| Abstract: | Classical methods of peptide synthesis in solution were used for the preparation of the two tetrapeptides alanyl-lysyl-arginyl-tyrosine and acetyl-alanyl-lysyl-arginyl-tyrosine-(N-methylamide). The two compounds were able to be recognized as substrates by proenkephalin processing enzymes and were used for the development of a quantitative assay for these enzymes. The first substrate proved to be convenient, although it was also partially degraded by amino- and carboxypeptidases under the conditions of the assay. The second was found to be hydrolyzed by the endopeptidases at too slow a rate to allow its routine use in the assay. |
