PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 38146

A new non-photoreducible protochlorophyll(ide-)-protein: P-649--642 from cucumber cotyledons: NADPH mediation of its transformation to photoreducible P-657--650.

B El Hamouri·C Sironval
View original source ↗Export metadata ↓

Abstract

The source did not provide an abstract. Follow the original record for more information.

Explore related subjects

ChlorophyllDarknessKineticsLightNADPOxidation-ReductionPlant ProteinsPlantsProtochlorophyllideSpectrophotometryJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B El Hamouri, C Sironval. 1979-07-15. A new non-photoreducible protochlorophyll(ide-)-protein: P-649--642 from cucumber cotyledons: NADPH mediation of its transformation to photoreducible P-657--650.. https://doi.org/10.1016/0014-5793(79)81359-9

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1979

Surface potential and reaction of membrane-bound electron transfer components. I. Reaction of P-700 in sonicated chloroplasts with redox reagents.

Salt- or pH-induced change of the rate of reduction of the photoxidized membrane bound electron transfer components, P-700, by ionic and nonionic reductants added in the outer medium was studied in sonicated chloroplasts. The rate with the negatively charged reductants increased with the increase of salt concentration at a neutral pH or with the decrease of medium pH. Salts of divalent cations were much more effective than those of monovalent cations. A trivalent cation was even more effective. The rate with a nonionic reductant was little affected by salts. The change of the reduction rate was analysed using the Guoy-Chapman theory, which explains the change of reduction rate by the changes of activities of ionic reductants at the charged membrane surface where the reaction takes place. This analysis gave more useful parameters and explained more satisfactorily the case with high-valence cation salts than the Brönsted type analysis. The values for the surface charge density and the surface potential of the membrane surface in the vicinity of P-700 estimated from the analysis were lower than those estimated for the surface in the vicinity of Photosystem II primary acceptor, suggesting the heterogeneity of the thylakoid surface. The salt-induced surface potential change was shown to affect the activation energy of the reaction between P-700 and the ionic reagent.

Chlorophyll↗
PubMed1979

The electrophoretic isolation and partial characterization of three chlorophyll-protein complexes from blue-green algae.

Three chlorophyll-protein complexes have been resolved from blue-green algae using an improved procedure for membrane solubilization and electrophoretic fractionation. One complex has a red absorbance maximum of 676 nm and a molecular weight equivalency of 255 000 +/- 15 000. A second complex has an absorbance maximum of 676 nm, a molecular weight equivalency of 118 000 +/- 8000, and resembles the previously described P-700-chlorophyll a-protein (CPI) of higher plants and algae. The third chlorophyll-protein has a red absorbance maximum of 671 nm and a molecular weight equivalency of 58 000 +/- 5000. Blue-green algal membrane fractions enriched in Photosystem I and heterocyst cells do not contain this third chlorophyll-protein, whereas Photosystem II-enriched membrane fractions and vegetative cells do. A component of the same spectral characteristics and molecular weight equivalency was also observed in chlorophyll b-deficient mutants of barley and maize. It is hypothesized that this third complex is involved in some manner with Photosystem II.

Chlorophyll↗