Dataset Information

Structure-based dissection of the natural product cyclopentapeptide chitinase inhibitor argifin.

ABSTRACT: Chitinase inhibitors have chemotherapeutic potential as fungicides, pesticides, and antiasthmatics. Argifin, a natural product cyclopentapeptide, competitively inhibits family 18 chitinases in the nanomolar to micromolar range and shows extensive substrate mimicry. In an attempt to map the active fragments of this large natural product, the cyclopentapeptide was progressively dissected down to four linear peptides and dimethylguanylurea, synthesized using a combination of solution and solid phase peptide synthesis. The peptide fragments inhibit chitinase B1 from Aspergillus fumigatus (AfChiB1), the human chitotriosidase, and chitinase activity in lung homogenates from a murine model of chronic asthma, with potencies ranging from high nanomolar to high micromolar inhibition. X-ray crystallographic analysis of the chitinase-inhibitor complexes revealed that the conformations of the linear peptides were remarkably similar to that of the natural product. Strikingly, the dimethylguanylurea fragment, representing only a quarter of the natural product mass, was found to harbor all significant interactions with the protein and binds with unusually high efficiency. The data provide useful information that could lead to the generation of drug-like, natural product-based chitinase inhibitors.

SUBMITTER: Andersen OA

PROVIDER: S-EPMC3764403 | biostudies-literature | 2008 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Structure-based dissection of the natural product cyclopentapeptide chitinase inhibitor argifin.

Andersen Ole A OA Nathubhai Amit A Dixon Mark J MJ Eggleston Ian M IM van Aalten Daan M F DM

Chemistry & biology 20080301 3

Chitinase inhibitors have chemotherapeutic potential as fungicides, pesticides, and antiasthmatics. Argifin, a natural product cyclopentapeptide, competitively inhibits family 18 chitinases in the nanomolar to micromolar range and shows extensive substrate mimicry. In an attempt to map the active fragments of this large natural product, the cyclopentapeptide was progressively dissected down to four linear peptides and dimethylguanylurea, synthesized using a combination of solution and solid phas ...[more]

PMID: 18355729

Similar Datasets

Project description:Natural products are an abundant source of potential drugs, and their diversity makes them a rich and viable prospective source of bioactive cannabinoid ligands. Cannabinoid receptor 1 (CB1) antagonists are clinically established and well documented as potential therapeutics for treating obesity, obesity-related cardiometabolic disorders, pain, and drug/substance abuse, but their associated CNS-mediated adverse effects hinder the development of potential new drugs and no such drug is currently on the market. This limitation amplifies the need for new agents with reduced or no CNS-mediated side effects. We are interested in the discovery of new natural product chemotypes as CB1 antagonists, which may serve as good starting points for further optimization towards the development of CB1 therapeutics. In search of new chemotypes as CB1 antagonists, we screened the in silico purchasable natural products subset of the ZINC12 database against our reported CB1 receptor model using the structure-based virtual screening (SBVS) approach. A total of 18 out of 192 top-scoring virtual hits, selected based on structural diversity and key protein?ligand interactions, were purchased and subjected to in vitro screening in competitive radioligand binding assays. The in vitro screening yielded seven compounds exhibiting >50% displacement at 10 ?M concentration, and further binding affinity (Ki and IC50) and functional data revealed compound 16 as a potent and selective CB1 inverse agonist (Ki = 121 nM and EC50 = 128 nM) while three other compounds-2, 12, and 18-were potent but nonselective CB1 ligands with low micromolar binding affinity (Ki). In order to explore the structure?activity relationship for compound 16, we further purchased compounds with >80% similarity to compound 16, screened them for CB1 and CB2 activities, and found two potent compounds with sub-micromolar activities. Most importantly, these bioactive compounds represent structurally new natural product chemotypes in the area of cannabinoid research and could be considered for further structural optimization as CB1 ligands.

Dataset Information

Structure-based dissection of the natural product cyclopentapeptide chitinase inhibitor argifin.

Publications

Structure-based dissection of the natural product cyclopentapeptide chitinase inhibitor argifin.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets