کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2185769 1096008 2010 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The Branched Photocycle of the Slow-Cycling Channelrhodopsin-2 Mutant C128T
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
The Branched Photocycle of the Slow-Cycling Channelrhodopsin-2 Mutant C128T
چکیده انگلیسی

Channelrhodopsins (ChRs) of green algae such as Chlamydomonas are used as neuroscience tools to specifically depolarize cells with light. A crude model of the ChR2 photocycle has been recently established, but details of the photoreactions are widely unknown. Here, we present the photoreactions of a slow-cycling ChR2 mutant (step function rhodopsin), with C128 replaced by threonine and 200-fold extended lifetime of the conducting-state P520. At a late state of the photocycle, a fraction of the proteins branches off into an inactive species, P380, which accumulates during prolonged illumination. At neutral pH, P380 is converted into P353, a species with a characteristic fine-structured spectrum that is interpreted as retroretinyl chromophore. The described branching reactions should be considered, when ChR is used as a neuroscience tool, especially in the case of fluorescence imaging at high light intensities.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 398, Issue 5, 21 May 2010, Pages 690–702
نویسندگان
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