title: Studying the Effects of Cysteine Residues on Protein Interactions with Silver Nanoparticles.
abstract: Studies of protein and organothiol interactions with silver nanoparticles (AgNPs) are important for understanding AgNP nanotoxicity, antimicrobial activity, and material fabrications. Reported herein is a systematic investigation of the effects of both reduced and oxidized protein cysteine residues on protein interactions with AgNPs. The model proteins included wild-type and mutated protein GB3 variants that contain 0, 1, or 2 reduced cysteine residues, respectively. Bovine serum albumin (BSA) that contains a total of 34 oxidized (disulfide-linked) cysteine residues and one reduced cysteine residue was also included. Protein cysteine content has no detectable effect on the kinetics of protein/AgNP binding. However, only proteins that contain reduced cysteine residues induce significant AgNP dissolution. Proteins can slow down, but do not prevent the AgNP dissolution induced by subsequently added organothiols. The insights provided in this work are important to the mechanistic understanding of AgNP stability in biofluids that are rich in proteins and amino acid thiols.
authors.affiliation: Department of Chemistry, Mississippi State University, Mississippi State Mississippi, 39762, United States.
authors.forename: Kumudu
authors.initials: K
authors.lastname: Siriwardana
authors.affiliation: Department of Chemistry, Mississippi State University, Mississippi State Mississippi, 39762, United States.
authors.forename: Ailin
authors.initials: A
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Mississippi State University, Mississippi State Mississippi, 39762, United States.
authors.forename: Manuel
authors.initials: M
authors.lastname: Gadogbe
authors.affiliation: Department of Chemistry, Tuskegee University, Tuskegee, Alabama 36088, United States.
authors.forename: Willard E
authors.initials: WE
authors.lastname: Collier
authors.affiliation: Department of Chemistry, Mississippi State University, Mississippi State Mississippi, 39762, United States.
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Fitzkee
authors.affiliation: Department of Chemistry, Mississippi State University, Mississippi State Mississippi, 39762, United States.
authors.forename: Dongmao
authors.initials: D
authors.lastname: Zhang