Effect of alpha 1-proteinase inhibitor and sulphated polysaccharides on the activity of m beta-acrosin

Purified m beta-acrosin catalysed amidolysis in vitro of several p-nitroanilides with C-terminal arginine residues. alpha 1-proteinase inhibitor inhibited amidolysis catalysed by the enzyme. This effect of alpha 1-Proteinase inhibitor was not prevented by pre-incubation of the enzyme with heparin or any other glycosaminoglycan. Pre-incubation of the enzyme with sulphated dextran or sulphated cellulose alleviated the effect of alpha 1-proteinase inhibitor. These results are discussed in terms of possible in vivo modulation by alpha 1-proteinase inhibitor of acrosin activity.