红细胞膜不对称性的状态：血影蛋白的作用。

Status of Membrane Asymmetry in Erythrocytes: Role of Spectrin.

机构信息

Crystallography & Molecular Biology Division, Saha Institute of Nuclear Physics, HBNI, Kolkata, India.

Surface Physics & Material Science Division, Saha Institute of Nuclear Physics, HBNI, Kolkata, India.

出版信息

Adv Exp Med Biol. 2018;1112:3-11. doi: 10.1007/978-981-13-3065-0_1.

DOI:10.1007/978-981-13-3065-0_1

PMID:30637686

Abstract

Spectrin-based proteinaceous membrane skeletal network has been found to be implicated in membrane disorders like hereditary spherocytosis (HS). HS greatly affects eryptosis via loss of membrane asymmetry which is seen to be the case in haemoglobin disorders like thalassemia and sickle cell disease as well. The biological implications of the status of membrane asymmetry are strongly correlated to spectrin interactions with aminophospholipids, e.g. PE and PS. Fluorescence and X-ray reflectivity (XRR) measurements of spectrin interactions with small unilamellar vesicles (SUVs) and cushioned bilayers of phospholipids, respectively, were studied. Both the XRR and fluorescence measurements led to the characterization of spectrin orientation on the surface of lipid bilayer of phosphatidylcholine (PC) and PC/aminophospholipid mixed membrane systems showing formation of a uniform layer of spectrin on top of the mixed phospholipid bilayer. Fluorescence studies show that spectrin interacts with PC and phosphatidylethanolamine (PE)/phosphatidylserine (PS) membranes with binding dissociation constants (K) in the nanomolar range indicating the role of spectrin in the maintenance of the overall membrane asymmetry of erythrocytes.

摘要

基于血影蛋白的蛋白质膜骨架网络已被发现与膜紊乱有关，如遗传性球形红细胞症 (HS)。HS 通过膜不对称性的丧失极大地影响了红细胞的凋亡，这种情况在血红蛋白紊乱如地中海贫血和镰状细胞病中也存在。膜不对称性状态的生物学意义与血影蛋白与氨基磷脂（如 PE 和 PS）的相互作用密切相关。研究了血影蛋白与小单层囊泡（SUV）和磷脂缓冲双层的相互作用的荧光和 X 射线反射率（XRR）测量。XRR 和荧光测量都导致了对血影蛋白在磷脂双层表面的取向的表征，表明在混合磷脂双层的顶部形成了一层均匀的血影蛋白。荧光研究表明，血影蛋白与 PC 和磷脂酰乙醇胺（PE）/磷脂酰丝氨酸（PS）膜相互作用，结合解离常数（K）在纳摩尔范围内，表明血影蛋白在维持红细胞整体膜不对称性中的作用。