Evaluation of a novel subtilisin inhibitor gene and mutant derivatives for the expresion and secretion of mouse tumor necrosis factor alpha by Streptomyces lividans

The complementary DNA of the murine tumor necrosis factor (mTNF) was fused with the signal sequence of the gene encoding novel subtilisin inhibitor (VSI) of Streptomyces venezuelae. Immunoblot analysis of the recombinant mTNF produced by S. lividans transformants with mutated VSI signal peptides indicated the presence of varied levels of mTNF secretion that was altered by the effect of positive charges in the N regions on the signal peptides. However, the presence of positive charges in the N region was not an integral component of protein export.