关键词: 植物乳杆菌, NP_785232蛋白, 聚合酶链式反应, 诱导表达, 纯化

Abstract:

Lactobacillus plantarum KLDS 1.0320 adhesion surface protein NP_785232 was selected as the candidate in thiswork, and its first two domains at N terminus were subcloned and heterologously expressed in E. coli expression system. Thepurified recombinant protein was subsequently tested. PCR method was utilized to clone the first two domains at N terminusof the protein NP_785232, and the cloned fragment was ligated into the expression vector pET30a to construct a recombinantplasmid pET30a/N2, which was then transformed into E. coli. After being induced with a final concentration of 1 mmol/LIPTG, the recombinant protein was purified through HisTrap affinity chromatography and then analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The polypeptide fragment with the right size in the SDS-PAGEwas further identified by mass spectrometry. The results showed that the recombinant protein was exactly the same as thefirst two domains at N terminus of NP_785232 protein. Thus, we concluded that the first two domains at N terminus ofNP_785232 protein was successfully heterologously expressed in E. coli expression system.

Key words: Lactobacillus plantarum, NP_785232 protein, polymerase chain reaction (PCR), expression, purification