Thermodynamic activation and structural analysis of trypsin I from Monterey sardine (Sardinops sagax caerulea)

In this work, we report the molecular characterisation of trypsin I (Try I) from Monterey sardine (Sardinops sagax caerulea). Aspects such as thermodynamic activation parameters, molecular model and cDNA-deduced amino acid sequence allow a more in depth understanding of its activity at low temperatures. The analysis of the thermodynamic activation parameters suggests that this molecule is a cold-adapted protease. From the molecular cloning, we deduced the amino acid sequence and predicted a theoretical structural model of sardine Try I with a classical trypsin fold. Cold-adaptation of this enzyme probably comes from amino acid replacement of key residues to improve flexibility at low temperature, thus increasing k(cat). The cold-adaptation of sardine Try I opens a wide range of biotechnological applications for this protease and also it is interesting from the structure function relationship point of view of serine protease proteins. (C) 2012 Elsevier Ltd. All rights reserved.