Purification and Characterization of al Protease Inhibitor from Camel Plasma

Abstract

Three drtferent serine protease Inhibitors were Isolated from camel plasma and purified to apparent homogeneity. The purification was achieved using (NH.hSO. predplation, affinity chromatography on Blue Sephal"O$e,Ionexchange chromatography on DEAE-Sephadex A-50 at pH 8.0 and 6.5, gel filtration on Sephacryl S200 and polyacrylamide gel electrophoresis (PAGE). Inhibitor I and II were found to Inhibit trypsin and chymotrypsln whiM! Inhlblor III Inhibited trypsin only, with no detectable chymotrypsin Inhibition. Inhibitor I was found to be analogous to human a,- protease inhibitor with relative molecular mass of 58,000, it inhibited trypsin and chymotrypsin at a 1:1 molar ratio. The Inhibitor was resistant to heat for 30 minutes at S·C and retillned only 16.7% of Its activity at 70·C for 1OrTin~es, The Inhibitor had a maximum Inhibitory activity at pH 8.0, however, no detectable Inhlbitlon was observed at pH 5.0 and 6.0. This study Indicated that Inhibitor I exhibited similar properties to human ai-protease inhlbitor