Involvement of electron transfer in the photoreaction of zebrafish Cryptochrome-DASH |
| |
Authors: | Zikihara Kazunori Ishikawa Tomoko Todo Takeshi Tokutomi Satoru |
| |
Affiliation: | Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, Japan. |
| |
Abstract: | Photoreaction of a blue-light photoreceptor Cryptochrome-DASH (Cry-DASH), a new member of the Cryptochrome family, from zebrafish was studied by UV-visible absorption spectroscopy in aqueous solutions at 293 K. Zebrafish Cry-DASH binds two chromophores, a flavin adenine dinucleotide (FAD) and a N5,N10-methenyl-5,6,7,8-tetrahydrofolate (MTHF) noncovalently. The bound FAD exists in the oxidized form (FAD(ox)) in the dark. Blue light converts FAD(ox) to the neutral radical form (FADH*). Formed FADH* is transformed to the fully reduced form FADH(2) (or FADH(-)) by successive light irradiation, or reverts to FAD(ox). FADH(2) (or FADH(-)) reverts to FADH* or possibly to FAD(ox) directly. The effect of dithiothreitol suggests a possible electron transfer between FAD in zebrafish Cry-DASH and reductants in the external medium. This is the first report on the photoreaction pathway and kinetics of a vertebrate Cry-DASH family protein. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|