Journal of Spectroscopy

Journal of Spectroscopy / 2003 / Article

Open Access

Volume 17 |Article ID 941801 | https://doi.org/10.1155/2003/941801

Ping Huang, Aichun Dong, "Thermal, chemical and chemothermal denaturation of yeast enolase", Journal of Spectroscopy, vol. 17, Article ID 941801, 15 pages, 2003. https://doi.org/10.1155/2003/941801

Thermal, chemical and chemothermal denaturation of yeast enolase

Abstract

We studied the temperature‒ and denaturant‒induced denaturation of yeast enolase by means of Fourier transform infrared spectroscopy. The temperature‒induced denaturation/aggregation of the enzyme in the absence of denaturant was highly cooperative and occurred between 55 and 65°C with a midpoint of ~58°C. Above 55°C, the intensity at 1656 cm−1 (predominantly α‒helix) decreases as a function of temperature, accompanied by the appearance of two new bands at 1622 and 1696 cm−1, indicating the formation of intermolecular β‒sheet aggregates. Five clearly defined isosbestic points were observed, indicating a two‒state conformational transition. Addition of a non‒denaturing concentration of gdnHCl (0.4 M) caused the thermal denaturation/aggregation of the enzyme to proceed faster, but this revealed no unfolding intermediate. The gdnHCl‒induced unfolding was first detected at a gdnHCl concentration of above 0.4 M, evidenced by loss of α‒helix and β‒sheet structures as functions of denaturant concentration. The fully unfolded state was reached at a gdnHCl concentration of 1.6 M. A significant amount of intermolecular β‒sheet aggregate was detected at gdnHCl concentrations between 0.6 and 1.0 M, which disappeared as the denaturant concentration increased further. The gdnHCl‒unfolded state is a heterogeneous ensemble of turns, helix/loops, and random structures, which continues to change at higher concentrations of denaturant.

Copyright © 2003 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


More related articles

 PDF Download Citation Citation
 Order printed copiesOrder
Views873
Downloads606
Citations

We are committed to sharing findings related to COVID-19 as quickly as possible. We will be providing unlimited waivers of publication charges for accepted research articles as well as case reports and case series related to COVID-19. Review articles are excluded from this waiver policy. Sign up here as a reviewer to help fast-track new submissions.