Akerström B, Lögdberg L, Berggård T, Osmark P, Lindqvist A
Department of Cell and Molecular Biology, University of Lund, Sweden.
Biochim Biophys Acta. 2000 Oct 18;1482(1-2):172-84. doi: 10.1016/s0167-4838(00)00157-6.
alpha(1)-Microglobulin, also called protein HC, is a lipocalin with immunosuppressive properties. The protein has been found in a number of vertebrate species including frogs and fish. This review summarizes the present knowledge of its structure, biosynthesis, tissue distribution and immunoregulatory properties. alpha(1)-Microglobulin has a yellow-brown color and is size and charge heterogeneous. This is caused by an array of small chromophore prosthetic groups, attached to amino acid residues at the entrance of the lipocalin pocket. A gene in the lipocalin cluster encodes alpha(1)-microglobulin together with a Kunitz-type proteinase inhibitor, bikunin. The gene is translated into the alpha(1)-microglobulin-bikunin precursor, which is subsequently cleaved and the two proteins secreted to the blood separately. alpha(1)-Microglobulin is found in blood and in connective tissue in most organs. It is most abundant at interfaces between the cells of the body and the environment, such as in lungs, intestine, kidneys and placenta. alpha(1)-Microglobulin inhibits immunological functions of white blood cells in vitro, and its distribution is consistent with an anti-inflammatory and protective role in vivo.
α1-微球蛋白，也称为蛋白HC，是一种具有免疫抑制特性的脂质运载蛋白。已在包括青蛙和鱼类在内的多种脊椎动物物种中发现了这种蛋白质。本综述总结了目前关于其结构、生物合成、组织分布和免疫调节特性的知识。α1-微球蛋白呈黄褐色，大小和电荷不均一。这是由一系列附着在脂质运载蛋白口袋入口处氨基酸残基上的小发色团辅基引起的。脂质运载蛋白簇中的一个基因编码α1-微球蛋白以及一种库尼茨型蛋白酶抑制剂比昆宁。该基因被翻译成α1-微球蛋白-比昆宁前体，随后被切割，两种蛋白质分别分泌到血液中。α1-微球蛋白存在于血液和大多数器官的结缔组织中。它在身体细胞与环境的界面处最为丰富，如在肺、肠道、肾脏和胎盘中。α1-微球蛋白在体外抑制白细胞的免疫功能，其分布与体内的抗炎和保护作用一致。
