Effect of Chloride Ion on the Thermal Decay Process of the Batho Intermediate of Iodopsin at Low Temperature

Yasushi Imamoto, Hideki Kandori, Toshiyuki Okano, Yoshitaka Fukada, Yoshinori Shichida, Tôru Yoshizawa

研究成果: Article

39 引用 (Scopus)


The photochemical and the subsequent thermal behaviors or iodopsin (Cl--bound form) and N-iodopsin (iodopsin whose Cl- was replaced by NO3-) in CHAPS-phosphatidylcholine (PC) were studied by low-temperature spectrophotometry. Irradiation of the iodopsin preparation at -185 °C produced a photo-steady-state mixture composed of iodopsin, bathoiodopsin, and isoiodopsin. Bathoiodopsin was thermally reverted to the original iodopsin. These results were almost the same as those reported previously [Yoshizawa, T., & Wald, G.(1967) Nature 214, 566-571] in which iodopsin was extracted with 2% digitonin. Therefore, photochemical and subsequent thermal behaviors or iodopsin were independent of the detergent to solubilize iodopsin. Irradiation of N-iodopsin at -185 °C produced the similar photo-steady-state mixture. However, N-bathoiodopsi was thermally converted to the next intermediate, presumably N-lumiiodopsin. These results suggest that the batho-lumi transition of iodopsin at low temperature is likely to be inhibited by the Cl- bound to the protein moiety of iodopsin, while at room temperature the Cl- bound to iodopsin could be released on the conversion process of batho- to lumiiodopsin.

出版物ステータスPublished - 1989 1 1


ASJC Scopus subject areas

  • Biochemistry