Active, purified Sensory rhodopsin-2 (Halobacterium salinarum)
Sensory rhodopsin-2 (SR-2) is a 7-transmembrane protein that acts as a phototaxis receptor in archaebacteria. Due to its covalently bound colored ligand, SR-2 is ideal for use as a control membrane protein, for example for crystallization assays and biochemical/biophysical experiments. We provide SR-2 of high purity, purified from E. coli as a his-tagged protein.
Figure 1: SDS-PAGE of sensory rhodopsin-2 from H. salinarum.
Figure 2: Absorbance spectrum of sensory rhodopsin-2 from H. salinarum.
Sensory rhodopsin-2 (SR-2, NpSRII)
Halobacterium salinarum S9
wild-type sequence, full-length, 6x His-tag (red)
243 amino acids; 26,103 Da
>98%, see Fig. 1
Extinction coefficient at 497 nm: 48,000 M-1 cm-1.
Extinction coefficient at 590 nm: 54,000 M-1 cm-1.
Binding of ligand all-trans retinal, covalently bound to a lysine residue. Evaluation of UV-VIS spectrum: absorbance ratio 280 nm / 497 nm = 1.7(additional vibronic bands at 460 nm and 420 nm)
Photoreceptor protein undergoing a photocycle, Retinal protein, photophobic phototaxis receptor