Vanadium inhibition of serine and cysteine proteases

A study was made on the effect of vanadium, in both the tetravalent state i n vanadyl sulphate and in the pentavalent state in sodium meta-vanadate, an d ortho-vanadate, on the proteolysis of azocasein by two serine proteases, trypsin and subtilisin and two cysteine proteases bromelain and papain. Als o the proteolysis of bovine azoalbumin by serine proteases was considered. An inhibitory effect was present in all cases, except meta-vanadate with su btilisin. The oxidation level of vanadium by itself did not determine the i nhibition kinetics, which also depended on the type and composition of the vanadium containing molecule and on the enzyme assayed. The pattern of inhi bition was similar for proteases belonging to the same class. The highest i nhibition was obtained with meta-vanadate on papain and with vanadyl sulpha te on bromelain. (C) 1999 Elsevier Science Inc. All lights reserved.