Jassim A, Foxon R, Purkis P, Gray A, al-Zuhdi Y
Department of Immunology, London Hospital Medical College, UK.
J Reprod Immunol. 1993 Mar;23(2):169-88. doi: 10.1016/0165-0378(93)90006-4.
A perinuclear theca protein of the human sperm subacrosome was detected using LH43 monoclonal antibody which was originally raised against human keratinocytes. Using indirect immunofluorescence, the antibody stained the acrosomal zone (AZ) of dried ejaculated spermatozoa but did not react with viable cells, thus suggesting that the antigen was intracellular. This was confirmed by immunogold electron microscopy which also revealed the ultrastructural localisation of the antigen to the subacrosomal fibrils. Throughout spermatogenesis the antigen was only detected on the AZ of developed testicular spermatozoa and its expression was continued during their epididymal passage. Biochemically, the protein was insoluble in Triton, and dithiothreitol (DTT) was required for its solubilisation. In Western blotting of sperm and keratinocyte lysates, the antibody detected similar 90-kDa protein doublets (AJ-p90). These biochemical features exclude the identity of AJ-p90 with various cyto- and karyo-skeletal antigens, including the intermediate filaments and microfilaments. AJ-p90 therefore represents a novel product of the subacrosomal perinuclear theca. The significance of these data is discussed together with the importance of the antibody for probing the perinuclear theca in normal and abnormal germ cells, including multinucleated spermatids which also showed reactivity with the antibody.
利用最初针对人角质形成细胞产生的LH43单克隆抗体，检测到了人精子顶体下膜的一种核周膜蛋白。通过间接免疫荧光法，该抗体可对干燥的射出精子的顶体区（AZ）进行染色，但不与活细胞发生反应，因此表明该抗原位于细胞内。免疫金电子显微镜证实了这一点，其还揭示了该抗原在顶体下纤维中的超微结构定位。在整个精子发生过程中，仅在发育成熟的睾丸精子的顶体区检测到该抗原，并且在其附睾通过过程中持续表达。从生化角度来看，该蛋白不溶于 Triton，需要二硫苏糖醇（DTT）才能使其溶解。在精子和角质形成细胞裂解物的蛋白质印迹分析中，该抗体检测到了类似的90 kDa蛋白双峰（AJ-p90）。这些生化特性排除了AJ-p90与各种细胞骨架和核骨架抗原（包括中间丝和微丝）的同一性。因此，AJ-p90代表了顶体下核周膜的一种新产物。本文讨论了这些数据的意义，以及该抗体在探测正常和异常生殖细胞（包括也与该抗体发生反应的多核精子细胞）的核周膜方面的重要性。
