奥利亚罗非鱼DMO和DMT蛋白二级结构和B细胞抗原表位的预测

以DMO和DMT氨基酸序列为基础，采用Garnier-Robson法、Chou-Fasman法和Karplus-Schulz法预测蛋白质的二级结构；按Kyte-Doolittle法、Emini法和Jameson-Wolf法预测DMO和DMT蛋白的B细胞抗原表位。预测结果表明：在DMO蛋白N-端第80～112，144～147，193～194，251～255，260～269区段和279～283区段，DMT蛋白N－端61～86，98～105，140～146，239～241区段和第269～273区段，可能是α-螺旋中心；DMO蛋白N-端第59～61，69～70，148～150区段和383～390区段，DMT蛋白的N-端第125～129，207～213，255～264区段和第281～284区段，可能是β-折叠中心；在DMO蛋白分子N-端40～41， 44～45，50～51，128～129，189～192，204～207，216～222，226～233，244～246，298～299区段和第323～326区段和DMT蛋白分子N-端第12～13，26～27，43～44，58～60，93～95，115～120，136～139区段和第149～151区段具有较柔软的结构，这些区段有可能进行一定幅度的摆动或折叠而形成较复杂的三级结构。DMO蛋白N-端第1～5，41～51，65～67，86～89，98～110，154～170，183～203，205～248，258～264，284～291，293～298，270～375，389～392，402～410区域和DMT蛋白N-端第1～9，17～28，77～84，114～123，131～139，157～184，196～207区域可能是B细胞表位优势区域。以蛋白质的二级结构预测作为辅助手段，用抗原指数，亲水性参数和可及性参数预测DMO和DMT蛋白的B细胞表位，为DMO和DMT蛋白单克隆抗体的制备提供了线索，为系统研究奥利亚罗非鱼DMO和DMT基因的性别调控机理研究提供参考。

Prediction of the Secondary Structure and B Cell Epitopes of DMO and DMT Protein in Oreochromis aureus

The secondary structure of the protein of DMO and DMT in Oreochromis aureus were predicted by the methods of Garnier-Robson, Chou-Fasman and Karplus-Schulz based on the amimo acid sequences of DMO and DMT. And Hydrophilicity plot, Surface probability and Antigenic index for DMO and DMT protein were obtained by the methods of Kyte-Doolittle, Emini and Jameson-Wolf, respectively. Combined the results according to these methods, the B cell epitopes for DMO and DMT protein were predicted. The results demonstrated that there were some centers of α-helix in the DMO protein`s N- terminal No. 80~112, 144~147, 193~194, 251~255, 260~269 and No. 279~283, and in the DMT protein`s N-terminal No. 61~86, 98~105, 140~146, 239~241 and No.269~273. And there are some centers of β-sheet in the DMO protein`s N-terminal No. 59~61, 69~70, 148~150 and No.383~390, and in the DMT protein`s N-terminal No.125~129, 207~213, 255~264 and No.281~284. Furthermore, the DMO protein`s N-terminal No. 40~41, 44~45, 50~51, 128~129, 189~192, 204~207, 216~222, 226~233, 244~246, 298~299 and No.323~326, and the DMT protein`s N-termianl No.12~13, 26~27, 43~44, 58~60, 93~95, 115~120, 136~139 and No.149~151 may be the flexible regions. Moreover the B-cell epitopes possibly localized in or nearby the DMO protein`s 1~5, 41~51, 65~67, 86~89, 98~110, 154~170, 183~203, 205~248, 258~264, 284~291, 293~298, 270~375, 389~392 and No.402~410, and DMT protein`s N-termianl No.1~9, 17~28, 77~84, 114~123, 131~139, 157~184 and No.96~207.Theses results are helpful for studies on sex-control mechanism of DMO and DMT in Oreochromis aureus.