This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Saha, A. Articles by Das Gupta, S. K. Search for Related Content PubMed PubMed Citation Articles by Saha, A. Articles by Das Gupta, S. K. Agricola Articles by Saha, A. Articles by Das Gupta, S. K.

Antagonists of Hsp16.3, a Low-Molecular-Weight Mycobacterial Chaperone and Virulence Factor, Derived from Phage-Displayed Peptide Libraries

Abhik Saha,¹ Archna Sharma,¹ Amlanjyoti Dhar,^2, Bhabatarak Bhattacharyya,³ Siddhartha Roy,^2, and Sujoy K. Das Gupta^1*

Department of Microbiology,¹ Department of Biophysics,² Department of Biochemistry, Bose Institute, P1/12 C.I.T. Scheme VIIM, Calcutta 700054, India³

Received 21 September 2004/ Accepted 5 June 2005

The persistence of Mycobacterium tuberculosis is a major cause of concern in tuberculosis (TB) therapy. In the persistent mode the pathogen can resist drug therapy, allowing the possibility of reactivation of the disease. Several protein factors have been identified that contribute to persistence, one of them being the 16-kDa low-molecular-weight mycobacterial heat shock protein Hsp16.3, a homologue of the mammalian eye lens protein alpha-crystallin. It is believed that Hsp16.3 plays a key role in the persistence phase by protecting essential proteins from being irreversibly denatured. Because of the close association of Hsp16.3 with persistence, an attempt has been made to develop inhibitors against it. Random peptide libraries displayed on bacteriophage M13 were screened for Hsp16.3 binding. Two phage clones were identified that bind to the Hsp16.3 protein. The corresponding synthetic peptides, an 11-mer and a 16-mer, were able to bind Hsp16.3 and inhibit its chaperone activity in vitro in a dose-dependent manner. Little or no effect of these peptides was observed on alphaB-crystallin, a homologous protein that is a key component of human eye lens, indicating that there is an element of specificity in the observed inhibition. Two histidine residues appear to be common to the selected peptides. Nuclear magnetic resonance studies performed with the 11-mer peptide indicate that in this case these two histidines may be the crucial binding determinants. The peptide inhibitors of Hsp16.3 thus obtained could serve as the basis for developing potent drugs against persistent TB.

Present address: Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Rd., Calcutta 700032, India.

This article has been cited by other articles:

• Sharma, A., Saha, A., Bhattacharjee, S., Majumdar, S., Das Gupta, S. K. (2006). Specific and Randomly Derived Immunoactive Peptide Mimotopes of Mycobacterial Antigens. CVI 13: 1143-1154 [Abstract] [Full Text]