Reversible control of F1-ATPase rotational motion using a photochromic ATP analog at the single molecule level

Abstract

Motor enzymes such as F1-ATPase and kinesin utilize energy from ATP for their motion. Molecular motions of these enzymes are critical to their catalytic mechanisms and were analyzed thoroughly using a single molecule observation technique. As a tool to analyze and control the ATP-driven motor enzyme motion, we recently synthesized a photoresponsive ATP analog with a p-tert-butylazobenzene tethered to the 2' position of the ribose ring. Using cis/trans isomerization of the azobenzene moiety, we achieved a successful reversible photochromic control over a kinesin-microtubule system in an in vitro motility assay. Here we succeeded to control the hydrolytic activity and rotation of the rotary motor enzyme, F1-ATPase, using this photosensitive ATP analog. Subsequent single molecule observations indicated a unique pause occurring at the ATP binding angle position in the presence of cis form of the analog.

Prediction of photolysis half-lives of dihydroindolizines by genetic algorithm-multiple linear regression (GA-MLR)

“…Photochromism is defined as a reversible transformation of a chemical species between two forms having different absorption spectra induced in one or both directions by photoirradiation . Photochromic materials are used widely in industrial applications including molecular mechanical devices, bio‐devices, light‐driven crystal actuators, molecular switches, photochromic lenses, and data storage …”

Synthesis and evaluation of an alkyne-modified ATP analog for enzymatic incorporation into RNA

“…In addition, since 7-EAA is an adenosine analog, its triphosphate is a mimic of ATP and could function as a substrate (or co-substrate) for other ATP-dependent enzymes. 13-15 For these reasons, we prepared 7-EAATP and evaluated it as a substrate for two different ATP-utilizing enzymes: T7 RNA polymerase and E. coli poly (A) polymerase. In addition, we showed that HeLa cells treated with the 7-EAA nucleoside produce RNAs reactive in CuAAC reactions indicating 7-EAA uptake and intracellular conversion to the triphosphate in human cells.…”