Department of Biology, Humboldt University Berlin, Invalidenstrasse 42, 10115 Berlin, Germany.
Biochemistry. 2010 Oct 26;49(42):9027-31. doi: 10.1021/bi101257c.
Seminal plasma proteins of the fibronectin type II (Fn2) family modulate mammalian spermatogenesis by triggering the release of the lipids phosphatidylcholine and cholesterol from sperm cells. Whereas the specific interaction of these proteins with phosphatidylcholine is well-understood, their selectivity for cholesterol is unknown. To characterize the interaction between the bovine Fn2 protein PDC-109 and cholesterol, we have investigated the effect of PDC-109 on the dynamics of fluorescent cholesterol analogues in lipid vesicles by time-resolved fluorescence anisotropy. The data show that PDC-109 decreases the rotational mobility of cholesterol within the membrane and that the extent of this impact depends on the cholesterol structure, indicating a specific influence of PDC-109 on cholesterol. We propose that the cholesterol recognition/interaction amino acid consensus (CRAC) regions of PDC-109 are involved in the interaction with cholesterol.
纤连蛋白 II 型（Fn2）家族的精浆蛋白通过触发精子细胞释放磷脂酰胆碱和胆固醇来调节哺乳动物的精子发生。虽然这些蛋白质与磷脂酰胆碱的特异性相互作用已得到很好的理解，但它们对胆固醇的选择性尚不清楚。为了表征牛 Fn2 蛋白 PDC-109 与胆固醇之间的相互作用，我们通过时间分辨荧光各向异性研究了 PDC-109 对脂质囊泡中荧光胆固醇类似物动力学的影响。数据表明，PDC-109 降低了胆固醇在膜内的旋转迁移率，并且这种影响的程度取决于胆固醇的结构，表明 PDC-109 对胆固醇有特异性影响。我们提出 PDC-109 的胆固醇识别/相互作用氨基酸共识（CRAC）区域参与了与胆固醇的相互作用。
