Table of Contents
Laser Chemistry
Volume 19, Issue 1-4, Pages 233-235

Temperature Induced Protein Unfolding and Folding of RNase a Studied by Time-Resolved Infrared Spectroscopy

1Institut für Biophysik und Strahlenbiologie, Albert-Ludwigs-Universität Albertstr. 23, Freiburg D-79104, Germany
2School of Biochemistry, University of Birmingham, Edgbaston, Birmingham B152TT, United Kingdom

Received 6 April 1997

Copyright © 1999 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.


When a protein finds its native three-dimensional structure from the unstructured amino-acid chain various processes spanning a large time range are relevant. To understand the mechanism of protein folding one needs to cover the entire folding/ refolding (U↔N) reaction on a structural level. In the case of RNase A, the main structural changes occur in the ms time range, that can be monitored with rapid-scan- FTIR spectroscopy combined with rapid mixing techniques. To induce unfolding we inject aqueous protein solution into a hot IR cuvette and record the time course of the spectral changes. A lag phase is found when the unfolding conditions are relatively weak, suggesting an unfolding intermediate.