsin D fluorogenic substrate was inhibited by all HIV-PIs in a dose-dependent manner, showing that the aspartic peptidase could be a possible target to these drugs. Additionally, we verified that ritonavir, lopinavir and nelfinavir reduced drastically the viability of clone Dm28c trypomastigotes, causing many morphological damages. Conclusions and Significance The results contribute to understand

  2. 40 CFR 261.31 - Hazardous wastes from non-specific sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Hazardous wastes from non-specific sources. 261.31 Section 261.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE Lists of Hazardous Wastes § 261.31 Hazardous wastes from non-specific sources....

  3. 40 CFR 261.31 - Hazardous wastes from non-specific sources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Hazardous wastes from non-specific sources. 261.31 Section 261.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE Lists of Hazardous Wastes § 261.31 Hazardous wastes from non-specific sources....

  4. Nonspecific Chronic Low Back Pain Patients Are Deconditioned and Have An Increased Body Fat Percentage

    ERIC Educational Resources Information Center

    Hodselmans, Audy P.

    2010-01-01

    The aim of this cross-sectional study was to compare data on the level of aerobic capacity and body composition of nonspecific chronic low back pain (CLBP) patients with normative data matched for sex, age and level of sporting activity. The study population consisted of 101 outpatients with nonspecific CLBP who had entered a rehabilitation…

  5. Experience of living with nonspecific building-related symptoms.

    PubMed

    Söderholm, Anna; Öhman, Ann; Stenberg, Berndt; Nordin, Steven

    2016-10-01

    Nonspecific building-related symptoms (NBRS) is a combination of general, skin and mucosal symptoms related to certain buildings. Despite high prevalence in the general population and severe symptomatology in certain cases there is no scientific documentation of quality of life in NBRS. The purpose of this study was to illuminate how individuals with NBRS experience daily life. Data were collected through descriptive, written texts and through telephone interviews with 11 individuals diagnosed with NBRS, and qualitative content analysis was conducted. Three main content areas were identified: (1) attitudes from the surrounding (categories: being questioned and lack of understanding from others; from zero to full support); (2) consequences (difficulties with daily activities; financial difficulties; affecting family and friends; emotional consequences); and (3) coping (learning to accept and finding solutions; avoiding; struggling; finding the positive; making one's home a sanctuary). As a conclusion, NBRS may affect several aspects of daily life, resulting in considerable alterations, limitations and emotional impact for the afflicted person and his/her family. Both environmental factors and attitudes from the surrounding can contribute to this impact on daily life. Strategies needed to cope with this impact may include both problem-focused and emotion-focused strategies, such as struggling, avoiding trigger factors and finding positive aspects. PMID:27532686

  6. Nonspecific uptake and homeostasis drive the oceanic cadmium cycle

    NASA Astrophysics Data System (ADS)

    Horner, Tristan J.; Lee, Renee B. Y.; Henderson, Gideon M.; Rickaby, Rosalind E. M.

    2013-02-01

    The global marine distributions of Cd and phosphate are closely correlated, which has led to Cd being considered as a marine micronutrient, despite its toxicity to life. The explanation for this nutrient-like behavior is unknown because there is only one identified biochemical function for Cd, an unusual Cd/Zn carbonic anhydrase. Recent developments in Cd isotope mass spectrometry have revealed that Cd uptake by phytoplankton causes isotopic fractionation in the open ocean and in culture. Here we investigate the physiochemical pathways that fractionate Cd isotopes by performing subcellular Cd isotope analysis on genetically modified microorganisms. We find that expression of the Cd/Zn carbonic anhydrase makes no difference to the Cd isotope composition of whole cells. Instead, a large proportion of the Cd is partitioned into cell membranes with a similar direction and magnitude of Cd isotopic fractionation to that seen in surface seawater. This observation is well explained if Cd is mistakenly imported with other divalent metals and subsequently managed by binding within the cell to avoid toxicity. This process may apply to other divalent metals, whereby nonspecific uptake and subsequent homeostasis may contribute to elemental and isotopic distributions in seawater, even for elements commonly considered as micronutrients.

  7. The Binding Process of a Nonspecific Enzyme with DNA

    SciTech Connect

    Chen, Chuanying; Pettitt, Bernard M.

    2011-09-07

    Protein-DNA recognition of a nonspecific complex is modeled to understand the nature of the transient encounter states. We consider the structural and energetic features and the role of water in the DNA grooves in the process of protein-DNA recognition. Here we have used the nuclease domain of colicin E7 (N-ColE7) from Escherichia coli in complex with a 12-bp DNA duplex as the model system to consider how a protein approaches, encounters, and associates with DNA. Multiscale simulation studies using Brownian dynamics and molecular-dynamics simulations were performed to provide the binding process on multiple length- and timescales. We define the encounter states and identified the spatial and orientational aspects. For the molecular length-scales, we used molecular-dynamics simulations. Several intermediate binding states were found, which have different positions and orientations of protein around DNA including major and minor groove orientations. The results show that the contact number and the hydrated interfacial area are measures that facilitate better understanding of sequence-independent protein-DNA binding landscapes and pathways.

  8. Cell adhesion. Competition between nonspecific repulsion and specific bonding.

    PubMed Central

    Bell, G I; Dembo, M; Bongrand, P

    1984-01-01

    We develop a thermodynamic calculus for the modeling of cell adhesion. By means of this approach, we are able to compute the end results of competition between the formation of specific macromolecular bridges and nonspecific repulsion arising from electrostatic forces and osmotic (steric stabilization) forces. Using this calculus also allows us to derive in a straightforward manner the effects of cell deformability, the Young's modulus for stretching of bridges, diffusional mobility of receptors, heterogeneity of receptors, variation in receptor number, and the strength of receptor-receptor binding. The major insight that results from our analysis concerns the existence and characteristics of two phase transitions corresponding, respectively, to the onset of stable cell adhesion and to the onset of maximum cell-cell or cell-substrate contact. We are also able to make detailed predictions of the equilibrium contact area, equilibrium number of bridges, and the cell-cell or cell-substrate separation distance. We illustrate how our approach can be used to improve the analysis of experimental data, by means of two concrete examples. PMID:6743742

  9. Nonspecific airway reactivity in a mouse model of asthma

    SciTech Connect

    Collie, D.D.; Wilder, J.A.; Bice, D.E.

    1995-12-01

    Animal models are indispensable for studies requiring an intact immune system, especially for studying the pathogenic mechanisms in atopic diseases, regulation of IgE production, and related biologic effects. Mice are particularly suitable and have been used extensively for such studies because their immune system is well characterized. Further, large numbers of mutants or inbred strains of mice are available that express deficiencies of individual immunologic processes, inflammatory cells, or mediator systems. By comparing reactions in such mice with appropriate control animals, the unique roles of individual cells or mediators may be characterized more precisely in the pathogenesis of atopic respiratory diseases including asthma. However, given that asthma in humans is characterized by the presence of airway hyperresponsiveness to specific and nonspecific stimuli, it is important that animal models of this disease exhibit similar physiologic abnormalities. In the past, the size of the mouse has limited its versatility in this regard. However, recent studies indicate the feasibility of measuring pulmonary responses in living mice, thus facilitating the physiologic evaluation of putative mouse models of human asthma that have been well charcterized at the immunologic and patholigic level. Future work will provide details of the morphometry of the methacholine-induced bronchoconstriction and will further seek to determine the relationship between cigarette smoke exposure and the development of NS-AHR in the transgenic mouse model.

  10. Proteomic analysis in usual and nonspecific interstitial pneumonia.

    PubMed

    Ohara, Ichiyo; Aida, Shinsuke; Shimazaki, Hideyuki; Kobayashi, Hideo; Tsuda, Hitoshi; Toda, Tosifusa; Nakanishi, Kuniaki; Tamai, Seiichi

    2014-03-01

    Differentiating nonspecific interstitial pneumonia (NSIP) from usual interstitial pneumonia (UIP) is important for the determination of both treatment and prognosis. Using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE), we examined 8 UIPs, 8 NSIPs, and 30 normal lung tissues. Comparisons with control in 2D-DIGE showed that (a) in UIP, nine protein spots were significantly upregulated and seven were significantly downregulated, (b) in NSIP, four protein spots were significantly upregulated and nine were significantly downregulated. The detected proteins were analyzed by MALDI-TOF mass spectrometry, allowing qualitative differences in vimentin subtypes to be characterized. One vimentin subtype was upregulated in UIP, while another one was downregulated in NSIP (vs. control). These different characteristics were partially supported by the results of Western blot analysis. Our immunohistochemistry revealed vimentin expression within fibroblasts (a) in fibroblastic foci in UIP and (b) in fibrotic alveolar walls in NSIP. Differences in vimentin subtypes may provide useful biomarkers for separating NSIP from UIP, alongside differences in histological characteristics. PMID:24048960

  11. Nonspecific Interstitial Pneumonia: What Is the Optimal Approach to Management?

    PubMed

    Tomassetti, Sara; Ryu, Jay H; Piciucchi, Sara; Chilosi, Marco; Poletti, Venerino

    2016-06-01

    We reviewed current aspects of the clinical and pathogenic profile of nonspecific interstitial pneumonia (NSIP), to better elucidate the complex issue of management and treatment options for NSIP patients. Recent findings suggest that idiopathic NSIP is a complex clinical entity with a disease spectrum that includes at least three different phenotypes: NSIP associated with autoimmune features, emphysema, and familial interstitial lung disease. This distinction, based mainly on clinical findings, may be of critical importance when it comes to making a decision on patients' management. This hypothesis warrants further studies. Currently, two major radiologic-pathologic different profiles have been well established. First, the "inflammatory type" characterized by prominent lymphocytic inflammation both on biopsy and bronchoalveolar lavage (BAL), and high-resolution computed tomography (HRCT) with mixed NSIP/organizing pneumonia pattern that tends to have a better response to corticosteroid and immunosuppressive treatment. Second, the "highly fibrotic" subgroup that shows prominent reticular changes and traction bronchiectasis by HRCT, high fibrotic background on biopsy, and no lymphocytosis on BAL. The latter fibrotic NSIP is the subgroup with less potential to respond to immunosuppressive treatment and a marginal risk to evolve into "full-blown idiopathic pulmonary fibrosis." The management of patients with fibrotic, progressive, and immunosuppressive treatment, refractory NSIP remains uncertain, and further studies are needed to address the role of antifibrotic drug in this settings. Oxygen therapy, pulmonary rehabilitation, and lung transplantation are of importance in the current management of severe, progressive, and refractory NSIP patients. PMID:27231862

  12. Francisella DnaK Inhibits Tissue-nonspecific Alkaline Phosphatase*

    PubMed Central

    Arulanandam, Bernard P.; Chetty, Senthilnath Lakshmana; Yu, Jieh-Juen; Leonard, Sean; Klose, Karl; Seshu, Janakiram; Cap, Andrew; Valdes, James J.; Chambers, James P.

    2012-01-01

    Following pulmonary infection with Francisella tularensis, we observed an unexpected but significant reduction of alkaline phosphatase, an enzyme normally up-regulated following inflammation. However, no reduction was observed in mice infected with a closely related Gram-negative pneumonic organism (Klebsiella pneumoniae) suggesting the inhibition may be Francisella-specific. In similar fashion to in vivo observations, addition of Francisella lysate to exogenous alkaline phosphatase (tissue-nonspecific isozyme) was inhibitory. Partial purification and subsequent proteomic analysis indicated the inhibitory factor to be the heat shock protein DnaK. Incubation with increasing amounts of anti-DnaK antibody reduced the inhibitory effect in a dose-dependent manner. Furthermore, DnaK contains an adenosine triphosphate binding domain at its N terminus, and addition of adenosine triphosphate enhances dissociation of DnaK with its target protein, e.g. alkaline phosphatase. Addition of adenosine triphosphate resulted in decreased DnaK co-immunoprecipitated with alkaline phosphatase as well as reduction of Francisella-mediated alkaline phosphatase inhibition further supporting the binding of Francisella DnaK to alkaline phosphatase. Release of DnaK via secretion and/or bacterial cell lysis into the extracellular milieu and inhibition of plasma alkaline phosphatase could promote an orchestrated, inflammatory response advantageous to Francisella. PMID:22923614

  13. [Treatment of non-specific, functional and somatoform bodily complaints].

    PubMed

    Sattel, H; Schaefert, R; Häuser, W; Herrmann, M; Ronel, J; Henningsen, P; Hausteiner-Wiehle, C

    2014-03-01

    In primary and secondary medicine "non-specific, functional, and somatoform bodily complaints" are common and often take a chronic course, with the patients' quality of life usually markedly impaired, and give rise to high direct and indirect costs. They are challenging as they can deteriorate in case of inappropriate behavior on the physician's part. Coordinated by both German professional associations of Psychosomatic Medicine a new evidence based guideline was developed, aiming to transfer relevant diagnostic and therapeutic knowledge to all physicians who are in charge of these patients. After establishing a stable therapeutic alliance a symptom- and coping-oriented attitude could be demonstrated to be helpful. A biopsychosocial diagnostic evaluation combines a thorough assessment of bodily complaints and early introduces a sensitive discussion of signs of psychosocial stress, which can be extended carefully in case problems of this type are present. In less severe courses, physical/social activation is recommended and the patient's explanatory disease model should be extended towards a psychological dimension. More severe and complicated courses require a more structured approach consisting of regular appointments (as opposed to ad-hoc appointments whenever the patient feels worse) and an active cooperation of the patient. A coordinated, multimodal management includes additional measures as graded activation, psychotherapy, relaxation training or--if indicated--temporary medication. PMID:24619719

  14. The Binding Process of a Nonspecific Enzyme with DNA

    PubMed Central

    Chen, Chuanying; Pettitt, B. Montgomery

    2011-01-01

    Protein-DNA recognition of a nonspecific complex is modeled to understand the nature of the transient encounter states. We consider the structural and energetic features and the role of water in the DNA grooves in the process of protein-DNA recognition. Here we have used the nuclease domain of colicin E7 (N-ColE7) from Escherichia coli in complex with a 12-bp DNA duplex as the model system to consider how a protein approaches, encounters, and associates with DNA. Multiscale simulation studies using Brownian dynamics and molecular-dynamics simulations were performed to provide the binding process on multiple length- and timescales. We define the encounter states and identified the spatial and orientational aspects. For the molecular length-scales, we used molecular-dynamics simulations. Several intermediate binding states were found, which have different positions and orientations of protein around DNA including major and minor groove orientations. The results show that the contact number and the hydrated interfacial area are measures that facilitate better understanding of sequence-independent protein-DNA binding landscapes and pathways. PMID:21889451

  15. [Chronic Duodenitis and Celiac Disease: a path between the nonspecific and the early stages of Marsh].

    PubMed

    Passera, Andrea Helena; Passera, Mario Luis; Higa, Antonio Luis; Nuñez, Maria; Armando, Lucas; Barzón, Silvia

    2015-01-01

    Given the advances in diagnosis for CD, some patients are detected with symptoms and signs of food intolerance, which have positive antibodies and autoantibodies for coeliac disease, whom present proximal bowel biopsies with chronic nonspecific duodenitis and are not associated with stages 0 and 1 Marsh. On the other hand, patients with bloating, abdominal pain, pondostatural delay, negative antibodies for CD, and chronic nonspecific duodenitis in whom removing cow's milk or gluten, the symptoms remit. There are also celiac patients with biopsies before diagnosis, with chronic nonspecific duodenitis. In this paper, we summarize three brothers with different degrees of chronic duodenitis, one with chronic nonspecific duodenitis, and two with histopathological sings of coeliac disease. It is an invitation to think that chronic nonspecific duodenitis in some patients may be an earlier manifestation of celiac disease. PMID:26544059

  16. SOM 1, a small new gene required for mitochondrial inner membrane peptidase function in Saccharomyces cerevisiae.

    PubMed

    Esser, K; Pratje, E; Michaelis, G

    1996-09-25

    IMP1 encodes a subunit of the mitochondrial inner membrane peptidase responsible for the proteolytic processing of cytochrome oxidase subunit 2 (Cox2) and cytochrome b2 (Cytb2). The molecular defect in an imp1 mutation and the characterisation of a high-copy-number suppressor is described. A deletion of the suppressor region causes respiration deficiency. The DNA sequence revealed three very small overlapping ORFs. Constructs which carried termination codons within the ORFs or lacked ATG initiation codons still retained complementing activity on a high-copy-number plasmid. Nevertheless, the possibility that the suppressor acts at DNA or RNA level could be excluded. Subcloning of the ORFs, complementation analysis in low-copy-number plasmids and transcript mapping identified the 222 bp ORF as the suppressor gene designated SOM1. The SOM1 gene is transcribed into a 375 bp polyadenylated RNA and the deduced amino acid sequence predicts a small protein of 8.4 kDa with no significant sequence similarity to known proteins. In the som1 deletion mutant, proteolytic processing of the Cox2 precursor is prevented and Cytb2 is strongly reduced. SOM1 represents a new small gene which encodes a novel factor that is essential for the correct function of the Imp1 peptidase and/or the protein sorting machinery. PMID:8879245

  17. Fly DPP10 acts as a channel ancillary subunit and possesses peptidase activity

    PubMed Central

    Shiina, Yohei; Muto, Tomohiro; Zhang, Zhili; Baihaqie, Ahmad; Yoshizawa, Takamasa; Lee, Hye-in J.; Park, Eulsoon; Tsukiji, Shinya; Takimoto, Koichi

    2016-01-01

    Mammalian DPP6 (DPPX) and DPP10 (DPPY) belong to a family of dipeptidyl peptidases, but lack enzyme activity. Instead, these proteins form complexes with voltage-gated K+ channels in Kv4 family to control their gating and other properties. Here, we find that the fly DPP10 ortholog acts as an ancillary subunit of Kv4 channels and digests peptides. Similarly to mammalian DPP10, the fly ortholog tightly binds to rat Kv4.3 protein. The association causes negative shifts in voltage dependence of channel activation and steady state inactivation. It also results in faster inactivation and recovery from inactivation. In addition to its channel regulatory role, fly DPP10 exhibits significant dipeptidyl peptidase activity with Gly-Pro-MCA (glycyl-L-proline 4-methylcoumaryl-7-amide) as a substrate. Heterologously expressed Flag-tagged fly DPP10 and human DPP4 show similar Km values towards this substrate. However, fly DPP10 exhibits approximately a 6-times-lower relative kcat value normalized with anti-Flag immunoreactivity than human DPP4. These results demonstrate that fly DPP10 is a dual functional protein, controlling Kv4 channel gating and removing bioactive peptides. PMID:27198182

  18. Plasma peptidases as prognostic biomarkers in patients with first-episode psychosis.

    PubMed

    Fernández-Atucha, Ainhoa; Echevarría, Enrique; Larrinaga, Gorka; Gil, Javier; Martínez-Cengotitabengoa, Mónica; González-Pinto, Ana M; Irazusta, Jon; Seco, Jesús

    2015-08-15

    The plasma activity of nine aminopeptidases was monitored over a year in first-episode psychotic patients. We observed significant differences in aminopeptidase B (APB), aminopeptidase N (APN) and dipeptidyl peptidase IV (DPPIV), but not in puromycin-sensitive aminopeptidase (PSA), prolyl endopeptidase (PEP), cysteine aminopeptidase (Cys-AP), aspartate aminopeptidase (Asp-AP), glutamate aminopeptidase (Glu) or piroglutamate aminopeptidase (PGI) in these patients compared to controls, and also a progressive increase in plasma activity, correlated to changes in scores on clinical scales, Global Assessment of Functioning scale (GAF) and Hamilton Depression Rating Scale (HDRS), at 1 month of follow-up. At 1 month after diagnosis, the median score obtained by patients on the GAF was negatively associated with the plasma activity of APB and PEP measured at the beginning of the psychotic episode, indicating a role as a negative prognostic factor that can predict psychiatric symptomatology. In the case of HDRS, scores at 1 month after diagnosis were found to be positively associated with the initial plasma activity of DPPIV, APN and PSA, indicating that their initial elevation is a negative prognostic factor that can predict subsequent depressive symptomatology. Taken together, these results suggest a pathophysiological involvement of plasma peptidases and indicate that aminopeptidase activity can predict the course of first-episode psychosis patients, acting as a prognostic indicator. PMID:25997998

  19. Arrabidaea chica Hexanic Extract Induces Mitochondrion Damage and Peptidase Inhibition on Leishmania spp.

    PubMed Central

    Rodrigues, Igor A.; Azevedo, Mariana M. B.; Chaves, Francisco C. M.; Alviano, Celuta S.; Alviano, Daniela S.; Vermelho, Alane B.

    2014-01-01

    Currently available leishmaniasis treatments are limited due to severe side effects. Arrabidaea chica is a medicinal plant used in Brazil against several diseases. In this study, we investigated the effects of 5 fractions obtained from the crude hexanic extract of A. chica against Leishmania amazonensis and L. infantum, as well as on the interaction of these parasites with host cells. Promastigotes were treated with several concentrations of the fractions obtained from A. chica for determination of their minimum inhibitory concentration (MIC). In addition, the effect of the most active fraction (B2) on parasite's ultrastructure was analyzed by transmission electron microscopy. To evaluate the inhibitory activity of B2 fraction on Leishmania peptidases, parasites lysates were treated with the inhibitory and subinhibitory concentrations of the B2 fraction. The minimum inhibitory concentration of B2 fraction was 37.2 and 18.6 μg/mL for L. amazonensis and L. infantum, respectively. Important ultrastructural alterations as mitochondrial swelling with loss of matrix content and the presence of vesicles inside this organelle were observed in treated parasites. Moreover, B2 fraction was able to completely inhibit the peptidase activity of promastigotes at pH 5.5. The results presented here further support the use of A. chica as an interesting source of antileishmanial agents. PMID:24818162

  20. Fly DPP10 acts as a channel ancillary subunit and possesses peptidase activity.

    PubMed

    Shiina, Yohei; Muto, Tomohiro; Zhang, Zhili; Baihaqie, Ahmad; Yoshizawa, Takamasa; Lee, Hye-In J; Park, Eulsoon; Tsukiji, Shinya; Takimoto, Koichi

    2016-01-01

    Mammalian DPP6 (DPPX) and DPP10 (DPPY) belong to a family of dipeptidyl peptidases, but lack enzyme activity. Instead, these proteins form complexes with voltage-gated K(+) channels in Kv4 family to control their gating and other properties. Here, we find that the fly DPP10 ortholog acts as an ancillary subunit of Kv4 channels and digests peptides. Similarly to mammalian DPP10, the fly ortholog tightly binds to rat Kv4.3 protein. The association causes negative shifts in voltage dependence of channel activation and steady state inactivation. It also results in faster inactivation and recovery from inactivation. In addition to its channel regulatory role, fly DPP10 exhibits significant dipeptidyl peptidase activity with Gly-Pro-MCA (glycyl-L-proline 4-methylcoumaryl-7-amide) as a substrate. Heterologously expressed Flag-tagged fly DPP10 and human DPP4 show similar Km values towards this substrate. However, fly DPP10 exhibits approximately a 6-times-lower relative kcat value normalized with anti-Flag immunoreactivity than human DPP4. These results demonstrate that fly DPP10 is a dual functional protein, controlling Kv4 channel gating and removing bioactive peptides. PMID:27198182

  1. Potential Role of Dipeptidyl Peptidase IV in the Pathophysiology of Heart Failure

    PubMed Central

    Salles, Thiago A.; dos Santos, Leonardo; Barauna, Valério G.; Girardi, Adriana C. C.

    2015-01-01

    Dipeptidyl peptidase IV (DPPIV) is a widely expressed multifunctional serine peptidase that exists as a membrane-anchored cell surface protein or in a soluble form in the plasma and other body fluids. Numerous substrates are cleaved at the penultimate amino acid by DPPIV, including glucagon-like peptide-1 (GLP-1), brain natriuretic peptide (BNP) and stromal cell-derived factor-1 (SDF-α), all of which play important roles in the cardiovascular system. In this regard, recent reports have documented that circulating DPPIV activity correlates with poorer cardiovascular outcomes in human and experimental heart failure (HF). Moreover, emerging evidence indicates that DPPIV inhibitors exert cardioprotective and renoprotective actions in a variety of experimental models of cardiac dysfunction. On the other hand, conflicting results have been found when translating these promising findings from preclinical animal models to clinical therapy. In this review, we discuss how DPPIV might be involved in the cardio-renal axis in HF. In addition, the potential role for DPPIV inhibitors in ameliorating heart disease is revised, focusing on the effects of the main DPPIV substrates on cardiac remodeling and renal handling of salt and water. PMID:25690036

  2. Inhibition of dipeptidyl peptidase IV by fluoroolefin-containing N-peptidyl-O-hydroxylamine peptidomimetics

    PubMed Central

    Lin, Jian; Toscano, Paul J.; Welch, John T.

    1998-01-01

    Dipeptidyl peptidase IV (EC 3.4.14.5; DPP IV), also known as the leukocyte differentiation antigen CD26 when found as an extracellular membrane-bound proline specific serine protease, cleaves a dipeptide from the N terminus of a polypeptide chain containing a proline residue in the penultimate position. Here we report that known (Z)-Ala-ψ[CF=C]-Pro dipeptide isosteres 1 and 2, which contain O-acylhydroxylamines, were isolated as diastereomeric pairs u-1, l-1, and l-2. The effect of each diastereomeric pair as an inhibitor of human placental dipeptidyl peptidase DPP IV has been examined. The inhibition of DPP IV by these compounds is rapid and efficient. The diastereomeric pair u-1 exhibits very potent inhibitory activity with a Ki of 188 nM. Fluoroolefin containing N-peptidyl-O-hydroxylamine peptidomimetics, by virtue of their inhibitory potency and stability, are superior to N-peptidyl-O-hydroxylamine inhibitors derived from an Ala-Pro dipeptide. PMID:9826645

  3. Overexpression of specific cysteine peptidases confers pathogenicity to a nonpathogenic Entamoeba histolytica clone.

    PubMed

    Matthiesen, Jenny; Bär, Ann-Katrein; Bartels, Anne-Kathrin; Marien, Dennis; Ofori, Susann; Biller, Laura; Tannich, Egbert; Lotter, Hannelore; Bruchhaus, Iris

    2013-01-01

    Cysteine peptidases (CPs) of Entamoeba histolytica are considered to be important pathogenicity factors. Previous studies have found that under standard axenic culture conditions, only four (ehcp-a1, ehcp-a2, ehcp-a5, and ehcp-a7) out of 35 papain-like ehcp genes present in the E. histolytica genome are expressed at high levels. Little is known about the expression of CPs in E. histolytica during amoebic liver abscess (ALA) formation. In the current study, a quantitative real-time PCR assay was developed to determine the expression of the various ehcp genes during ALA formation in animal models. Increased expression of four ehcp genes (ehcp-a3, -a4, -a10, and -c13) was detected in the gerbil and mouse models. Increased expression of another three ehcp genes (ehcp-a5, -a6, and -a7) was detected in the mouse model only, and two other ehcp genes (ehcp-b8 and -b9) showed increased expression in the gerbil model only. Trophozoites of the nonpathogenic E. histolytica HM-1:IMSS clone A1, which was unable to induce ALAs, were transfected with vectors enabling overexpression of those CPs that are expressed at high levels under culture conditions or during ALA formation. Interestingly, overexpression of ehcp-b8, -b9, and -c13 restored the pathogenic phenotype of the nonpathogenic clone A1 whereas overexpression of various other peptidase genes had no effect on the pathogenicity of this clone. PMID:23532975

  4. 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

  5. Identification and characterization of a dipeptidyl peptidase IV inhibitor from aronia juice

    SciTech Connect

    Kozuka, Miyuki; Yamane, Takuya; Nakano, Yoshihisa; Nakagaki, Takenori; Ohkubo, Iwao; Ariga, Hiroyoshi

    2015-09-25

    Aronia berries have many potential effects on health, including an antioxidant effect, effect for antimutagenesis, hepatoprotection and cardioprotection, an antidiabetic effect and inhibition of cancer cell proliferation. Previous human studies have shown that aronia juice may be useful for treatment of obesity disorders. In this study, we found that aronia juice has an inhibitory effect against dipeptidyl peptidase IV (DPP IV) (EC 3.4.14.5). DPP IV is a peptidase that cleaves the N-terminal region of incretins such as glucagon-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Inactivation of incretins by DPP IV induces reduction of insulin secretion. Furthermore, we identified that cyanidin 3, 5-diglucoside as the DPP IV inhibitor in aronia juice. DPP IV was inhibited more strongly by cyanidin 3, 5-diglucoside than by cyanidin and cyanidin 3-glucoside. The results suggest that DPP IV is inhibited by cyanidin 3, 5-diglucoside present in aronia juice. The antidiabetic effect of aronia juice may be mediated through DPP IV inhibition by cyanidin 3, 5-diglucoside. - Highlights: • DPP IV activity is inhibited by aronia juice. • DPP IV inhibitor is cyanidin 3, 5-diglucoside in aronia juice. • DPP IV is inhibited by cyanidin 3, 5-diglucoside more than cyanidin and cyanidin 3-glucoside.

  6. Fish skin gelatin hydrolysates produced by visceral peptidase and bovine trypsin: Bioactivity and stability.

    PubMed

    Ketnawa, Sunantha; Benjakul, Soottawat; Martínez-Alvarez, Oscar; Rawdkuen, Saroat

    2017-01-15

    The peptidase from the viscera of farmed giant catfish was used for producing gelatin hydrolysates (HG) and compared with those produced from commercial bovine trypsin (HB). The degree of hydrolysis (DH) observed suggests that proteolytic cleavage rapidly occurred within the first 120min of incubation, and there was higher DH in HG than in HB. HG demonstrated the highest ACE-inhibitory activity, DPPH, ABTS radical scavenging activity, and FRAP. HB showed the highest FRAP activity. The DPPH radical scavenging activity of HG was quite stable over the pH range of 1-11, but it increased slightly when the heating duration time reached 240min at 100°C. The ACE-inhibitory activity of HG showed the highest stability at a pH of 7, and it remained very stable at 100°C for over 15-240min. The visceral peptidase from farmed giant catfish could be an alternative protease for generating protein hydrolysates with desirable bioactivities. The resulting hydrolysates showed good stability, making them potential functional ingredients for food formulations. PMID:27542490

  7. Identification and characterization of a dipeptidyl peptidase IV inhibitor from aronia juice.

    PubMed

    Kozuka, Miyuki; Yamane, Takuya; Nakano, Yoshihisa; Nakagaki, Takenori; Ohkubo, Iwao; Ariga, Hiroyoshi

    2015-09-25

    Aronia berries have many potential effects on health, including an antioxidant effect, effect for antimutagenesis, hepatoprotection and cardioprotection, an antidiabetic effect and inhibition of cancer cell proliferation. Previous human studies have shown that aronia juice may be useful for treatment of obesity disorders. In this study, we found that aronia juice has an inhibitory effect against dipeptidyl peptidase IV (DPP IV) (EC 3.4.14.5). DPP IV is a peptidase that cleaves the N-terminal region of incretins such as glucagon-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Inactivation of incretins by DPP IV induces reduction of insulin secretion. Furthermore, we identified that cyanidin 3, 5-diglucoside as the DPP IV inhibitor in aronia juice. DPP IV was inhibited more strongly by cyanidin 3, 5-diglucoside than by cyanidin and cyanidin 3-glucoside. The results suggest that DPP IV is inhibited by cyanidin 3, 5-diglucoside present in aronia juice. The antidiabetic effect of aronia juice may be mediated through DPP IV inhibition by cyanidin 3, 5-diglucoside. PMID:26296465

  8. Cysteine Peptidase B Regulates Leishmania mexicana Virulence through the Modulation of GP63 Expression

    PubMed Central

    Casgrain, Pierre-André; Martel, Caroline; McMaster, W. Robert; Mottram, Jeremy C.; Olivier, Martin; Descoteaux, Albert

    2016-01-01

    Cysteine peptidases play a central role in the biology of Leishmania. In this work, we sought to further elucidate the mechanism(s) by which the cysteine peptidase CPB contributes to L. mexicana virulence and whether CPB participates in the formation of large communal parasitophorous vacuoles induced by these parasites. We initially examined the impact of L. mexicana infection on the trafficking of VAMP3 and VAMP8, two endocytic SNARE proteins associated with phagolysosome biogenesis and function. Using a CPB-deficient mutant, we found that both VAMP3 and VAMP8 were down-modulated in a CPB-dependent manner. We also discovered that expression of the virulence-associated GPI-anchored metalloprotease GP63 was inhibited in the absence of CPB. Expression of GP63 in the CPB-deficient mutant was sufficient to down-modulate VAMP3 and VAMP8. Similarly, episomal expression of GP63 enabled the CPB-deficient mutant to establish infection in macrophages, induce the formation of large communal parasitophorous vacuoles, and cause lesions in mice. These findings implicate CPB in the regulation of GP63 expression and provide evidence that both GP63 and CPB are key virulence factors in L. mexicana. PMID:27191844

  9. Characterization of a novel acylaminoacyl peptidase with hexameric structure and endopeptidase activity.

    PubMed

    Szeltner, Zoltán; Kiss, András L; Domokos, Klarissza; Harmat, Veronika; Náray-Szabó, Gábor; Polgár, László

    2009-08-01

    We have overexpressed in E. coli, purified and investigated the kinetic, thermodynamic and biophysical properties of an acylaminoacyl peptidase (AAP), from the thermophile Pyrococcus horikoshii (PhAAP). It was shown that the electrostatic environment of the catalytic site of PhAAP substantially influenced the pH dependence of the specificity rate constant (k(cat)/K(m)). However, 0.3 M NaCl, which depressed the electrostatic effects, simplified the complex pH-rate profile. The rate of formation of the enzyme-substrate complex (k(1)) was obtained from a non-linear Arrhenius plot. The lack of substrate leaving group effects indicated that k(1) is the rate determining step in the catalysis. DSC and CD measurements demonstrated that PhAAP displayed a stable structure in the catalytically competent pH range. It was shown that PhAAP is not just an acylaminoacyl peptidase, but it also has an endopeptidase activity and so differs from the mammalian AAPs. Size exclusion chromatography with PhAAP revealed a hexameric structure, which is unique among the known members of the prolyl oligopeptidase family that includes AAPs and suggests that its cellular function may be different from that of the dimeric AAP also found in the same organism. PMID:19303951

  10. A Computational Study of the Glycine-Rich Loop of Mitochondrial Processing Peptidase

    PubMed Central

    Kučera, Tomáš; Otyepka, Michal; Matušková, Anna; Samad, Abdul; Kutejová, Eva; Janata, Jiří

    2013-01-01

    An all atomic, non-restrained molecular dynamics (MD) simulation in explicit water was used to study in detail the structural features of the highly conserved glycine-rich loop (GRL) of the α-subunit of the yeast mitochondrial processing peptidase (MPP) and its importance for the tertiary and quaternary conformation of MPP. Wild-type and GRL-deleted MPP structures were studied using non-restrained MD simulations, both in the presence and the absence of a substrate in the peptidase active site. Targeted MD simulations were employed to study the mechanism of substrate translocation from the GRL to the active site. We demonstrate that the natural conformational flexibility of the GRL is crucial for the substrate translocation process from outside the enzyme towards the MPP active site. We show that the α-helical conformation of the substrate is important not only during its initial interaction with MPP (i.e. substrate recognition), but also later, at least during the first third of the substrate translocation trajectory. Further, we show that the substrate remains in contact with the GRL during the whole first half of the translocation trajectory and that hydrophobic interactions play a major role. Finally, we conclude that the GRL acts as a precisely balanced structural element, holding the MPP subunits in a partially closed conformation regardless the presence or absence of a substrate in the active site. PMID:24058582

  11. Differential expression of cysteine peptidase genes in the inner integument and endosperm of developing seeds of Jatropha curcas L. (Euphorbiaceae).

    PubMed

    Rocha, Antônio J; Soares, Emanoella L; Costa, José H; Costa, Washington L G; Soares, Arlete A; Nogueira, Fábio C S; Domont, Gilberto B; Campos, Francisco A P

    2013-12-01

    In several plant tissues, programmed cell death (PCD) is mediated by the combined action of cysteine peptidases, namely KDEL-tailed cysteine peptidases (KDEL-CysEP) and vacuolar processing enzymes (VPE). Here, we performed a search of the draft genome of Jatropha curcas L. (Euphorbiaceae) and identified 2 genes for KDEL-CysEP (Jc-CysEP1 and Jc-CysEP2) and 3 genes for VPE (Jc-βVPE, Jc-γVPE and Jc-δVPE) and determined the expression patterns of these genes by RT-qPCR in integument and cellular endosperm of seeds collected at seven different developmental stages. We were able to demonstrate that the expression of Jc-CysEP1, Jc-CysEP2, Jc-βVPE and Jc-γVPE proceeded rapidly from Stage IV, with Jc-CysEP2 displaying the highest relative expression; expression of Jc-δVPE could not be detected in any of the tissues/developmental stages analyzed. Additionally, we showed that the expression pattern of these peptidases correlates with anatomical changes in integument and cellular endosperm, thus suggesting a role for both classes of peptidases in PCD and in protein processing, both of which occur simultaneously in each of these tissues. PMID:24157205

  12. Expression patterns of cysteine peptidase genes across the Tribolium castaneum life cycle provide clues to biological function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red flour beetle, Tribolium castaneum, is a major agricultural pest responsible for considerable loss of stored grain and cereal products worldwide. T. castaneum larvae have a highly compartmentalized gut, with cysteine peptidases mostly in the acidic anterior part of the midgut. We have descri...

  13. Crucial role of nonspecific interactions in amyloid nucleation.

    PubMed

    Šarić, Anđela; Chebaro, Yassmine C; Knowles, Tuomas P J; Frenkel, Daan

    2014-12-16

    Protein oligomers have been implicated as toxic agents in a wide range of amyloid-related diseases. However, it has remained unsolved whether the oligomers are a necessary step in the formation of amyloid fibrils or just a dangerous byproduct. Analogously, it has not been resolved if the amyloid nucleation process is a classical one-step nucleation process or a two-step process involving prenucleation clusters. We use coarse-grained computer simulations to study the effect of nonspecific attractions between peptides on the primary nucleation process underlying amyloid fibrillization. We find that, for peptides that do not attract, the classical one-step nucleation mechanism is possible but only at nonphysiologically high peptide concentrations. At low peptide concentrations, which mimic the physiologically relevant regime, attractive interpeptide interactions are essential for fibril formation. Nucleation then inevitably takes place through a two-step mechanism involving prefibrillar oligomers. We show that oligomers not only help peptides meet each other but also, create an environment that facilitates the conversion of monomers into the β-sheet-rich form characteristic of fibrils. Nucleation typically does not proceed through the most prevalent oligomers but through an oligomer size that is only observed in rare fluctuations, which is why such aggregates might be hard to capture experimentally. Finally, we find that the nucleation of amyloid fibrils cannot be described by classical nucleation theory: in the two-step mechanism, the critical nucleus size increases with increases in both concentration and interpeptide interactions, which is in direct contrast with predictions from classical nucleation theory. PMID:25453085

  14. A Nonhost Peptidase Inhibitor of ~14 kDa from Butea monosperma (Lam.) Taub. Seeds Affects Negatively the Growth and Developmental Physiology of Helicoverpa armigera

    PubMed Central

    Pandey, Prabhash K.; Singh, Dushyant; Singh, Sangram; Khan, M. Y.; Jamal, Farrukh

    2014-01-01

    Helicoverpa armigera is one of the major devastating pests of crop plants. In this context a serine peptidase inhibitor purified from the seeds of Butea monosperma was evaluated for its effect on developmental physiology of H. armigera larvae. B. monosperma peptidase inhibitor on 12% denaturing polyacrylamide gel electrophoresis exhibited a single protein band of ~14 kDa with or without reduction. In vitro studies towards total gut proteolytic enzymes of H. armigera and bovine trypsin indicated measurable inhibitory activity. B. monosperma peptidase inhibitor dose for 50% mortality and weight reduction by 50% were 0.5% w/w and 0.10% w/w, respectively. The IC50 of B. monosperma peptidase inhibitor against total H. armigera gut proteinases activity was 2.0 µg/mL. The larval feeding assays suggested B. monosperma peptidase inhibitor to be toxic as reflected by its retarded growth and development, consequently affecting fertility and fecundity of pest and prolonging the larval-pupal duration of the insect life cycle of H. armigera. Supplementing B. monosperma peptidase inhibitor in artificial diet at 0.1% w/w, both the efficiencies of conversion of ingested as well as digested food were downregulated, whereas approximate digestibility and metabolic cost were enhanced. The efficacy of Butea monosperma peptidase inhibitor against progressive growth and development of H. armigera suggest its usefulness in insect pest management of food crops. PMID:24860667

  15. Crystal structure of bacterial cell-surface alginate-binding protein with an M75 peptidase motif

    SciTech Connect

    Maruyama, Yukie; Ochiai, Akihito; Mikami, Bunzo; Hashimoto, Wataru; Murata, Kousaku

    2011-02-18

    Research highlights: {yields} Bacterial alginate-binding Algp7 is similar to component EfeO of Fe{sup 2+} transporter. {yields} We determined the crystal structure of Algp7 with a metal-binding motif. {yields} Algp7 consists of two helical bundles formed through duplication of a single bundle. {yields} A deep cleft involved in alginate binding locates around the metal-binding site. {yields} Algp7 may function as a Fe{sup 2+}-chelated alginate-binding protein. -- Abstract: A gram-negative Sphingomonas sp. A1 directly incorporates alginate polysaccharide into the cytoplasm via the cell-surface pit and ABC transporter. A cell-surface alginate-binding protein, Algp7, functions as a concentrator of the polysaccharide in the pit. Based on the primary structure and genetic organization in the bacterial genome, Algp7 was found to be homologous to an M75 peptidase motif-containing EfeO, a component of a ferrous ion transporter. Despite the presence of an M75 peptidase motif with high similarity, the Algp7 protein purified from recombinant Escherichia coli cells was inert on insulin B chain and N-benzoyl-Phe-Val-Arg-p-nitroanilide, both of which are substrates for a typical M75 peptidase, imelysin, from Pseudomonas aeruginosa. The X-ray crystallographic structure of Algp7 was determined at 2.10 A resolution by single-wavelength anomalous diffraction. Although a metal-binding motif, HxxE, conserved in zinc ion-dependent M75 peptidases is also found in Algp7, the crystal structure of Algp7 contains no metal even at the motif. The protein consists of two structurally similar up-and-down helical bundles as the basic scaffold. A deep cleft between the bundles is sufficiently large to accommodate macromolecules such as alginate polysaccharide. This is the first structural report on a bacterial cell-surface alginate-binding protein with an M75 peptidase motif.

  16. Characterization of a soluble, catalytically active form of Escherichia coli leader peptidase: requirement of detergent or phospholipid for optimal activity.

    PubMed

    Tschantz, W R; Paetzel, M; Cao, G; Suciu, D; Inouye, M; Dalbey, R E

    1995-03-28

    Leader peptidase is a novel serine protease in Escherichia coli, which functions to cleave leader sequences from exported proteins. Its catalytic domain extends into the periplasmic space and is anchored to the membrane by two transmembrane segments located at the N-terminal end of the protein. At present, there is no information on the structure of the catalytic domain. Here, we report on the properties of a soluble form of leader peptidase (delta 2-75), and we compare its properties to those of the wild-type enzyme. We find that the truncated leader peptidase has a kcat of 3.0 S-1 and a Km of 32 microM with a pro-OmpA nuclease A substrate. In contrast to the wild-type enzyme (pI of 6.8), delta 2-75 is water-soluble and has an acidic isoelectric point of 5.6. We also show with delta 2-75 that the replacement of serine 90 and lysine 145 with alanine residues results in a 500-fold reduction in activity, providing further evidence that leader peptidase employs a catalytic serine/lysine dyad. Finally, we find that the catalysis of delta 2-75 is accelerated by the presence of the detergent Triton X-100, regardless if the substrate is pro-OmpA nuclease A or a peptide substrate. Triton X-100 is required for optimal activity of delta 2-75 at a level far below the critical micelle concentration. Moreover, we find that E. coli phospholipids stimulate the activity of delta 2-75, suggesting that phospholipids may play an important physiological role in the catalytic mechanism of leader peptidase. PMID:7696258

  17. Post-injury administration of NAAG peptidase inhibitor prodrug, PGI-02776, in experimental TBI.

    PubMed

    Feng, Jun-Feng; Van, Ken C; Gurkoff, Gene G; Kopriva, Christina; Olszewski, Rafal T; Song, Minsoo; Sun, Shifeng; Xu, Man; Neale, Joseph H; Yuen, Po-Wai; Lowe, David A; Zhou, Jia; Lyeth, Bruce G

    2011-06-13

    Traumatic brain injury (TBI) leads to a rapid and excessive increase in glutamate concentration in the extracellular milieu, which is strongly associated with excitotoxicity and neuronal degeneration. N-acetylaspartylglutamate (NAAG), a prevalent peptide neurotransmitter in the vertebrate nervous system, is released along with glutamate and suppresses glutamate release by actions at pre-synaptic metabotropic glutamate autoreceptors. Extracellular NAAG is hydrolyzed to N-acetylaspartate and glutamate by peptidase activity. In the present study PGI-02776, a newly designed di-ester prodrug of the urea-based NAAG peptidase inhibitor ZJ-43, was tested for neuroprotective potential when administered intraperitoneally 30 min after lateral fluid percussion TBI in the rat. Stereological quantification of hippocampal CA2-3 degenerating neurons at 24 h post injury revealed that 10 mg/kg PGI-02776 significantly decreased the number of degenerating neurons (p<0.05). Both average latency analysis of Morris water maze performance and assessment of 24-hour memory retention revealed significant differences between sham-TBI and TBI-saline. In contrast, no significant difference was found between sham-TBI and PGI-02776 treated groups in either analysis indicating an improvement in cognitive performance with PGI-02776 treatment. Histological analysis on day 16 post-injury revealed significant cell death in injured animals regardless of treatment. In vitro NAAG peptidase inhibition studies demonstrated that the parent compound (ZJ-43) exhibited potent inhibitory activity while the mono-ester (PGI-02749) and di-ester (PGI-02776) prodrug compounds exhibited moderate and weak levels of inhibitory activity, respectively. Pharmacokinetic assays in uninjured animals found that the di-ester (PGI-02776) crossed the blood-brain barrier. PGI-02776 was also readily hydrolyzed to both the mono-ester (PGI-02749) and the parent compound (ZJ-43) in both blood and brain. Overall, these findings

  18. Adrenomedullin for Risk Stratification of Emergency Patients With Nonspecific Complaints

    PubMed Central

    Nickel, Christian Hans; Messmer, Anna Sarah; Ghanim, Leyla; Ilsemann-Karakoumis, Julia; Giersdorf, Sven; Hertel, Sabine; Ernst, Susanne; Geigy, Nicolas; Bingisser, Roland

    2016-01-01

    Abstract Patients with nonspecific complaints (NSC) presenting to the emergency department (ED) are at risk of life-threatening conditions. New stress biomarkers such as the midregional portion of adrenomedullin (MR-proADM) promise to support decision-making. This study tested the following hypotheses: biomarker-assisted disposition of patients with NSC will not increase mortality. Second, discharge from the ED will increase if clinical risk assessment is combined with low MR-proADM levels. Third, inappropriate disposition to a lower level of care will decrease, if clinical assessment is combined with high MR-proADM levels, and fourth that this algorithm is feasible in the ED setting. Prospective, multicenter, randomized, controlled interventional feasibility study with a 30-day follow-up, including patients with NSC. Patients were randomly assigned to either the standard group (decision-making solely based on clinical assessment) or the Novum group (biomarker-assisted). Regarding disposition, patients were assigned to 1 of 3 risk classes: high-risk (admission to hospital), intermediate risk (community geriatric hospital), and low-risk patients (discharge). In the Novum group, in addition to clinical risk assessment, the information of the MR-proADM level was used. Unless there were overruling criteria, patients were transferred or discharged according to the risk assessment. Primary endpoint was 30-day mortality. Secondary endpoints were comparisons of patient disposition and related mortality rates, ED, and hospital length of stay and readmission. The final study cohort consisted of 398 patients (210 in the Standard group and 188 in the Novum group). Overruling, that is, disposition not according to the result of the proposed algorithm occurred in 51 cases. Baseline characteristics between Standard and Novum groups were similar. The mortality rate in the Novum group was 4.3%, as compared to the Standard group mortality of 6.2%, which was not significantly

  19. CPDadh: A new peptidase family homologous to the cysteine protease domain in bacterial MARTX toxins

    PubMed Central

    Pei, Jimin; Lupardus, Patrick J; Garcia, K Christopher; Grishin, Nick V

    2009-01-01

    A cysteine protease domain (CPD) has been recently discovered in a group of multifunctional, autoprocessing RTX toxins (MARTX) and Clostridium difficile toxins A and B. These CPDs (referred to as CPDmartx) autocleave the toxins to release domains with toxic effects inside host cells. We report identification and computational analysis of CPDadh, a new cysteine peptidase family homologous to CPDmartx. CPDadh and CPDmartx share a Rossmann-like structural core and conserved catalytic residues. In bacteria, domains of the CPDadh family are present at the N-termini of a diverse group of putative cell-cell interaction proteins and at the C-termini of some RHS (recombination hot spot) proteins. In eukaryotes, catalytically inactive members of the CPDadh family are found in cell surface protein NELF (nasal embryonic LHRH factor) and some putative signaling proteins. PMID:19309740

  20. Dipeptidyl Peptidase-4 Regulation of SDF-1/CXCR4 Axis: Implications for Cardiovascular Disease

    PubMed Central

    Zhong, Jixin; Rajagopalan, Sanjay

    2015-01-01

    Dipeptidyl peptidase-4 (DPP4) is a ubiquitously expressed protease that regulates diverse number of physiological functions. As a dipeptidase, it exerts its catalytic effects on proteins/peptides with proline, alanine, or serine in the penultimate (P1) amino acid residue from the amino terminus. The evidence to date supports an important effect of DPP4 in catalytic cleavage of incretin peptides and this perhaps represents the main mechanism by which DPP4 inhibition improves glycemic control. DPP4 also plays an important role in the degradation of multiple chemokines of which stromal cell-derived factor-1 (SDF-1, also known as CXCL12) is perhaps an increasingly recognized target, given its importance in processes, such as hematopoiesis, angiogenesis, and stem cell homing. In the current review, we will summarize the importance of DPP4-mediated enzymatic processing of cytokines/chemokines with an emphasis on SDF-1 and resultant implications for cardiovascular physiology and disease. PMID:26441982

  1. Role of dipeptidyl peptidase-4 inhibitors in new-onset diabetes after transplantation

    PubMed Central

    Lim, Sun Woo; Jin, Ji Zhe; Jin, Long; Jin, Jian; Li, Can

    2015-01-01

    Despite strict pre- and post-transplantation screening, the incidence of new-onset diabetes after transplantation (NODAT) remains as high as 60%. This complication affects the risk of cardiovascular events and patient and graft survival rates. Thus, reducing the impact of NODAT could improve overall transplant success. The pathogenesis of NODAT is multifactorial, and both modifiable and nonmodifiable risk factors have been implicated. Monitoring and controlling the blood glucose profile, implementing multidisciplinary care, performing lifestyle modifications, using a modified immunosuppressive regimen, administering anti-metabolite agents, and taking a conventional antidiabetic approach may diminish the incidence of NODAT. In addition to these preventive strategies, inhibition of dipeptidyl peptidase-4 (DPP4) by the gliptin family of drugs has recently gained considerable interest as therapy for type 2 diabetes mellitus and NODAT. This review focuses on the role of DPP4 inhibitors and discusses recent literature regarding management of NODAT. PMID:26552451

  2. Inhibitors of signal peptide peptidase (SPP) affect HSV-1 infectivity in vitro and in vivo

    PubMed Central

    Allen, Sariah J.; Mott, Kevin R.; Ghiasi, Homayon

    2014-01-01

    Recently we have shown that the highly conserved herpes simplex virus glycoprotein K (gK) binds to signal peptide peptidase (SPP), also known as minor histocompatibility antigen H13. In this study we have demonstrated for the first time that inhibitors of SPP, such as L685,458, (Z-LL)2 ketone, aspirin, ibuprofen and DAPT, significantly reduced HSV-1 replication in tissue culture. Inhibition of SPP activity via (Z-LL)2 ketone significantly reduced viral transcripts in the nucleus of infected cells. Finally, when administered during primary infection, (Z-LL)2 ketone inhibitor reduced HSV-1 replication in the eyes of ocularly infected mice. Thus, blocking SPP activity may represent a clinically effective and expedient approach to the reduction of viral replication and the resulting pathology. PMID:24768597

  3. Parasite Cathepsin D-Like Peptidases and Their Relevance as Therapeutic Targets.

    PubMed

    Sojka, Daniel; Hartmann, David; Bartošová-Sojková, Pavla; Dvořák, Jan

    2016-09-01

    Inhibition of aspartic cathepsin D-like peptidases (APDs) has been often discussed as an antiparasite intervention strategy. APDs have been considered as virulence factors of Trypanosoma cruzi and Leishmania spp., and have been demonstrated to have important roles in protein trafficking mechanisms of apicomplexan parasites. APDs also initiate blood digestion as components of multienzyme proteolytic complexes in malaria, platyhelminths, nematodes, and ticks. Increasing DNA and RNA sequencing data indicate that parasites express multiple APD isoenzymes of various functions that can now be specifically evaluated using new functional-genomic and biochemical tools, from which we can further assess the potential of APDs as targets for novel effective intervention strategies against parasitic diseases that still pose an alarming threat to mankind. PMID:27344362

  4. Dipeptidyl Peptidase-4 Regulation of SDF-1/CXCR4 Axis: Implications for Cardiovascular Disease.

    PubMed

    Zhong, Jixin; Rajagopalan, Sanjay

    2015-01-01

    Dipeptidyl peptidase-4 (DPP4) is a ubiquitously expressed protease that regulates diverse number of physiological functions. As a dipeptidase, it exerts its catalytic effects on proteins/peptides with proline, alanine, or serine in the penultimate (P1) amino acid residue from the amino terminus. The evidence to date supports an important effect of DPP4 in catalytic cleavage of incretin peptides and this perhaps represents the main mechanism by which DPP4 inhibition improves glycemic control. DPP4 also plays an important role in the degradation of multiple chemokines of which stromal cell-derived factor-1 (SDF-1, also known as CXCL12) is perhaps an increasingly recognized target, given its importance in processes, such as hematopoiesis, angiogenesis, and stem cell homing. In the current review, we will summarize the importance of DPP4-mediated enzymatic processing of cytokines/chemokines with an emphasis on SDF-1 and resultant implications for cardiovascular physiology and disease. PMID:26441982

  5. Three ileus cases associated with the use of dipeptidyl peptidase-4 inhibitors in diabetic patients.

    PubMed

    Kanasaki, Keizo; Konishi, Kazunori; Hayashi, Ranji; Shiroeda, Hisakazu; Nomura, Tomoe; Nakagawa, Atsushi; Nagai, Takako; Takeda-Watanabe, Ai; Ito, Hiroki; Tsuda, Shin-Ichi; Kitada, Munehiro; Fujii, Mizue; Kanasaki, Megumi; Nishizawa, Makoto; Nakano, Yasuharu; Tomita, Yasuto; Ueda, Nobuhiko; Kosaka, Takeo; Koya, Daisuke

    2013-11-27

    Dipeptidyl peptidase (DPP)-4 inhibitors are a new class of antidiabetic drugs that increase incretin hormone levels to enhance blood sugar level-dependent insulinotropic effects, suppress glucagon action, and reduce bowel motility. These incretin effects are ideal for blood sugar control. However, the safety profile of DPP-4 inhibitors is not yet established. Herein, we present three cases of ileus, considered to be closely related to the use of DPP-4 inhibitors, in diabetic patients. Each of the three patients exhibited some risk of a deficiency in bowel movement; the onset of ileus was within 40 days after strengthened inhibition of DPP-4. The use of a DPP-4 inhibitor could be safe, although the cases presented herein enable us to inform the scientific community to some of the potential adverse effects of the use of DPP-4 inhibitors in select populations. PMID:24843724

  6. Inhibition of kallikrein-related peptidases by the serine protease inhibitor of Kazal-type 6.

    PubMed

    Kantyka, Tomasz; Fischer, Jan; Wu, Zhihong; Declercq, Wim; Reiss, Karina; Schröder, Jens-Michael; Meyer-Hoffert, Ulf

    2011-06-01

    Kallikrein-related peptidases (KLKs) are a group of serine proteases, expressed in several tissues. Their activity is regulated by inhibitors including members of the serine protease of Kazal-type (SPINK) family. Recently, we discovered that SPINK6 is expressed in human skin and inhibits KLK5, KLK7, KLK14 but not KLK8. In this study we tested whether SPINK6 inhibits other members of the KLK family and caspase-14. Using chromogenic substrates, SPINK6 exhibited inhibitory activity against KLK12 and KLK13 with K(i) around 1nM, KLK4 with K(i)=27.3nM, KLK6 with K(i)=140nM, caspase-14 with a K(i) approximating 1μM and no activity against KLK1, KLK3 and KLK11. Taken together, SPINK6 is a potent inhibitor of distinct KLKs members. PMID:21439340

  7. Role of mitochondrial processing peptidase and AAA proteases in processing of the yeast acetohydroxyacid synthase precursor.

    PubMed

    Dasari, Suvarna; Kölling, Ralf

    2016-07-01

    We studied presequence processing of the mitochondrial-matrix targeted acetohydroxyacid synthase (Ilv2). C-terminal 3HA-tagging altered the cleavage pattern from a single step to sequential two-step cleavage, giving rise to two Ilv2-3HA forms (A and B). Both cleavage events were dependent on the mitochondrial processing peptidase (MPP). We present evidence for the involvement of three AAA ATPases, m- and i-AAA proteases, and Mcx1, in Ilv2-3HA processing. Both, precursor to A-form and A-form to B-form cleavage were strongly affected in a ∆yme1 mutant. These defects could be suppressed by overexpression of MPP, suggesting that MPP activity is limiting in the ∆yme1 mutant. Our data suggest that for some substrates AAA ATPases could play an active role in the translocation of matrix-targeted proteins. PMID:27398316

  8. NAAG peptidase as a therapeutic target: Potential for regulating the link between glucose metabolism and cognition.

    PubMed

    Baslow, Morris H

    2006-04-01

    There is a new class of CNS drugs, N-acetylaspartylglutamate (NAAG) peptidase inhibitors, that can affect a two-step, neuron-astrocyte/astrocyte-vascular endothelium, signaling mechanism. Using this homeostatic mechanism, activated neurons continuously interact with the vascular system to indicate ongoing requirements for supplies of glucose (Glc) and oxygen needed to maintain cognitive functions. These new drugs impact the first step by inhibiting NAAG peptidase, located on the astrocyte surface, that cleaves glutamate (Glu) from the neuropeptide NAAG after it has docked with the astrocyte surface metabotropic Glu receptor 3 (mGluR3). As a result, this interferes with initiation of the second step, the astrocyte-vascular endothelium signal, activation of which results in a rapid hyperemic response that increases focal availability of energy supplies. Since NAAG is liberated upon each neuron depolarization, its release is linked to the level of neuronal spiking. This insures that its mGluR3 signal function reflects current levels of neuronal stimulation, so that Glc and oxygen can be supplied in a timely manner for metabolic replacement of ATP stocks depleted during the repolarization process. The metabolism of NAAG is very complex, being a component of the only metabolic sequence in the brain requiring three major brain cell types--neurons, astrocytes and oligodendrocytes--for its successful completion. In this review, we describe the unique NAAG tricellular metabolic cycle and survey some reported actions of these new and novel drugs. We also consider their probable site and mode of action and speculate upon their therapeutic potential. PMID:16804566

  9. Differential Inhibition of Signal Peptide Peptidase Family Members by Established γ-Secretase Inhibitors

    PubMed Central

    Ran, Yong; Ladd, Gabriela Z.; Ceballos-Diaz, Carolina; Jung, Joo In; Greenbaum, Doron; Felsenstein, Kevin M.; Golde, Todd E.

    2015-01-01

    The signal peptide peptidases (SPPs) are biomedically important proteases implicated as therapeutic targets for hepatitis C (human SPP, (hSPP)), plasmodium (Plasmodium SPP (pSPP)), and B-cell immunomodulation and neoplasia (signal peptide peptidase like 2a, (SPPL2a)). To date, no drug-like, selective inhibitors have been reported. We use a recombinant substrate based on the amino-terminus of BRI2 fused to amyloid β 1-25 (Aβ1-25) (FBA) to develop facile, cost-effective SPP/SPPL protease assays. Co-transfection of expression plasmids expressing the FBA substrate with SPP/SPPLs were conducted to evaluate cleavage, which was monitored by ELISA, Western Blot and immunoprecipitation/MALDI-TOF Mass spectrometry (IP/MS). No cleavage is detected in the absence of SPP/SPPL overexpression. Multiple γ-secretase inhibitors (GSIs) and (Z-LL)2 ketone differentially inhibited SPP/SPPL activity; for example, IC50 of LY-411,575 varied from 51±79 nM (on SPPL2a) to 5499±122 nM (on SPPL2b), while Compound E showed inhibition only on hSPP with IC50 of 1465±93 nM. Data generated were predictive of effects observed for endogenous SPPL2a cleavage of CD74 in a murine B-Cell line. Thus, it is possible to differentially inhibit SPP family members. These SPP/SPPL cleavage assays will expedite the search for selective inhibitors. The data also reinforce similarities between SPP family member cleavage and cleavage catalyzed by γ-secretase. PMID:26046535

  10. Mechanisms of Intramolecular Communication in a Hyperthermophilic Acylaminoacyl Peptidase: A Molecular Dynamics Investigation

    PubMed Central

    Papaleo, Elena; Renzetti, Giulia; Tiberti, Matteo

    2012-01-01

    Protein dynamics and the underlying networks of intramolecular interactions and communicating residues within the three-dimensional (3D) structure are known to influence protein function and stability, as well as to modulate conformational changes and allostery. Acylaminoacyl peptidase (AAP) subfamily of enzymes belongs to a unique class of serine proteases, the prolyl oligopeptidase (POP) family, which has not been thoroughly investigated yet. POPs have a characteristic multidomain three-dimensional architecture with the active site at the interface of the C-terminal catalytic domain and a β-propeller domain, whose N-terminal region acts as a bridge to the hydrolase domain. In the present contribution, protein dynamics signatures of a hyperthermophilic acylaminoacyl peptidase (AAP) of the prolyl oligopeptidase (POP) family, as well as of a deletion variant and alanine mutants (I12A, V13A, V16A, L19A, I20A) are reported. In particular, we aimed at identifying crucial residues for long range communications to the catalytic site or promoting the conformational changes to switch from closed to open ApAAP conformations. Our investigation shows that the N-terminal α1-helix mediates structural intramolecular communication to the catalytic site, concurring to the maintenance of a proper functional architecture of the catalytic triad. Main determinants of the effects induced by α1-helix are a subset of hydrophobic residues (V16, L19 and I20). Moreover, a subset of residues characterized by relevant interaction networks or coupled motions have been identified, which are likely to modulate the conformational properties at the interdomain interface. PMID:22558199

  11. Gene Pyramiding of Peptidase Inhibitors Enhances Plant Resistance to the Spider Mite Tetranychus urticae

    PubMed Central

    Santamaria, Maria Estrella; Cambra, Inés; Martinez, Manuel; Pozancos, Clara; González-Melendi, Pablo; Grbic, Vojislava; Castañera, Pedro; Ortego, Felix; Diaz, Isabel

    2012-01-01

    The two-spotted spider mite Tetranychus urticae is a damaging pest worldwide with a wide range of host plants and an extreme record of pesticide resistance. Recently, the complete T. urticae genome has been published and showed a proliferation of gene families associated with digestion and detoxification of plant secondary compounds which supports its polyphagous behaviour. To overcome spider mite adaptability a gene pyramiding approach has been developed by co-expressing two barley proteases inhibitors, the cystatin Icy6 and the trypsin inhibitor Itr1 genes in Arabidopsis plants by Agrobacterium-mediated transformation. The presence and expression of both transgenes was studied by conventional and quantitative real time RT-PCR assays and by indirect ELISA assays. The inhibitory activity of cystatin and trypsin inhibitor was in vitro analysed using specific substrates. Single and double transformants were used to assess the effects of spider mite infestation. Double transformed lines showed the lowest damaged leaf area in comparison to single transformants and non-transformed controls and different accumulation of H2O2 as defence response in the leaf feeding site, detected by diaminobenzidine staining. Additionally, an impact on endogenous mite cathepsin B- and L-like activities was observed after feeding on Arabidopsis lines, which correlates with a significant increase in the mortality of mites fed on transformed plants. These effects were analysed in view of the expression levels of the target mite protease genes, C1A cysteine peptidase and S1 serine peptidase, identified in the four developmental mite stages (embryo, larvae, nymphs and adults) performed using the RNA-seq information available at the BOGAS T. urticae database. The potential of pyramiding different classes of plant protease inhibitors to prevent plant damage caused by mites as a new tool to prevent pest resistance and to improve pest control is discussed. PMID:22900081

  12. Characterization of atrial natriuretic peptide degradation by cell-surface peptidase activity on endothelial cells

    NASA Technical Reports Server (NTRS)

    Frost, S. J.; Whitson, P. A.

    1993-01-01

    Atrial natriuretic peptide (ANP) is a fluid-regulating peptide hormone that promotes vasorelaxation, natriuresis, and diuresis. The mechanisms for the release of ANP and for its clearance from the circulation play important roles in modulating its biological effects. Recently, we have reported that the cell surface of an endothelial cell line, CPA47, could degrade 125I-ANP in the presence of EDTA. In this study, we have characterized this degradation of 125I-ANP. The kinetics of ANP degradation by the surface of CPA47 cells were first order, with a Km of 320 +/- 60 nM and Vmax of 35 +/- 14 pmol of ANP degraded/10 min/10(5) cells at pH 7.4. ANP is degraded by the surface of CPA47 cells over a broad pH range from 7.0-8.5. Potato carboxypeptidase inhibitor and bestatin inhibited 125I-ANP degradation, suggesting that this degradative activity on the surface of CPA47 cells has exopeptidase characteristics. The selectivity of CPA47 cell-surface degradation of ANP was demonstrated when 125I-ANP degradation was inhibited in the presence of neuropeptide Y and angiotensin I and II but not bradykinin, bombesin, endothelin-1, or substance P. The C-terminal amino acids phe26 and tyr28 were deduced to be important for ANP interaction with the cell-surface peptidase(s) based on comparison of the IC50 of various ANP analogues and other natriuretic peptides for the inhibition of ANP degradation. These data suggest that a newly characterized divalent cation-independent exopeptidase(s) that selectively recognizes ANP and some other vasoactive peptides exists on the surface of endothelial cells.

  13. Plasmodium falciparum signal peptide peptidase cleaves malaria heat shock protein 101 (HSP101). Implications for gametocytogenesis

    SciTech Connect

    Baldwin, Michael; Russo, Crystal; Li, Xuerong; Chishti, Athar H.

    2014-08-08

    Highlights: • PfSPP is an ER resident protease. • PfSPP is expressed both as a monomer and dimer. • The signal peptide of HSP101 is the first known substrate of PfSPP. • Reduced PfSPP activity may significantly affect ER homeostasis. - Abstract: Previously we described the identification of a Plasmodium falciparum signal peptide peptidase (PfSPP) functioning at the blood stage of malaria infection. Our studies also demonstrated that mammalian SPP inhibitors prevent malaria parasite growth at the late-ring/early trophozoite stage of intra-erythrocytic development. Consistent with its role in development, we tested the hypothesis that PfSPP functions at the endoplasmic reticulum of P.falciparum where it cleaves membrane-bound signal peptides generated following the enzyme activity of signal peptidase. The localization of PfSPP to the endoplasmic reticulum was confirmed by immunofluorescence microscopy and immunogold electron microscopy. Biochemical analysis indicated the existence of monomer and dimer forms of PfSPP in the parasite lysate. A comprehensive bioinformatics screen identified several candidate PfSPP substrates in the parasite genome. Using an established transfection based in vivo luminescence assay, malaria heat shock protein 101 (HSP101) was identified as a substrate of PfSPP, and partial inhibition of PfSPP correlated with the emergence of gametocytes. This finding unveils the first known substrate of PfSPP, and provides new perspectives for the function of intra-membrane proteolysis at the erythrocyte stage of malaria parasite life cycle.

  14. Colorimetrical rate assay for urinary dipeptidyl peptidase IV (DPPIV) activity using a new substrate.

    PubMed

    Shibuya-Saruta, H; Sugiyama, M; Kasahara, Y

    1995-01-01

    We synthesized a new substrate glycyl-L-proline 3,5-dibromo-4-hydroxyanilide (Gly-Pro-DBAP), for dipeptidyl peptidase IV (DPPIV). Its hydrolysis by DPPIV resulted in the formation of a chromophore, 2,6-dibromophenol-indo-p-xylenol, and its maximal absorption wavelength (600 nm) was longer than that of p-nitroaniline (415 nm) released from conventional substrate, glycyl-L-proline p-nitroanilide (Gly-Pro-pNA). We also established the rate assay for urinary DPPIV activity using Gly-Pro-DBAP. The optimum pH was between 8.5 and 9.0. The apparent Km was 1.1 mmol/1. The detectable range was 2.5-350 U/l. No changes in blank values occurred throughout the enzyme reaction in the optimum pH. Its value was also much lower than Gly-Pro-pNA. CVs for within-run and between-run were 1.1% (n = 10) and 3.0% (n = 10), respectively. Among tested peptidases, only DPPIV could hydrolyze Gly-Pro-DBAP. Among the protease inhibitors, only two, diprotin-A and phenylmethylsulfonyl fluoride (PMSA), could inhibit DPPIV activity. The present method did not interfere with urinary ingredients such as hemoglobin. The correlation between the present (y) and conventional (x) methods is presented by the equation y = 1.121x + 0.096 (r = 0.993). Thus the present method provides practical advantages over the conventional method for routine laboratory use. PMID:7714663

  15. Optimal Redundancy Management in Reconfigurable Control Systems Based on Normalized Nonspecificity

    NASA Technical Reports Server (NTRS)

    Wu, N.Eva; Klir, George J.

    1998-01-01

    In this paper the notion of normalized nonspecificity is introduced. The nonspecifity measures the uncertainty of the estimated parameters that reflect impairment in a controlled system. Based on this notion, a quantity called a reconfiguration coverage is calculated. It represents the likelihood of success of a control reconfiguration action. This coverage links the overall system reliability to the achievable and required control, as well as diagnostic performance. The coverage, when calculated on-line, is used for managing the redundancy in the system.

  16. Nonspecific collagenolytic activity of the femoral bone in immobilized rat extremities.

    PubMed

    Prokopová, D; Tesárek, B; Susta, A

    1975-01-01

    Nonspecific collagenolytic activity was studied in rat bones after immobilization. The left hind limb was immobilized by sectioning the sciatic nerve. Enzyme activity was determined by using synthetic pentapeptide substrate (Pz-Pro-Leu-Gly-Pro-D-Arg). After immobilization the activity of nonspecific collagenase increased and reached its maximum on the third day after the operation. The activity was decreased after one week and attained levels of control bones three weeks after sciatic nerve section. PMID:167392

  17. Synthesis and biological evaluation of bicyclo[3.3.0] octane derivatives as dipeptidyl peptidase 4 inhibitors for the treatment of type 2 diabetes.

    PubMed

    Cho, Tang Peng; Gang, Lin Zhi; Long, Yang Fang; Yang, Wang; Qian, Wang; Lei, Zhang; Jing, Luo Jing; Ying, Feng; Ke, Yan Pang; Ying, Leng; Jun, Feng

    2010-06-15

    A series of novel bicyclo[3.3.0]octane derivatives have been synthesized and found to be dipeptidyl peptidase 4 (DPP-4) inhibitors. Compounds 10a and 10b demonstrate good efficacies in oral glucose tolerance tests. PMID:20488704

  18. Peptidase-1 expression in some organs of the salamander Pleurodeles waltl submitted to a 12-day space flight

    NASA Astrophysics Data System (ADS)

    Bautz, A.; Rudolf, E.; Mitashov, V.; Dournon, C.

    In Pleurodeles, the peptidase-1 is a sex-linked enzyme encoded by two codominant genes (Pep-1A and Pep-1B) located on the Z and W sex chromosomes. The sexual genotype can be determined by the electrophoretic pattern of the peptidase from erythrocytes. A_AW_B genotypic females characterized by 3 electrophoretic bands AA, AB and BB were embarked on Cosmos 2229. The pattern in ovary, muscles and gut issued from the embarked or synchrone females displayed the 3 characteristic bands. In heart and kidney, the bands AA and BB were revealed, while the band BB appeared very fainly. The specific enzymatic activity in the same organs was compared. Except for the kidney, no statistical significant difference was observed between flight and synchrone samples. This enzyme can be efficiently used as sexual genotypic marker of Pleurodeles experimentally submitted to the effects of space environment.

  19. Plasma native and peptidase-derivable Met-enkephalin responses to restraint stress in rats. Adaptation to repeated restraint.

    PubMed Central

    Pierzchala, K; Van Loon, G R

    1990-01-01

    Met-enkephalin and related proenkephalin A-derived peptides circulate in plasma at picomolar concentration as free, native pentapeptide and at nanomolar concentration in cryptic forms. We have optimized conditions for measurement of immunoreactive Met-enkephalin in plasma and for generation by trypsin and carboxypeptidase B of much greater amounts of total peptidase-derivable Met-enkephalin in plasma of rats, dogs, and humans. Free Met-enkephalin (11 pM) is constituted by native pentapeptide and its sulfoxide. Characterization of plasma total Met-enkephalin derived by peptidic hydrolysis revealed a small amount (38 pM) of Met-enkephalin associated with peptides of molecular mass less than 30,000 D, and probably derived from proenkephalin A, but much larger amounts of Met-enkephalin associated with albumin (1.2 nM) and with a globulin-sized protein (2.8 nM). Thus, plasma protein precursors for peptidase-derivable Met-enkephalin differ structurally and chemically from proenkephalin A. Met-enkephalin generated from plasma by peptidic hydrolysis showed naloxone-reversible bioactivity comparable to synthetic Met-enkephalin. Prolonged exposure of adult, male rats to restraint stress produced biphasic plasma responses, with peaks occurring at 30 s and 30 min in both free native and total peptidase-derivable Met-enkephalin. Repeated daily exposure to this 30-min stress resulted in adaptive loss of responses of both forms to acute restraint. Initial plasma responses of Met-enkephalin paralleled those of epinephrine and norepinephrine, but subsequently showed divergence of response. In conclusion, Met-enkephalin circulates in several forms, some of which may be derived from proteins other than proenkephalin A, and plasma levels of both free native, and peptidase-derivable Met-enkephalin are modulated physiologically. PMID:2312729

  20. Structure and Mechanism of Cysteine Peptidase Gingipain K (Kgp), a Major Virulence Factor of Porphyromonas gingivalis in Periodontitis*

    PubMed Central

    de Diego, Iñaki; Veillard, Florian; Sztukowska, Maryta N.; Guevara, Tibisay; Potempa, Barbara; Pomowski, Anja; Huntington, James A.; Potempa, Jan; Gomis-Rüth, F. Xavier

    2014-01-01

    Cysteine peptidases are key proteolytic virulence factors of the periodontopathogen Porphyromonas gingivalis, which causes chronic periodontitis, the most prevalent dysbiosis-driven disease in humans. Two peptidases, gingipain K (Kgp) and R (RgpA and RgpB), which differ in their selectivity after lysines and arginines, respectively, collectively account for 85% of the extracellular proteolytic activity of P. gingivalis at the site of infection. Therefore, they are promising targets for the design of specific inhibitors. Although the structure of the catalytic domain of RgpB is known, little is known about Kgp, which shares only 27% sequence identity. We report the high resolution crystal structure of a competent fragment of Kgp encompassing the catalytic cysteine peptidase domain and a downstream immunoglobulin superfamily-like domain, which is required for folding and secretion of Kgp in vivo. The structure, which strikingly resembles a tooth, was serendipitously trapped with a fragment of a covalent inhibitor targeting the catalytic cysteine. This provided accurate insight into the active site and suggested that catalysis may require a catalytic triad, Cys477-His444-Asp388, rather than the cysteine-histidine dyad normally found in cysteine peptidases. In addition, a 20-Å-long solvent-filled interior channel traverses the molecule and links the bottom of the specificity pocket with the molecular surface opposite the active site cleft. This channel, absent in RgpB, may enhance the plasticity of the enzyme, which would explain the much lower activity in vitro toward comparable specific synthetic substrates. Overall, the present results report the architecture and molecular determinants of the working mechanism of Kgp, including interaction with its substrates. PMID:25266723

  1. Beneficial Effects of HIV Peptidase Inhibitors on Fonsecaea pedrosoi: Promising Compounds to Arrest Key Fungal Biological Processes and Virulence

    PubMed Central

    Palmeira, Vanila F.; Kneipp, Lucimar F.; Rozental, Sonia; Alviano, Celuta S.; Santos, André L. S.

    2008-01-01

    Background Fonsecaea pedrosoi is the principal etiologic agent of chromoblastomycosis, a fungal disease whose pathogenic events are poorly understood. Current therapy for chromoblastomycosis is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. Compounding these problems is the fact that endemic countries and regions are economically poor. Purpose and Principal Findings In the present work, we have investigated the effect of human immunodeficiency virus (HIV) peptidase inhibitors (PIs) on the F. pedrosoi conidial secreted peptidase, growth, ultrastructure and interaction with different mammalian cells. All the PIs impaired the acidic conidial-derived peptidase activity in a dose-dependent fashion, in which nelfinavir produced the best inhibitory effect. F. pedrosoi growth was also significantly reduced upon exposure to PIs, especially nelfinavir and saquinavir. PIs treatment caused profound changes in the conidial ultrastructure as shown by transmission electron microscopy, including invaginations in the cytoplasmic membrane, disorder and detachment of the cell wall, enlargement of fungi cytoplasmic vacuoles, and abnormal cell division. The synergistic action on growth ability between nelfinavir and amphotericin B, when both were used at sub-inhibitory concentrations, was also observed. PIs reduced the adhesion and endocytic indexes during the interaction between conidia and epithelial cells (CHO), fibroblasts or macrophages, in a cell type-dependent manner. Moreover, PIs interfered with the conidia into mycelia transformation when in contact with CHO and with the susceptibility killing by macrophage cells. Conclusions/Significance Overall, by providing the first evidence that HIV PIs directly affects F. pedrosoi development and virulence, these data add new insights on the wide-spectrum efficacy of HIV PIs, further arguing for the potential chemotherapeutic targets for aspartyl-type peptidase produced by this human

  2. Structural and mutational analyses of dipeptidyl peptidase 11 from Porphyromonas gingivalis reveal the molecular basis for strict substrate specificity

    PubMed Central

    Sakamoto, Yasumitsu; Suzuki, Yoshiyuki; Iizuka, Ippei; Tateoka, Chika; Roppongi, Saori; Fujimoto, Mayu; Inaka, Koji; Tanaka, Hiroaki; Yamada, Mitsugu; Ohta, Kazunori; Gouda, Hiroaki; Nonaka, Takamasa; Ogasawara, Wataru; Tanaka, Nobutada

    2015-01-01

    The dipeptidyl peptidase 11 from Porphyromonas gingivalis (PgDPP11) belongs to the S46 family of serine peptidases and preferentially cleaves substrates with Asp/Glu at the P1 position. The molecular mechanism underlying the substrate specificity of PgDPP11, however, is unknown. Here, we report the crystal structure of PgDPP11. The enzyme contains a catalytic domain with a typical double β-barrel fold and a recently identified regulatory α-helical domain. Crystal structure analyses, docking studies, and biochemical studies revealed that the side chain of Arg673 in the S1 subsite is essential for recognition of the Asp/Glu side chain at the P1 position of the bound substrate. Because S46 peptidases are not found in mammals and the Arg673 is conserved among DPP11s, we anticipate that DPP11s could be utilised as targets for antibiotics. In addition, the present structure analyses could be useful templates for the design of specific inhibitors of DPP11s from pathogenic organisms. PMID:26057589

  3. Reduction of food intake by central administration of cholecystokinin octapeptide in the rat is dependent upon inhibition of brain peptidases.

    PubMed Central

    Griesbacher, T.; Leighton, G. E.; Hill, R. G.; Hughes, J.

    1989-01-01

    1. The effects of intracerebroventricular (i.c.v.) injections of cholecystokinin-octapeptide (CCK-8) and caerulein, an amphibian decapeptide structurally related to CCK-8, are inconsistent in the rat. We have therefore investigated the possibility that enzymatic degradation could be responsible for the lack of activity of CCK-8 seen in some studies on food intake. 2. Injections of CCK-8 at doses of 2.5 nmol and 25 nmol into the lateral cerebral ventricle of rats did not reduce the intake of a highly palatable diet whereas injections of the same doses of caerulein reduced food intake potently and dose-dependently. 3. Co-administration of CCK-8 with a combination of the peptidase inhibitors bestatin (70 nmol), captopril (100 nmol) and thiorphan (120 nmol) resulted in an inhibition of feeding similar to that seen after the injection of caerulein alone. The peptidase inhibitors alone did not affect food intake. 4. When caerulein was injected i.c.v. in combination with bestatin, captopril and thiorphan the effect of caerulein was potentiated, suggesting that enzymatic breakdown of caerulein does occur. 5. It is concluded that the effect of centrally administered CCK-8 on food intake is dependent on the activity of cleaving enzymes in the brain. It is emphasized that the action of brain peptidases is a major factor which has to be considered when investigating the role of peptides in the central nervous system. PMID:2647203

  4. Dopamine D3 receptor inhibits the ubiquitin-specific peptidase 48 to promote NHE3 degradation

    PubMed Central

    Armando, Ines; Villar, Van Anthony M.; Jones, John E.; Lee, Hewang; Wang, Xiaoyan; Asico, Laureano D.; Yu, Peiying; Yang, Jian; Escano, Crisanto S.; Pascua-Crusan, Annabelle M.; Felder, Robin A.; Jose, Pedro A.

    2014-01-01

    The dopamine D3 receptor (D3R) is crucial in the regulation of blood pressure and sodium balance, in that Drd3 gene ablation in mice results in hypertension and failure to excrete a dietary salt load. The mechanism responsible for the renal sodium retention in these mice is largely unknown. We now offer and describe a novel mechanism by which D3R decreases sodium transport in the long term by inhibiting the deubiquitinylating activity of ubiquitin-specific peptidase 48 (USP48), thereby promoting Na+-H+ exchanger (NHE)-3 degradation. We found that stimulation with the D3R-specific agonist PD128907 (1 μM, 30 min) promoted the interaction and colocalization among D3R, NHE3, and USP48; inhibited USP48 activity (−35±6%, vs. vehicle), resulting in increased ubiquitinylated NHE3 (+140±10%); and decreased NHE3 expression (−50±9%) in human renal proximal tubule cells (hRPTCs). USP48 silencing decreased NHE3's half-life (USP48 siRNA t1/2=6.1 h vs. vehicle t1/2=12.9 h), whereas overexpression of USP48 increased NHE3 half-life (t1/2=21.8 h), indicating that USP48 protects NHE3 from degradation via deubiquitinylation. USP48 accounted for ∼30% of the total deubiquitinylating activity in these cells. Extending our studies in vivo, we found that pharmacologic blockade of D3R via the D3R-specific antagonist GR103691 (1 μg/kg/min, 4 d) in C57Bl/6J mice increased renal NHE3 expression (+310±15%, vs. vehicle), whereas an innovative kidney-restricted Usp48 silencing via siRNA (3 μg/d, 7 d) increased ubiquitinylated NHE3 (+250±30%, vs. controls), decreased total NHE3 (−23±2%), and lowered blood pressure (−24±2 mm Hg), compared with that in control mice that received either the vehicle or nonsilencing siRNA. Our data demonstrate a crucial role for the dynamic interaction between D3R and USP48 in the regulation of NHE3 expression and function.—Armando, I., Villar, V. A. M., Jones J. E., Lee, H., Wang, X., Asico L. D., Yu, P., Yang, J., Escano, C. S. Jr., Pascua

  5. Identification and characterization of a cathepsin-L-like peptidase in Eimeria tenella.

    PubMed

    Liu, Renqiang; Ma, Xueting; Liu, Aijun; Zhang, Lei; Cai, Jianping; Wang, Ming

    2014-12-01

    Avian coccidiosis, caused by Eimeria spp., is one of the major parasitic diseases in birds. Cysteine protease is a major virulence factor in parasitic protozoa, and it may be a suitable chemotherapeutic target and vaccine candidate molecule. A 100 amino acid (aa.) partial sequence of cathepsin L, which is a cysteine protease, was reported by Katrib et al. (Ac. No. CDJ41293) (2012). A 219 aa. sequence was reported by Reid et al. (Ac. No. AFV92863) (2013). However, the open reading frame (ORF) was not reported. In this study, a full sequence of a cathepsin-L-like peptidase in Eimeria tenella (EtcatL) was obtained and its biochemical characterizations and expression profiles were analyzed across different stages of the parasite's life cycle. Results showed that the EtcatL gene encodes a protein 470 aa. in length, with 47 and 49% identity to Toxoplasma gondii and Eimeria acervulina. Considering the close phylogenetic relationship, TgcatL (PDB. ID 3F75) was selected for use as a template for homology modeling with quality factors of 90.9. Gelatin SDS-PAGE showed it to exert protease activity at ≈38 and ≈26 kDa. Further analysis showed the kinetic parameters of the recombinant peptidase to be K m  = 8.9 μM and V max = 5.7 RFU/s μM at pH 5.5 containing 10 mM dithiothreitol (DTT) in the reaction matrix, and the IC50 value of E64 was 65.32 ± 3.02 nM. The recombinant protein was active from 25 to 50 °C, with optimal activity at 42 °C. The RT-PCR and Western blot results showed it to be expressed mainly at the endogenous stages and the initial phase of the sporulation. The protective experiment showed that chickens immunized with 100 and 200 μg rEtcatL had reduction of weight loss values 48.7 and 57.9% those of infected controls, respectively. Their reduction of lesion scores (RLS) were 25.0 and 47.2% that of control chickens, and relative oocyst production (ROP) was 39.6 and 15.5% that of control chickens. These results indicate that the EtcatL can be

  6. Microbe-dependent and nonspecific effects of procedures to eliminate the resident microbiota from Drosophila melanogaster.

    PubMed

    Ridley, Emma V; Wong, Adam C N; Douglas, Angela E

    2013-05-01

    Comparisons of animals bearing and lacking microorganisms can offer valuable insight into the interactions between animal hosts and their resident microbiota. Most hosts are naturally infected, and therefore, these comparisons require specific procedures (e.g., antibiotic treatment or physical exclusion of microorganisms) to disrupt the microbiota, but the potential for confounding nonspecific effects of the procedure on the traits of the host exists. Microbe-dependent and nonspecific effects can be discriminated by using multiple procedures: microbe-dependent effects are evident in hosts made microbe free by different procedures, but nonspecific effects are unique to individual procedures. As a demonstration, two procedures, oral administration of chlortetracycline (50 μg ml(-1) diet) and microbiota removal by egg dechorionation, were applied to Drosophila melanogaster in a 2-by-2 factorial design. Microorganisms were undetectable in flies from dechorionated eggs and reduced by >99% in chlortetracycline-treated flies. Drosophila flies subjected to both protocols displayed an extended preadult development time, suggesting that the microbiota promotes the development rate. Female chlortetracycline-treated flies, whether from untreated or dechorionated eggs, displayed reduced protein content and egg fecundity, which could be attributed to the nonspecific effect of the antibiotic. We recommend that procedures used to disrupt the microbiota of animals should be selected, following systematic analysis of alternative mechanistically distinct procedures, on the basis of two criteria: those that achieve the greatest reduction (ideally, elimination) of the microbiota and those that achieve minimal nonspecific effects. PMID:23475620

  7. Self-harm to preferentially harm the pathogens within: non-specific stressors in innate immunity.

    PubMed

    LeGrand, Edmund K; Day, Judy D

    2016-04-13

    Therapies with increasing specificity against pathogens follow the immune system's evolutionary course in maximizing host defence while minimizing self-harm. Nevertheless, even completely non-specific stressors, such as reactive molecular species, heat, nutrient and oxygen deprivation, and acidity can be used to preferentially harm pathogens. Strategic use of non-specific stressors requires exploiting differences in stress vulnerability between pathogens and hosts. Two basic vulnerabilities of pathogens are: (i) the inherent vulnerability to stress of growth and replication (more immediately crucial for pathogens than for host cells) and (ii) the degree of pathogen localization, permitting the host's use of locally and regionally intense stress. Each of the various types of non-specific stressors is present during severe infections at all levels of localization: (i) ultra-locally within phagolysosomes, (ii) locally at the infected site, (iii) regionally around the infected site and (iv) systemically as part of the acute-phase response. We propose that hosts strategically use a coordinated system of non-specific stressors at local, regional and systemic levels to preferentially harm the pathogens within. With the rising concern over emergence of resistance to specific therapies, we suggest more scrutiny of strategies using less specific therapies in pathogen control. Hosts' active use of multiple non-specific stressors is likely an evolutionarily basic defence whose retention underlies and supplements the well-recognized immune defences that directly target pathogens. PMID:27075254

  8. Self-harm to preferentially harm the pathogens within: non-specific stressors in innate immunity

    PubMed Central

    2016-01-01

    Therapies with increasing specificity against pathogens follow the immune system's evolutionary course in maximizing host defence while minimizing self-harm. Nevertheless, even completely non-specific stressors, such as reactive molecular species, heat, nutrient and oxygen deprivation, and acidity can be used to preferentially harm pathogens. Strategic use of non-specific stressors requires exploiting differences in stress vulnerability between pathogens and hosts. Two basic vulnerabilities of pathogens are: (i) the inherent vulnerability to stress of growth and replication (more immediately crucial for pathogens than for host cells) and (ii) the degree of pathogen localization, permitting the host's use of locally and regionally intense stress. Each of the various types of non-specific stressors is present during severe infections at all levels of localization: (i) ultra-locally within phagolysosomes, (ii) locally at the infected site, (iii) regionally around the infected site and (iv) systemically as part of the acute-phase response. We propose that hosts strategically use a coordinated system of non-specific stressors at local, regional and systemic levels to preferentially harm the pathogens within. With the rising concern over emergence of resistance to specific therapies, we suggest more scrutiny of strategies using less specific therapies in pathogen control. Hosts' active use of multiple non-specific stressors is likely an evolutionarily basic defence whose retention underlies and supplements the well-recognized immune defences that directly target pathogens. PMID:27075254

  9. Nonspecific interstitial pneumonitis: a common cause of pulmonary disease in the acquired immunodeficiency syndrome

    SciTech Connect

    Suffredini, A.F.; Ognibene, F.P.; Lack, E.E.; Simmons, J.T.; Brenner, M.; Gill, V.J.; Lane, H.C.; Fauci, A.S.; Parrillo, J.E.; Masur, H.

    1987-07-01

    During a 4.4-year period, nonspecific interstitial pneumonitis was seen in 41 of 110 (38%) patients with the acquired immunodeficiency syndrome and accounted for 32% (48/152) of all episodes of clinical pneumonitis. Diffuse alveolar damage was typically a feature of nonspecific interstitial pneumonitis, but neither lung biopsy nor bronchoalveolar lavage detected a pathogen. Of these 41 patients, 13 had no associated pulmonary tumor and had not been exposed to pulmonary toxins, whereas 28 patients had either concurrent pulmonary Kaposi sarcoma, previous experimental therapies, or a history of pneumocystis pneumonia or drug abuse. Of these 41, 23 had normal chest radiographs. The clinical features of patients with nonspecific interstitial pneumonitis were similar to those of patients with pneumocystis pneumonia, although histologic findings showed less severe alveolar damage in patients with nonspecific interstitial pneumonitis (p less than 0.001). Pathologic evaluation and clinical follow-up suggest that many clinical episodes of pneumonitis in patients with the acquired immunodeficiency syndrome are due to nonspecific interstitial pneumonitis of unknown cause.

  10. The Stimulation by Endotoxin of the Nonspecific Resistance of Mice to Bacterial Infections

    PubMed Central

    Hill, A. W.; Hibbitt, K. G.; Shears, A.

    1974-01-01

    The nonspecific resistance of mice to challenge was enhanced following the administration of an E. coli O55 B5 endotoxin. Although the route of administration of the endotoxin and the challenge organism were varied, the nonspecific resistance of the animal was enhanced in all the experiments. The efficiency of this resistance was highest when the inducing substance and the challenge dose of bacteria were administered intraperitoneally. Poly I: C and double stranded RNA were also studied but were much less effective than endotoxin in stimulating a resistance to infection. Stimulation of the fixed macrophages could not explain fully the enhanced resistance, since the clearance rates of colloidal carbon and radioactively labelled bacteria from the blood were not significantly enhanced after the administration of endotoxin. Furthermore, splenectomized animals, and animals injected with agents which interfere with the RES activity, trypan blue and corticosteroids, still developed a degree of nonspecific resistance to infection. PMID:4599349

  11. Tuneable surface shear forces to physically displace nonspecific molecules in protein biomarker detection.

    PubMed

    Vaidyanathan, Ramanathan; Rauf, Sakandar; Shiddiky, Muhammad J A; Trau, Matt

    2014-11-15

    We report a simple method to remove nonspecifically adsorbed species from sensor surface and also improve the detection sensitivity of the sensor using tuneable alternating current (ac) electrohydrodynamics (ac-EHD) forces. These forces generated within few nanometers of an electrode surface (i.e., double layer) engender fluid flow within a serpentine channel containing a long array of the asymmetric electrode pairs, and can easily be tuned externally by changing the frequency and amplitude of the ac-EHD field. Under the optimized experimental conditions, we achieved a 3.5-fold reduction in nonspecific adsorption of non-target proteins with a 1000-fold enhancement in detection sensitivity of the device for the analysis of human epidermal growth factor receptor 2 (HER2) protein spiked in serum. This approach can be applicable in diverse fields including biosensors, cellular and molecular separation systems and biomedical applications to remove/reduce nonspecific adsorption of molecular and cellular species. PMID:24880656

  12. Emerging role of dipeptidyl peptidase-4 inhibitors in the management of type 2 diabetes

    PubMed Central

    Richter, Bernd; Bandeira-Echtler, Elizabeth; Bergerhoff, Karla; Lerch, Christian

    2008-01-01

    Background: In type 2 diabetes mellitus (T2DM) there is a progressive loss of β-cell function. One new approach yielding promising results is the use of the orally active dipeptidyl peptidase-4 (DPP-4) inhibitors. However, every new compound for T2DM has to prove long-term safety especially on cardiovascular outcomes. Objectives: Systematic review and meta-analysis of the effects of sitagliptin and vildagliptin therapy on main efficacy parameters and safety. Selection criteria, data collection, and analysis: Randomized controlled clinical studies of at least 12 weeks’ duration in T2DM. Results: DPP-4 inhibitors versus placebo showed glycosylated hemoglobin A1c(A1c) improvements of 0.7% versus placebo but not compared to monotherapy with other hypoglycemic agents (0.3% in favor of controls). The overall risk profile of DPP-4 inhibitors was low, however a 34% relative risk increase (95% confidence interval 10% to 64%, P = 0.004) was noted for all cause infection associated with sitagliptin use. No data on immune function, health-related quality of life and diabetic complications could be extracted. Conclusions: DPP-4 inhibitors have some theoretical advantages over existing therapies with oral antidiabetic compounds but should currently be restricted to individual patients. Long-term data on cardiovascular outcomes and safety are needed before widespread use of these new agents. PMID:19065993

  13. Kallikrein-related peptidase 8 is expressed in myocardium and induces cardiac hypertrophy

    PubMed Central

    Cao, Buqing; Yu, Qing; Zhao, Wei; Tang, Zhiping; Cong, Binghai; Du, Jiankui; Lu, Jianqiang; Zhu, Xiaoyan; Ni, Xin

    2016-01-01

    The tissue kallikrein-related peptidase family (KLK) is a group of trypsin- and chymotrypsin-like serine proteases that share a similar homology to parent tissue kallikrein (KLK1). KLK1 is identified in heart and has anti-hypertrophic effects. However, whether other KLK family members play a role in regulating cardiac function remains unknown. In the present study, we demonstrated for the first time that KLK8 was expressed in myocardium. KLK8 expression was upregulated in left ventricle of cardiac hypertrophy models. Both intra-cardiac adenovirus-mediated and transgenic-mediated KLK8 overexpression led to cardiac hypertrophy in vivo. In primary neonatal rat cardiomyocytes, KLK8 knockdown inhibited phenylephrine (PE)-induced cardiomyocyte hypertrophy, whereas KLK8 overexpression promoted cardiomyocyte hypertrophy via a serine protease activity-dependent but kinin receptor-independent pathway. KLK8 overexpression increased epidermal growth factor (EGF) production, which was blocked by the inhibitors of serine protease. EGF receptor (EGFR) antagonist and EGFR knockdown reversed the hypertrophy induced by KLK8 overexpression. KLK8-induced cardiomyocyte hypertrophy was also significantly decreased by blocking the protease-activated receptor 1 (PAR1) or PAR2 pathway. Our data suggest that KLK8 may promote cardiomyocyte hypertrophy through EGF signaling- and PARs-dependent but a kinin receptor-independent pathway. It is implied that different KLK family members can subtly regulate cardiac function and remodeling. PMID:26823023

  14. Rhizobial peptidase HrrP cleaves host-encoded signaling peptides and mediates symbiotic compatibility

    PubMed Central

    Price, Paul A.; Tanner, Houston R.; Dillon, Brett A.; Shabab, Mohammed; Walker, Graham C.; Griffitts, Joel S.

    2015-01-01

    Legume–rhizobium pairs are often observed that produce symbiotic root nodules but fail to fix nitrogen. Using the Sinorhizobium meliloti and Medicago truncatula symbiotic system, we previously described several naturally occurring accessory plasmids capable of disrupting the late stages of nodule development while enhancing bacterial proliferation within the nodule. We report here that host range restriction peptidase (hrrP), a gene found on one of these plasmids, is capable of conferring both these properties. hrrP encodes an M16A family metallopeptidase whose catalytic activity is required for these symbiotic effects. The ability of hrrP to suppress nitrogen fixation is conditioned upon the genotypes of both the host plant and the hrrP-expressing rhizobial strain, suggesting its involvement in symbiotic communication. Purified HrrP protein is capable of degrading a range of nodule-specific cysteine-rich (NCR) peptides encoded by M. truncatula. NCR peptides are crucial signals used by M. truncatula for inducing and maintaining rhizobial differentiation within nodules, as demonstrated in the accompanying article [Horváth B, et al. (2015) Proc Natl Acad Sci USA, 10.1073/pnas.1500777112]. The expression pattern of hrrP and its effects on rhizobial morphology are consistent with the NCR peptide cleavage model. This work points to a symbiotic dialogue involving a complex ensemble of host-derived signaling peptides and bacterial modifier enzymes capable of adjusting signal strength, sometimes with exploitative outcomes. PMID:26401024

  15. Inhibition of dipeptidyl peptidase 4 regulates microvascular endothelial growth induced by inflammatory cytokines

    SciTech Connect

    Takasawa, Wataru; Ohnuma, Kei; Hatano, Ryo; Endo, Yuko; Dang, Nam H.

    2010-10-08

    Research highlights: {yields} TNF-{alpha} or IL-1{beta} induces EC proliferation with reduction of CD26 expression. {yields} CD26 siRNA or DPP-4 inhibition enhances TNF-{alpha} or IL-1{beta}-induced EC proliferation. {yields} Loss of CD26/DPP-4 enhances aortic sprouting induced by TNF-{alpha} or IL-1{beta}. {yields} Capillary formation induced by TNF-{alpha} or IL-1{beta} is enahced in the CD26{sup -/-} mice. -- Abstract: CD26/DPP-4 is abundantly expressed on capillary of inflamed lesion as well as effector T cells. Recently, CD26/dipeptidyl peptidase 4 (DPP-4) inhibition has been used as a novel oral therapeutic approach for patients with type 2 diabetes. While accumulating data indicate that vascular inflammation is a key feature of both micro- and macro-vascular complications in diabetes, the direct role of CD26/DPP-4 in endothelial biology is to be elucidated. We herein showed that proinflammatory cytokines such as tumor necrosis factor or interleukin-1 reduce expression of CD26 on microvascular endothelial cells, and that genetical or pharmacological inhibition of CD26/DPP-4 enhances endothelial growth both in vitro and in vivo. With DPP-4 inhibitors being used widely in the treatment of type 2 diabetes, our data strongly suggest that DPP-4 inhibition plays a pivotal role in endothelial growth and may have a potential role in the recovery of local circulation following diabetic vascular complications.

  16. Signal peptide peptidase (SPP) assembles with substrates and misfolded membrane proteins into distinct oligomeric complexes

    PubMed Central

    Schrul, Bianca; Kapp, Katja; Sinning, Irmgard; Dobberstein, Bernhard

    2010-01-01

    SPP (signal peptide peptidase) is an aspartyl intramembrane cleaving protease, which processes a subset of signal peptides, and is linked to the quality control of ER (endoplasmic reticulum) membrane proteins. We analysed SPP interactions with signal peptides and other membrane proteins by co-immunoprecipitation assays. We found that SPP interacts specifically and tightly with a large range of newly synthesized membrane proteins, including signal peptides, preproteins and misfolded membrane proteins, but not with all co-expressed type II membrane proteins. Signal peptides are trapped by the catalytically inactive SPP mutant SPPD/A. Preproteins and misfolded membrane proteins interact with both SPP and the SPPD/A mutant, and are not substrates for SPP-mediated intramembrane proteolysis. Proteins interacting with SPP are found in distinct complexes of different sizes. A signal peptide is mainly trapped in a 200 kDa SPP complex, whereas a preprotein is predominantly found in a 600 kDa SPP complex. A misfolded membrane protein is detected in 200, 400 and 600 kDa SPP complexes. We conclude that SPP not only processes signal peptides, but also collects preproteins and misfolded membrane proteins that are destined for disposal. PMID:20196774

  17. Signal peptide peptidase functions in ERAD to cleave the unfolded protein response regulator XBP1u.

    PubMed

    Chen, Chia-yi; Malchus, Nicole S; Hehn, Beate; Stelzer, Walter; Avci, Dönem; Langosch, Dieter; Lemberg, Marius K

    2014-11-01

    Signal peptide peptidase (SPP) catalyzes intramembrane proteolysis of signal peptides at the endoplasmic reticulum (ER), but has also been suggested to play a role in ER-associated degradation (ERAD). Here, we show that SPP forms a complex with the ERAD factor Derlin1 and the E3 ubiquitin ligase TRC8 to cleave the unfolded protein response (UPR) regulator XBP1u. Cleavage occurs within a so far unrecognized type II transmembrane domain, which renders XBP1u as an SPP substrate through specific sequence features. Additionally, Derlin1 acts in the complex as a substrate receptor by recognizing the luminal tail of XBP1u. Remarkably, this interaction of Derlin1 with XBP1u obviates the need for ectodomain shedding prior to SPP cleavage, commonly required for intramembrane cuts. Furthermore, we show that XBP1u inhibits the UPR transcription factor XBP1s by targeting it toward proteasomal degradation. Thus, we identify an ERAD complex that controls the abundance of XBP1u and thereby tunes signaling through the UPR. PMID:25239945

  18. Signal peptide peptidase functions in ERAD to cleave the unfolded protein response regulator XBP1u

    PubMed Central

    Chen, Chia-yi; Malchus, Nicole S; Hehn, Beate; Stelzer, Walter; Avci, Dönem; Langosch, Dieter; Lemberg, Marius K

    2014-01-01

    Signal peptide peptidase (SPP) catalyzes intramembrane proteolysis of signal peptides at the endoplasmic reticulum (ER), but has also been suggested to play a role in ER-associated degradation (ERAD). Here, we show that SPP forms a complex with the ERAD factor Derlin1 and the E3 ubiquitin ligase TRC8 to cleave the unfolded protein response (UPR) regulator XBP1u. Cleavage occurs within a so far unrecognized type II transmembrane domain, which renders XBP1u as an SPP substrate through specific sequence features. Additionally, Derlin1 acts in the complex as a substrate receptor by recognizing the luminal tail of XBP1u. Remarkably, this interaction of Derlin1 with XBP1u obviates the need for ectodomain shedding prior to SPP cleavage, commonly required for intramembrane cuts. Furthermore, we show that XBP1u inhibits the UPR transcription factor XBP1s by targeting it toward proteasomal degradation. Thus, we identify an ERAD complex that controls the abundance of XBP1u and thereby tunes signaling through the UPR. PMID:25239945

  19. Dipeptidyl peptidase-4 inhibitors and fracture risk: an updated meta-analysis of randomized clinical trials

    PubMed Central

    Fu, Jianying; Zhu, Jianhong; Hao, Yehua; Guo, Chongchong; Zhou, Zhikun

    2016-01-01

    Data on the effects of dipeptidyl peptidase-4 (DPP-4) inhibitors on fracture risk are conflicting. Here, we performed a systematic review and meta-analysis of randomized controlled trials (RCTs) assessing the effects of DPP-4 inhibitors. Electronic databases were searched for relevant published articles, and unpublished studies presented at ClinicalTrials.gov were searched for relevant clinical data. Eligible studies included prospective randomized trials evaluating DPP-4 inhibitors versus placebo or other anti-diabetic medications in patients with type 2 diabetes. Study quality was determined using Jadad scores. Statistical analyses were performed to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) using fixed-effects models. There were 62 eligible RCTs with 62,206 participants, including 33,452 patients treated with DPP-4 inhibitors. The number of fractures was 364 in the exposed group and 358 in the control group. The overall risk of fracture did not differ between patients exposed to DPP-4 inhibitors and controls (RR, 0.95; 95% CI, 0.83–1.10; P = 0.50). The results were consistent across subgroups defined by type of DPP-4 inhibitor, type of control, and length of follow-up. The study showed that DPP-4 inhibitor use does not modify the risk of bone fracture compared with placebo or other anti-diabetic medications in patients with type 2 diabetes. PMID:27384445

  20. Dipeptidyl peptidase-4 inhibition by Pterocarpus marsupium and Eugenia jambolana ameliorates streptozotocin induced Alzheimer's disease.

    PubMed

    Kosaraju, Jayasankar; Madhunapantula, Subbarao V; Chinni, Santhivardhan; Khatwal, Rizwan Basha; Dubala, Anil; Muthureddy Nataraj, Satish Kumar; Basavan, Duraiswamy

    2014-07-01

    Alzheimer's disease (AD), the most common form of dementia, is characterized by the loss of normal functions of brain cells and neuronal death, ultimately leading to memory loss. Recent accumulating evidences have demonstrated the therapeutic potential of anti-diabetic agents, such as dipeptidyl peptidase-4 (DPP-4) inhibitors, for the treatment of Alzheimer's disease (AD), providing opportunities to explore and test the DPP-4 inhibitors for treating this fatal disease. Prior studies determining the efficacy of Pterocarpus marsupium (PM, Fabaceae) and Eugenia jambolana (EJ, Myrtaceae) extracts for ameliorating type 2 diabetes have demonstrated the DPP-4 inhibitory properties indicating the possibility of using of these extracts even for the treating AD. Therefore, in the present study, the neuroprotective roles of PM and EJ for ameliorating the streptozotocin (STZ) induced AD have been tested in rat model. Experimentally, PM and EJ extracts, at a dose range of 200 and 400mg/kg, were administered orally to STZ induced AD Wistar rats and cognitive evaluation tests were performed using radial arm maze and hole-board apparatus. Following 30 days of treatment with the extracts, a dose- and time-dependent attenuation of AD pathology, as evidenced by decreasing amyloid beta 42, total tau, phosphorylated tau and neuro-inflammation with an increase in glucagon-like peptide-1 (GLP-1) levels was observed. Therefore, PM and EJ extracts contain cognitive enhancers as well as neuroprotective agents against STZ induced AD. PMID:24667360

  1. Cleavage by signal peptide peptidase is required for the degradation of selected tail-anchored proteins

    PubMed Central

    Boname, Jessica M.; Bloor, Stuart; Wandel, Michal P.; Nathan, James A.; Antrobus, Robin; Dingwell, Kevin S.; Thurston, Teresa L.; Smith, Duncan L.; Smith, James C.; Randow, Felix

    2014-01-01

    The regulated turnover of endoplasmic reticulum (ER)–resident membrane proteins requires their extraction from the membrane lipid bilayer and subsequent proteasome-mediated degradation. Cleavage within the transmembrane domain provides an attractive mechanism to facilitate protein dislocation but has never been shown for endogenous substrates. To determine whether intramembrane proteolysis, specifically cleavage by the intramembrane-cleaving aspartyl protease signal peptide peptidase (SPP), is involved in this pathway, we generated an SPP-specific somatic cell knockout. In a stable isotope labeling by amino acids in cell culture–based proteomics screen, we identified HO-1 (heme oxygenase-1), the rate-limiting enzyme in the degradation of heme to biliverdin, as a novel SPP substrate. Intramembrane cleavage by catalytically active SPP provided the primary proteolytic step required for the extraction and subsequent proteasome-dependent degradation of HO-1, an ER-resident tail-anchored protein. SPP-mediated proteolysis was not limited to HO-1 but was required for the dislocation and degradation of additional tail-anchored ER-resident proteins. Our study identifies tail-anchored proteins as novel SPP substrates and a specific requirement for SPP-mediated intramembrane cleavage in protein turnover. PMID:24958774

  2. Membrane-associated transcription factor peptidase, site-2 protease, antagonizes ABA signaling in Arabidopsis.

    PubMed

    Zhou, Shun-Fan; Sun, Le; Valdés, Ana Elisa; Engström, Peter; Song, Ze-Ting; Lu, Sun-Jie; Liu, Jian-Xiang

    2015-10-01

    Abscisic acid plays important roles in maintaining seed dormancy while gibberellins (GA) and other phytohormones antagonize ABA to promote germination. However, how ABA signaling is desensitized during the transition from dormancy to germination is still poorly understood. We functionally characterized the role of membrane-associated transcription factor peptidase, site-2 protease (S2P), in ABA signaling during seed germination in Arabidopsis. Genetic analysis showed that loss-of-function of S2P conferred high ABA sensitivity during seed germination, and expression of the activated form of membrane-associated transcription factor bZIP17, in which the transmembrane domain and endoplasmic reticulum (ER) lumen-facing C-terminus were deleted, in the S2P mutant rescued its ABA-sensitive phenotype. MYC and green fluorescent protein (GFP)-tagged bZIP17 were processed and translocated from the ER to the nucleus in response to ABA treatment. Furthermore, genes encoding negative regulators of ABA signaling, such as the transcription factor ATHB7 and its target genes HAB1, HAB2, HAI1 and AHG3, were up-regulated in seeds of the wild-type upon ABA treatment; this up-regulation was impaired in seeds of S2P mutants. Our results suggest that S2P desensitizes ABA signaling during seed germination through regulating the activation of the membrane-associated transcription factor bZIP17 and therefore controlling the expression level of genes encoding negative regulators of ABA signaling. PMID:25919792

  3. The Role of Dipeptidyl Peptidase – 4 Inhibitors in Diabetic Kidney Disease

    PubMed Central

    Panchapakesan, Usha; Pollock, Carol

    2015-01-01

    Despite major advances in the understanding of the molecular mechanisms that underpin the development of diabetic kidney disease, current best practice still leaves a significant proportion of patients with end-stage kidney disease requiring renal replacement therapy. This is on a background of an increasing diabetes epidemic worldwide. Although kidney failure is a major cause of morbidity the main cause of death remains cardiovascular in nature. Hence, diabetic therapies which are both “cardio-renal” protective seem the logical way forward. In this review, we discuss the dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4inh), which are glucose-lowering agents used clinically and their role in diabetic kidney disease with specific focus on renoprotection and surrogate markers of cardiovascular disease. We highlight the novel pleiotropic effects of DPP4 that make it an attractive additional target to combat the fibrotic and inflammatory pathways in diabetic kidney disease and also discuss the current literature on the cardiovascular safety profile of DPP4inh. Clearly, these observed renoprotective effects will need to be confirmed by clinical trials to determine whether they translate into beneficial effects to patients with diabetes. PMID:26379674

  4. Molecular insights into mechanisms of intramembrane proteolysis through signal peptide peptidase (SPP).

    PubMed

    Schröder, Bernd; Saftig, Paul

    2010-05-01

    The processing of membrane-anchored signalling molecules and transcription factors by RIP (regulated intramembrane proteolysis) is a major signalling paradigm in eukaryotic cells. Intramembrane cleaving proteases liberate fragments from membrane-bound precursor proteins which typically fulfil functions such as cell signalling and regulation, immunosurveillance and intercellular communication. Furthermore, they are thought to be involved in the development and propagation of several diseases, such as Alzheimer's disease and hepatitis C virus infection. In this issue of the Biochemical Journal, Schrul and colleagues investigate the interaction of the endoplasmic reticulum-resident intramembrane cleaving SPP (signal peptide peptidase) with different type II oriented transmembrane proteins. A combination of co-immunoprecipitation experiments using wild-type and a dominant-negative SPP with electrophoretic protein separations under native conditions revealed selectivity of the interaction. Depending on the interacting protein, SPP formed complexes of different sizes. SPP could build tight interactions not only with signal peptides, but also with pre- and mis-folded proteins. Whereas signal peptides are direct substrates for SPP proteolysis, the study suggests that SPP may be involved in the controlled sequestration of possibly toxic membrane protein species in a proteolysis-independent manner. These large oligomeric membrane protein aggregates may then be degraded by the proteasome or autophagy. PMID:20388122

  5. Dipeptidyl Peptidase 4 Distribution in the Human Respiratory Tract: Implications for the Middle East Respiratory Syndrome.

    PubMed

    Meyerholz, David K; Lambertz, Allyn M; McCray, Paul B

    2016-01-01

    Dipeptidyl peptidase 4 (DPP4, CD26), a type II transmembrane ectopeptidase, is the receptor for the Middle Eastern respiratory syndrome coronavirus (MERS-CoV). MERS emerged in 2012 and has a high mortality associated with severe lung disease. A lack of autopsy studies from MERS fatalities has hindered understanding of MERS-CoV pathogenesis. We investigated the spatial and cellular localization of DPP4 to evaluate an association MERS clinical disease. DPP4 was rarely detected in the surface epithelium from nasal cavity to conducting airways with a slightly increased incidence in distal airways. DPP4 was also found in a subset of mononuclear leukocytes and in serous cells of submucosal glands. In the parenchyma, DPP4 was found principally in type I and II cells and alveolar macrophages and was also detected in vascular endothelium (eg, lymphatics) and pleural mesothelia. Patients with chronic lung disease, such as chronic obstructive pulmonary disease and cystic fibrosis, exhibited increased DPP4 immunostaining in alveolar epithelia (type I and II cells) and alveolar macrophages with similar trends in reactive mesothelia. This finding suggests that preexisting pulmonary disease could increase MERS-CoV receptor abundance and predispose individuals to MERS morbidity and mortality, which is consistent with current clinical observations. We speculate that the preferential spatial localization of DPP4 in alveolar regions may explain why MERS is characterized by lower respiratory tract disease. PMID:26597880

  6. The dipeptidyl peptidase-4 inhibitor sitagliptin suppresses mouse colon tumorigenesis in type 2 diabetic mice.

    PubMed

    Yorifuji, Naoki; Inoue, Takuya; Iguchi, Munetaka; Fujiwara, Kaori; Kakimoto, Kazuki; Nouda, Sadaharu; Okada, Toshihiko; Kawakami, Ken; Abe, Yosuke; Takeuchi, Toshihisa; Higuchi, Kazuhide

    2016-02-01

    Patients with type 2 diabetes mellitus are known to have an increased risk of colorectal neoplasia. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been used as a new therapeutic tool for type 2 diabetes. Since the substrates for DPP-4 include intestinotrophic hormones and chemokines such as GLP-2 and stromal cell-derived factor-1 (SDF-1), which are associated with tumor progression, DPP-4 inhibitors may increase the risk of colorectal tumors. However, the influence of DPP-4 inhibitors on colorectal neoplasia in patients with type 2 diabetes remains unknown. In the present study, we show that long-term administration of a DPP-4 inhibitor, sitagliptin (STG), suppressed colon carcinogenesis in leptin-deficient (ob/ob) C57BL/6J mice. Colonic mucosal concentrations of glucagon‑like peptide-1 (GLP-1) and GLP-2 were significantly elevated in the ob/ob mice. However, mucosal GLP concentrations and the plasma level of SDF-1 were not affected by the administration of STG. Real‑time PCR analysis revealed that colonic mucosal IL-6 mRNA expression, which was significantly upregulated in the ob/ob mice, was significantly suppressed by the long-term administration of STG. These results suggest that a DPP-4 inhibitor may suppress colon carcinogenesis in mice with type 2 diabetes in a GLP-independent manner. Since DPP-4 has multiple biological functions, further studies analyzing other factors related to colon carcinogenesis are needed. PMID:26573958

  7. Prostate Cancer-Associated Kallikrein-Related Peptidase 4 Activates Matrix Metalloproteinase-1 and Thrombospondin-1.

    PubMed

    Fuhrman-Luck, Ruth A; Stansfield, Scott H; Stephens, Carson R; Loessner, Daniela; Clements, Judith A

    2016-08-01

    Prostate cancer metastasis to bone is terminal; thus, novel therapies are required to prevent end-stage disease. Kallikrein-related peptidase 4 (KLK4) is a serine protease that is overproduced in localized prostate cancer and is abundant in prostate cancer bone metastases. In vitro, KLK4 induces tumor-promoting phenotypes; however, the underlying proteolytic mechanism is undefined. The protein topography and migration analysis platform (PROTOMAP) was used for high-depth identification of KLK4 substrates secreted by prostate cancer bone metastasis-derived PC-3 cells to delineate the mechanism of KLK4 action in advanced prostate cancer. Thirty-six putative novel substrates were determined from the PROTOMAP analysis. In addition, KLK4 cleaved the established substrate, urokinase-type plasminogen activator, thus validating the approach. KLK4 activated matrix metalloproteinase-1 (MMP1), a protease that promotes prostate tumor growth and metastasis. MMP1 was produced in the tumor compartment of prostate cancer bone metastases, highlighting its accessibility to KLK4 at this site. KLK4 further liberated an N-terminal product, with purported angiogenic activity, from thrombospondin-1 (TSP1) and cleaved TSP1 in an osteoblast-derived matrix. This is the most comprehensive analysis of the proteolytic action of KLK4 in an advanced prostate cancer model to date, highlighting KLK4 as a potential multifunctional regulator of prostate cancer progression. PMID:27378148

  8. A misassembled transmembrane domain of a polytopic protein associates with signal peptide peptidase

    PubMed Central

    2004-01-01

    The endoplasmic reticulum (ER) exerts a quality control over newly synthesized proteins and a variety of components have been implicated in the specific recognition of aberrant or misfolded polypeptides. We have exploited a site-specific cross-linking approach to search for novel ER components that may specifically recognize the misassembled transmembrane domains present in truncated polytopic proteins. We find that a single probe located in the transmembrane domain of a truncated opsin fragment is cross-linked to several ER proteins. These components are distinct from subunits of the Sec61 complex and represent a ‘post-translocon’ environment. In this study, we identify one of these post-translocon cross-linking partners as the signal peptide peptidase (SPP). We find that the interaction of truncated opsin chains with SPP is mediated by its second transmembrane domain, and propose that this interaction may contribute to the recognition of misassembled transmembrane domains during membrane protein quality control at the ER. PMID:15373738

  9. Characterization of a cellular immunostimulating peptide from a soybean protein fraction digested with peptidase R.

    PubMed

    Egusa, Shintaro; Otani, Hajime

    2009-01-01

    An immunostimulating glutamine-rich peptide was purified from a soybean protein fraction digested with Peptidase R produced by Rhizopus oryzae (Ro-digest) by a combination of SP-Sepharose column chromatography and reversed-phase high-performance liquid chromatography. The purified peptide was supposed to be located at or near the glutamine-rich region 202 to 222 of the glycinin G4 subunit. The peptide significantly increased the number of CD8(+), CD11b(+), and CD49b(+) cells in C3H/HeN mouse spleen cell cultures, while 2 chemically synthesized glutamine-rich peptides corresponding to residues 202 to 213 (QQQQQQKSHGGR) and residues 214 to 225 (KQGQHQQEEEEE) of the glycinin G4 subunit increased the number of interleukin (IL)-12(+)CD11b(+) cells. The peptide 202-213 also significantly increased the number of CD49b(+), IL-2(+)CD4(+), and interferon-gamma(+)CD4(+) cells and stimulated the cytotoxic activity of spleen cells toward the human erythroleukemia cell line K562. These results indicate that the glutamine-rich region of the soybean glycinin G4 subunit stimulates the cellular immune system in mouse spleen cell cultures. PMID:19926930

  10. Isolation and characterisation of dipeptidyl peptidase IV from Prevotella loescheii ATCC 15930.

    PubMed

    Koreeda, Y; Hayakawa, M; Ikemi, T; Abiko, Y

    2001-08-01

    A proline-specific dipeptidyl aminopeptidase, dipeptidyl peptidase IV (EC 3.4.14.5), was purified from a cell sonicate soluble fraction of Prevotella loescheii ATCC 15930 by sequential column chromatography. The molecular mass of the native enzyme was estimated as 160 kDa by high-pressure liquid gel filtration column chromatography and unheated sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The subunit molecular mass was 80 kDa when the enzyme was heated to 100 degrees C in the presence of 2-mercaptoethanol before SDS-PAGE, suggesting that the native enzyme consists of two identical subunits and is folded in 2% SDS. The optimum pH, with glycyl-prolyl-4-methyl-coumaryl-7-amide as the substrate, was 8.0; the isoelectric point was 5.2. Purified enzyme showed a strong preference for dipeptide substrates containing proline and, less efficiently, alanine in the P1 position. The enzyme was markedly inhibited by Cd(2+), Zn(2+), Hg(2+), Co(2+), and serine proteinase inhibitor di-isopropylfluorophosphate. PMID:11389867