Methods for carboxypeptidases

Abstract

A method for detecting alteration in a kinase or phosphatase reaction is provided. In the method, a test substance is contacted to a peptide substrate including a reporter compound and amino acids under conditions in which the kinase or phosphatase is active. The substrate is cleaved with a carboxypeptidase. Phosphorylation of the substrate affects cleavage by the carboxypeptidase. Output of the reporter compound is detected. The reporter compound exhibits a different output property when bound to at least one amino acid of the substrate when compared to when it is not bound to amino acids. Change in output compared to output of a control sample that has not been contacted with the test substance is a measure of the alteration in the kinase or phosphatase reaction.

1 . A method for detecting alteration in a kinase or phosphatase reaction, the method comprising: 
 (A) contacting a test substance to a peptide substrate including a reporter compound and amino acids under conditions in which the kinase or phosphatase is active;    (B) cleaving the substrate with a carboxypeptidase, wherein phosphorylation of the substrate affects cleavage by the carboxypeptidase; and    (C) detecting output of the reporter compound, wherein the reporter compound exhibits a different output property when bound to at least one amino acid of the substrate when compared to when it is not bound to amino acids, wherein change in output compared to output of a control sample that has not been contacted with the test substance is a measure of the alteration in the kinase or phosphatase reaction.    
     
     
         2 . A method of  claim 1 , wherein the carboxypeptidase comprises carboxypeptidase A or carboxypeptidase B.  
     
     
         3 . A method of  claim 2 , wherein the carboxypeptidase comprises carboxypeptidase A.  
     
     
         4 . A method of  claim 2 , wherein the carboxypeptidase comprises carboxypeptidase B.