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Chemical modification of porcine kidney aminopeptidase P indicates the involvement of two critical histidine residues
Author(s) -
Lim Jaeseung,
Turner Anthony J.
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00124-x
Subject(s) - hydroxylamine , histidine , chemistry , chemical modification , bradykinin , enzyme , biochemistry , kidney , tetrapeptide , aminopeptidase , peptide , amino acid , biology , receptor , endocrinology , leucine
Aminopeptidase P (AP‐P), purified to homogeneity from porcine kidney membranes, was completely inactivated by treatment with 0.2 mM diethylpyrocarbonate (DEP) at pH 7.0. Treatment of the modified enzyme with 20 mM hydroxylamine resulted in recovery of AP‐P activity. The differential absorption of native and modified AP‐P at 240 nm showed that DEP modified two histidyl residues per mol of AP‐P. The substrates, bradykinin(1–5) and Gly‐Pro‐Hyp, and also the inhibitor, apstatin, could protect against DEP inactivation. These results suggest that histidine residues are critical for AP‐P activity.