Identification of the active site serine of the X-prolyl dipeptidyl aminopeptidase from Lactococcus lactis

• Published in: FEBS letters Vol. 314; no. 2; pp. 139 - 142
• Main Authors: Chich, J.-F., Chapot-Chartier, M.-P., Ribadeau-Dumas, B., Gripon, J.-C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 14.12.1992; Elsevier; Wiley
• Subjects: Active site; Amino Acid Sequence; Aminopeptidases - chemistry; Aminopeptidases - drug effects; Aminopeptidases - metabolism; Analytical, structural and metabolic biochemistry; Binding Sites; Biological and medical sciences; Cellular Biology; Cyanogen Bromide - pharmacology; DFP; Diisopropylfluorophosphate; dipeptidyl peptidase IV; DPAB; DPPIV; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Hydrolases; Lactococcus lactis; Lactococcus lactis - enzymology; Life Sciences; Molecular Sequence Data; Peptide Fragments - chemistry; Peptide Fragments - isolation & purification; PepX; phenylthiohydantoin; polyvinylidene difluoride; PTH; PVDF; Sequence Homology, Amino Acid; Serine Endopeptidases - chemistry; Serine Endopeptidases - metabolism; Serine protease; TFA; trifluoroacetic acid; X-prolyl dipeptidyl aminopeptidase; X-prolyl dipeptidyl aminopeptidase from Lactococcus lactis; yeast dipeptidyl aminopeptidase B; Lactococcus lactis; DPPIV; PTH; Active site; PepX; Serine protease; Diisopropylfluorophosphate; X-prolyl dipeptidyl aminopeptidase; DPAB; PVDF; TFA; DFP; Streptococcaceae; Enzyme; HPLC chromatography; Bacteria; Micrococcales; Serine proteinase; Comparative study; Aminoacid sequence; LACTOCOCCUS LACTIS
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(92)80960-O

The active site serine of the X-prolyl dipeptidyl aminopeptidase from Lactococcus lactis (PepX) was identified. The enzyme was labeled by [ 3H]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.