Development of Photo-Controlled Molecular Shuttle Utilizing ATP Driven Motor Kinesin

Abstract

The ATP driven motor kinesin has many possibilities for the application to the molecular machines. Previously, we introduced photochromic molecules into the functional key region of the kinesin as a photo-switch and tried to control the function of kinesin by ultraviolet (UV) and visible (VIS) light irradiations. The kinesin mutant S275C modified with thiol reactive azobenzene derivative exhibited photo-controlled ATPase activity correlating to photo isomerization of photochromic molecules.In this study, we tried to prepare the photo-controlled molecular shuttles using kinesin and liposome modified with photochromic molecule.We prepared the kinesin motor domain (K355) mutant that has a single cysteine at neck linker region and His-tag at C-terminal. Subsequently the kinesin mutant was dimerized with photochromic bifunctional cross-linker, azobenzene dimaleimide (ABDM). And the photo-reversible regulation of the ATPase and motor activities of the kinesin dimer cross-linked with ABDM was studied.We also tried to develop photo-responsive vesicle composed of photochromic molecules as a cargo for the photo-controlled kinesin. Diacyl glycerol was coupled with carboxypropyl-spiropyran to be phospholipid analogue using carbonyldiimidazole condensation reagent. The spiropyran moiety performs photo-reversible isomerization between hydrophobic spiro form and merocyanine zwitterion form upon visible light and ultraviolet light, respectively. Therefore, it is expected that the merocyanine form of the mimic phospholipid results in formation liposome like vesicle. The photo-reversible formation of the vesicle was studied using water-soluble fluorescent probe.