Gum J R, Byrd J C, Hicks J W, Toribara N W, Lamport D T, Kim Y S
Gastrointestinal Research Laboratory (151M2), Veterans Administration Medical Center, San Francisco, California 94121.
J Biol Chem. 1989 Apr 15;264(11):6480-7.
A human small intestine lambda gt11 cDNA library was screened using antisera prepared against the deglycosylated protein backbone of human colon cancer xenograft mucin. Three cDNAs were isolated from this screening, designated SMUC 40-42. These cDNAs were all found to contain tandem repeats of 69 nucleotides which encoded a threonine- and proline-rich protein consensus sequence of PTTTPITTTTTVTPTPTPTGTQT. RNA blots probed with one of these cDNAs, SMUC 41, exhibited large, polydisperse hybridization bands at approximately 7,600 bases. Band intensities were strongest when human small intestine, colon, and colon cancer poly(A)+ RNA was used. In vitro translation of poly(A)+ RNA from human small intestine, colon, and colon cancer cells produced a 162,000-dalton peptide that was immunoprecipitated with antibodies to deglycosylated mucin. SMUC 41 was also used to probe DNA blots, which indicated the presence of restriction fragment length polymorphisms in the intestinal mucin gene. These findings may be important in assessing the abnormal mucins found associated with several human diseases.
利用针对人结肠癌异种移植粘蛋白去糖基化蛋白骨架制备的抗血清，筛选人小肠λgt11 cDNA文库。从该筛选中分离出三个cDNA，命名为SMUC 40 - 42。这些cDNA均含有69个核苷酸的串联重复序列，其编码富含苏氨酸和脯氨酸的蛋白质共有序列PTTTPITTTTTVTPTPTPTGTQT。用其中一个cDNA（SMUC 41）探测RNA印迹，在约7600个碱基处出现大的、多分散的杂交带。当使用人小肠、结肠和结肠癌的多聚腺苷酸加尾（poly(A)+）RNA时，条带强度最强。对人小肠、结肠和结肠癌细胞的多聚腺苷酸加尾RNA进行体外翻译，产生了一个162,000道尔顿的肽，该肽能用去糖基化粘蛋白抗体进行免疫沉淀。SMUC 41也用于探测DNA印迹，这表明肠道粘蛋白基因存在限制性片段长度多态性。这些发现对于评估与几种人类疾病相关的异常粘蛋白可能具有重要意义。
