Expression of a novel gene encoding protease inhibitor from metagenome of sponge in Vietnam

Abstract

Marine sponge is known as a “gold mine” of natural products from marine environment. Many novel bioactive compounds have been isolated from marine sponges and sponge-associated microorganisms such as antibiotics, anti-cancer compounds, protease inhibitors, etc. In this study, we selected a gene encoding protease inhibitor from metagenome of a sponge collected in Quang Tri to express in Escherichia coli (E. coli) BL21(DE3). The gene PI-DN9encoding protease inhibitor (1.3 kb) was cutoff cloning vector pUC57/PI-DN9 containing gene PI-DN9and inserted into expression vector pET-32a(+), the recombinant vector pET-32a(+)/PI-DN9 then was transformed and expressed in the E. coli strain BL21(DE3). Results showed that recombinant protein (50kDa) was expressed successfully at 25°C, 1 mM of IPTG in 5 hours. The recombinant protein was purified using Ni-NTA affinity chromatography column. Western blot assay and bioactive assay showed good activity of the purified protein.