Diseño y producción de diversas proteínas fusión de la nicotinamida/nicotinato mononucleótido adenilil transferasa (NMNAT) de Plasmodium falciparum

Recombinant proteins have become useful tools in biochemistry research. During their production, however, inclusion bodies (IB) appear, on the one hand, due to the high expression rate from the recombinant plasmids, which have high efficiency promoters, and, on the other hand, intrinsic characteristics of the expressed protein. Furhtermore, the nicotinamide/nicotinate mononucleotide adenilyl transferase (NMNAT) is a central protein in NAD(H)+ biosynthesis, an essential cofactor in cell metabolism, and in protozoon parasite has been studied. To study the NMNAT protein of these parasites, their recombinant version in E. coli has been expressed, getting a great quantity of IB as a by-product. To increase the solubility of the protein, the coding sequence of the NMNAT enzyme of Plasmodium falciparum was cloned in different expression plasmids which were subsequently transformed into E. coli BL21(DE3) expression strain. The solubility of the recombinant proteins was assessed and the one with the highest presence in the soluble fraction was subsequently purified and its enzyme activity was determined. The recombinant protein with a MBP (maltose-binding protein) tag showed an increased solubility and purity.