Hosoi K, Tada J, Tsumura K, Kanamori N, Yamanaka N
Department of Physiology, Tokushima University School of Dentistry, Tokushima, 770-8504, Japan.
J Biochem. 1998 Aug;124(2):368-76. doi: 10.1093/oxfordjournals.jbchem.a022121.
A protein product of the tissue kallikrein gene family was isolated from the submandibular gland of DBA/2N mice. Amino acid sequencing showed this protein to be highly homologous to two tissue kallikreins, mK13 and mK26, also known as prorenin-converting enzymes PRECE and PRECE-2, respectively. The cDNA corresponding to the present enzyme was cloned, and its complete nucleotide sequence was determined. The cloned cDNA was different in 6 and 12 bases out of 783 nucleotides from those of mK1k-13 and mK1k-26 cDNAs, respectively, the homologies being 99.2 and 98.5% (nucleotide), or 98.3 and 96.2% (amino acid). Upon incubation with either bovine kininogens or mouse Ren 2 prorenin, this tissue kallikrein generated bradykinin and renin, respectively, as judged by Western blotting and protein sequence analysis. Isoelectric focusing analysis of the submandibular gland tissue kallikreins suggested that the present enzyme was not expressed in CD-1 or ICR mice and that no mK13 protein was present in DBA/2N mice. These data suggest that the enzyme is an allozyme of mK13, a prorenin-converting enzyme highly expressed in the submandibular gland of DBA/2N mice. The mK1k-13 gene in mice is therefore suggested to be polymorphic, having at least two allelic forms with a high sequence homology. The designation mK13(b) and mK1k-13(b) for the protein and gene of this tissue kallikrein is proposed.
从DBA/2N小鼠的颌下腺中分离出一种组织激肽释放酶基因家族的蛋白质产物。氨基酸测序表明，该蛋白质与两种组织激肽释放酶mK13和mK26高度同源，它们也分别被称为前肾素转化酶PRECE和PRECE-2。克隆了与该酶相对应的cDNA，并测定了其完整的核苷酸序列。克隆的cDNA在783个核苷酸中分别有6个和12个碱基与mK1k-13和mK1k-26的cDNA不同，同源性分别为99.2%和98.5%（核苷酸），或98.3%和96.2%（氨基酸）。通过蛋白质免疫印迹法和蛋白质序列分析判断，该组织激肽释放酶与牛激肽原或小鼠Ren 2前肾素孵育后，分别产生缓激肽和肾素。颌下腺组织激肽释放酶的等电聚焦分析表明，该酶在CD-1或ICR小鼠中不表达，且DBA/2N小鼠中不存在mK13蛋白。这些数据表明，该酶是mK13的一种同工酶，mK13是一种在前肾素转化酶在DBA/2N小鼠颌下腺中高表达。因此，小鼠中的mK1k-13基因被认为是多态性的，至少有两种具有高度序列同源性的等位基因形式。建议将这种组织激肽释放酶的蛋白质和基因命名为mK13(b)和mK1k-13(b)。
