Myles D G, Primakoff P, Koppel D E
J Cell Biol. 1984 May;98(5):1905-9. doi: 10.1083/jcb.98.5.1905.
Using the technique of fluorescence redistribution after photobleaching, we are studying the cellular mechanisms involved in localizing surface molecules to particular domains. A number of antigens localized to discrete surface regions have been identified with monoclonal antibodies on guinea pig sperm cells ( Primakoff , P., and D. G. Myles , 1983, Dev. Biol., 98:417-428). One of these monoclonal antibodies, PT-1, binds exclusively to the posterior tail region of the sperm cell surface. PT-1 recognizes an integral membrane protein that in complex with n-octyl-beta-D-glucopyranoside has a sedimentation coefficient of 6.8S in sucrose density gradients. Fluorescence redistribution after photobleaching measurements reveal that within its surface domain the PT-1 antigen diffuses rapidly (D = 2.5 X 10(-9) cm2/s) and completely (greater than 90% recovery after bleaching). These results rule out for this membrane protein all models that invoke immobilization as a mechanism for maintaining localization. We propose that the mechanism for localization of the PT-1 antigen may be a barrier to diffusion at the domain boundary.
利用光漂白后的荧光再分布技术，我们正在研究将表面分子定位到特定区域所涉及的细胞机制。用豚鼠精子细胞上的单克隆抗体已鉴定出许多定位于离散表面区域的抗原（普里马科夫，P.，和D.G.迈尔斯，1983年，《发育生物学》，98:417 - 428）。其中一种单克隆抗体PT - 1仅与精子细胞表面的尾部区域结合。PT - 1识别一种整合膜蛋白，该蛋白与正辛基 - β - D - 吡喃葡萄糖苷形成复合物后，在蔗糖密度梯度中的沉降系数为6.8S。光漂白后的荧光再分布测量结果表明，在其表面区域内，PT - 1抗原扩散迅速（扩散系数D = 2.5×10⁻⁹平方厘米/秒）且完全（漂白后恢复率大于90%）。这些结果排除了所有将固定化作为维持定位机制的该膜蛋白模型。我们提出，PT - 1抗原的定位机制可能是在区域边界处对扩散的一种屏障。
