Abstract
Four new macrocyclic polypeptides were isolated and identified from an extract of the tropical tree Chassalia parvifolia. Circulins C-F are 29-30 amino acid cyclic peptides in which the entire primary amino acid chain is covalently cyclized via peptide bonds. Their structures were deduced from a combination of FABMS analyses, N-terminal Edman degradation, endoproteinase digestion, and amino acid analyses. All the peptides share a high degree of sequence homology and contain six cysteine residues forming three intramolecular disulfide bridges. Circulins C-F inhibited the cytopathic effects of in vitro HIV-1 infection with EC(50) values of 50-275 nM.
Publication types
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Alkylation
-
Amino Acid Sequence
-
Anti-Bacterial Agents / analysis*
-
Anti-Bacterial Agents / isolation & purification
-
Anti-Bacterial Agents / pharmacology
-
Anti-HIV Agents / analysis*
-
Anti-HIV Agents / isolation & purification
-
Anti-HIV Agents / pharmacology
-
Chromatography, High Pressure Liquid
-
Cyclotides*
-
Cysteine / analysis
-
HIV-1 / drug effects
-
Humans
-
Microbial Sensitivity Tests
-
Molecular Sequence Data
-
Oxidation-Reduction
-
Plant Stems / chemistry
-
Plants, Medicinal / chemistry*
-
Spectrometry, Mass, Fast Atom Bombardment
-
Tasmania
Substances
-
Anti-Bacterial Agents
-
Anti-HIV Agents
-
Cyclotides
-
circulin
-
Cysteine