Proteinase Resistance of Carnosine, Pyrrolylcarnosine and Salicylcarnosine

Objective: The resistance of carnosine, pyrrolylcarnosine (PC) and salicylcarnosine (SC) to the action of leucine aminopeptidase and carboxypeptidases B and Y was evaluated. Methods: Proteolysis of carnosine and its derivatives under the action of leucine aminopeptidase, carboxypeptidases Y and B, or under the action of enzyme systems of plasma membranes of rat brain cells or blood plasma. Results and Discussion: It was found that proteolysis of carnosine, PC and SC under the action of leucine aminopeptidase does not occur. Carboxypeptidases B and Y, as well as the enzyme systems of blood plasma and plasma membranes of rat brain cells, degraded peptides containing β-alanyl, N-pyrrolyl, N-salicylic fragments to varying degrees. In all cases, histidine was formed. The formation of pyrrole or salicylic acid did not occur. Conclusions: It was found that carnosine, PC and SC showed high resistance to the action of amino- and carboxypeptidases in in vitro experiments.