A zinc metalloendopeptidase associated with dog pancreatic membranes.
1980; Elsevier BV; Volume: 255; Issue: 6 Linguagem: Inglês
10.1016/s0021-9258(19)85874-x
ISSN1083-351X
AutoresRichard A. Mumford, Arnold W. Strauss, James C. Powers, P A Pierzchala, Naoki Nishino, M.D. Zimmerman,
Tópico(s)Oral and gingival health research
ResumoAssay of solubilized dog pancreas microsomes revealed the presence of an endopeptidase which hydrolyzed the fluorogenic peptide substrate Suc-Ala-Ala-Phe-7-amino-4-methylcoumarin (AMC) between the alanine and phenylalanine positions.This activity was inhibited by phosphoramidon, 1,lO-phenanthroline, and a number of synthetic inhibitors of thermolysin indicating that the enzyme is a zinc metallopeptidase.Endopeptidase activity was not inhibited by the serine protease inhibitors elastatinal, antipain, leupeptin, Ncarbobenzyloxy-L-phenylethyl chloromethyl ketone, Ltosylamido-2-lysylethyl chloromethyl ketone, L-tosylamido-2-phenylethyl chloromethyl ketone, phenylmethanesulfonyl fluoride, or low levels of chymostatin.The endopeptidase had a pH optimum between 7.0 and 7.5.The enzyme also hydrolyzed Suc-Ala-Ala-Ala-AMC and Suc-Ala-Gly-Ala-AMC in an analogous way to yield Ala-AMC. Thermolysin hydrolyzed Suc-Ala-Ala-Phe-AMC in an analogous way to the endopeptidase.However, thermolysin did not hydrolyze Suc-Ala-Ala-Ala-AMC or Suc-Ala-Gly-Ala-AMC, demonstrating that its substrate specificity differs from the endopeptidase.
Referência(s)