The effect of calcium ion on the urea denaturation of immobilized bovine trypsin.

Abstract

The effect of calcium ion on the urea denaturation of trypsin has been investigated. By using trypsin immobilized on glass beads, all possibilities of autolysis occurring during the denaturation process are eliminated. It was found that in 8 M urea calcium ion markedly decreases the denaturation rate of the immobilized trypsin. Conversely, the presence of calcium ion markedly accelerates the rate of renaturation of denatured immobilized trypsin. Calcium may exert its stabilizing effect on the tertiary structure of the protein by coordination to the side chains of Asp 194, Ser 190 and the carbonyl group of Ser 139 (using the chymotryptic numbering system).

• Authors: J E Gomez, E R Birnbaum, G P Royer, D W Darnall
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 495 Issue 1 Pg. 177-82 (Nov 25 1977) ISSN: 0006-3002 [Print] Netherlands
• PMID: 562193 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Enzymes, Immobilized
• Urea
• Trypsin
• Calcium

Topics

• Animals
• Calcium
• Cattle
• Enzymes, Immobilized
• Kinetics
• Protein Denaturation
• Trypsin
• Urea