Low-temperature spectroscopy of fully active cores. Comparison with CP43, CP47,

• Comparisons of absorption spectra of photosystem II (PSII) core complexes with those of isolated CP43, CP47 and D1/D2/cyt b559 complexes show broadenings and shifts upon disassembly of the PSII core material. Spectra of PSII cores isolated from plants and cyanobacteria reveal marked changes in energies and intensities of the sharp features associated with P680. Low-temperature, illumination-induced electrochromic shifts in PSII cores allow identification of an excitation localized on pheopytin-a (pheo a) in D1. A weak interaction between an exciton component of P680 and the D1 pheo a, both located near 684 nm, is suggested. MCD spectra of 5- and 6-chlorophyll a D1/D2/cytochrome b559 preparations provide links to photoactive pigments in intact PSII cores.

Subject headings

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Keyword

STARK SHIFTS

RESOLUTION

REACTION CENTERS

PHOTOSYSTEM-II

CRYSTAL-STRUCTURE

PROTEIN

PIGMENTS

COMPLEXES

Publication and Content Type

art (subject category)

ref (subject category)