ABSTRACT
AIMS: To develop an efficient and facile expression system supply of high purity and stable activity of rFip-fve for oral administration, medicinal study and applications. METHODS AND RESULTS: A recombinant virus that contained the chimera gene, encoding a bombyxin signal peptide sequence fused to a Fip-fve-6His sequence, was constructed. The rFip-fve was purified from the supernatant of the infected Sf21 cells using a nickel-chelated affinity column, and was verified by Western blot and MALDI-MS (matrix-assisted laser desorption ionization mass spectrometry) analyses. Results showed that a glycosylated mature rFip-fve was produced and secreted into the infected cell supernatant. The immunomodulatory activity of rFip-fve was evaluated by measuring the amount of interleukin-2 released from murine splenocytes. CONCLUSIONS: A reliable scheme to express and purify active rFip-fve in a baculovirus/insect cell system for medicinal applications and genetic study is a feasible means of solving potential problems related to the production and activity of rFip-fve protein. SIGNIFICANCE AND IMPACT OF THE STUDY: The rFip-fve expressed in insect cells was processed and modified in a manner more similar to that of its native counterpart than that in bacterial cells. Therefore, the potential applications of rFip-fve that is generated in Sf21 cells can be more effectively evaluated that produced in Escherichia coli.
Subject(s)
Baculoviridae/physiology , Fungal Proteins/isolation & purification , Immunologic Factors/isolation & purification , Industrial Microbiology , Lectins/isolation & purification , Animals , Bioreactors , Cell Line , Cells, Cultured , Escherichia coli , Fungal Proteins/pharmacology , Immunologic Factors/pharmacology , Interleukin-2/biosynthesis , Lectins/pharmacology , Mice , Recombinant Proteins/isolation & purification , Recombinant Proteins/pharmacology , Spleen/drug effects , Spleen/immunology , Spodoptera/virologyABSTRACT
A sweet potato (Ipomoea batatas cv. Tainong 57) trypsin inhibitor gene was introduced into tobacco plants (Nicotiana tabaccum cv. W38) by Agrobacterium tumefaciens- mediated transformation. From 30 independent transformants, three lines with high level of expression were further analyzed. The trypsin inhibitor gene, under control of the 35S CaMV promoter, led to the production of the trypsin inhibitor proteins up to 0.2% of the total protein. In insecticidal bioassays of transgenic tobacco plants, larval, growth of Spodoptera litura (F.), the tobacco cutworm, was severely retarded as compared to their growth on control plants. This observation implied that expression of sweet potato trypsin inhibitor can provide an efficient method for crop protection.
