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Temperature adaptation of glutathione S-transferase P1-1. A case for homotropic regulation of substrate binding.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 1999 Jul 02; Vol. 274 (27), pp. 19276-80. - Publication Year :
- 1999
-
Abstract
- Human glutathione S-transferase P1-1 (GST P1-1) is a homodimeric enzyme expressed in several organs as well as in the upper layers of epidermis, playing a role against carcinogenic and toxic compounds. A sophisticated mechanism of temperature adaptation has been developed by this enzyme. In fact, above 35 degrees C, glutathione (GSH) binding to GST P1-1 displays positive cooperativity, whereas negative cooperativity occurs below 25 degrees C. This binding mechanism minimizes changes of GSH affinity for GST P1-1 because of temperature fluctuation. This is a likely advantage for epithelial skin cells, which are naturally exposed to temperature variation and, incidentally, to carcinogenic compounds, always needing efficient detoxifying systems. As a whole, GST P1-1 represents the first enzyme which displays a temperature-dependent homotropic regulation of substrate (e.g. GSH) binding.
- Subjects :
- Amino Acid Substitution
Glutathione metabolism
Glutathione S-Transferase pi
Glutathione Transferase metabolism
Isoenzymes metabolism
Models, Chemical
Models, Molecular
Mutagenesis, Site-Directed
Protein Binding
Tyrosine metabolism
Adaptation, Physiological
Glutathione Transferase physiology
Isoenzymes physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 274
- Issue :
- 27
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 10383436
- Full Text :
- https://doi.org/10.1074/jbc.274.27.19276