van Noort M, Rommerts F F, van Amerongen A, Wirtz K W
Department of Biochemistry, Medical Faculty, Erasmus University Rotterdam, The Netherlands.
Biochem Biophys Res Commun. 1988 Jul 15;154(1):60-5. doi: 10.1016/0006-291x(88)90649-3.
Sterol carrier protein2 (SCP2) also designated non specific lipid transfer protein (nsL-TP), added to tumour Leydig cell mitochondria as a pure compound or in cytosolic preparations, stimulates pregnenolone production two- to three-fold. This stimulation can be abolished by addition of anti rat SCP2 but not by preimmune IgG-antibodies. SCP2- levels in the cytosol are increased in less than two minutes after addition of lutropin (LH). This increased SCP2 level may contribute to stimulation of steroid production in intact cells. After hormonal stimulation the subcellular distribution of SCP2 changes. A two-fold increase of SCP2- levels in the supernatant fraction and four-fold decrease in extracts of the particulate fraction was observed 30 min after stimulation of tumour Leydig cells with LH and subsequent fractionation. This apparent shift of SCP2 can be explained by an altered association with membranes or a true relocation of the protein from the particulate to the supernatant fractions under the influence of the hormone.
固醇载体蛋白2（SCP2）也被称为非特异性脂质转运蛋白（nsL-TP），作为一种纯化合物或存在于胞质制剂中时，添加到肿瘤间质细胞线粒体中，可使孕烯醇酮的产量提高两到三倍。添加抗大鼠SCP2可消除这种刺激作用，但免疫前IgG抗体则不能。添加促黄体生成素（LH）后不到两分钟，胞质中的SCP2水平就会升高。这种升高的SCP2水平可能有助于完整细胞中类固醇生成的刺激。激素刺激后，SCP2的亚细胞分布会发生变化。用LH刺激肿瘤间质细胞并随后进行分级分离后30分钟，观察到上清液部分的SCP2水平增加了两倍，颗粒部分提取物中的SCP2水平降低了四倍。SCP2的这种明显转移可以通过与膜的结合改变或在激素影响下蛋白质从颗粒部分真正重新定位到上清液部分来解释。
