Vector developed for purification of Mycobacterium tuberculosis proteins.

2003 AUG 20 - (NewsRx.com & NewsRx.net) -- A modified vector for efficient purification of recombinant Mycobacterium tuberculosis proteins expressed in Escherichia coli has been constructed.

"A major problem in assessing the vaccine and diagnostic potential of various proteins encoded by Mycobacterium tuberculosis genome is the inability to produce large quantities of these proteins, even when Escherichia coli or other heterologous systems are employed for recombinant protein production. To overcome these barriers, we have constructed a modified expression vector, using pGEX-4T-1 vector as the backbone.

"In addition to the features offered by the pGEX-4T vectors, the new vector allowed easy purification of recombinant proteins on the highly versatile Ni-NTA-agarose affinity matrix," scientists writing in the journal Protein Expression and Purification report.

"The utility of the new vector was demonstrated by expressing and purifying, to near homogeneity, two M. tuberculosis proteins, i.e., Rv3872 (a member of the multigene PE subfamily) and Rv3873 (a member of the multi-gene PPE subfamily), which are encoded by the RD1 region of M. tuberculosis," said Suhail Ahmad and colleagues at Kuwait University. "The proteins encoded by rv3872 and rv3873 were expressed at high levels as fusion proteins with glutathione-S-transferase in E. coli."

The researchers reported, "The recombinant Rv3872 and Rv3873 proteins were purified and isolated free of the fusion partner (GST) by affinity purification on ...