EPR OF BLEOMYCIN MODEL COMPLEX

锰与脱脂凝集素的结合是其生物学特性所必需的。 作为碳水化合物结合蛋白的功能。之前的ESEEM研究 刀豆凝集素的锰位置 证明了组氨酸连接，但也没有水配体 从Dioclea中分离出ConA凝集素的晶体结构，如 来自康纳瓦利亚的那些也具有高度特异性地结合碳水化合物， 但与Dioclea凝集素的G.A晶体结构非常不同 显示了与ConA相同的碳水化合物结合部位。 两者碳水化合物结合热力学的差异 凝集素的种类可能是溶剂包装不同的结果 这并没有在晶体结构中得到解决。五个教区的EPR 凝集素(D.rostrata、D.guianensis、D.Vioracea、D.virgata、D. Grand diflora)和一株产自Cratylia floribunda的植物与 来自Conavalia(C.brasilisis、C.bonariensis和C.ensformis) [CON A])。除轮藻和金缕梅外，其它植物均表现出 与Con A.ESEEM类似的EPR谱研究正在进行中 来检测这些凝集素的锰位置，并与 以便调查在不同的情况下 水的连接在不同的热力学中起作用 这两类凝集素的碳水化合物结合。

The binding of Mn to apo lectins is required for their biological functionas carbohydrate-binding proteins. A previous ESEEM study of the Mn site of the lectin from Conavalia ensiformis (Con A) not only demonstrated histidine ligation, but also water ligands that were not resolved in the crystal structure of Con A. Lectins from Dioclea, like those from Conavalia, also binds carbohydrates with high specificity, but with a very different G. A crystal structure of a Dioclea lectin shows an identical carbohydrate-binding site to that of Con A. The difference in the thermodynamics of carbohydrate-binding of the two classes of lectins may be the result of difference in solvent packing that is not resolved in the crystal structure. EPR of five Dioclea lectins (D. rostrata, D. guianensis, D. violacea, D. virgata, D. grandiflora) and one from Cratylia floribunda are compared to those from Conavalia (C. brasiliensis, C. bonariensis and C. ensiformis [Con A]). All except D. rostrata and Cratylia floribunda, exhibit an EPR spectrum similar to that of Con A. ESEEM studies are being conducted to examine the Mn site of these lectins and compared to that of Con A in order to investigate the possibility that difference in water ligation plays a role in the different thermodynamics of carbohydrate-binding of the two classes of lectins.