The hepatitis C virus (HCV) nonstructural 5A, a phosphorylated zinc metalloprotein, is an essential component of the HCV replication complex. An amphipathic ?-helical peptide (HCV peptide [C5A]) derived from nonstructural 5A membrane anchor domain possesses potent anti-HCV and anti-HIV activity in vitro. In this study, we aimed to investigate the potential ...

The model amyloid peptide AAKLVFF was expressed as a His-tagged fusion protein with the immunoglobulin-binding domain B1 of streptococcal protein G (GB1), a small (56 residues), stable, single-domain protein. It is shown that expression of this model amyloid peptide is possible and is not hindered by aggregation. Formylation side ...

... activity. The Xenopus oocyte protein expression system can be used to study heterologous G-protein coupled receptors. ...

... Title : SYNTHESIS OF TYROSINE, TRYPTOPHAN AND METHIONINE PEPTIDES USING N-FORMYL PROTECTION AND N,N ...

Although the level of serum amyloid A has been reported to be up-regulated during inflammatory response, the role of serum amyloid A on the regulation of inflammation and immune response has not been elucidated. We found that serum amyloid A stimulated the production of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10, which are proinflammatory and anti-inflammatory cytokines, ...

The pattern of binding of chemotactic formyl peptides to their receptors on intact rabbit neutrophils was investigated using three different radiolabeled formyl peptides. The purpose of the study was both to establish suitable procedures for the analysis of complex receptor-binding data and to evaluate the ...

... messenger RNA ... When RNA was size fractionated, a single peak of FPCR activit) at 2 kilobases was observed after injection ofmRNA into oocytes. ...

The physiological functions of the mouse telomeric major histocompatibility complex (MHC) class I molecules, including Hmt, are unknown. Hmt presents a polymorphic, N-formylated peptide encoded by the mitochondrial gene ND1 forming the cell surface maternally transmitted antigen (Mta). Because the N-formyl moiety is required for Hmt ...

Peptides derived from the membrane proximal region of fusion proteins of human immunodeficiency viruses 1 and 2, Coronavirus 229 E, severe acute respiratory syndrome coronavirus and Ebola virus were all potent antagonists of the formyl peptide receptor expressed in Chinese hamster ovary cells. Binding of viral ...

A group of synthetic N-formyl tri- and tetra-peptides are useful as leucoattractants. The group includes f-Met-Leu-Phe-R, f-Met-Met-Phe-R, f-Met-Met-Met-Met-R, f-Nle-Leu-Phe-R, f-Met-Leu-Phe-Lys-R, and their pharmaceutically acceptable non-toxic acid addi...

The migration of phagocytic cells from the blood to sites of infection is an essential component of host defense. This response is mediated by a number of chemoattractants including the bacterially derived formyl peptides which activate cell surface recep...

F2L is an acetylated amino-terminal peptide derived from the cleavage of the human heme-binding protein. Very recently, F2L was identified as an endogenous chemoattractant peptide acting specifically through formyl peptide receptor-like (FPRL)2. In the present study, we report that F2L stimulates chemotactic ...

Peptide deformylase is an essential Fe2+ metalloenzyme that catalyzes the removal of the N-terminal formyl group from nascent polypeptides in eubacteria. In vivo, the deformylase is capable of deformylating most of the polypeptides in a bacterial cell, which contain diverse N-terminal sequences. In this work, we have developed a combinatorial method to ...

The synthesis and antibacterial activity of 3-methylenepyrrolidine formyl hydroxyamino derivatives are reported. The antibacterial activities of these derivatives were evaluated to discover SAR at P(1') and P(3') positions, and most of these derivatives exhibit better in vitro antibacterial activity than existing drugs against drug-resistant clinical isolates including MRSA, ...

Commensal bacteria and/or their products engender beneficial effects to the mammalian gut, including stimulating physiological cellular turnover and enhancing wound healing, without activating overt inflammation. In the present study, we observed commensal bacteria-mediated activation of the noninflammatory extracellular signal-regulated kinase[ERK]/mitogen-activated protein kinase and Akt ...

The biochemistry and subcellular source of new formyl peptide chemotactic receptor appearing at the human neutrophil and differentiated HL-60 (d-HL-60) cell surface after stimulation with phorbol myristate acetate (PMA) were examined. Formyl peptide receptor was analyzed by affinity labeling with ...

A family of N-formyl Met peptides is known to have chemotactic activity for neutrophils and macrophages, and neutrophil activating potency. The SAR of these peptides have been well-documented. Recently structures of two of these peptides have been well-do...

We use the N-formyl peptide receptor (FPR) as a model for G protein- coupled receptor (GPCR) activity in the absence of arrestins. GPCRs are beginning to take center stage in understanding cancer metastasis specifically breast cancer metastasis. Also GPCR...

Intestinal absorption and enterohepatic circulation of N-formyl-methionyl-leucyl-/sup 125/I-tyrosine, a bioactive synthetic analog of the bacterial chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine has been investigated in the rat. In ileum and proximal and distal colon, dithiothreitol, which increases mucosal permeability, ...

Chemotaxis is the stimulated directional migration of cells in response to chemotactic factors, manifested for instance during leukocyte interaction with chemoattractants in inflammation. The N-formyl-Met-Leu-Phe (fMLF) bacterial peptide family is particularly potent in attracting and activating neutrophilic granulocytes. To accomplish defined ...

Urokinase receptor (uPAR) plays a key role in physiological and pathological processes sustained by an altered cell migration. We have developed peptides carrying amino acid substitutions along the Ser(88)-Arg-Ser-Arg-Tyr(92) (SRSRY) uPAR chemotactic sequence. The peptide pyro glutamic acid (pGlu)-Arg-Glu-Arg-Tyr-NH2 (pERERY-NH(2)) shares the same binding ...

A series of N-formyl hydroxylamine peptide deformylase inhibitors containing a cyclic azaamino acid moiety between the P1' and P3' substituents are presented. Selected compounds display antibacterial activity against pathogens associated with respiratory tract infections with representative compounds showing excellent MICs against Haemophilus influenzae. ...

In inflammation, pain is regulated by a balance of pro- and analgesic mediators. Analgesic mediators include opioid peptides which are secreted by neutrophils at the site of inflammation, leading to activation of opioid receptors on peripheral sensory neurons. In humans, local opioids and opioid peptides significantly downregulate postoperative as well as ...

The identification of receptors that detect environmental stimuli lays a foundation for exploring the mechanisms and neural circuits underlying sensation. The mouse vomeronasal organ (VNO), which detects pheromones and other semiochemicals, has 2 known families of chemoreceptors, V1Rs and V2Rs. Here, we report a third family of mouse VNO receptors comprising 5 of 7 members of the ...

Following a ligand-based drug design approach, a potent mixed formyl peptide receptor 1 (FPR1) and formyl peptide receptor-like 1 (FPRL1) agonist (14a) and a potent and specific FPRL1 agonist (14x) were identified. These compounds belong to a large series of pyridazin-3(2H)-one derivatives substituted with a methyl ...

The authors' have shown previously that formyl peptide chemotactic receptors (FPCR) of human phagocytic cells contain at least two asparagine-linked oligosaccharide chains located at the distal end of the receptor. The requirement of these N-linked oligosaccharide chains for expression and function of FPCR was investigated in HL-60 cells induced ...

HIV-1(LAV-1) particles were collected by ultracentrifugation, treated with subtilisin, and then purified by Sepharose CL-4B column chromatography to remove microvesicles. The lysate of the purified human immunodeficiency virus type 1 (HIV-1) particles was subjected to two-dimensional (2D) gel electrophoresis and stained, and the stained spots were excised and digested with trypsin. The resulting ...

Evidence suggests that beta-amyloid (Abeta) has chemokine-like properties and may act through formyl chemotactic receptors (FPR) to induce pathophysiologically important functional changes in Alzheimer's disease (AD) microglia. We have shown that Abeta 1-42, fibrillar Abeta 1-40, and Abeta 25-35 potentiate the release of interleukin-1beta (IL-1beta) from LPS activated human ...

The initiation of reovirus messenger RNA-directed protein synthesis in vitro was investigated in a cell-free protein synthesizing system prepared from Krebs ascites tumor cells. The principal translation products of the mixture of 10 reovirus mRNA species transcribed in vitro by reovirus cores were polypeptides ..mu../sub 0/, ..mu../sub 1/, sigma/sub 2a/, and sigma/sub 3/. Translation could be ...

Formyl peptide receptors (FPRs) are a small group of 7-transmembrane domain, G protein-coupled receptors that are expressed mainly by mammalian phagocytic leukocytes and known to be important in host defense and inflammation. The three human FPRs (FPR1, FPR2/ALX and FPR3) share significant sequence homology and are encoded by clustered genes. Collectively, ...

Loss of Wnt-5a protein expression is associated with shorter recurrence-free survival in breast carcinoma patients and increased motility in mammary cell lines. Based on sequence analysis of Wnt-5a, we identified 14 peptide fragments and investigated their ability to mimic the effects of Wnt-5a on mammary cell adhesion and migration. Two of these peptides ...

Mutations in the fmt gene (encoding formyl methionine transferase) that eliminate formylation of initiator tRNA (Met-tRNA(i)) confer resistance to the novel antibiotic class of peptide deformylase inhibitors (PDFIs) while concomitantly reducing bacterial fitness. Here we show in Salmonella typhimurium that novel mutations in initiation ...

Mutations in the fmt gene (encoding formyl methionine transferase) that eliminate formylation of initiator tRNA (Met-tRNA_i) confer resistance to the novel antibiotic class of peptide deformylase inhibitors (PDFIs) while concomitantly reducing bacterial fitness. Here we show in Salmonella typhimurium that novel ...

... Title : The Formyl Fluoride Photochemical Laser: Photochemistry and Energy Content of the HF Photoelimination Product. ...

The association of hepatobiliary disorders with colonic inflammation is well recognized. Although the pathophysiology is obscure, increased permeation of toxic bacterial products across the inflamed gut to the portal circulation might be one mechanism. Potentially toxic metabolites include N-formylated chemotactic peptides that are produced by several ...

Neisseria gonorrhoeae suppresses the oxidative burst of human polymorphonuclear leukocytes Alison K, elicited a minor PMN oxidative burst. PMN ROS production in response to Opa- and OpaB+ Gc was markedly inhibited the PMN oxidative burst elicited by isogenic dead bacteria, formylated peptides or Staphylococcus

Stimulation of human neutrophils with the chemoattractant N-formyl peptide caused rapid polymerization of F-actin as detected by right angle light scatter and 7-nitrobenz-2-oxa-1,3-diazol (NBD)-phallacidin staining of F-actin. After labeling neutrophils with 32P, exposure to N-formyl peptide induced a fast decrease ...

The chemoattractant neutrophil formyl peptide receptor (FPR) binds bacterial and mitochondrial N-formylated peptides, which allows the neutrophils to find the bacterial source and/or site of tissue damage. Certain inflammatory disorders may be due in part to an impaired innate immune system that does not respond to ...

Polyethylene glycol (PEG) is used widely, and many biologically active molecules are modified with oligoethylene glycol substituents to enhance their half-life in circulation. The pervasive use of PEG substituents is partly due to their presumed inertness. Our investigation of formyl peptide receptor (FPR)-mediated chemotaxis reveals that oligoethylene ...

Structural modifications to the peptide deformylase inhibitor BB-3497 are described. In this paper, we describe the initial SAR around this lead for modifications to the methylene spacer and the P1' side chain. Enzyme inhibition and antibacterial activity data revealed that the optimum distance between the N-formyl hydroxylamine metal binding group and the ...

We investigated in IMR90 cells the effects of N-formyl-Met-Leu-Phe (N-fMLP) and WKYMVm (W peptide) on activation of the NADPH oxidase-like enzyme. In serum-deprived human fibroblasts, exposure to 100 microM N-fMLP or 10 microM peptide W for 1 min induced both p47phox translocation and NADPH-dependent superoxide generation. These ...

Non-ribosomally synthesized peptides have compelling biological activities ranging from antimicrobial to immunosuppressive and from cytostatic to antitumor. The broad spectrum of applications in modern medicine is reflected in the great structural diversity of these natural products. They contain unique building blocks, such as d-amino acids, fatty acids, sugar moieties, and ...

Deformylases are metalloproteases in bacteria, plants, and humans that remove the N-formyl-methionine off peptides in vitro. The human homolog of peptide deformylase (HsPDF) resides in the mitochondria, along with its putative formylated substrates; however, the cellular function of HsPDF remains elusive. Here we ...

The formyl peptide receptor (FPR), a heptahelical G protein-coupled receptor on phagocytic leukocytes, can be triggered by bacterially derived oligopeptides of the prototype fMLP. Although FPR expression and activation have been associated with cells of myeloid origin and bacterial inflammation, the receptor has recently been identified in nonmyeloid ...

The N-terminal part of the calcium-regulated and phospholipid-binding protein annexin AI contains peptide sequences with pro- and anti-inflammatory activities. We have earlier shown that a proinflammatory signal triggered by one of these peptides, Gln⁹�Lys²⁵, is mediated by FPR1, a member of the ...

Previous studies demonstrated an upregulation of pyruvate formate lyase (Pfl) and NAD-dependent formate dehydrogenase (Fdh) in Staphylococcus aureus biofilms. To investigate their physiological role, we constructed fdh and pfl deletion mutants (?fdh and ?pfl). Although formate dehydrogenase activity in the fdh mutant was lost, it showed little phenotypic alterations under oxygen-limited ...

Previous studies demonstrated an upregulation of pyruvate formate lyase (Pfl) and NAD-dependent formate dehydrogenase (Fdh) in Staphylococcus aureus biofilms. To investigate their physiological role, we constructed fdh and pfl deletion mutants (?fdh and ?pfl). Although formate dehydrogenase activity in the fdh mutant was lost, it showed little phenotypic alterations under oxygen-limited ...

Binding of N-formyl-methionyl-leucyl-phenylalanine (fMLP) to its specific cell surface receptor, N-formyl peptide receptor (FPR), triggers different cascades of biochemical events, eventually leading to cellular activation. However, the physiological role of fMLP and FPR during differentiation of mesenchymal stem cells is unknown. In ...

Rats have at least 61 major histocompatibility complex (MHC) genes or fragments; in the mouse, 61 class I genes, pseudogenes, and gene fragments have been mapped and ordered. Despite their abundance and ubiquity, the biological relevance of the MHC class Ib genes is hotly debated and their function generally unknown. However, it is clear that some of them can bind and present ...

The three-dimensional structure of the chemotactic peptide N-formyl-L-Met-L-Leu-L-Phe-OH was determined by using solid-state NMR (SSNMR). The set of SSNMR data consisted of 16 13C-15N distances and 18 torsion angle constraints (on 10 angles), recorded from uniformly 13C,15N- and 15N-labeled samples. The peptide's structure was ...

Microcin C (McC), a natural antibacterial compound consisting of a heptapeptide attached to a modified adenosine, is actively taken up by the YejABEF transporter, after which it is processed by cellular aminopeptidases, releasing the nonhydrolyzable aminoacyl adenylate, an inhibitor of aspartyl-tRNA synthetase. McC analogues with variable length of the peptide moiety were ...

The complete primary structure of the hemoglobin from the Pallid Bat (Antrozous pallidus, Microchiroptera) is presented. This hemoglobin consists of two components with identical amino-acid sequences, differing, however, in the N-terminus which is formylated in 12.5% of the beta-chains. The alpha- and beta-chains were separated by reversed phase high performance liquid ...

Subcellular fractionation of human neutrophils on linear sucrose density gradients was utilized to test the hypothesis that priming regulates the subcellular and sub-plasma membrane distribution of neutrophil G-protein subunits, G(ialpha2) and G(ialpha3), N-formyl peptide receptor, Lyn kinase and phospholipase C(beta2). G(ialpha2), but not G(ialpha3), ...

Because fluoresceinated ligands of the neutrophil formyl peptide receptor can be protonated either upon binding to the receptor on the cell surface or in acidified intracellular compartments, the authors synthesized a ligand conjugated to the pH sensitive fluorescent probe SNAFL (CHO-Met-Leu-Phe-Phe-Lys-SNAFL). In the three laser flow cytometer at LANL, ...

Injury causes a systemic inflammatory response syndrome (SIRS) clinically much like sepsis 1. Microbial pathogen-associated molecular patterns (PAMPs) activate innate immunocytes through pattern recognition receptors 2. Similarly, cellular injury can release endogenous damage-associated molecular patterns (DAMPs) that activate innate immunity 3. Mitochondria are evolutionary endosymbionts that ...

The formyl peptide-like receptor FPRL1 is a member of the chemoattractant subfamily of G protein- coupled receptors involved in regulating leukocyte migration in inflammation. To elucidate mechanisms underlying the internalization of ligand-bound FPRL1 and possible receptor recycling, we characterized the endocytic itinerary of FPRL1. We show that ...

The N-formyl peptide receptors (FPRs) are a family of G-protein coupled receptors that respond to proinflammatory N-formylated bacterial peptides (e.g., formyl-Met-Leu-Phe, fMLF) and, thus, contribute to the host response to bacterial infection. Paradoxically, a growing body of evidence ...

G-protein-coupled receptors play a major role in the activation of the innate immune system, such as polymorphonuclear neutrophils. Members of the formyl peptide receptor family recognize chemotactic peptides as well the amylo�d-beta peptide and fragments of the human immunodeficiency virus envelope and may thus ...

The peptide F2L was previously characterized as a high-affinity natural agonist for the human formyl peptide receptor (FPR) 3. F2L is an acetylated 21-aa peptide corresponding with the N terminus of the intracellular heme-binding protein 1 (HEBP1). In the current work, we have investigated which proteases were able ...

Antimicrobial peptides are effector molecules of the innate immune system and contribute to host defense and regulation of inflammation. The human cathelicidin antimicrobial peptide LL-37/hCAP-18 is expressed in leukocytes and epithelial cells and secreted into wound and airway surface fluid. Here we show that LL-37 induces angiogenesis mediated by ...

In this study, we determined receptor preferences for compound 43, a nitrosylated pyrazolone derivative, and the eicosanoid lipoxin A(4) (LXA(4) ), potent anti-inflammatory mediators in many experimental in vivo models. Their effects have been suggested to be mediated through binding to formyl peptide receptor (FPR)2 [earlier known as ...

We have used rapid-mix flow cytometry to analyze the early subsecond dynamics of the disassembly of ternary complexes of G protein-coupled receptors (GPCRs) immobilized on beads to examine individual steps associated with guanine nucleotide activation. Our earlier studies suggested that the slow dissociation of Galpha and Gbetagamma subunits was unlikely to be an essential component of cell ...

HypothesisFractures and femoral reaming are associated with lung injury. The mechanisms linking fractures and inflammation are unclear; but tissue disruption might release mitochondria. Mitochondria are evolutionarily derived from bacteria and contain �Damage Associated Molecular Patterns� (DAMPs) like formylated peptides that can activate immunocytes. ...

Recent studies suggest that the chemotactic G protein-coupled receptor formyl-peptide-receptor-like-1 (FPRL1) or the scavenger receptor MARCO (macrophage receptor with collagenous structure) plays an essential role in the inflammatory response of host defense mechanisms and neurodegenerative disorders such as Alzheimer's disease. We therefore analyzed the involvement of FPRL1 ...

BackgroundCytochalasin B does not directly activate the oxygen-radical-producing NADPH oxidase activity of neutrophils but transfers desensitized G-protein coupled receptors (GPCR) into an active signaling state by uncoupling GCPR from the cytoskeleton. The receptor uncoupling results in respiratory burst activity when signals generated by reactivated formyl ...

In the present study, it was investigated which components are responsible for the anti-inflammatory properties of Crotalus durissus terrificus venom (CdtV). The effect of crotoxin, as well as of other CdtV components was evaluated on edema, cell migration and alterations in leukocyte-endothelium interactions induced by carrageenan. Crotoxin (40 microg kg(-1)) was injected at different time ...

The formyl peptide receptor gene family encodes G protein-coupled receptors for phagocyte chemoattractants, including bacteria- and mitochondria-derived N-formylpeptides. The human family has 3 functional genes, whereas the mouse family has 7 functional genes and 2 possible pseudogenes (?Fpr-rs2 and ?Fpr-rs3). Here we characterize ?Fpr-rs2, a duplication ...

The mechanisms used by the immune system to discriminate between pathogenic and commensal bacteria have remained largely unclear. Recently, we have shown that virulence of Staphylococcus aureus depends on secretion of phenol-soluble modulin (PSM) peptides that disrupt neutrophils at micromolar concentrations. Moreover, all S. aureus PSMs stimulate and attract neutrophils at ...

Formyl peptide receptor-like 1 (FPRL1), which is a G protein-coupled receptor of chemoattractant subfamily, plays an important role in the regulation of host defense against pathogenic infection and the chemotactic and activating effects of Abeta42 on mononuclear phagocytes as well as in the elimination of damaged or pathogen-infected cells. In the present ...

Peptide deformylase proteins (PDFs) participate in the N-terminal methionine excision pathway of newly synthesized peptides. We show that the human PDF (HsPDF) can deformylate its putative substrates derived from mitochondrial DNA-encoded proteins. The first structural model of a mammalian PDF (1.7 A), HsPDF, shows a dimer with conserved topology of the ...

Peptide deformylase (PDF) catalyzes the hydrolytic removal of the N-terminal formyl group from nascent proteins. This is an essential step in bacterial protein synthesis, making PDF an attractive target for antibacterial drug development. Essentiality of the def gene, encoding PDF from Mycobacterium tuberculosis, was demonstrated through genetic knockout ...

It has been reported that the stimulation of neutrophils with N-formyl-Met-Leu-Phe (fMLF), an agonist for formyl peptide receptor (Fpr) 1, renders cells unresponsive to other chemoattractants in vitro. This is known as cross-desensitization, but its functional relevance in neutrophil migration in vivo has not been investigated. Here, ...

Calpain inhibitors induce pertussis toxin (PTx)-sensitive chemotaxis in human neutrophils and monocytes. Here, we show that various calpain inhibitors (PD150606, PD151746, N-acetyl-Leu-Leu-Nle-CHO [ALLN], N-acetyl-Leu-Leu-Met-CHO [ALLM], and calpeptin) and ?-secretase inhibitor I induced PTx-sensitive increase in cytoplasmic free Ca(2+) ([Ca(2+)](i)) in human neutrophils and neutrophil migration. ...

Inflammatory pain can be controlled by intraplantar opioid injection or by secretion of endogenous opioid peptides from leukocytes in inflamed rat paws. Antinociception requires binding of opioid peptides to opioid receptors on peripheral sensory nerve terminals. In the absence of inflammation, hydrophilic opioid peptides do not ...

Experimental and clinical investigations using hyperosmotic solutions for resuscitation of hemorrhagic shock demonstrated modulation of the inflammatory response. Decreased postinjury hyperinflammation has been attributed to a reduction in neutrophil-mediated tissue damage. This study shows that cytoskeletal disruption with cytochalasinB did not reverse or prevent the inhibitory effect of an ...

Chlorophyll (Chl) b serves an essential function in accumulation of light-harvesting complexes (LHCs) in plants. In this article, this role of Chl b is explored by considering the properties of Chls and the ligands with which they interact in the complexes. The overall properties of the Chls, not only their spectral features, are altered as consequences of chemical modifications on the periphery ...

Chlorophyll (Chl) b serves an essential function in accumulation of light-harvesting complexes (LHCs) in plants. In this article, this role of Chl b is explored by considering the properties of Chls and the ligands with which they interact in the complexes. The overall properties of the Chls, not only their spectral features, are altered as consequences of chemical modifications on the periphery ...

Helicobacter pylori, the bacterial pathogen associated with gastritis and peptic ulcers, is highly successful in establishing infection in the human gastric mucosa, a process typically associated with massive infiltration of inflammatory cells. Colonization of the mucosa is suggested to be facilitated by H. pylori-produced cecropin-like peptides with antibacterial properties, ...

We present a novel solid-state magic angle-spinning NMR method for measuring the NHi-NHi+1 projection angle ?i,i+1 in peptides. The experiment is applicable to uniformly 15N-labeled peptides and is demonstrated on the chemotactic tripeptide N-formyl-l-Met-l-Leu-l-Phe. The projection angle ?i,i+1 is directly related ...

Zinc, at physiologic concentrations, inhibits in vitro histamine release from human basophils induced by several immunologic (i.e., antigen and anti-immunoglobulin E (IgE) and nonimmunologic (Ca/sup + +/ ionophore A23187 and formylated tripeptide formyl-methionyl-leucyl-phenylalanine (f-met peptide)) stimuli in a dose-dependent manner. ...

Peptide deformylase activity was thought to be limited to ribosomal protein synthesis in prokaryotes, where new peptides are initiated with an N-formylated methionine. We describe here a new human peptide deformylase (Homo sapiens PDF, or HsPDF) that is localized to the mitochondria. HsPDF is capable of removing ...

Amyloid-? (A?) peptides, derived from the amyloid precursor protein, and the microtubule-associated protein tau are key pathogenic factors in Alzheimer�s disease (AD). How exactly they impair cognitive functions is unknown. Here we assessed the effects of A? and tau on axonal transport of mitochondria and the neurotrophin receptor TrkA, cargoes that are critical for neuronal ...

CONTENTS I. Introduction 599 II. Formylation of various organic compounds 600 III. Acylation of organic compounds 615

High-speed (14 kHz) solid-state magic angle spinning (MAS) 1H NMR has been applied to several membrane peptides incorporated into nondeuterated dilauroyl or dimyristoylphosphatidylcholine membranes suspended in H2O. It is shown that solvent suppression methods derived from solution NMR, such as presaturation or jump-return, can be used to reduce water resonance, even at ...

Brain accumulation of the amyloid-? peptide (A?) and oxidative stress underlie neuronal dysfunction and memory loss in Alzheimer's disease (AD). Hexokinase (HK), a key glycolytic enzyme, plays important pro-survival roles, reducing mitochondrial reactive oxygen species (ROS) generation and preventing apoptosis in neurons and other cell types. Brain isozyme HKI is mainly ...

Protein splicing is a post-translational autocatalytic process that results in excision of internal peptide (intein) from a precursor protein and the ligation of the flanking protein sequences (exteins). High specificity of the intein-mediated excision of protein precursors allows the use of protein splicing in biotechnology. This work was aimed at the obtaining of human ...

The three-dimensional structure of the chemotactic peptide N-formyl-l-Met-l-Leu-l-Phe-OH was determined by using solid-state NMR (SSNMR). The set of SSNMR data consisted of 16 ¹³C�¹⁵N distances and 18 torsion angle constraints (on 10 angles), recorded from uniformly ...

Introduced in the late 1980s as a reducing reagent, Tris (2-carboxyethyl) phosphine (TCEP) has now become one of the most widely used protein reductants. To date, only a few studies on its side reactions have been published. We report the observation of a side reaction that cleaves protein backbones under mild conditions by fracturing the cysteine residues, thus generating heterogeneous ...

In order to generate highly labelled neurotensin analogues, synthesis has been performed of two types of precursors, one for iodination and one for tritiation. Iodination of native neurotensin occurs on both tyrosines in position 3 and 11 and thus affects greatly its binding capacities. In this article, synthesis and chemical characterization of [Trp11]-neurotensin are described which can be ...

Clearance of the intracellular bacterial pathogen Listeria monocytogenes requires antigen-specific CD8⁺ T cells. Recently it was shown that activation of class Ib major histocompatibility complex (MHC)-restricted CD8⁺ T cells alone is sufficient for immune protection against listeriae. A major component of the class Ib MHC-restricted T-cell ...

The neutrophil formyl peptide receptors (FPR1 and FPR2) are G-protein coupled receptors that can induce pro-inflammatory as well as anti-inflammatory activities when activated. Accordingly, these receptors may become therapeutic targets for the development of novel drugs to be used for reducing the inflammation induced injuries in asthma, rheumatoid ...

Serum amyloid A (SAA) is a major acute-phase reactant, and has been demonstrated to mediate proinflammatory cellular responses. Although SAA has been used as an indicator for a variety of inflammatory diseases, the role of SAA in synovial hyperplasia and proliferation of endothelial cells, a pathological hallmark of rheumatoid arthritis (RA), has yet to be elucidated. In this study, we have ...

Mitochondria are cellular organelles involved in host-cell metabolic processes and the control of programmed cell death. A direct link between mitochondria and innate immune signalling was first highlighted with the identification of MAVS-a crucial adaptor for RIGI-like receptor signalling-as a mitochondria-anchored protein. Recently, other innate immune molecules, such as NLRX1, TRAF6, NLRP3 and ...

Analysis of a tryptic digest of a recombinant D83A mutant of the murine dioxin receptor (D83A-DR) by CapHPLC-MALDI-TOF/TOF-MS/MS revealed a peptide corresponding to cleavage at a lysine that had either been mutated to an arginine or modified by dimethylation or formylation (Ser-Phe-Phe-Ala-Val-Ala-Leu-Me2K/FormK/Arg). High mass accuracy data were obtained ...

[Ala3-15N][Val1]Gramicidin A has been prepared by solid-phase peptide synthesis and studied by solid-state 15N nuclear magnetic resonance spectroscopy. The synthesis of desformyl[Ala3-15N][Val1]gramicidin A employed N-hydroxysuccinimide esters of 9-fluorenylmethoxycarbonyl-N alpha-amino acids and completely avoided the use of acid. Since deblocking was done with piperidine and ...

(Ala/sup 3-15/N)(Val/sup 1/)Gramicidin A has been prepared by solid-phase peptide synthesis and studied by solid-state /sup 15/N nuclear magnetic resonance spectroscopy. The synthesis of desformyl(Ala/sup 3-15/N)(Val/sup 1/)gramicidin A employed N-hydroxysuccinimide esters of 9-fluorenylmethoxycarbonyl-N/sup ..cap alpha../-amino acids and completely avoided the use of acid. ...

... (Author). Descriptors : (*DRUGS, *STEREOCHEMISTRY), (*PYRIDINES, STEREOCHEMISTRY), (*MOLECULAR ORBITALS, STEREOCHEMISTRY ...

In chronic viral hepatitis, autoimmune hepatitis, and some chronic cholestatic liver diseases, T lymphocytes serve as effector cells of the immunostimulatory processes. Cellular interactions of immune cells with extracellular matrix components are regulated primarily via the beta 1 subfamily of integrin receptors. The target epitope of several such integrin receptors is the Arg-Gly-Asp sequence, a ...

The loss of synapses and neurons in Alzheimer's disease (AD) is thought to be at least partly induced by toxic species formed by the amyloid beta (A?) peptide; therefore, therapeutics aimed at reducing A? toxicity could be of clinical use for treatment of AD. Liposomes are suitable vehicles for therapeutic agents and imaging probes, and a promising way of targeting the various ...

The formyl peptide receptor (FPR) is a G-protein-coupled receptor (GPCR) that mediates chemotaxis and stimulates the mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinase pathway. We have examined the functional effects of substitutions of a conserved aspartic acid residue in the second transmembrane domain (D71A) and of residues in ...

The effect of the synthetic peptide bioregulator Vilon on structural and facultative heterochromatin of cultured lymphocytes from old people has been studied. The data obtained indicate that Vilon (a) induces unrolling (deheterochromatinization) of total heterochromatin; (b) activates synthetic processes caused by the reactivation of ...

We recently showed that phosphatidylinositol trisphosphate (PIP3) was present in a unique lipid fraction generated in neutrophils during activation. Here, we demonstrate that the band containing this fraction isolated from thin layer chromatography consists primarily of PIP3 and that only small amounts of radiolabeled PIP3 exist prior to activation. In addition, high performance liquid ...

To identify the TLR4-initiated signaling events that couple to formyl peptide receptor (FPR)1 mRNA stabilization, macrophages were treated with LPS along with a selection of compounds targeting several known signaling pathways. Although inhibitors of protein tyrosine kinases, MAPKs, and stress-activated kinases had little or no effect on the response to ...

G-protein coupled receptors (GPCRs) participate in a wide range of vital regulations of our physiological actions. They are also of pharmaceutical importance and have become many therapeutic targets for a number of disorders and diseases. Purified GPCR-based approaches including structural study and novel biophysical and biochemical function analyses are increasingly being used in GPCR-directed ...

Curing HIV-1 infection has remained elusive because of low and fluctuating drug levels arising from poor absorption, the development of viral reservoirs and sanctuary sites, toxicity, and patient nonadherence. The present study addresses the issue of insufficient drug exposure in macrophages. Viral reservoir sites such as macrophages are believed to be responsible for the viral rebound effect ...

Among human N-formyl peptide chemoattractant receptors, FPR2/ALX and FPR3 share the highest degree of amino acid identity (83%), and trigger similar cell responses upon ligand binding. Although FPR2/ALX is a promiscuous receptor, FPR3 has only one specific high affinity ligand, F2L, and a more restricted tissue/cell distribution. In this study, we showed ...

Gliomas are the most common and lethal tumor type in the brain. The present study investigated the effect of oligomer procyanidins (F2) (F2, degree of polymerization 2-15), a natural fraction isolated from grape seeds on the biological behavior of glioblastoma cells. We found that F2 significantly inhibited the glioblastoma growth, with little cytotoxicity on normal cells, induced G2/M arrest and ...

Development of immunomodulatory agents that enhance innate immune responses represents a promising strategy for combating infectious diseases. In the present studies, we screened a series of 71 arylcarboxylic acid hydrazide derivatives for their ability to induce macrophage tumor necrosis factor alpha (TNF-alpha) production and identified six such compounds, including one compound previously shown ...

Development of immunomodulatory agents that enhance innate immune responses represents a promising strategy for combating infectious diseases. In the present studies, we screened a series of 71 arylcarboxylic acid hydrazide derivatives for their ability to induce macrophage tumor necrosis factor ? (TNF-?) production and identified 6 such compounds, including one compound previously shown to be a ...

Formyl peptide receptor 1 (FPR1) and FPR2/ALX are known to control neutrophil chemotaxis in response to various ligands. In this study, we investigated the inhibitory mechanism of compound 43 (Cpd43), an FPR1 and FPR2/ALX dual agonist, on human neutrophil chemotaxis. Precedent stimulation of human peripheral blood neutrophils with Cpd43 rendered the cells ...

The NPXXY motif (X represents any amino acid) in the seventh transmembrane domain of the chemotactic formyl peptide receptor (FPR) is highly conserved among G protein-coupled receptors. Recent work suggested that this motif contributes to G protein-coupled receptor internalization and signal transduction; however, its role in FPR signaling remains unclear. ...

Injury causes a systemic inflammatory response syndrome (SIRS) that is clinically much like sepsis. Microbial pathogen-associated molecular patterns (PAMPs) activate innate immunocytes through pattern recognition receptors. Similarly, cellular injury can release endogenous 'damage'-associated molecular patterns (DAMPs) that activate innate immunity. Mitochondria are evolutionary endosymbionts that ...

Peptide deformylase (PDF) is an essential bacterial metalloenzyme which deformylates the N-formylmethionine of newly synthesized polypeptides and as such represents a novel target for antibacterial chemotherapy. To identify novel PDF inhibitors, we screened a metalloenzyme inhibitor library and identified an N-formyl-hydroxylamine derivative, BB-3497, and ...

Peptide deformylase (PDF) is an essential bacterial metalloenzyme which deformylates the N-formylmethionine of newly synthesized polypeptides and as such represents a novel target for antibacterial chemotherapy. To identify novel PDF inhibitors, we screened a metalloenzyme inhibitor library and identified an N-formyl-hydroxylamine derivative, BB-3497, and ...

Highly malignant human gliomas overexpress the G-protein-coupled chemoattractant receptor formyl peptide receptor (FPR1), which promotes tumor progression when activated. Our previous studies demonstrated that necrotic glioblastoma cells release chemotactic agonist(s) that activate FPR1 on viable tumor cells. In the present study, we identified an FPR1 ...

Formyl peptide receptor (FPR) is a chemoattractant G protein-coupled receptor (GPCR) involved in the innate immune response against bacteria. Receptor activation is terminated by receptor phosphorylation of two serine- and threonine-rich regions located in the distal half of the cytoplasmic tail. In this study we show that introduction of an amino acid ...

Messenger-RNA-directed protein synthesis is accomplished by the ribosome. In eubacteria, this complex process is initiated by a specialized transfer RNA charged with formylmethionine (tRNA(fMet)). The amino-terminal formylated methionine of all bacterial nascent polypeptides blocks the reactive amino group to prevent unfavourable side-reactions and to enhance the efficiency of ...

Amyloid-? (A?) peptide- induced neurotoxicity is typically associated with apoptosis. In previous studies, we have shown that tauroursodeoxycholic acid (TUDCA), an endogenous anti-apoptotic bile acid, modulates A?-induced apoptosis. Here, we investigated stress signaling events triggered by soluble A? and further explored alternative pathways of ...

Amyloid-? (A?) peptide-induced neurotoxicity is typically associated with cell death through mechanisms not entirely understood. Here, we investigated stress signaling events triggered by soluble A? in differentiated rat neuronal-like PC12 cells. Morphologic evaluation of apoptosis confirmed that A? induced nuclear fragmentation that ...

Emerging evidence indicates that amyloid ? peptide (A?) initially induces subtle alterations in synaptic function in Alzheimer disease. We have recently shown that A? binds to ?(2) adrenergic receptor (?(2)AR) and activates protein kinase A (PKA) signaling for glutamatergic regulation of synaptic activities. Here we show that in the cerebrums of mice expressing human familial ...

Ammodytoxins (Atxs) are presynaptically neurotoxic phospholipases present in Vipera ammodytes ammodytes snake venom. Atxs show a high sequence homology and contain 14 cysteines which form seven biologically relevant disulfide bridges-connecting non-neighboring cysteines. Formic acid cleavage was performed to confirm protein sequences by MALDI RTOF MS and resulted in 95.6% sequence coverage ...

The effect of the neuropeptides substance P, neurokinin A and alpha-calcitonin gene-related peptide (CGRP) on human neutrophil granulocytes was investigated. Substance P induced secondary granule secretion at a concentration of 100 microM. CGRP induced a significant secretory response at 10 microM and thus appeared to be about 10 times more potent than substance P. Calcitonin ...

Reduction of the 7-formyl groups in chlorophyll (Chl) b and its demetalated compound pheophytin (Phe) b was kinetically analyzed by using tert-butylamine-borane complex (t-BuNH(2)�BH(3)), and was compared with that of the 3-formyl groups in Chl d and Phe d. Reduction kinetics of the 7-formyl group in Chl b was similar to that in Phe ...

Bacterial peptide deformylase (PDF) belongs to a sub-family of metalloproteases that catalyse the removal of the N-terminal formyl group from newly synthesised proteins. PDF is essential in prokaryotes and conserved throughout the eubacteria. It is therefore considered an attractive target for developing new antibacterial agents. Here, we report the ...

The responsiveness of isolated guinea pig lung parenchymal strips to substance P was enhanced by at least 100-fold in the presence of the endopeptidase inhibitors phosphoramidon (1 microM) or thiorphan (1 microM), but not with the converting enzyme inhibitor, captopril, or an inhibitor of serum carboxypeptidase N (both 1 microM). Responses of guinea pig tracheal rings to substance P were also ...

Peptide deformylase (PDF) is an enzyme that is responsible for removing the formyl group from nascently synthesized polypeptides in bacteria, attracting much attention as a potential target for novel antibacterial agents. Efforts to develop potent inhibitors of the enzyme have progressed based on classical medicinal chemistry, combinatorial chemistry, and ...

The N-formyl-methionyl peptides, F-Met-Leu-Phe, F-Met-Met-Phe and F-Met-Phe, when tested at differing concentrations, proportionally increased both in vitro cell locomotion and the expression of surface receptors for C3b on human peripheral blood neutrophils and monocytes. In contrast, the unformylated peptides, Met-Leu-Phe and ...

Chlamydia trachomatis is an obligate intracellular bacterium responsible for a number of health problems, including sexually transmitted infection in humans. We recently discovered that C. trachomatis infection in cell culture is highly susceptible to inhibitors of peptide deformylase, an enzyme that removes the N-formyl group from newly synthesized ...

SummaryChlamydia trachomatis is an obligate intracellular bacterium responsible for a number of health problems, including sexually transmitted infection in humans. We recently discovered that C. trachomatis infection in cell culture is highly susceptible to inhibitors of peptide deformylase, an enzyme that removes the N-formyl group from newly synthesized ...

Peptide deformylase (PDF) catalyses the removal of the N-formyl group from the nascent polypeptide during protein maturation. The PDF of Mycobacterium tuberculosis H37Rv (MtbPDF), overexpressed and purified from Escherichia coli, was characterized as an iron-containing enzyme with stability towards H(2) O(2) and moderate thermostability. Substitution of ...

The number of microglia surrounding senile plaques is correlated with the size of plaques in Alzheimer's disease (AD). It is unclear whether more microglia are passively recruited toward larger senile plaques or, conversely, microglia recruited to senile plaques directly contribute to the growth of plaques. In this study, BV-2 microglia were used to delineate the role of microglia in the growth of ...

Elongation Factor P (EF-P) is an essential component of bacterial protein synthesis, enhancing the rate of translation by facilitating the addition of amino acids to the growing peptide chain. Using purified Staphylococcus aureus EF-P and a reconstituted Escherichia coli ribosomal system, an assay monitoring the addition of radiolabeled N-formyl methionine ...

The amyloid-? peptide (A?) plays a central role in the mechanism of Alzheimer's disease, being the main constituent of the plaque deposits found in AD brains. A? amyloid formation and deposition are due to a conformational switching to a ?-enriched secondary structure. Our strategy to inhibit A? aggregation involves the re-conversion of A? conformation by adsorption to ...

Beta amyloid (A?), a peptide generated from the amyloid precursor protein (APP) by neurons, is widely believed to underlie the pathophysiology of Alzheimer�s Disease. Recent studies indicate that this peptide can drive loss of surface AMPA and NMDA type glutamate receptors. We now show that A? employs signaling pathways of long-term depression (LTD) to ...