Identification and Characterization of Three Members of the Human Metallocarboxypeptidase Gene Family

摘要: Amino acid homology searches of the human genome revealed three members metallocarboxypeptidase (metallo-CP) family that had not been described in literature addition to 14 known genes. One these three, named CPA5, is present a gene cluster with CPA1, CPA2, and CPA4 on chromosome 7. The cDNA encoding mouse homolog CPA5 was isolated from testis library sequenced. deduced amino sequence has highest identity (60%) CPA1. Modeling analysis shows overall structure be very similar other A/B subfamily metallocarboxypeptidases. active site predicted cleave substrates C-terminal hydrophobic residues, as do -2, -3. Using Northern blot analysis, mRNA detected but kidney, liver, brain, or lung. In situ hybridization localized germ cells. Mouse pro-CPA5 protein expressed Sf9 cells using baculovirus system retained particulate fraction secreted into media. Pro-CPA5 enzymatically toward standard CPA substrates, after incubation prohormone convertase 4 resulting able furylacryloyl-Gly-Leu, 3-4-fold greater activity at pH 7.4 than 5.6. Two additional CP were also studied. indicates both contain necessary acids required for enzymatic activity. 8 have CPA-like specificity residues CPA6. 2 acidic CPO.