Atkinson K H, Atkinson B G
Mol Biochem Parasitol. 1981 Dec;4(3-4):205-16. doi: 10.1016/0166-6851(81)90019-0.
Cercariae of Schistosoma mansoni were labeled with [14C]leucine in vivo and their protein studied by one- and two-dimensional electrophoretic fluorography. With molecular weight (Mr) and isoelectric point (pI) as parameters, polypeptides from different stages of cercarial embryogenesis were compared with each other and with those of adult worms. Up to six polypeptides with different isoelectric points were found in a single electrophoretic band of the same Mr. Three polypeptides of high molecular weight were synthesized by cercariae 3 days before escape, and were similar to polypeptides synthesized by adults. The most prominent cercarial polypeptides synthesized three days before emergence (during tail elongation) are two which comigrate electrophoretically with actin and heavy chain of myosin. The rate of actin synthesis decreased at 48 and 24 h, with little or no synthesis in the 4 h preceding emergence. Many polypeptides found in cercariae labeled 4 h before emergence differ in pI and Mr from those synthesized in earlier stages of embryogenesis. From the water in which the cercariae emerge, labeled polypeptides were precipitated which are identical to several found both in shed, washed cercariae and the infected hepatopancreas. Polypeptides of high Mr are not synthesized by cercariae in the period shortly before escape; this stage is represented by polypeptide products with Mr values of 35 000, 53 000 and 58 000.
用[¹⁴C]亮氨酸在体内标记曼氏血吸虫尾蚴，并通过一维和二维电泳荧光自显影技术研究其蛋白质。以分子量（Mr）和等电点（pI）为参数，比较尾蚴胚胎发育不同阶段的多肽以及与成虫的多肽。在相同Mr的单个电泳条带中发现多达六种具有不同等电点的多肽。逸出前3天的尾蚴合成了三种高分子量多肽，与成虫合成的多肽相似。逸出前三天（尾部长出期间）合成的最突出的尾蚴多肽是两种在电泳时与肌动蛋白和肌球蛋白重链迁移率相同的多肽。肌动蛋白的合成速率在48小时和24小时时下降，在逸出前4小时几乎没有或没有合成。在逸出前4小时标记的尾蚴中发现的许多多肽在pI和Mr上与胚胎发育早期合成的多肽不同。从尾蚴逸出的水中沉淀出标记的多肽，这些多肽与在脱落、洗涤后的尾蚴和受感染的肝胰腺中发现的几种多肽相同。在逸出前不久，尾蚴不合成高分子量多肽；这个阶段由Mr值为35000、53000和58000的多肽产物代表。
