Differences in the mechanical unfolding pathways of apo- and copper-bound azurins.

ABSTRACT: Metalloproteins carry out diverse biological functions including metal transport, electron transfer, and catalysis. At present, the influence of metal cofactors on metalloprotein stability is not well understood. Here, we report the mechanical stability and unfolding pathway of azurin, a cupredoxin family protein with β-barrel topology and type I copper-binding centre. Single-molecule force spectroscopy (SMFS) experiments reveal 2-state and 3-state unfolding pathways for apo-azurin. The intermediate in the 3-state pathway occurs at an unfolding contour length of 7.5 nm from the native state. Steered molecular dynamics (SMD) simulations show that apo-azurin unfolds via a first transition state (TS) where β2Β-β8 and β7-β8 strand pairs rupture to form the intermediate, which subsequently unfo

SUBMITTER: Yadav A 

PROVIDER: S-EPMC5792602 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature