The kinetics of formation of metarhodopsin in intact photoreceptors of the fly.
نویسندگان
چکیده
The formation of metarhodopsin in fly photoreceptor no. 1--6 occurs at room temperature with a time constant of 125 microseconds (Q10 approximately 2.5). The formation of rhodopsin is faster by factor of 1/10 to 1/100 at least.
منابع مشابه
Photosensitivity spectrum of crayfish rhodopsin measured using fluorescence of metarhodopsin
Discrepancies exist among spectral measurements of sensitivity of crayfish photoreceptors, their absorption in situ, and the number and absorption spectra of crayfish photopigments that are extracted by digitonin solutions. We have determined the photosensitivity spectrum of crayfish rhodopsin in isolated rhabdoms using long wavelength fluorescence emission from crayfish metarhodopsin as an int...
متن کاملPhotosensitivity Spectrum of Crayfish
Discrepancies exist among spectral measurements of sensitivity of crayfish photoreceptors, their absorption in situ, and the number and absorption spectra of crayfish photopigments that are extracted by digitonin solutions. We have determined the photosensitivity spectrum ofcrayfish rhodopsin in isolated rhabdoms using long wavelength fluorescence emission from crayfish metarhodopsin as an intr...
متن کاملFast electrical potentials arising from activation of metarhodopsin in the fly
The cellular origin and properties of fast electrical potentials arising from activation of Calliphora photopigment were investigated. It was found by intracellular recordings that only the corneal-negative M1 phase of fly M potential arises in the photoreceptors' membrane. This M1 phase has all the accepted characteristics of an early receptor potential (ERP). It has no detectable latency, it ...
متن کاملThe contribution of a sensitizing pigment to the photosensitivity spectra of fly rhodopsin and metarhodopsin
Most of the photoreceptors of the fly compound eye have high sensitivity in the ultraviolet (UV) as well as in the visible spectral range. This UV sensitivity arises from a photostable pigment that acts as a sensitizer for rhodopsin. Because the sensitizing pigment cannot be bleached, the classical determination of the photosensitivity spectrum from measurements of the difference spectrum of th...
متن کاملMechanism of arrestin 2 function in rhabdomeric photoreceptors.
Arrestins have emerged as one family of proteins that mediate the inactivation of G-protein-coupled receptors. We have isolated cDNA clones encoding two arrestin isoforms of the dipteran visual system, Calliphora arrestin 1 (Arr1) and arrestin 2 (Arr2). Microsequencing established that the arr2 gene encodes the Calliphora 49-kDa protein characterized previously as a photoreceptor-specific prote...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Zeitschrift fur Naturforschung. Section C, Biosciences
دوره 33 11-12 شماره
صفحات -
تاریخ انتشار 1978