ISSN 2375-0731
African Journal of Pig Farming ISSN 2375-0731 Vol. 3 (1), pp. 001-009, January, 2015. © International Scholars Journals
Full Length Research Paper
An efficient secretion of the protein fused to the AgfA signal sequence in Salmonella
Ho Young Kang1, Ki Hwan Moon1, Se Won Kim2, Jeong Dong Bahk 2, Sang Wan Gal3, Kwang-Keun Cho4, Chul-Wook Kim4, John Hwa Lee5 and Sam Woong Kim6*
1Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 609-735, South Korea.
2Division of Applied Life Sciences (BK21-EBNCRC), Graduate School of Gyeongsang National University, Jinju 660-701,Korea.
3Department of Pharmaceutical Engineering, Gyeongnam National University of Science and Technology, 150 Chilam-dong, Jinju 660-758, Korea.
4Department of Animal Resources Technology, Gyeongnam National University of Science and Technology, 150 Chilam-dong, Jinju, Gyeongnam, 660-758, South Korea.
5College of Veterinary Medicine, Chonbuk National University, Chon-ju 561-756, South Korea.
6Swine Science and Technology Center, Gyeongnam National University of Science and Technology, 150 Chilam-dong, Jinju, Gyeongnam, 660-758, South Korea.
Accepted 02 December, 2014
Abstract
Signal sequence (SS) of surface or secreting proteins plays an important function for protein secretion in bacterial system. The SS of various proteins may mediate different level of protein excretion yield of the proteins. In order to examine the effect of SS types in protein secretion, signal sequences of Bla (b– lactamase), AgfA (thin aggregative fimbriae A), StfA (Salmonella typhimurium fimbriae A) and OmpW (outer membrane protein W) were selected for the secretion of PspA protein which was used as a test protein. The PCR-amplified DNAs corresponding to each SS were cloned into the plasmid pYA3342. A primer used in PCR was designed to insert a His6-tag at the C- terminal of SS for the convenient detection of expressed SS. The 0.8 kb EcoRI-Hin dIII pspA gene was cloned into the recombinant plasmids, resulting pMMP66, pMMP67, pMMP68 and pMMP70. The S. typhimurium strains harboring the recombinant plasmids expressed the His6-tagged PspA, demonstrating in-frame fusion of PspA to each Depending upon the type of SS, cell lysate as well as secreted PspA of each Salmonella samples was found different. Relatively, S. typhimurium containing pMMP67 (carrying AgfA SS) secreted the highest level of PspA than others, and suggested that the AgfA SS mediates efficient translocation of the PspA. Conclusively, the AgfA SS mediated secretion system in pMMP67 can be used in variety fields required for the high level of protein secretion, especially antigen delivery in recombinant attenuated Salmonella vaccines.
Key words: b–Lactamase, thin aggregative fimbriae A, outer membrane protein W, Salmonella typhimurium fimbriae A, signal sequence, secretion.