Sequencing, expression and biochemical characterization of the Porphyromonas gingivalis pepO gene encoding a protein homologous to human endothelin-converting enzyme

We have determined the nucleotide sequence of the clone pAL2 obtained from Porphyromonas gingivalis 381 in the previous study [Ansai ct al, (1995) Microbiology 141, 2047-2052], The DNA sequence analysis of this fragment revealed one complete ORF and one incomplete ORF, The ORF encoded a protein (PgPepO) of 690 amino acids with a calculated molecular weight of 78796, The deduced amino acid sequence exhibited a significant homology with human endothelin-converting enzyme (ECE)-1. Recombinant PgPepO was purified to homogeneity and characterized. The purified enzyme was strongly inhibited by phosphoramidon, and converted big endothelin-1 to endothelin-1. Furthermore, the purified PgPepO strongly cross-reacted with a monoclonal antibody against rat ECE-1, These results indicate that PgPepO has striking similarity to mammalian ECE in structure and function. (C) 1999 Federation of European Biochemical Societies.