β-乳球蛋白的结构及其与血浆视黄醇结合蛋白的相似性。

The structure of beta-lactoglobulin and its similarity to plasma retinol-binding protein.

作者信息

Papiz M Z, Sawyer L, Eliopoulos E E, North A C, Findlay J B, Sivaprasadarao R, Jones T A, Newcomer M E, Kraulis P J

出版信息

Nature. 1986;324(6095):383-5. doi: 10.1038/324383a0.

Abstract

Since its first isolation, bovine beta-lactoglobulin (BLG) has been an enigma: although it is abundant in the whey fraction of milk, its function is still not clear. The results of the many physicochemical studies on the protein need a structural interpretation. We report here the structure of the orthorhombic crystal form of cow BLG at pH 7.6, at a resolution of 2.8 A. It has an unusual protein fold, composed of two slabs of antiparallel beta-sheet, which shows a remarkable similarity to plasma retinol-binding protein. A possible binding site for retinol in BLG has been identified by model-building. This suggests a role for BLG in vitamin A transport and we have discovered specific receptors for the BLG-retinol complex in the intestine of neonate calves.

摘要

自首次分离以来，牛β-乳球蛋白（BLG）一直是个谜：尽管它在牛奶的乳清部分含量丰富，但其功能仍不清楚。对该蛋白质进行的许多物理化学研究结果需要从结构角度进行解释。我们在此报告了pH 7.6条件下处于正交晶型的奶牛BLG的结构，分辨率为2.8埃。它具有不寻常的蛋白质折叠结构，由两片反平行β-折叠片组成，与血浆视黄醇结合蛋白有显著相似性。通过模型构建确定了BLG中视黄醇的一个可能结合位点。这表明BLG在维生素A运输中发挥作用，并且我们在新生小牛的肠道中发现了BLG-视黄醇复合物的特异性受体。