Hatzoglou A, Prekezes J, Tsami M, Castanas E
Laboratory of RIA and Hormone Receptors, School of Medicine, University of Crete, Heraclion, Greece.
Ann Clin Biochem. 1992 Nov;29 ( Pt 6):659-62. doi: 10.1177/000456329202900607.
Protein concentration measurements are critical in biochemical work with cellular membranes, including the determination of cell surface receptor concentration in human malignant tissues obtained at surgery or after biopsy. In this study we compared the results of protein concentration measurements in ovine liver cellular membranes using either particulate preparations or membranes solubilized with four different detergents. In all cases protein was determined by two different indirect methods (Lowry's Folin phenol method and Bradford's Coomassie Brilliant Blue dye binding method) and compared to the direct biuret method. Our results indicate that the direct biuret method gives the highest protein concentrations followed by the method of Lowry. Maximal concentrations (approaching those obtained by the direct biuret method) were obtained after membrane solubilization with Triton X-100 (3-5%). It is suggested that either the direct biuret method (whenever protein concentrations permit it) or the method of Lowry after solubilization of membranes with Triton X-100 (3-5%) should be used preferentially for the determination of membrane protein samples.
蛋白质浓度测量在细胞膜的生化研究中至关重要，包括测定手术或活检后获取的人类恶性组织中的细胞表面受体浓度。在本研究中，我们比较了使用颗粒制剂或用四种不同去污剂溶解的膜来测定绵羊肝细胞膜中蛋白质浓度的结果。在所有情况下，蛋白质均通过两种不同的间接方法（洛瑞氏福林酚法和布拉德福德氏考马斯亮蓝染料结合法）进行测定，并与直接双缩脲法进行比较。我们的结果表明，直接双缩脲法得出的蛋白质浓度最高，其次是洛瑞氏法。在用 Triton X - 100（3 - 5%）溶解膜后，可获得最高浓度（接近直接双缩脲法获得的浓度）。建议在测定膜蛋白样品时，优先使用直接双缩脲法（只要蛋白质浓度允许）或在用 Triton X - 100（3 - 5%）溶解膜后使用洛瑞氏法。
