Enzyme activation by urea reveals the interplay between conformational dynamics and substrate binding: a single-molecule FRET study.

ABSTRACT: Proteins often harness extensive motions of domains and subunits to promote their function. Deciphering how these movements impact activity is key for understanding life's molecular machinery. The enzyme adenylate kinase is an intriguing example for this relationship; it ensures efficient catalysis by large-scale domain motions that lead to the enclosure of the bound substrates ATP and AMP. At high concentrations, AMP also operates as an allosteric inhibitor of the protein. Surprisingly, the enzyme is activated by urea, a compound commonly acting as a denaturant. Combining single-molecule FRET spectroscopy and enzymatic activity studies, we find that urea interferes with two key mechanisms that contribute to enzyme efficacy. First, urea promotes the open conformation of the enzyme, aiding

SUBMITTER: Scheerer D 

PROVIDER: S-EPMC11384010 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature