野花生豆(Crotalaria mucronata)凝集素的细胞表面受体的研究

STUDY ON CELL SURFACE RECEPTOR OF THE CROTALARIA MUCRONATA LECTIN

研究了异硫氰基荧光素和^(125)I标记的野花生豆凝集素,对A型细胞和牛精细胞表面的凝集素受体的定位、分布和数量。结果表明这些细胞表面的凝集素受体比较复杂,难以用一般动力学方法加以说明。D-葡萄糖、D-甘露糖、D-半乳糖和N-乙酰半乳糖胺等糖类和Con A、PHA、BSA对标记凝集素与A型细胞结合的影响各不相同。通过饱和曲线计算出A型细胞和牛精细胞表面的凝集素受体数目,分别为1.29×10~7和3.09×10~6个/细胞.

The Crotalaria mucronata Lectin (CML) not only agglutinates human type A erythrocytes specifically, but also agglutinates cattle sperms very strongly. When the concentration of CML is 0,49g/ml, cattle sperms are agglutinated in a head to head way. By studying the distribution of the surface receptors on type A erythrocytes and cattle sperms with FITC-CML, it shows that the binding sites on type A cells are well distributed while those on the cattle sperms mainly exist in acrosome and post nuclear cap. Binding of 125I-CML to type A cells with different concentrations of the cells shows that the relative binding rates trend to become saturated as the concentration of type A cells increases. The competitive bindings of certain amount of l25I-CML at different concentrions of CML to type A cells or cattle sperms were studied. The Scatchard plots indicate that the CML-receptors on these cells may be so complicated that they are hardly be easily explained by ordinary kinetic methods. D-Glc, D-Man, D-Gal, GalNAc, Con A, PHA and BSA affect 125I-CML's binding to its receptors on type A cells but there are differences in influencing. Based on the saturate curves, the numbers of CML receptors per cell of human blood group A and cattle's sperm have been calculated as follows:R sperm, 3.09X106 number of molecules/per cellR erythrocyte, 1.29X107 number of molecules/per cell