2TBS

COLD-ADAPTION OF ENZYMES: STRUCTURAL COMPARISON BETWEEN SALMON AND BOVINE TRYPSINS

Replaces:  1TBS

Summary for 2TBS

• Entry DOI: 10.2210/pdb2tbs/pdb
• Descriptor: TRYPSIN, CALCIUM ION, BENZAMIDINE, ... (4 entities in total)
• Functional Keywords: hydrolase(serine proteinase)
• Biological source: Salmo salar (Atlantic salmon)
• Cellular location: Secreted, extracellular space: P35031
• Total number of polymer chains: 1
• Total formula weight: 23944.87

Authors

Smalas, A.O. (deposition date: 1994-01-14, release date: 1994-04-30, Last modification date: 2024-12-25)

Primary citation

Smalas, A.O.,Heimstad, E.S.,Hordvik, A.,Willassen, N.P.,Male, R.
Cold adaption of enzymes: structural comparison between salmon and bovine trypsins.
Proteins, 20:149-166, 1994

PubMed Abstract: The crystal structure of an anionic form of salmon trypsin has been determined at 1.82 A resolution. We report the first structure of a trypsin from a phoikilothermic organism in a detailed comparison to mammalian trypsins in order to look for structural rationalizations for the cold-adaption features of salmon trypsin. This form of salmon trypsin (ST II) comprises 222 residues, and is homologous to bovine trypsin (BT) in about 65% of the primary structure. The tertiary structures are similar, with an overall displacement in main chain atomic positions between salmon trypsin and various crystal structures of bovine trypsin of about 0.8 A. Intramolecular hydrogen bonds and hydrophobic interactions are compared and discussed in order to estimate possible differences in molecular flexibility which might explain the higher catalytic efficiency and lower thermostability of salmon trypsin compared to bovine trypsin. No overall differences in intramolecular interactions are detected between the two structures, but there are differences in certain regions of the structures which may explain some of the observed differences in physical properties. The distribution of charged residues is different in the two trypsins, and the impact this might have on substrate affinity has been discussed.

PubMed: 7846025
DOI: 10.1002/prot.340200205

Experimental method

X-RAY DIFFRACTION (1.8 Å)