Molecular cloning of glycoprotein antigens MGP57/53 recognized by monoclonal antibodies raised against bovine milk fat globule membrane
Molecular cloning of glycoprotein antigens MGP57/53 recognized by monoclonal antibodies raised against bovine milk fat globule membrane
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DOI：
10.1016/0304-4165(95)00110-7
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发表时间：
1995-12-14
影响因子：
3
通讯作者：
Matsuda, T
中科院分区：
文献类型：
--
作者：
Aoki, N;Kishi, M;Matsuda, T
一种编码57 kDa和53 kDa抗原(MGP57/53)的基因，可被抗牛乳脂球膜(MFGM)的单抗识别。生物群落。ACTA1199(1994)87-95是通过逆转录-聚合酶链式反应(RT-PCR)和3‘-RACE(3’-RACE)相结合的方法从哺乳期牛乳腺组织中克隆到的。推导的氨基酸序列表明，成熟的MGP57/53由409个氨基酸残基组成，其分子量为45 544，等电点为6.42。计算机分析表明，它与小鼠乳腺上皮细胞表面蛋白MFG-E8和人乳腺肿瘤相关糖蛋白抗原BA46-1有显著的相似性。其中N端的富含半胱氨酸的结构域和C端的重复序列高度保守，但牛MGP57/53缺少36个氨基酸残基，包含在小鼠MFG-E8中发现的5个脯氨酸簇。Northern杂交分析表明，该基因与奶牛乳腺组织中约2.0kb的mRNA杂交。这些结果有力地支持了我们先前的报告，即这两个MFGM抗原起源于一个基因，是具有不同N-连锁糖链的异构体。
A cDNA encoding 57 kDa and 53 kDa antigens (MGP57/53) recognized by monoclonal antibodies raised against bovine milk fat globule membrane (MFGM) (Biochim. Biophys. Acta 1199 (1994) 87-95) was cloned from lactating bovine mammary gland by a combination of reverse transcriptase-coupled polymerase chain reaction (RT-PCR) and 3'-rapid amplification of cDNA ends (3'-RACE). The deduced amino-acid sequence showed that mature MGP57/53 consists of 409 amino-acid residues and the calculated molecular weight and isoelectric point are 45 544 and 6.42, respectively. Computer analysis reveals that it has a significant similarity to mouse mammary epithelial cell surface protein, MFG-E8 and a human breast tumor-associated glycoprotein antigen, BA46-1. An N-terminal cysteine-rich domain and a C-terminal tandemly repeated sequence were highly conserved among them, but bovine MGP57/53 lacks 36 amino-acid residues containing a cluster of 5 prolines found in mouse MFG-E8. Northern blot analysis showed that the cDNA hybridized to about 2.0 kb mRNA of lactating bovine mammary gland. These results strongly support our previous report that the two MFGM antigens originate from a single gene and are isoforms with different N-linked sugar chains.