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The βαβαβ elementary supersecondary structure of the Rossmann fold from porcine lactate dehydrogenase exhibits characteristics of a molten globule
Author(s) -
Coinçon Mathieu,
Heitz Annie,
Chiche Laurent,
Derreumaux Philippe
Publication year - 2005
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.20507
Subject(s) - molten globule , protein secondary structure , protein folding , chemistry , crystallography , fold (higher order function) , circular dichroism , protein tertiary structure , lactate dehydrogenase , folding (dsp implementation) , protein structure , biophysics , biochemistry , biology , enzyme , computer science , electrical engineering , programming language , engineering
Protein classifications show that the Rossmann fold, which consists of two βαβαβ motifs (BABAB) related by a rough twofold axis, is the most populated αβ fold, and that the βαβ submotif (BAB) is a widespread elementary structural arrangement. Herein, we report MD simulations, circular dichroism and NMR analyses on BAB and BABAB from porcine lactate dehydrogenase to evaluate their intrinsic stability. Our results demonstrate that BAB is not stable in solution and is not a folding nucleus. We also find that BABAB, despite its appearance of a functional and structural unit, is not an independent and thermodynamically stable folding unit. Rather, we show that BABAB retains most native secondary structure but very little tertiary structure, thus displaying characteristics of a molten globule. Proteins 2005. © 2005 Wiley‐Liss, Inc.