Yagi F, Sawada R, Imada T, Toyonaga S, Tadera K, Ishihata K
Department of Biochemical Science and Technology, Faculty of Agriculture, Kagoshima University, Japan.
Plant Cell Physiol. 1994 Oct;35(7):1087-95.
Two isolectins were isolated from leaves of winged bean and characterized. They differed from each other in terms of their immunological properties, hemagglutinating activities, sugar inhibition patterns, and amino acid compositions. Both lectins were acidic and one of them (L-I), which was inactive toward trypsinized human type O erythrocytes, was similar to one of green shell lectins (WGS-1); which resembled basic seed lectin in its immunological properties. The amino-terminal sequence of L-I was homologous to that of WGS-1. The amino acid composition of L-I was similar to that of basic seed lectin, but the extent of the homology between amino-terminal sequences was low when L-I and basic seed lectin were compared. Examination by ELISA revealed that L-I and WGS-1 were distinct from the basic lectins of seeds and tuberous roots. L-I had a disulfide bridge between two subunits and it exhibited high hemagglutinating activity toward human type A erythrocytes, as compared to its activity toward other erythrocytes. By contrast, the properties of a second acidic lectin from winged bean leaves (L-II) were very similar to those of acidic lectins from seeds and tuberous roots, and the similarities extended as far as the immunological properties.
从四棱豆叶片中分离并鉴定出两种同工凝集素。它们在免疫特性、血凝活性、糖抑制模式和氨基酸组成方面彼此不同。两种凝集素均为酸性，其中一种（L-I）对胰蛋白酶处理的人O型红细胞无活性，与绿壳凝集素之一（WGS-1）相似；其免疫特性类似于碱性种子凝集素。L-I的氨基末端序列与WGS-1的同源。L-I的氨基酸组成与碱性种子凝集素相似，但将L-I与碱性种子凝集素的氨基末端序列进行比较时，同源程度较低。酶联免疫吸附测定显示，L-I和WGS-1与种子和块根的碱性凝集素不同。L-I在两个亚基之间有一个二硫键，与对其他红细胞的活性相比，它对人A型红细胞表现出高血凝活性。相比之下，四棱豆叶片中第二种酸性凝集素（L-II）的特性与种子和块根中的酸性凝集素非常相似，这种相似性甚至延伸到免疫特性。
