Kotrba P, Pospisil P, de Lorenzo V, Ruml T
Dept. of Biochemistry and Microbiology, ICT, Prague, Czech Republic.
J Recept Signal Transduct Res. 1999 Jan-Jul;19(1-4):703-15. doi: 10.3109/10799899909036681.
The lamB gene was inserted at with DNA fragments encoding N-terminal beta- and C-terminal alpha-domains of human metallothionein 1A (HMT1A). The hybrid LamB proteins were expressed as full-length products. Virtually whole pool of hybrid LamB proteins was found localized in the outer membrane of E. coli to and cells expressing LamB variants retained sensitivity to lambda phage, indicating their correct folding. Expression of hybrid LamB proteins increased natural ability of E. coli accumulate bivalent heavy metals ions with the highest efficiency observed for cadmium. The order of amount of cadmium accumulated is alpha-domain of HMT1A > HMT1A >> beta-domain of HMT1A. This correlates with affinity for cadmium and stability of metallothionein and its individual domains. This confirms suitability of LamB vehicle for surface display of various bioactive molecules and suggests possibility of engineering of cell surface for bioremediation of heavy metals.
将lamB基因与编码人金属硫蛋白1A（HMT1A）N端β结构域和C端α结构域的DNA片段一起插入。杂合LamB蛋白以全长产物形式表达。几乎所有杂合LamB蛋白都定位于大肠杆菌的外膜，表达LamB变体的细胞对λ噬菌体仍保持敏感性，表明它们折叠正确。杂合LamB蛋白的表达提高了大肠杆菌积累二价重金属离子的天然能力，其中对镉的积累效率最高。镉积累量的顺序为：HMT1A的α结构域>HMT1A>>HMT1A的β结构域。这与对镉的亲和力以及金属硫蛋白及其各个结构域的稳定性相关。这证实了LamB载体适用于各种生物活性分子的表面展示，并暗示了对细胞表面进行工程改造以用于重金属生物修复的可能性。
