Figure 3.

Analogue pigments of PR. [a] Normalized absorbance spectra of purified pigments in DDM containing A1 (black), A2 (pink), MOA2 (green), DMAR (orange), or MMAR (blue). [b–d] Proton pumping activities of the pigments (same colors as in [a]) in starved E. coli UT5600 cells upon illumination with [b] 617 nm, [c] 660 nm, and [d] 730 nm LEDs. Controls without retinal are represented as dotted gray lines.