Comparison of the folding mechanism of highly homologous proteins in the lipid-binding protein family.

ABSTRACT: The folding mechanism of two closely related proteins in the intracellular lipid-binding protein family, human bile acid-binding protein (hBABP), and rat bile acid-binding protein (rBABP) were examined. These proteins are 77% identical (93% similar) in sequence. Both of these single domain proteins fit well to a two-state model for unfolding by fluorescence and circular dichroism at equilibrium. Three phases were observed during the unfolding of rBABP by fluorescence but only one phase was observed during the unfolding of hBABP, suggesting that at least two kinetic intermediates accumulate during the unfolding of rBABP that are not observed during the unfolding of hBABP. Fluorine NMR was used to examine the equilibrium unfolding behavior of the W49 side chain in 6-fluorotryptophan-labeled

SUBMITTER: Ropson IJ 

PROVIDER: S-EPMC6336386 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature