Structural analysis of kinetic folding intermediates for a TIM barrel protein, indole-3-glycerol phosphate synthase, by hydrogen exchange mass spectrometry and Go model simulation.

ABSTRACT: The structures of partially folded states appearing during the folding of a (betaalpha)(8) TIM barrel protein, the indole-3-glycerol phosphate synthase from Sulfolobus solfataricus (sIGPS), was assessed by hydrogen exchange mass spectrometry (HX-MS) and Gō model simulations. HX-MS analysis of the peptic peptides derived from the pulse-labeled product of the sub-millisecond folding reaction from the urea-denatured state revealed strong protection in the (betaalpha)(4) region, modest protection in the neighboring (betaalpha)(1-3) and (betaalpha)(5)beta(6) segments and no significant protection in the remaining N and C-terminal segments. These results demonstrate that this species is not a collapsed form of the unfolded state under native-favoring conditions nor is it the native state formed

SUBMITTER: Gu Z 

PROVIDER: S-EPMC2735044 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature