Design and synthesis of a dimeric derivative of RK-682 with increased inhibitory activity against VHR, a dual-specificity ERK phosphatase: implications for the molecular mechanism of the inhibition

Background: VHR is a dual-specificity phosphatase, which dephosphorylates activated ERK1/2 and weakens the ERK signaling cascade in mammalian cells. A selective inhibitor is expected to be useful for revealing the physiological function of VHR. Results: First, we investigated the molecular mechanism of VHR inhibition by a known natural product, RK-682. Kinetic analysis indicated that inhibition was competitive toward the substrate, and two molecules of RK-682 were required to inhibit one molecule of VHR. Based on the structure-activity relationships for VHR inhibition by RK-682 derivatives, we constructed a binding model using molecular dynamics calculation. Based on this model, we designed and synthesized a novel dimeric derivative. As expected, the dimeric derivative showed increased inhibition of VHR, supporting our proposed mechanism of VHR inhibition by RK-682, Conclusion: We have developed a novel inhibitor of VHR based on the results of kinetic analysis and docking simulation. (C) 2001 Elsevier Science Ltd. All rights reserved.