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Identification of the active site serine of the X‐prolyl dipeptidyl aminopeptidase from Lactococcus lactis
Author(s) -
Chich J.-F.,
Chapot-Chartier M.-P.,
Ribadeau-Dumas B.,
Gripon J.-C.
Publication year - 1992
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(92)80960-o
Subject(s) - serine , aminopeptidase , lactococcus lactis , biochemistry , active site , exopeptidase , proteases , peptide sequence , serine protease , peptide , biology , enzyme , amino acid , chemistry , dipeptidyl peptidase , leucine , bacteria , protease , gene , lactic acid , genetics
The active site serine of the X‐prolyl dipeptidyl aminopeptidase from Lactococcus lactis (PepX) was identified. The enzyme was labeled by [ 3 H]DFP, treated by CNBr and the resulting peptides were separated by reverse‐phase‐HPLC. The main radiolabeled peptide was sequenced. Ser‐348, in the following sequence, Gly‐Lys‐Ser‐Tyr‐Leu‐Gly, was identified as the active site serine. A sequence comparison between the active site of PepX and other serine proteases was made, showing only limited sequence homologies in this area. The consensus sequence surrounding the active site serine in the three known X‐prolyl dipeptidyl aminopeptidases (mammalian DPPIV, yeast DPAB and PepX) is G‐X‐S‐Y‐X‐G, where X is a non‐conserved amino acid.