Study on the antibacterial activities of emodin derivatives against clinical drug-resistant bacterial strains and their interaction with proteins.

ABSTRACT: Background:Novel haloemodin (HEI2) synthesized by modifying emodin, a traditional Chinese medicine component, possesses remarkable antibacterial activity, being much more effective than its parent nucleus, emodin. Methods:Firstly, we discovered that HEI2 increases bacterial cell membrane permeability to potassium ions more drastically than emodin. We thus further investigated the interaction of haloemodin and protein using a fluorescence quenching and circular dichroism (CD) study based on bovine serum albumin (BSA). Results:HEI2 spontaneously bound to BSA at Trp 212 residue (subdomain IIA) by hydrogen bonds and van der Waals interactions to forms HEI2-BSA complexes, and this binding decreased the ?-helical content of BSA. We also confirmed that emodin bound to BSA by hydrophobic interaction alone. Conclusions:These results suggest that the main responses for the substantial antibacterial activities of HEI2 are a disruption of the bacterial plasma membrane function and the interaction with biological functional proteins. Furthermore, the study of the interaction of drugs with BSA, which has a fluorescent group tryptophan residue similar to many bio-functional proteins, will be a simple and inexpensive scope-reducing method in screening new drugs.

SUBMITTER: Ji C 

PROVIDER: S-EPMC7049003 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature