2tbs
From Proteopedia
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COLD-ADAPTION OF ENZYMES: STRUCTURAL COMPARISON BETWEEN SALMON AND BOVINE TRYPSINS
Overview
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.
About this Structure
2TBS is a Single protein structure of sequence from Salmo salar with CA and BEN as ligands. This structure superseeds the now removed PDB entry 1TBS. Active as Trypsin, with EC number 3.4.21.4 Full crystallographic information is available from OCA.
Reference
Cold adaption of enzymes: structural comparison between salmon and bovine trypsins., Smalas AO, Heimstad ES, Hordvik A, Willassen NP, Male R, Proteins. 1994 Oct;20(2):149-66. PMID:7846025
Page seeded by OCA on Wed Nov 21 14:03:52 2007
