Petty H R
Immunology. 1987 Feb;60(2):269-73.
Murine macrophage Fc receptor function has been studied with the membrane-impermeable sulphydryl-blocking reagent p-chloromercuribenzenesulphonic acid (PCMBSA). Antibody-dependent endocytosis of fluorescein-labelled immune complexes was studied with video intensification microscopy. PCMBSA was found to inhibit the endocytosis of immune complexes at 10 nM. Control experiments indicate that the inhibition is due to an effect upon the cell, not the immune complex. Furthermore, specificity is suggested by the fact that complement-mediated and latex bead phagocytosis were not affected. 203Hg-PCMBSA labelled three macrophage proteins of molecular weight (MW) 25,000, 35,000 and 50,000. A 25,000 MW PCMBSA-binding protein has been found that is specifically immunoprecipitated by an anti-Fc receptor antibody. These studies suggest that perturbation of a cell surface sulphydryl group(s) of one of the three major PCMBSA binding membrane proteins, possibly an Fc receptor-associated protein, blocks a molecular signal required for antibody-dependent endocytosis.
已使用膜不透性巯基阻断剂对氯汞苯磺酸（PCMBSA）研究了小鼠巨噬细胞Fc受体功能。用视频增强显微镜研究了荧光素标记的免疫复合物的抗体依赖性内吞作用。发现PCMBSA在10 nM时可抑制免疫复合物的内吞作用。对照实验表明，这种抑制作用是由于对细胞而非免疫复合物的影响。此外，补体介导的吞噬作用和乳胶珠吞噬作用未受影响这一事实表明了其特异性。203Hg-PCMBSA标记了分子量（MW）为25,000、35,000和50,000的三种巨噬细胞蛋白。已发现一种25,000 MW的PCMBSA结合蛋白可被抗Fc受体抗体特异性免疫沉淀。这些研究表明，三种主要的PCMBSA结合膜蛋白之一（可能是一种Fc受体相关蛋白）的细胞表面巯基的扰动会阻断抗体依赖性内吞作用所需的分子信号。
