睾丸特异抗原C_2B细胞抗原决定簇的定位

免疫性不育病人的血清（ＩＰＳ）能１００％地抑制人体外受精．用该血清筛选人睾丸ｃＤＮＡ基因表达文库，发现了一种新的睾丸特异抗原（称作Ｃ２）．通过ＤＮＡ顺序研究，并与基因库中的有关同源性基因数据进行比较，证实Ｃ２是一个新的特异蛋白．Ｃ２基因仅与睾丸组织的ｍＲＮＡ杂交．该克隆在大肠杆菌中所表达的融合蛋白能够被３个不同的不育病人血清识别．利用嵌套缺失和Ｗｅｓｔｅｒｎ印迹的方法研究其抗原决定簇定位，发现Ｂ细胞抗原决定簇在羧基端２９个氨基酸范围内．用ＧＣＧ软件分析该抗原的氨基酸的亲水性和疏水性以及其存在于蛋白表面的可能性，确定其中的１５个氨基酸为抗原决定簇所必需，并合成了多肽

Identification and B cell Epitope Mapping of Testis Specific Antigen C 2 *

An Immunological infertile patient serum (IIPS) caused 100% inhibition of human in vitro fertilization was used in screening human testis cDNA expression library.A new testis specific candidate antigen was identified (designated C 2)by IIPS.DNA sequencing and homology searching in databases showed that C 2 is a new testis specific protein.Northern blot analysis showed that clone C 2 recognized a single message present only in testis.The fusion protein expressed in E.coli was recognized by sera from 3 different infertile patients.A B cell epitope was identified in region of 29 amino acid residues near the carboxy terminus of the C 2 protein by unidirectional nested deletion method and Western blot analyses.15 amino acid residues epitope was predicted by computerized analysis.Based on hydrophilicity and surface probability analyses of the protein,a chimeric peptide containing the predicted epitope have been designed and synthesized.