박테리아 헤모글로빈 공발현에 의한 Carbonic Anhydrase의 대장균 재조합 발현 향상

Abstract

Carbonic anhydrase (CA) is a zinc-containing enzyme that catalyzes the CO2 hydration reaction. CA has gained much attention as a green and sustainable biocatalyst to accelerate CO2 capture and utilization. For industrial applications, it is desirable to reduce the enzyme production cost by improving the recombinant production of CA. Vitreoscilla hemoglobin (VHb) is a bacterial hemoglobin whose heterologous expression in Escherichia coli can improve cellular respiration and thereby recombinant protein production. In this study, Neisseria gonorrhoeae CA (NgCA) as a model CA was co-expressed with VHb in E. coli to improve the production of NgCA. When the VHb co-expression was controlled by the hypoxia-inducible Nar promoter, no visible VHb expression nor improvement in NgCA production was observed. In contrast, the bicistronic expression of VHb along with NgCA by the isopropyl-β-D-thiogalactopyranoside-inducible Trc promoter improved the expression level of NgCA by 15%-18%. The activity of purified NgCA was not affected by the VHb co-expression. Thus, the VHb co-expression should have general use as an effective strategy to increase the bacterial production of industrially relevant CA enzymes.