Time-resolved FTIR difference spectroscopy in combination with specific isotope labeling for the study of A1, the secondary electron acceptor in photosystem 1.

ABSTRACT: A phylloquinone molecule (2-methyl, 3-phytyl, 1, 4-naphthoquinone) occupies the A(1) binding site in photosystem 1 particles from Synechocystis sp. 6803. In menB mutant photosystem 1 particles from the same species, plastoquinone-9 occupies the A(1) binding site. By incubation of menB mutant photosystem 1 particles in the presence of phylloquinone, it was shown in another study that phylloquinone will displace plastoquinone-9 in the A(1) binding site. We describe the reconstitution of unlabeled ((16)O) and (18)O-labeled phylloquinone back into the A(1) binding site in menB photosystem 1 particles. We then produce time-resolved A(1)(-)/A(1) Fourier transform infrared (FTIR) difference spectra for these menB photosystem 1 particles that contain unlabeled and (18)O-labeled phylloquinone. By s

SUBMITTER: Hastings G 

PROVIDER: S-EPMC2480661 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature