Ubiquitin-proteasome pathway (UPP) is one of the ways utilized for selective degradation of many proteins in cells, and the 20S proteasome takes the functional machinery where hydrolysis of targeted proteins takes place. Based on existing peptide inhibitors, a series of novel tripeptidic tetrazoles have been designed, synthesized, and the structures have been confirmed with 1H NMR, MS and elemental analysis. Among them, three compounds (6b, 6d and 6h) showed inhibitory activities of ChT-L of 20S proteasome.
Biological Assay ; Drug Design ; Molecular Structure ; Oligopeptides ; chemical synthesis ; chemistry ; pharmacology ; Proteasome Endopeptidase Complex ; chemistry ; Proteasome Inhibitors ; chemical synthesis ; chemistry ; pharmacology ; Tetrazoles ; chemical synthesis ; chemistry ; pharmacology

4-Hydroxycoumarins ; chemical synthesis ; chemistry ; pharmacology ; Anti-HIV Agents ; chemical synthesis ; chemistry ; pharmacology ; Atazanavir Sulfate ; HIV Protease Inhibitors ; chemical synthesis ; chemistry ; pharmacology ; Humans ; Molecular Structure ; Oligopeptides ; chemical synthesis ; chemistry ; pharmacology ; Pyridines ; chemical synthesis ; chemistry ; pharmacology ; Saquinavir ; chemical synthesis ; chemistry ; pharmacology ; Urea ; analogs & derivatives ; chemical synthesis ; chemistry ; pharmacology

To find anti-hypertensive lead drug, angiotensin converting enzyme (ACE) inhibitory peptides were synthesized and their effects on inhibiting ACE activity were investigated. ACE inhibitory peptides were synthesized via Fmoc solid-phase synthesis, isolated and purified through reversed phase high-performance liquid chromatography (RP-HPLC), and identified by mass spectrometry. A RP-HPLC analysis method was used to test ACE inhibitory activity in vitro of these ACE inhibitory peptides. Six octapeptides were successfully synthesized, and the analytical results of mass spectrum were consistent with their theoretically calculated data. Among these synthetic octapeptides, the anti-SARS (severe acute respiratory syndromes) octapeptide had the most obvious ACE inhibitory activity with an IC50 value of 3.4 x 10(-5) mol x L(-1). So octapeptide AVLQSGFR-OH (anti-SARS peptide) was found to be the strongest candidate for potential development as an anti-hypertensive drug and had the implication of further study.
Angiotensin-Converting Enzyme Inhibitors ; chemical synthesis ; chemistry ; pharmacology ; Antihypertensive Agents ; chemical synthesis ; chemistry ; pharmacology ; Chromatography, High Pressure Liquid ; methods ; Mass Spectrometry ; Molecular Structure ; Oligopeptides ; chemical synthesis ; chemistry ; pharmacology ; Peptidyl-Dipeptidase A ; drug effects ; Solid-Phase Synthesis Techniques

A humanized monoclonal antibody against HER2 has been using in a clinical setting and has been shown to possess therapeutic properties. A mimetic peptide against HER2 was also reported to bind to the HER2 receptor with some therapeutic potential. Based on a previous report and the sequence of Herceptin, we designed oligonucleotides of anti-HER2 mimetic peptides, named V2 and V3 peptides, in order to develop a peptide- producing vector system for biologic therapy against HER2- overexpressing cancers. We also adopted the sequence of a previously reported mimetic peptide, V1 (Park BW et al. Nat. Biotechnol, 2000, 18: 194-198), as a reference peptide. We examined the effects of the V2 and V3 peptides against the HER2-overexpressing cell lines, SK-BR-3 and T6-17. Transient transfection of the construct expressing V1 and V2 inhibited cell proliferation in HER2-overexpressing cell lines by 20 - 30%, but had no effect on the HER2-negative NIH3T3 cells. The proliferation inhibition shown by V2 was slightly better than that shown by V1. Recombinant peptides V2 and V3 were produced on a large scale in an E. coli system, and the V2 peptide showed anti-HER2-specific tumor cell proliferation inhibition of 10% to 30%. Current results suggest that anti-HER2 mimetic peptides, overexpressed by a constitutive promoter or produced in an E. coli system, could specifically inhibit the proliferation of HER2-expressing cancer cells. Further efforts to augment the biologic specificity and efficacy and to develop new technologies for the purification of the peptide from the E coli system are needed.
Amino Acid Sequence ; Animals ; Cell Division/drug effects ; Cell Line ; Mice ; Oligopeptides/chemical synthesis/pharmacology ; Peptide Fragments/*chemical synthesis/*pharmacology ; Receptor, erbB-2/*chemistry ; Recombinant Proteins/chemical synthesis/pharmacology ; Support, Non-U.S. Gov't ; *Technology, Pharmaceutical ; Transfection

The aim of this experiment is to graft synthesizing Arg-Gly-Asp peptides (RGD) on the surface of polymer materials, combine endothelial cells with its special site, enhance the adhesion of endothelial cells on the surface, promote the blood compatibility of the biomaterials. Carboxy group (-COOH) was grafted on the materials surface by ultraviolet (UV) radiation, and the RGD serial obtained by liquid phase synthesis was successfully grafted on the disposed materials by chemical reaction. The endothelialization experiment was made also. The grafting results were measured by X-ray photoelectron spectroscopy (XPS), and endothelialization was observed using optical microscope and scanning electron microscope (SEM). The results indicated that the method improves the effect of materials endothelialization. The experiment has made successful use of UV grafting and chemical coupling methods to graft bioactive RGD onto PET film surface. This is a new method of grafting bioactive peptide.
Biocompatible Materials ; chemistry ; Cells, Cultured ; Cells, Immobilized ; Endothelium ; cytology ; drug effects ; Humans ; Oligopeptides ; chemical synthesis ; chemistry ; pharmacology ; Polyethylene Terephthalates ; chemistry ; Surface Properties

The RGD-containing peptide was used to modify the surface of porous PLGA-[ASP-PEG], and was incubated in the modified simulated body fluid (mSBF) for two weeks. The mineralization of PLGA-[ASP-PEG] was explored. The active peptide was used to modify PLGA-[ASP-PEG] through cross-linker (Sulfo-LC-SPDP), characterized by X-ray photoelectron spectroscopy (XPS) the peptide-modified PLGA-[ASP-PEG] (Experiment group, EG) and PLGA-[ASP-PEG] without modification (Control group, CG) were all incubated in mSBF for two weeks, confirmed by observation of Scanning electron microscope(SEM) and measurements of Energy dispersive analysis system of X-ray (EDS) and X-ray diffractometry (XRD). XPS indicated that the binding energy of sulphur in EG was 164eV, and the ratio of carbon to sulphur in EG was 99.746 : 0.1014, however, sulphur was not detected in CG; SEM analysis demonstrated that the mineralization layers were more consecutive and compact in EG than in CG. The results of EDS and XRD indicated that the main component of mineral was hydroxyapatite, and the ratio of Ca/P was 1.60 in EG, and 1.52 in CG. RGD-containing peptide provided enough functional groups for mineralization; the mineralized peptide- modified PLGA-[ASP-PEG] possessed the bonelike microstructure.
Biocompatible Materials ; chemistry ; Bone Substitutes ; Bone and Bones ; metabolism ; Calcification, Physiologic ; Lactic Acid ; chemistry ; Oligopeptides ; chemistry ; Osteogenesis ; drug effects ; Peptides ; chemical synthesis ; pharmacology ; Polyglycolic Acid ; chemistry ; Surface Properties

The study is designed to synthesize nano-carrier Tyr-RGD (cyclo-[Arg-Gly-Asp-d-Tyr-Lys]) and poly(ethylene glycol) modified polyethylenimine (Tyr-RGD-PEG-PEI) targeting vascular endothelial cells, then analyze its nanoparticle properties and the characteristics of drug carrying and targeting properties in vivo / in vitro tumor. The nano-carrier Tyr-RGD-PEG-PEI was synthesized with the method of chemical synthesis and the properties of this nanoparticle and drug carrying characteristics were identified. Its effect of targeting vascular endothelial cells in vitro was studied with the method of competitive binding assay. The fluorescent labeled nano-drug was injected into tumor-bearing nude mice to observe its tumor-targeting. The mean size of nano-carrier Tyr-RGD-PEG-PE was about 145 nm, good in encapsulation efficiency of siRNA. After incubation in plasma for half an hour, only about 3 percent of siRNA out. It was confirmed that it was a single spot with TLC analysis, the R(f) value was 0.65. Receptor competition experiments showed that the nano could effectively compete with RGD in binding the receptors on endothelial cells. Tumor-bearing nude mice experiments showed that when containing a fluorescent-labeled siRNA of Tyr-RGD-PEG-PEI nano-drug was injected into mice, after 24 hours this nano-drug mainly distributed within the tumor tissue. However, nano-drug without Tyr-RGD appeared in tumor tissue as well as other organs such as livers, lungs, etc. The Tyr-RGD-targeted gene vector Tyr-RGD-PEG-PEI synthesized in this study has good nanoparticle properties and high efficiency of gene-drug encapsulation. Study of nude mice shows that the ability of its tumor-targeting is significantly better than nano-drug without Tyr-RGD.
Animals ; Endothelial Cells ; metabolism ; Gene Transfer Techniques ; Genetic Vectors ; Humans ; Integrins ; biosynthesis ; Mice ; Mice, Nude ; Nanoparticles ; Oligopeptides ; chemical synthesis ; pharmacology ; RNA, Small Interfering

OBJECTIVETest the cytokines secretion by peripheral blood mononuclear cells (PBMC) from hepatitis C patients after stimulation with highly variable region (HVR1) synthetic peptides.

METHODSELISA was used to test the cytokines secretion, flow cytometry to group the proliferated cells, and the antigenicity of synthetic peptide was predicted by the computer modeling.

RESULTS(1)There were PBMC proliferation when stimulated by HVR1 antigen synthetic peptides. (2) There was a rise of IFN-gamma, IL-4 and IL-10. But no rise of IL-2 and TNF-gamma was found. (3) The proliferated cells were mainly CD4+ lymphocytes.

CONCLUSIONPMBC from hepatitis C patients tend to secret Th2 cytokines after stimulation with HVR1 designed by the authors.

Amino Acid Sequence ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Hepatitis C ; blood ; virology ; Humans ; Interferon-gamma ; metabolism ; Interleukin-10 ; metabolism ; Interleukin-4 ; metabolism ; Leukocytes, Mononuclear ; cytology ; drug effects ; metabolism ; Oligopeptides ; chemical synthesis ; chemistry ; pharmacology ; Time Factors

OBJECTIVETo measure the immunogenicity of a synthetic peptide of glucosyltransferase (GTF) for designing synthetic peptide-based vaccine of dental caries.

METHODSA fusion 27-mer peptide, containing the conserved regions within catalytic and glucan-binding domains of GTF, was synthesized. Serum antibodies to the synthetic peptide were determined by ELISA method. Inhibitions of both GTF activity and S. mutans adherence were detected for the functions of antisera.

RESULTSThe sequence of fusion peptide vaccine was ANDVDNSNPVVQAEQLYFRANGVQVKG. The spleen weights of immunized mice were heavier than the control ones. Specific antibodies were effectually elicited. The immune sera not only inhibited GTF enzymatic activity but also inhibited the vitro adherence of S. mutans.

CONCLUSIONSThe peptide vaccine which involves antibody-mediated inhibition of the catalytic and the glucan-binding activities of GTF may be valuable for controlling the dental caries.

Amino Acid Sequence ; Animals ; Antibodies ; blood ; Bacterial Adhesion ; drug effects ; Dose-Response Relationship, Drug ; Glucosyltransferases ; antagonists & inhibitors ; genetics ; immunology ; Immune Sera ; pharmacology ; Immunization ; Male ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Oligopeptides ; administration & dosage ; chemical synthesis ; immunology ; Rats ; Streptococcus mutans ; drug effects ; physiology ; Vaccines, Subunit ; administration & dosage ; chemical synthesis ; immunology

His-Phe-Tyr-Leu-Pro-Met (HFYLPM) is a synthetic peptide that stimulates Jurkat T cells resulting in intracellular calcium ([Ca2+]i) increase in a pertussis toxin (PTX)-sensitive manner. We have examined the physiological role of the peptide in T cell activity by comparative investigation of intracellular signaling pathways accompanied with HFYLPM-induced T cell chemotaxis with a well-known chemokine, stromal cell-derived factor-1 (SDF-1)-induced signalings. Wortmannin and genistein inhibited both of HFYLPM- and SDF-1-induced Jurkat T cell chemotaxis indicating that phosphoinositide-3-kinase and tyrosine kinase activity were required for the processes. However, U-73122 and BAPTA/AM preferentially blocked HFYLPM- but not SDF-1-induced T cell chemotaxis. It indicates that phospholipase C/calcium signaling is necessary for only chemotaxis by HFYLPM. One of the well-known cellular molecules involving chemotaxis, extracellular signal-regulated protein kinase (ERK), was activated by SDF-1 but not by HFYLPM ruling out a possible role of ERK on the peptide-mediated chemotaxis. These results indicate that the synthetic peptide, HFYLPM, stimulates T cell chemotaxis showing unique signaling and provide a useful tool for the study of T cell activation mechanism.
1-Phosphatidylinositol 3-Kinase/metabolism ; Androstadienes/pharmacology ; Calcium/metabolism ; Cell Line ; Chemokines, CXC/*pharmacology ; Chemotaxis, Leukocyte/drug effects/*physiology ; Dose-Response Relationship, Drug ; Genistein/pharmacology ; Human ; Jurkat Cells ; Oligopeptides ; Peptide Fragments/chemical synthesis/metabolism/*physiology ; Pertussis Toxin ; Phospholipase C/metabolism ; Protein-Tyrosine Kinase/metabolism ; Signal Transduction/drug effects ; T-Lymphocytes/*drug effects ; Virulence Factors, Bordetella/pharmacology