Research Groups

Mammalian Biology: Recombinant Gene Products

Research Interests and Description

Staff Research Scientist: Anand Ranganathan

Research Interests

Genetically engineered biomolecules, codon-shuffling, pathogenesis of tuberculosis.

Description of Research

The lab has previously developed a method for laboratory-directed evolution of proteins, called ‘codon-shuffling’. The potential of this method to create stand-alone de novo protein/peptide libraries, for their eventual use as antibacterial entities is being realised. Because of an inherent property of each of the fourteen dicodons in the ‘dicodon set’ to possess a secondary structure imprint, the Group realized that assembly of such dicodons would create proteins with well-folded characteristics, largely due to the accumulation of so-called secondary structure imprints and form predefined helical and sheet protein folds. Indeed, the Group was able to select for some codon-shuffled de novo proteins that were antibacterial in nature. The extent of their activity was extensively studied by growth-inhibition and zone-clearance experiments, as well as by Electron Microscopy. All such proteins exhibited good secondary structure attributes, as judged by circular-dichroism spectroscopy and theoretical predictions.
Current efforts are now directed towards extending the method to create similar antibacterial proteins against pathogenic organisms like Mycobacterium tuberculosis. We have recently unearthed potent binders against an essential protein of M. tuberculosis, called hupB. Expression of this ‘codon-shuffled’ protein in Mycobacteria caused growth retardation, as well as other effects commensurate with the inhibition of hupB inside mycobateria. We are now extending this approach further, by using a two-hybrid system, for identifying other potent binders against the many important secretary protein of M. tuberculosis.

Recent Publications

Rao, A., Ram, G., Saini, A.K., Vohra, R., Kumar, K., Singh, Y., Ranganathan, A. 2007. Synthesis and selection of de novo proteins that bind and impede cellular functions of an essential mycobacterial protein. Appl. Environ. Microbiol. 73, 1320-1331

Gopalan, G., Chopra, S., Ranganathan, A., Swaminathan, K. 2006 Crystal structure of uncleaved L-aspartate-alpha-decarboxylase from Mycobacterium tuberculosis. Proteins. 65, 796-802

Rao, A., Chopra, S., Ram, G., Gupta, A., Ranganathan, A. 2005. Application of the "codon-shuffling" method. Synthesis and selection of de novo proteins as antibacterials. J. Biol. Chem. 280, 23605-23614