Intracellular proteinase ofLactococcus lactissubsp.lactisNCDO 763

Abstract

SummaryAn intracellular proteinase was purified fromLactococcus lactissubsp.lactisNCDO 763 after spheroplast formation from cell wall proteinase-deficient variants. The proteinase was active at pH 7·5 and 45 °C and affected by metalloenzyme inhibitors. Its specificity, determined on B-chain of insulin, was thermolysin-like. The B-chain of insulin was hydrolysed rapidly while hydrolysis of β-casein was slower. This enzyme has aMrof ∽ 93000.