1kav
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| , resolution 2.35Å | |||||||
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| Ligands: | |||||||
| Activity: | Protein-tyrosine-phosphatase, with EC number 3.1.3.48 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Human Tyrosine Phosphatase 1B Complexed with an Inhibitor
OverviewOverview
Protein tyrosine phosphatases (PTPases) are signal-transducing enzymes that dephosphorylate intracellular proteins that have phosphorylated tyrosine residues. It has been demonstrated that protein tyrosine phosphatase 1B (PTP1B) is an attractive therapeutic target because of its involvement in regulating insulin sensitivity (Elcheby et al. Science 1999, 283, 1544-1548). The identification of a second binding site in PTP1B (Puius et al., Proc. Natl. Acad. Sci. U.S.A.1997, 94, 13420-13425) suggests a new strategy for inhibitor design, where appropriate compounds may be made to simultaneously occupy both binding sites to gain much higher affinity and selectivity. To test this hypothesis and gain further insights into the structural basis of inhibitor binding, we have determined the crystal structure of PTP1B complexed with two non-peptidyl inhibitors, 4 and 5, both of which contain two aryl difluoromethylenephosphonic acid groups, a nonhydrolyzable phosphate mimetic. The structures were determined and refined to 2.35 and 2.50 A resolution, respectively. Although one of the inhibitors seems to have satisfied the perceived requirement for dual binding, it did not bind both the active site and the adjacent noncatalytic binding site as expected. The second or distal phosphonate group instead extends into the solvent and makes water-mediated interactions with Arg-47. The selectivity of the more potent of these two inhibitors, as well as four other inhibitors bearing two such phosphate mimetics for PTP1B versus seven other PTPases, was examined. In general, selectivity was modest to good when compared to PTPases Cdc25a, PTPmeg-1, PTPbeta, and CD45. However, selectivity was generally poor when compared to other PTPases such as SHP-1, SHP-2, and especially TCPTP, for which almost no selectivity was found. The implications these results have concerning the utility of dual-binding inhibitors are discussed.
DiseaseDisease
Known diseases associated with this structure: Abdominal body fat distribution, modifier of OMIM:[176885], Insulin resistance, susceptibility to OMIM:[176885]
About this StructureAbout this Structure
1KAV is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Structure of protein tyrosine phosphatase 1B in complex with inhibitors bearing two phosphotyrosine mimetics., Jia Z, Ye Q, Dinaut AN, Wang Q, Waddleton D, Payette P, Ramachandran C, Kennedy B, Hum G, Taylor SD, J Med Chem. 2001 Dec 20;44(26):4584-94. PMID:11741477
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