J. Lenoir

Metalloproteases from Penicillium caseicolum and P. roqueforti: Comparison of specificity and cemical characterization

Abstract 1. 1. The specificity of P. caseicolum protease was determined on the oxidized insulin B-chain and on synthetic peptides. This specificity was different from that of thermolysin-like neutral metalloproteases, but similar to that of P. roqueforti protease. 2. 2. Metal determination confirmed that P. caseicolum and P. roqueforti proteases were metalloproteases each containing one atome of zinc per molecule which was essential for enzymatic activity. 3. 3. The determination of amino acid compositions and N-terminal sequences showed a strong homology between the two metalloproteases. 4. 4. A specific neutral metalloprotease inhibitor, phosphoramidon, had no action on P. caseicolum and P. roqueforti enzymes. 5. 5. A. sojae and A. oryzae metalloproteases had properties similar to those of the proteins studied, and it is suggested that those enzymes be grouped under the term “acid metalloproteases”.