Using mass spectrometry to study the photo-affinity labeling of protein tyrosine phosphatase 1B

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• 作者：LeRiche ; Tammy ; Skorey ; Kathryn ; Roy ; Patrick ; McKay ; Dan ; Bateman ; Kevin P.
• 关键词：Photoprobe ; Phosphatase ; Photo-affinity
• 刊名：International Journal of Mass Spectrometry
• 出版年：2004
• 出版时间：November 1, 2004
• 年：2004
• 卷：238
• 期：2
• 页码：99-106
• 全文大小：208 K

文摘

Protein tyrosine phosphatase 1B (PTP1B) is a potential target for the treatment of Type II diabetes and several companies are developing small molecule inhibitors of this enzyme. Part of the characterization of these compounds as PTP1B inhibitors is the understanding of how they bind in the enzyme active site. The use of photo-activated inhibitors that target the active site can provide such insight. This paper describes the characterization of a photoprobe directed at the active site of PTP1B. Mass spectrometry revealed the specific binding of the probe to the intact protein. Digestion of the labeled protein followed by LC–MS and LC–MS/MS was used to show that the photoprobe binds to a specific active site amino acid. This was confirmed by comparison with the X-ray structure of PTP1B with a PTP1B inhibitor. The probe labels a conserved acidic residue (Asp) that is required for catalytic activity. This photoprobe may prove to be a useful tool for the development of a PTP1B inhibitor or for the study of PTPs in general.