Complex kinetics and residual structure in the thermal unfolding of yeast triosephosphate isomerase

BMC Biochemistry
Ariana Labastida-PolitoAndrés Hernández-Arana

Abstract

Saccharomyces cerevisiae triosephosphate isomerase (yTIM) is a dimeric protein that shows noncoincident unfolding and refolding transitions (hysteresis) in temperature scans, a phenomenon indicative of the slow forward and backward reactions of the native-unfolded process. Thermal unfolding scans suggest that no stable intermediates appear in the unfolding of yTIM. However, reported evidence points to the presence of residual structure in the denatured monomer at high temperature. Thermally denatured yTIM showed a clear trend towards the formation of aggregation-prone, β-strand-like residual structure when pH decreased from 8.0 to 6.0, even though thermal unfolding profiles retained a simple monophasic appearance regardless of pH. However, kinetic studies performed over a relatively wide temperature range revealed a complex unfolding mechanism comprising up to three observable phases, with largely different time constants, each accompanied by changes in secondary structure. Besides, a simple sequential mechanism is unlikely to explain the observed variation of amplitudes and rate constants with temperature. This kinetic complexity is, however, not linked to the appearance of residual structure. Furthermore, the rate constant fo...Continue Reading

References

Feb 20, 1989·Journal of Molecular Biology·P L PrivalovN N Khechinashvili
Sep 1, 1971·Archives of Biochemistry and Biophysics·E E RozackyR W Gracy
Jan 1, 1995·Methods in Molecular Biology·B A Shirley
Apr 27, 1995·Biochimica Et Biophysica Acta·A Arroyo-Reyna, A Hernández-Arana
Jan 1, 1996·Folding & Design·R L Baldwin
Dec 19, 2002·Journal of Molecular Biology·Ignacio E Sánchez, Thomas Kiefhaber
Feb 13, 2003·Current Opinion in Structural Biology·Neil Ferguson, Alan R Fersht
May 29, 2004·Journal of Molecular Biology·Kiyoto KamagataKunihiro Kuwajima
Jul 21, 2004·Journal of Computational Chemistry·Chris OostenbrinkWilfred F van Gunsteren
Oct 12, 2004·Biochemical and Biophysical Research Communications·Mary C PearceStephen P Bottomley
Sep 4, 2007·The Protein Journal·Edgar Mixcoha-HernándezClaudia G Benítez-Cardoza
Jan 23, 2009·Current Opinion in Structural Biology·Carlo Travaglini-AllocatelliStefano Gianni
Oct 26, 2013·Journal of Molecular Biology·Luis M Blancas-MejíaMarina Ramirez-Alvarado
Mar 1, 2008·Journal of Chemical Theory and Computation·Berk HessErik Lindahl

❮ Previous
Next ❯

Methods Mentioned

BETA
circular dichroism

Software Mentioned

PROPKA
GROMOS96
GROMACS

Related Concepts

Related Feeds

Bacterial Cell Wall Structure

Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids. Here is the latest research on bacterial cell wall structures.

Bacterial Cell Wall Structure (ASM)

Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids. Here is the latest research on bacterial cell wall structures.