19th-banner-rev.gif

Book of Abstracts: Albany 2005

category image Volume 22
No. 6
June 2005

In Silico Structure-Based Design of a Potent and Selective Small Peptide Inhibitor of Protein Tyrosine Phosphatase 1B, A Novel Therapeutic Target for Type 2 Diabetes Mellitus and Obesity

Protein Tyrosine Phosphatase 1B (PTP1B) has been shown to be a negative regulator of insulin signaling by dephosphorylating key tyrosine residues within the regulatory domain of the β-subunit of the insulin receptor. Recent gene knockout studies in mice have shown the mice to have increased insulin sensitivity and improved glucose tolerance. Furthermore, these mice also exhibited a resistance to diet induced obesity. Inhibitors of PTP1B would have the potential of enhancing insulin action by prolonging the phosphorylated state of the insulin receptor. In addition, recent clinical studies have shown that the haplotype ACTTCAG0 of the PTPN1 gene which encodes PTP1B, is a major risk contributor to type 2 diabetes mellitus (T2DM). Thus there is compelling evidence that small molecule inhibitors of PTP1B may be effective in treating insulin resistance at an early stage, thereby leading to a prevention strategy for T2DM, and obesity.

Based on the crystal structure of the complex of PTP1B with a known inhibitor, we have identified a tetrapeptide inhibitor with the sequence WKPD. Docking calculations indicate that this peptide is as potent as the existing inhibitors. Moreover, the peptide is also found to be selective for PTP1B with a greatly reduced potency against other biologically important protein tyrosine phosphatases such as PTP-LAR, Calcineurin and the highly homologous T-Cell Protein Tyrosine Phosphatase (TCPTP). Thus the designed tetrapeptide is a suitable lead compound for the development of new drugs against type 2 diabetes and obesity.

Gita Subba Rao1, *
Manoj V. Ramachandran1
J.S. Bajaj2

1Department of Biophysics
All India Institute of Medical Sciences
New Delhi, India -110029
2Chief Consultant and Director
Diabetes, Endocrine and Metabolic Medicine
Batra Hospital and Medical Research Centre
New Delhi, India - 110062

*Phone: 91-11-26594816
Fax: 91-11-26588663
Email: gitarao@aiims.ac.in