Stability and folding studies of the N-domain of troponin C. Evidence for the formation of an intermediate

Protein Folding, Misfolding and Aggregation: Evolving Concepts and Conformational Diseases

“…The best studied examples of proteins that exhibit hierarchic folding behavior are dihydrofolate reductase [63] and apomyoglobin ( [64], see also the review by Jamin in this issue). Recent simulation [65] and experimental [24,25] studies have provided additional support for the hierarchic mechanism of folding. By contrast, a non-hierarchic model of folding assumes that non-local interactions not only stabilize but also determine the secondary structures.…”

“…Does that mean that two different mechanisms of folding exist (i.e., small two-state folders versus larger proteins that exhibit folding intermediates)? Recent studies showing that even small proteins may deviate from a twostate unfolding profile and populate an intermediate during unfolding [24] and that proteins that normally fold through intermediates can be "transformed" into two-state folders by site-directed mutagenesis [25] suggest that the answer to this question is probably no. Along the same line, studies with small de novo designed model proteins have illuminated interesting aspects of folding [26].…”

“…[137,140,142]. The presence of more than one transition or non-superimposable curves would indicate that the unfolding process is more complex than a two-state mechanism and the presence of one or more intermediates in the folding pathway [5,11,24].…”

Identification of a Dimeric Intermediate in the Unfolding Pathway for the Calcium-Binding Protein S100B

“…Other proteins such as the C-terminal of calmodulin are conformationally heterogeneous in the absence of calcium, exhibiting slow conformational motion consistent with multiple partly folded states. 30,31 Further, protein folding experiments have shown that calmodulin, 32 the N-terminal domain from troponin-C, 33 and CIB1 29 form at least one stable intermediate at low denaturant concentrations. Recently, the folding kinetics of apo-S100A11 have been studied by mass spectrometry and show that at least two kinetic intermediates are formed during the folding pathway for this protein.…”

Characterization of the fast skeletal troponin C (<i>TNNC2</i>) gene in three Chinese native sheep breeds

“…Hence, it is essential to test the association between TNNC2 and meat quality. Previous studies about TNNC2 gene mostly concerned on the effect of structure on muscle contraction in human and model animals (GILLIS and TIBBITS, 2000;RAMOS et al, 2004). The aim of this study is to investigate the effects of TNNC2 single nucleotide polymorphism (SNP) on sheep meat quality traits in three Chinese native sheep populations by means of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP).…”