Small heat shock protein HSPB5 uses disorder to bind zinc with high affinity.

ABSTRACT: Zinc is an essential metal that supports diverse cellular functions. Zinc exerts its biological activity through protein binding, serving as catalytic cofactors and structural stabilizers of many enzymes, transcription factors, and ubiquitin E3 ligases, among others. Despite total cellular zinc concentrations reaching hundreds of micromolar, free zinc levels are tightly buffered. Elevated free zinc promotes mismetalation and protein aggregation. While zinc is redox-inert, its cysteine-based protein ligands are readily oxidized. Oxidative modification of cysteines leads to zinc dissociation and a rapid increase in free zinc. With ~3000 proteins in the human zinc proteome, uncontrolled zinc release could be highly deleterious. Metallothioneins buffer zinc under basal conditions, but their re

SUBMITTER: Janowska MK 

PROVIDER: S-EPMC12632755 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature