FEBS Letters · 1997 · 12 citations · 27 references
Life SciencesBiochemistryMolecular BiologyEnzymologyProtein FoldingStructural BiologyDisulfide Bond FormationEnzyme StabilityFolding IntermediatesFolding KineticsMolecular ChaperonesProtein Folding PathwaysBeta-lactamase Structure-function RelationshipsDisulfide Bond IsomerizationDisulfide Bond StabilityDisulfide Bond StructureDisulfide-bonded IntermediatesLate Folding IntermediatesMisfolding KineticsProline Isomerization Intermediates
beta-Lactamase, from which the disulfide bond was removed by two Cys-->Ala mutations, forms stable complexes with GroEL only during the first 30 s of folding, while wild-type beta-lactamase forms no stable complex under these conditions. The 3-phasic kinetics of folding are very similar between wild-type and mutant. After 4 s, Trp-210 is already juxtaposed to the disulfide bond, but proline cis-trans isomerization has not yet taken place and almost no enzymatic activity is observed. This shows that GroEL is unable to bind late folding intermediates and also discriminates between the degree of unfolding possible in wild-type disulfide-containing beta-lactamase and the Cys-Ala mutant.
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Evidence for a molten globule state as a general intermediate in protein folding
Oleg B. Ptitsyn, Roger H. Pain, Gennady V. Semisotnov et al. · FEBS Letters · 1990 · 678 citations