Figure 1.
HPLC analysis of carotenes extracted from E. coli cells accumulating cis-ζ-carotene in the absence (A) and presence (B) of CRTISO. To identify the isomers, the sample in B was mixed with a synthetic all-trans-ζ-carotene and analyzed by HPLC (C). MaxPlot chromatograms showing each peak at its λmax are presented. Peak 1, All-trans-ζ-carotene; peak 2, 9,15,9′-tri-cis-ζ-carotene; peak 3, 9,9′-di-cis-ζ-carotene; peaks 4a and 4b are cis-isomers of phytofluene; peak 5, 15-cis-phytoene. Absorption spectra of specific peaks are presented to the boxes. 9,15,9′-Tri-cis-ζ-carotene is distinguished from the 9,9′-cis-isomer by the typical absorbance at 297.5 nm.