Four macrocyclic cystine-knot peptides of 29–31 residues, kalata, circulin A and B (CirA CirB), cyclopsychotride, have been isolated from coffee plants but undetermined physiological functions. These macrocycles 10 their analogs prepared by chemical synthesis were tested against nine strains microbes. Kalata CirA specific for the Gram-positive Staphylococcus aureus with a minimum inhibition concentration ≈0.2 μM. They relatively ineffective Gram-negative bacteria such as Escherichia coli...

Dendrimeric peptides selective for microbial surfaces have been developed to achieve broad antimicrobial activity and low hemolytic human erythrocytes. The dendrimeric core is an asymmetric lysine branching tethered with two eight copies of a tetrapeptide (R4) or octapeptide (R8). R4 (RLYR) contains putative surface recognition BHHB motif (B = basic, H hydrophobic amino acid) found in protegrins tachyplesins whereas the R8 (RLYRKVYG) consists degenerated repeat. Antimicrobial assays against...

We show here an effective and novel approach to engineer peptide-based vaccines using a chemically defined system, known as multiple peptide antigen systems (MAPs), protect inbred mouse strain from infection against rodent malaria. 10 mono- di-epitope MAP models containing different arrangements stoichiometry of functional B and/or T helper cell epitopes the circumsporozoite protein Plasmodium berghei were used immunize A/J mice. While these mice did not respond mono-epitope bearing only or...

We describe an approach to the synthesis of peptides from segments bearing no protecting groups through orthogonal coupling method capture acyl segment as a thioester that then undergoes intramolecular transfer amine component with formation peptide bond. Two methods give covalent ester intermediate were achieved by either thiol-thioester exchange mediated trialkylphosphine and alkylthiol or thioesterification C alpha-thiocarboxylic acid reacting beta-bromo amino acid. With this approach,...

Abstract This paper describes a simple biomimetic strategy to prepare small cyclic proteins containing multiple disulfide bonds. Our involves intramolecular acyl transfer reactions assist both the synthesis and fragmentation of these highly constrained structures in aqueous solution. To illustrate our strategy, we synthesized naturally occurring circulin B cyclopsychotride (CPT), consisting 31 amino acid residues tightly packed cystine‐knot motif with three bonds an end‐to‐end form. The can...

Multiple Ag peptide (MAP) system without the use of a protein carrier was used as vaccine model in three species animals. Synthetic peptides from V3 region gp120 IIIB, RF and MN HIV-1 isolates were Ag. MAP consisting various chain lengths, 11 to 24 residues, prepared monoepitope configuration containing four repeats each individual peptide. In parallel, they synthesized diepitope adding at carboxyl-terminus conserved sequence, known be Th cell epitope gp120. The antibody response elicited by...

We report the development of two models for synthetic hepatitis B vaccines. The were based on multiple antigen peptide (MAP) system and contained relevant B- T-cell epitopes without any macromolecular carrier. Two peptides, representing a determinant S region (S protein) surface antigen, dominant serotype virus infection found in humans, residues 12-26 pre-S(2) middle protein incorporated as either monoepitope or diepitope MAP models. Immunizations outbred rabbits with that contains resulted...

This paper describes the mechanism and application of an efficient thia zip cyclization that involves a series intramolecular rearrangements in cysteine-rich peptide for synthesis large end-to-end cyclic peptides. Key functional groups required this reaction include Nα-cysteine, thioester, at least one internal free thiol peptide. The is initiated by transthioesterification through with thioester. A thiolactone formed under ring−chain tautomeric equilibrium favors ring formation aqueous...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoupling Difficulty Associated with Interchain Clustering and Phase Transition in Solid Peptide SynthesisJames P. Tam Yi-An LuCite this: J. Am. Chem. Soc. 1995, 117, 49, 12058–12063Publication Date (Print):December 1, 1995Publication History Published online1 May 2002Published inissue 1 December 1995https://pubs.acs.org/doi/10.1021/ja00154a004https://doi.org/10.1021/ja00154a004research-articleACS PublicationsRequest reuse permissionsArticle...

Diabetic retinopathy (DR) is a leading cause of vision loss among adults. This study evaluates Optical Coherence Tomography Angiography (OCTA) vessel density (VD) as marker for DR in diabetes mellitus (DM) patients. An observational was conducted with 47 type 2 DM patients and 21 healthy controls. OCTA measured superficial deep retinal VD the parafoveal region. Statistical analyses, including logistic regression ROC curve analysis, were used to assess association between presence. Results...

To track quantitative laryngeal electromyography (LEMG) and voice outcome survey (VOS) changes over 12 months postiatrogenic unilateral vocal fold paralysis (UVFP). explore the factors influencing these changes. Historical cohort study. Tertiary medical center. Patients who developed UVFP after surgery underwent a series of assessments, including LEMG, videolaryngostroboscopy, acoustic analysis, completion VOS at diagnosis 12-month follow-up. The subsequent data from assessments were then...

The electrostatic interaction of the charge cluster an amphipathic peptide antibiotic with microbial membranes is a salt-sensitive step that often determines organism specificity. We have examined correlation between clusters and salt insensitivity specificity in linear, cyclic, retro-isomeric cystine-stabilized β-strand (CSβ) tachyplesin (TP) panel 10 test organisms. Cyclic tachyplesins consisting 14 18 amino acids are constrained by end-to-end backbone two or three disulfide bonds to...

We have characterized the immune response of mice to multiple Ag peptide systems (MAP) containing immunodominant B cell epitope (NANP)3 and one three distinct Th epitopes, Th2R, Th3R, CS.T3, C terminal region circumsporozoite protein Plasmodium falciparum, a human malaria parasite. Mice different MHC haplotypes (H-2k, H-2d, H-2a) were immunized with various MAP constructs. all strains produced antibodies, but their anti-sporozoite titers considerably lower than anti-peptide as detected by...

Esophageal cancer is a deadly disease, and neoadjuvant chemoradiotherapy can improve patient survival, particularly for patients achieving pathological complete response (ypCR). However, existing imaging methods struggle to accurately predict ypCR. This study explores computer-aided detection methods, considering both data radiotherapy dose variations enhance prediction accuracy. It involved with node-positive esophageal squamous cell carcinoma undergoing surgery, collected from 2014 2017,...

Abstract The aim of this study was to assess associations between fat pad areas at various anatomic levels and the sites lateral wall collapse disease severity in adult patients with obstructive sleep apnea (OSA). Forty-one OSA who prospectively underwent drug-induced computed tomography were included. Areas parapharyngeal pads degrees three representative (nasopharynx, oropharynx, subglosso-supraglottis), apnea-hypopnea index (AHI) measured. In subglosso-supraglottic region, area 17 (41%)...

Cyclic peptide backbone and cystine constraints were used to develop a broadly active salt-insensitive antimicrobial [Gly6]ccTP 1a with eight Gly residues in an 18-residue sequence. The importance of rigidity amphipathicity imparted by the cyclic was examined two series based on tachyplesin, known β-stranded peptide. first series, which retained charge hydrophobic amino acids but contained zero four covalent constraints, included tricystine tachyplesin (ccTP 1). Corresponding [Gly6]...

Conditions have been developed for the site‐specific pegylation (NH 2 ‐terminus, side‐chain and carboxyterminus) of a potent analog growth hormone‐releasing factor, [Ala 15 ]‐hGRF(1‐29)‐NH . These pegylated peptides were prepared by solid‐phase peptide synthesis using Fmoc/tBu strategy, fully characterized analytical HPI.C, amino‐acid analysis, 1 H‐NMR spectroscopy laser desorption mass spectrometry. Biological activities hGRF analogs determined in vitro utilizing stimulation hormone release...