Qu A, Leahy D J
Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Proc Natl Acad Sci U S A. 1995 Oct 24;92(22):10277-81. doi: 10.1073/pnas.92.22.10277.
We report the 1.8-A crystal structure of the CD11a I-domain with bound manganese ion. The CD11a I-domain contains binding sites for intercellular adhesion molecules 1 and 3 and can exist in both low- and high-affinity states. The metal-bound form reported here is likely to represent a high-affinity state. The CD11a I-domain structure reveals a strained hydrophobic ridge adjacent to the bound metal ion that may serve as a ligand-binding surface and is likely to rearrange in the absence of bound metal ion. The CD11a I-domain is homologous to domains found in von Willebrand factor, and mapping of mutations found in types 2a and 2b von Willebrand disease onto this structure allows consideration of the molecular basis of these forms of the disease.
我们报道了结合有锰离子的CD11a免疫球蛋白结构域的1.8埃晶体结构。CD11a免疫球蛋白结构域包含细胞间粘附分子1和3的结合位点，并且可以以低亲和力和高亲和力两种状态存在。此处报道的金属结合形式可能代表高亲和力状态。CD11a免疫球蛋白结构域结构揭示了与结合的金属离子相邻的一条应变疏水脊，其可能作为配体结合表面，并且在没有结合金属离子的情况下可能会重新排列。CD11a免疫球蛋白结构域与血管性血友病因子中的结构域同源，将2a型和2b型血管性血友病中发现的突变映射到该结构上，有助于思考这些疾病形式的分子基础。
