Dedicated in memory of the late Prof. Elkan R. Blout who pioneered the art and science of physical protein chemistry and will be remembered for his unique virtue in bringing together wisdom, vision, and “mentchlichkeit.”
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Structural insights into cold inactivation of tryptophanase and cold adaptation of subtilisin S41†
Article first published online: 15 OCT 2007
DOI: 10.1002/bip.20866
Copyright © 2008 Wiley Periodicals, Inc.
Issue
Biopolymers
Special Issue: This issue is dedicated to the memory of Elkan R. Blout, a founding editor of Biopolymers
Volume 89, Issue 5, pages 354–359, May 2008
Additional Information
How to Cite
Almog, O., Kogan, A., Leeuw, M. d., Gdalevsky, G. Y., Cohen-Luria, R. and Parola, A. H. (2008), Structural insights into cold inactivation of tryptophanase and cold adaptation of subtilisin S41. Biopolymers, 89: 354–359. doi: 10.1002/bip.20866
- †
Publication History
- Issue published online: 28 FEB 2008
- Article first published online: 15 OCT 2007
- Manuscript Accepted: 5 OCT 2007
- Manuscript Revised: 3 OCT 2007
- Manuscript Received: 23 JUL 2007
Funded by
- James Frank Foundation on Light Matter Interaction
- Helen Soref grant
- Stanley Medical Research Foundations
- Abstract
- Article
- References
- Cited By
Keywords:
- psychro-meso-and thermophilic organisms;
- hydrophobic interactions;
- surface charge;
- crystal structure;
- thermolabile;
- PLP-dependent enzymes;
- quaternary structure
Abstract
A wide variety of enzymes can undergo a reversible loss of activity at low temperature, a process that is termed cold inactivation. This phenomenon is found in oligomeric enzymes such as tryptophanase (Trpase) and other pyridoxal phosphate dependent enzymes. On the other hand, cold-adapted, or psychrophilic enzymes, isolated from organisms able to thrive in permanently cold environments, have optimal activity at low temperature, which is associated with low thermal stability. Since cold inactivation may be considered “contradictory” to cold adaptation, we have looked into the amino acid sequences and the crystal structures of two families of enzymes, subtilisin and tryptophanase. Two cold adapted subtilisins, S41 and subtilisin-like protease from Vibrio, were compared to a mesophilic and a thermophilic subtilisins, as well as to four PLP-dependent enzymes in order to understand the specific surface residues, specific interactions, or any other molecular features that may be responsible for the differences in their tolerance to cold temperatures. The comparison between the psychrophilic and the mesophilic subtilisins revealed that the cold adapted subtilisins have a high content of acidic residues mainly found on their surface, making it charged. The analysis of the Trpases showed that they have a high content of hydrophobic residues on their surface. Thus, we suggest that the negatively charged residues on the surface of the subtilisins may be responsible for their cold adaptation, whereas the hydrophobic residues on the surface of monomeric Trpase molecules are responsible for the tetrameric assembly, and may account for their cold inactivation and dissociation. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 354–359, 2008.
This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com