Angele C, Wellman M, Thioudellet C, Guellaen G, Siest G
Centre du Médicament, URA CNRS N'597, Nancy, France.
Biochem Biophys Res Commun. 1989 May 15;160(3):1040-6. doi: 10.1016/s0006-291x(89)80107-x.
To obtain the expression of rat kidney gamma-glutamyltransferase (GGT) cDNA in E. coli, plasmids containing the cDNA sequences coding for various parts of GGT were constructed. Transformation of E. coli cells by these hybrid vectors results in a production of unglycosylated recombinant proteins, immunologically recognized by specific antirat kidney GGT antibodies. Plasmid, expressing the complete coding sequence of GGT cDNA, allows the production of enzymatically active proteins localized in the periplasmic space, while the same sequence without the N-terminal hydrophobic region results in a production of cytoplasmic proteins. These recombinant proteins present a very basic isoelectric point (pI greater than 9). These results suggest that the presence of the N-terminal region seems to be necessary to direct the expressed proteins enzymatically active in the periplasmic space.
为了在大肠杆菌中获得大鼠肾脏γ-谷氨酰转移酶（GGT）cDNA的表达，构建了包含编码GGT各个部分的cDNA序列的质粒。用这些杂交载体转化大肠杆菌细胞会产生未糖基化的重组蛋白，可被特异性抗大鼠肾脏GGT抗体免疫识别。表达GGT cDNA完整编码序列的质粒能够产生定位于周质空间的具有酶活性的蛋白质，而去除N端疏水区域的相同序列则会产生细胞质蛋白。这些重组蛋白具有非常碱性的等电点（pI大于9）。这些结果表明，N端区域的存在似乎是引导表达的蛋白在周质空间中具有酶活性所必需的。
