Biochemistry Department, University of Oxford, Oxford, OX1 3QU, England, United Kingdom.
Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester, LE1 7RH, England, United Kingdom.
Sci Rep. 2017 Nov 22;7(1):16057. doi: 10.1038/s41598-017-16413-2.
Two crystal structures of Japanin, an 18 kDa immune-modulatory lipocalin from the Brown Ear Tick (Rhipicephalus appendiculatus), have been determined at 2.2 and 2.4 Å resolution. In both crystal forms the protein is in complex with cholesterol, which sits in a closed pocket at the centre of the lipocalin barrel. Both crystal forms are dimers, which are also observed in solution. Molecular modelling suggests that previously-described members of a tick protein family bearing high sequence homology to Japanin are also likely to bind cholesterol or cholesterol derivatives.
已经确定了来自棕色耳蜱（Rhipicephalus appendiculatus）的 18 kDa 免疫调节脂联蛋白 Japanin 的两个晶体结构，分辨率分别为 2.2 和 2.4 Å。在这两种晶体形式中，蛋白质都与胆固醇形成复合物，胆固醇位于脂联蛋白桶的中心封闭口袋内。两种晶体形式均为二聚体，在溶液中也观察到了二聚体。分子建模表明，先前描述的与 Japanin 具有高度序列同源性的蜱蛋白家族成员也可能结合胆固醇或胆固醇衍生物。
