NACSDKP ANALOGS RESISTANT TO ANGIOTENSIN-CONVERTING ENZYME

Two series of analogues of the tetrapeptide NAcSDKP, an inhibitor of h ematopoietic stem cell proliferation, were prepared, and their enzymat ic stability toward rabbit lung angiotensin-converting enzyme (ACE) wa s evaluated as well as their capacity to inhibit NAcSDKP hydrolysis by this enzyme. In the first series, each of the peptide bonds has been successively replaced by an aminomethylene bond. In the second one, th e C-terminus of the peptide has been modified by decarboxylation or am idation. The results reported here indicate that all of these molecule s but one have good stability toward the enzyme but none of the compou nds is able to inhibit NAcSDKP hydrolysis by ACE.