Cloning and expression of the phospholipase C gene from Clostridium perfringens and Clostridium bifermentans

Abstract

The phospholipase C gene from Clostridium perfringens was isolated, and its sequence was determined. It was found that the structural gene codes for a protein of 399 amino acid residues. The NH2-terminal residues have the typical features of a signal peptide and are probably cleaved after secretion. Escherichia coli cells harboring the phospholipase C gene-containing plasmid expressed high levels of this protein in the periplasmic space. Phospholipase C purified from E. coli transformants was enzymatically active, hemolytic to erythrocytes, and toxic to animals when injected intravenously. The phospholipase C gene from a related organism, Clostridium bifermentans, was also isolated. The two phospholipase C genes were found to be 64% homologous in coding sequence. The C. bifermentans protein, however, was 50-fold less active enzymatically than the C. perfringens enzyme.