1. In Vitro Demonstration of Dual Light-Driven Na+/H+ Pumping by a Microbial Rhodopsin 
Hai Li, Oleg A. Sineshchekov, Giordano F.Z. da Silva, John L. Spudich 
Biophysical Journal 
Volume 109, Issue 7, Pages (October 2015)
DOI: /j.bpj
Copyright © 2015 Biophysical Society Terms and Conditions

2. Figure 1
UV-Vis spectra and flash photolysis of IAR and KR2 in DDM and IAR in LUVs. (A) Absorption spectra of IAR in DDM and 100 mM Na+ (black line), DDM and 100 mM K+ (blue line), and LUVs and 100 mM Na+ (red line). Normalized flash-induced absorption changes at 412 nm (B) and 612 nm (C) in IAR in DDM and 100 mM Na+ or 100 mM K+ (solid black lines), and IAR in LUVs in 100 mM Na+ or 100 mM K+ (solid red lines). For comparison, absorption changes in KR2 in DDM and 100 mM Na+ or 100 mM K+ (dashed black lines). Results of curve fitting are located in Table 1.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2015 Biophysical Society Terms and Conditions

3. Figure 2
Non-H+ ion pumping and H+ pumping activities of WT IAR in E. coli cell suspensions. Light-induced proton fluxes were assessed by pH changes of E. coli cell suspensions in the presence of ions and uncouplers, as indicated. Initial pH values ranged from 6.30 to 6.65.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2015 Biophysical Society Terms and Conditions

4. Figure 3
Room temperature continuous-wave EPR of spin-labeled IAR mutants Y12C and H277C probing orientation of insertion of the pigment in LUVs. The addition of the exchange reagent NiEDDA in excess amount shows no observable effect on the line shape of the spin-labeled Y12C mutant (top). The addition of Triton X-100 exposes the labeled Y12C to NiEDDA causing a line-broadening effect (middle). The labeled H277C mutant undergoes line broadening immediately after addition of NiEDDA (bottom). Cartoon (upper right of each panel) of the spin-labeled mutant in an LUV with the orientation concluded from the data.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2015 Biophysical Society Terms and Conditions

5. Figure 4
Light-induced fluorescence changes of IAR-LUVs in NaCl or KCl. (A) Na+ pumping measurements in IAR-LUVs in the presence of NaCl only (solid line); the sample after the addition of 0.1 μM CCCP (dashed line); the sample with further addition of 0.1 μM gramicidin (dotted line). Light-induced fluorescence changes ON and OFF (vertical dashed lines). (B) Na+ pumping measurements in IAR-LUVs in NaCl only (solid line); the sample after addition of CCCP (dashed line); the sample with further addition of 0.1 μM monensin (dotted line). (C) H+ pumping measurements performed on IAR-LUVs in KCl only (solid line); the sample after the addition of 0.1 μM CCCP (dashed line). (D) IAR-LUVs with KCl outside and NaCl inside (solid line) and IAR-LUVs with NaCl outside and KCl inside in the presence of CCCP (dashed line).
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2015 Biophysical Society Terms and Conditions

6. Figure 5
Cartoon representation of light-induced Na+ flux and passive H+ flux in IAR-LUVs. IAR is preferentially oriented with its intracellular side toward the extravesicular compartment. Light-driven Na+ transport generates a membrane electrical potential positive inside. In the presence of CCCP, the electrical potential drives a proton efflux. (Green) Intravesicular pyranine.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2015 Biophysical Society Terms and Conditions