It was determined that each DPL molecule possesses 4 Tryptophan residues by means of pronase degradation with DAB as visualization reagent. Only one Trp residue was detected through NBS chemical modification in the pH 4.0, 0.1 mol/L acetic acid buffer.

• 本文采用链霉蛋白酶酶解,对二甲基氨基苯甲醛(DAB)为显色剂的方法,测得每个黑皮扁豆凝集素(Dolichos purpureus lectin,DPL)分子约含有4个色氨酸残基;