岩豆凝集素的纯化及其分子残基的化学修饰和活性关系

岩豆种子经侵取、硫酸铵分级、ＤＥＡＥ－纤维素离子交换和ＳｅｐｈａｄｅｘＧ－１００分子筛层析，获得ＦＰＬＣ上单一的凝集素样品，对此纯化的凝集素样品用Ｎ－溴代丁二酰亚胺、Ｎ－乙基顺丁烯二酰亚胺、二流苏糖醇，碘乙酸和对氯汞苯甲酸修饰其分子内的色氨酸和巯基．经计算，该凝集素分子内含有４个色氨酸和２４个流基，当色氨酸被修饰后其凝集活性全部丧失，而巯基被修饰后对其凝血活性无任何影响，表明巯基与凝集素分子的凝血活性无关，而色氨酸则是凝集活性所必需的基团．

STUDY ON THE RELATION BETWEEN RESIDUE MODIFICATION AND BIOLOGICAL ACTIVITY OF MILLETTIA DIELSIANA HARMS. LECTIN

Millettia dielsiana Harms. Lectin (MDL)was purified from the seeds of Millettia dielsiana Harmesx Diels by extraction, fraction with (NH4 )2SO4, DEAE-Cellulose ion-exchange chromatography and followed by gel filtration of Sephadex G- 100. The purified MDL showed single protein peak on FPLC,mwhfication disulfide groups(-SH)and Tryptophan(Trp)in MDL. The result showed that MDL did not need the -SH to deep its activity,but Trp was essential for MDL to keep activity. There were 4 Trp and 24 -SH in MDL molecules.