A process to identify peptide antagonists of Hsp16.3, a chaperon protein
necessary for the survival of Mycobacterium tuberculosis in the dormant
phase is described. Affinity selection of a 7-mer and a 12-mer random
peptide libraries displayed on bacteriophage M13 was performed using
recombinant Hsp16.3 as template and two peptide phage clones, which bind
to the Hsp16.3 protein were identified. Synthetic peptides corresponding
to the peptide sequences displayed on these phage clones were able to
specifically bind and inhibit the chaperone function of Hsp16.3 in vitro
in a dose dependent manner. The corresponding inhibitory effect of these
peptides on the chaperon activity of alphaB-crystallin, a constituent of
human eye lens and a homologue of Hsp16.3, was found to be substantially
less. These peptide inhibitors, or similar inhibitors generated by the
process described, which specifically target Hsp16.3, can hence be used
as lead compounds to obtain better therapeutics against latent
tuberculosis.