SH2 domains in non-receptor tyrosine kinases, such as p56lck, represent molecular targets that are central to cellular signaling pathways related to immune response. Based on the essential role of SH2 domains a large number of peptides or peptidomimetic compounds that bind to and inhibit SH2 domains have been synthesized. However, these compounds will typically have poor bioavailability and/or stability due to both their peptidic nature and the presence of phosphotyrosine, or related charged chemical moieties. In the proposed study we will apply computer-aided rational drug design to identify small molecules that inhibit cell signaling via binding to the p56lck SH2 domain and lack the undesirable properties of presently available inhibitors. This will be achieved based on the following specific aims.
Specific Aim 1) Identify small molecules with a high potential to bind specifically to the p56lck SH2 domain via three-dimensional (3D) chemical database screening. Simultaneous use of the p56lck, Hck, Fyn, Src, Shc and ZAP-70 SH2 domains will allow for selectivity to be included in the computer screening process.
Specific Aim 2) Biological assays of compounds identified in Specific Aim 1 including: 2.i) Initial screening for compounds that inhibit OKT-3 mediated stimulation of cellular protein tyrosine phosphorylation in Jurkat cells. 2.ii) Qualitative and quantitative p56lck SH2 binding analysis of active compounds from 2.i). 2.iii) Test the ability of compounds identified in 2.i and 2.ii to inhibit the biological function of T cells, including IL-2 production and mixed lymphocyte culture assay. 2.iv) Test the ability of compounds identified in 2.i, 2.ii, and 2.iii to inhibit in vivo immune response of delayed- type hypersensitivity (DTH) and anti-type II collagen-induced rheumatoid arthritis in mice.
Specific Aim 3) Experimental determination of the specificity for p56lck SH2 domain of the active compounds using comparative binding parameters with the SH2 domains of Hck, Fyn, Src, Shc and ZAP-70. Following completion of the proposed study compounds that inhibit the p56lck SH2 domain will be available as research tools and as lead compounds for the development of novel immunosuppressant drugs.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA095200-03
Application #
6754485
Study Section
Special Emphasis Panel (ZRG1-SSS-4 (10))
Program Officer
Lees, Robert G
Project Start
2002-07-01
Project End
2005-06-30
Budget Start
2004-07-01
Budget End
2005-06-30
Support Year
3
Fiscal Year
2004
Total Cost
$231,289
Indirect Cost
Name
University of Maryland Baltimore
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Chen, Fengming; Hancock, Chad N; Macias, Alba T et al. (2006) Characterization of ATP-independent ERK inhibitors identified through in silico analysis of the active ERK2 structure. Bioorg Med Chem Lett 16:6281-7
Hancock, Chad N; Macias, Alba; Lee, Eun Kyoung et al. (2005) Identification of novel extracellular signal-regulated kinase docking domain inhibitors. J Med Chem 48:4586-95
Boresch, Stefan; Leitgeb, Martin; Beselman, Aleksandra et al. (2005) Unexpected relative aqueous solubilities of a phosphotyrosine analogue and two phosphonate derivatives. J Am Chem Soc 127:4640-8
Macias, Alba T; Mia, Md Younus; Xia, Guanjun et al. (2005) Lead validation and SAR development via chemical similarity searching; application to compounds targeting the pY+3 site of the SH2 domain of p56lck. J Chem Inf Model 45:1759-66
Markowitz, Joseph; Chen, Ijen; Gitti, Rossi et al. (2004) Identification and characterization of small molecule inhibitors of the calcium-dependent S100B-p53 tumor suppressor interaction. J Med Chem 47:5085-93