Specific Inhibition of Sensitized Protein Tyrosine Phosphatase 1B (PTP1B) with a Biarsenical Probe
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- 作者：Oliver B. Davis ; Anthony C. Bishop
- 刊名：Bioconjugate Chemistry
- 出版年：2012
- 出版时间：February 15, 2012
- 年：2012
- 卷：23
- 期：2
- 页码：272-278
- 全文大小：328K
- 年卷期：v.23,no.2(February 15, 2012)
- ISSN：1520-4812
文摘
Protein tyrosine phosphatase 1B (PTP1B) is a key regulator of the insulin-receptor and leptin-receptor signaling pathways, and it has therefore emerged as a critical antitype-II-diabetes and antiobesity drug target. Toward the goal of generating a covalent modulator of PTP1B activity that can be used for investigating its roles in cell signaling and disease progression, we report that the biarsenical probe FlAsH-EDT2 can be used to inhibit PTP1B variants that contain cysteine point mutations in a key catalytic loop of the enzyme. The site-specific cysteine mutations have little effect on the catalytic activity of the enzyme in the absence of FlAsH-EDT2. Upon addition of FlAsH-EDT2, however, the activity of the engineered PTP1B is strongly inhibited, as assayed with either small-molecule or phosphorylated-peptide PTP substrates. We show that the cysteine-rich PTP1B variants can be targeted with the biarsenical probe in either whole-cell lysates or intact cells. Together, our data provide an example of a biarsenical probe controlling the activity of a protein that does not contain the canonical tetra-cysteine biarsenical-labeling sequence CCXXCC. The targeting of 鈥渋ncomplete鈥?cysteine-rich motifs could provide a general means for controlling protein activity by targeting biarsenical compounds to catalytically important loops in conserved protein domains.