TY - JOUR
T1 - Substrate specificity differences between recombinant rat testes endopeptidase EC 3.4.24.15 and the native brain enzyme
AU - Lew, Rebecca A.
AU - Hey, Nina J.
AU - Tetaz, Timothy J.
AU - Glucksman, Marc J.
AU - Roberts, James L.
AU - Ian Smith, A.
PY - 1995/4/26
Y1 - 1995/4/26
N2 - We have characterized and compared the substrate specificity of affinity-purified recombinant rat testes endopeptidase EC 3.4.24.15 (EP 24.15) with that reported for the isolated brain enzyme. Of the peptides tested, only bradykinin, dynorphin A1-8, and neurotensin were efficiently cleaved by the recombinant enzyme (kcat/Km = 3.0, 2.8 and 0.5 × 105 M-1sec-1, respectively); other peptides considered substrates of EP 24.15 (gonadotropin-releasing hormone, substance P, somatostatin and angiotensin) were not metabolized. The enzyme was inhibited by metal ion chelators and thiol-reactive agents, as well as a specific EP 24.15 inhibitor (N-[1(R, S)-carboxy-3-phenylpropyl]-Ala-Ala-Tyr-p-aminobenzoate), thus confirming the enzyme as a thiol-dependent metalloendopeptidase. The observed discrepancies in substrate specificity of the recombinant testicular and the isolated brain enzymes may result from tissue-specific forms and/or post-translational modifications of EP 24.15.
AB - We have characterized and compared the substrate specificity of affinity-purified recombinant rat testes endopeptidase EC 3.4.24.15 (EP 24.15) with that reported for the isolated brain enzyme. Of the peptides tested, only bradykinin, dynorphin A1-8, and neurotensin were efficiently cleaved by the recombinant enzyme (kcat/Km = 3.0, 2.8 and 0.5 × 105 M-1sec-1, respectively); other peptides considered substrates of EP 24.15 (gonadotropin-releasing hormone, substance P, somatostatin and angiotensin) were not metabolized. The enzyme was inhibited by metal ion chelators and thiol-reactive agents, as well as a specific EP 24.15 inhibitor (N-[1(R, S)-carboxy-3-phenylpropyl]-Ala-Ala-Tyr-p-aminobenzoate), thus confirming the enzyme as a thiol-dependent metalloendopeptidase. The observed discrepancies in substrate specificity of the recombinant testicular and the isolated brain enzymes may result from tissue-specific forms and/or post-translational modifications of EP 24.15.
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U2 - 10.1006/bbrc.1995.1569
DO - 10.1006/bbrc.1995.1569
M3 - Article
C2 - 7733970
AN - SCOPUS:0029048092
VL - 209
SP - 788
EP - 795
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 3
ER -