Figure 2. Isolation and characterization of trimeric PSI.
(A) Ten percent to 30% sucrose gradient of solubilized C. aponinum membranes following an anion exchange chromatography. (B) SDS–PAGE of the main sucrose gradient band (Trimer) compared to PSI isolated from Synechocystis. A notable difference between the PsaL bands is clearly observable around 13 kD. (C) Absorption spectra of the purified trimer of C. aponinum (green) and Synechocystis (black) normalized to the area between 550 and 775 nm (D) Difference of the C. aponinum – Synechocystis absorbance spectra, shown are averages of three biological replicas, blue edges indicate± SD. (E) The negative peak at 701 nm of the absorbance difference spectrum (dashed black line) is fitted to a sum of three gaussian components colored blue, purple, and red with the sum as a solid black line and the residual of the fit (F) 77 K fluorescence of C. aponinum (green) and Synechocystis (black) using an excitation wavelength of 440 nm. Samples were normalized to their max peak.
Figure 2—figure supplement 1. Photosystem I protein sequence alignment comparison between C.
