Twenty-three proteinase inhibitors were isolated from Syrian local small lentils (L ens culinaris) by ammonium sulphate fractionation of the acidic extract followed by affinity chromatography on anhydrotrypsin-Sepharose. They all inhibited human and bovine trypsin and chymotrypsin. Three inhibitors (LCI-1É7, -3É3 and -4É6) were separated and puriÐed to homogeneity by anion exchange chromatography and preparative isoelectric focusing (IEF) with immobilised pH gradients ; a fourth (LCI-2É2) required additional reversed-phase highpressure liquid chromatography. The four inhibitors were similar in their amino acid composition, with high cystine and aspartic acid/asparagine content, and lack of free sulphydryl groups, methionine and tryptophan. The calculated minimum number of amino acid residues per molecule, the calculated molecular masses conÐrmed by gel liquid chromatography, gel-permeation high-pressure liquid chromatography and sodium-dodecylsulphate polyacrylamide gel electrophoresis, and the isoelectric points determined by IEF (immobilised pH gradients and carrier ampholytes) were 84, 77, 68 and 60 residues per molecule, 9200, 8500, 7200 and 6750, and 5É26, 5É88, 6É80 and 7É80 for LCI-1É7, -2É2, -3É3 and -4É6, respectively. All four inhibitors inhibited human trypsin less than bovine trypsin, and human chymotrypsin more than the bovine enzyme. All these properties are in accordance with the classiÐcation of the four lentil inhibitors as members of the Bowman-Birk proteinase inhibitor family.
Society of Chemical ( 1998 Industry.