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.