用单抗5C5和5C5—G1筛选的613bp cDNA的核苷酸序列分析

用识别人活化Ｂ细胞分化抗原５Ｃ５的单克隆抗体５Ｃ５和５Ｃ５－Ｇ１的混合物从人扁桃体细胞λｇｔ１１ ｃＤＮＡ文库筛选到３个阳性克隆。其ｃＤＮＡ插入到质粒ｐＵＣ１８，经双链双脱氧测序法作核苷酸序列分析，知其中一个ｃＤＮＡ长６１３ｂｐ，另二个长４６７ｂｐ，后者与前者的前４６７ｂｐ完全重叠。６１３ｂｐ ｃＤＮＡ中有一个开放阅读框架，从１０３ｂｐ到４２９ｂｐ，共３２７ｂｐ。Ｎｏｒｔｈｅｒｎ印迹分析显示，此６

A 613bp cDNA screened from a human tonsil lambda gtll cDNA library by a mixture of McAb 5C5 and 5C5-G1

positive clones have been obtained from a human tonsil cell lambda gt 11 cDNA library screened with a mixture of McAb 5C5 and 5C5-G1 . The cDNAs of the positive clones were inserted into plasmid pUC1 8. The cDNAs were sequenced with . dideoxy-necleotide chain termination method. One cDNA was 613bp long and the length of the other two were 467bp. The latter overlapped the first 467bp of the former completely. There existed an open reading frame of 327bp (from 103bp to 429bp ) in the 6 1 3bp cDNA, Northern blot analysis revealed that the 6 1 3bp cDNA hybridized the RNA extracted from human tonsil cells or 3D5 cells at the site around 2. 0kb. The sequence of the cDNA is not homologous to any DNA saquence published in the world , hance has been accessioned by GenBank with a accessed number of U25041. In the protein deduced from the nucleotide sequence there existed a hydrophobic region from amino acid residue 20 to 30.