Redshifted and Near ‐infrared Active Analog Pigments Based upon Archaerhodopsin‐3

In this study, we investigated the effect of analogs of the native ligand all ‐trans retinal A1 on the spectral properties and proton ‐pumping activity of AR3 and its single mutant AR3 (F229S). While, surprisingly, the 3‐methoxyretinal A2 analog did not redshift the absorbance maximum of AR3, the analogs retinal A2 and 3‐methylamino‐16‐nor‐1,2,3,4‐didehydroretinal (MMAR) did generate active redshifted AR3 pigments. T he MMAR analog pigments could even be activated by near‐infrared light. Furthermore, the MMAR pigments showed strongly enhanced fluorescence with an emission band in the near‐infrared peaking around 815 nm. We anticipate that the AR3 pigments generated in this study have widespread potential fo r near‐infrared exploitation as fluorescent voltage‐gated sensors in optogenetics and artificial leafs and as proton pumps in bioenergy‐based applications.

Source: Photochemistry and Photobiology - July 18, 2019 Category: Science Authors: Srividya Ganapathy, Svenja Kratz, Que Chen, Klaas J. Hellingwerf, Huub J.M. Groot, Kenneth J. Rothschild, Willem J. Grip Tags: Research Article Source Type: research