Influence of Amino Acid Substitutions in a Recombinant Cow Chymosin Molecule on the Dependence of its Coagulation Activity on the Concentration of Calcium Chloride in Milk

The influence of substitutions of amino acids involved in the formation of salt bridges on the cow chymosin technological properties has been studied. It was shown that point amino acid mutations Asp198→Lys, Asp156→Val and their combination decrease the sensitivity of coagulation activity of engineering recombinant chymosins to change in the concentration of calcium chloride in milk in the range of 1-5 mM. The found effect is a positive technological evidence in terms of cheese making, since it allows varying the content of calcium chloride added to the milk mixture without a threat of significant changes in the undesired proteolytic activity of used milk-clotting enzyme. recombinant chymosin, technological properties, amino acid substitutions, milk-clotting activity, concentration of calcium chloride. The work was performed within the framework of the state task of the Ministry of science and higher education of the Russian Federation (topic number fzmw-2020-0002, "Development of recombinant enzyme producers for cheese making").