Alrazi IMD, Sadakane K, Maruta S. Novel photochromic inhibitor for mitotic kinesin Eg5 which forms multiple isomerization states.
J Biochem 2021;
170:229-237. [PMID:
33752234 DOI:
10.1093/jb/mvab035]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/15/2021] [Indexed: 11/14/2022] Open
Abstract
The mitotic kinesin Eg5 is a plus-end directed homotetrameric molecular motor essential for the formation of bipolar spindles during cell division. Kinesin Eg5 is overexpressed in cancer cells and hence considered a target for cancer therapy; the inhibitors specific for Eg5 have been developed as anti-cancer drugs. In this study, we synthesized a novel functional photoresponsive inhibitor composed of spiropyran and azobenzene derivatives to control Eg5 function with multi-stage inhibitory activity accompanied by the formation of different isomerization states. The photochromic inhibitor spiropyran-sulfo-azobenzene (SPSAB) exhibited three isomerization states: Spiro (SP)-trans, Merocyanine (MC)-cis, and MC-trans, upon exposure to visible light (VIS), ultraviolet (UV), and in the dark, respectively. SPSAB induced reversible changes in the inhibitory activity of ATPase and motor activities correlating with photo-isomerization among the three states. Among the three isomerization states of SPSAB, the SP-trans isomer showed potent inhibitory activity at an IC50 value of 30 µM in the basal ATPase assay. MC-trans and MC-cis exhibited less inhibitory activity at IC50 values of 38 µM and 86 µM, respectively. The results demonstrated that the novel photochromic inhibitor enabled precise control of Eg5 function at three different levels using light irradiation.
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