Pigment content of D1-D2-cytochrome b{sub 559} reaction center preparations after removal of CP47 contamination: An immunological study

Journal Article · Tue Nov 21 04:00:00 EST 1995 · Biochemistry (Eaton)

DOI:https://doi.org/10.1021/bi00046a029· OSTI ID:430190

Pueyo, J J; Moliner, E; Siebert, M ^[1]

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1. National Renewable Energy Lab., Golden, CO (United States); and others

Isolated D1-D2-cytochrome b{sub 559} photosystem II reaction center preparations with pigment stoichiometry higher than 4 chlorophylls per 2 pheophytins can be contaminated with CP47 proximal antenna complex. Reaction centers prepared by a modification of the Nanba-Satoh procedure and containing about 6 chlorophylls per 2 pheophytins showed immuno-cross-reactivity when probed with a monoclonal antibody raised against the CP47 polypeptide. Furthermore, they could be fractionated successfully by Superose-12 sieve chromatography into two different populations. The first few fractions off the column contained a more definitive 435 nm shoulder corresponding to increased chlorophyll content, and showed strong immuno-cross-reactivity with the CP47 antibody. The peak fractions off the column displayed a less prominent 435 nm shoulder, and did not cross-react with the antibody. Moreover, when a 6-chlorophyll preparation was mixed with Sepharose beads coupled to CP47 antibody. the eluted material corresponded to a preparation of about 4 chlorophylls per 2 pheophytins and did not show any cross-reaction with the antibody against CP47. The amount of CP47 protein in the 6-chlorophyll preparation as quantitated using Coomassie Blue staining or from gel blots was sufficient to account for most of the extra 2 chlorophylls. We conclude that D1-D2-cytochrome b{sub 559} preparations containing more than 4 chlorophylls per 2 pheophytins can be contaminated with small amounts of CP47-D1-D2-Cyt b{sub 559} complex and that native photosystem II reaction centers contain 4 core chlorophylls per 2 pheophytins. 38 refs., 4 figs., 1 tab.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC36-83CH10093
• OSTI ID: 430190
• Journal Information: Biochemistry (Eaton), Journal Name: Biochemistry (Eaton) Journal Issue: 46 Vol. 34; ISSN 0006-2960; ISSN BICHAW
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
CHLOROPHYLL
CONCENTRATION RATIO
CYTOCHROMES
MONOCLONAL ANTIBODIES
PHOTOSYNTHETIC REACTION CENTERS
PIGMENTS
SAMPLE PREPARATION
STOICHIOMETRY