Protection of chlorophyll a from photo-oxidation byβ-carotene in binary mixture of organic solvents

1971 ◽  
Vol 27 (12) ◽  
pp. 1406-1408 ◽  
Author(s):  
G. Tomita ◽  
T. Oku
Keyword(s):  
Binary Mixture ◽  
Chlorophyll A ◽  
Organic Solvents ◽  
Photo Oxidation

Fluorometric Properties of N-Methyltetraphenylporphine and Several Derivatives: Evaluation as Standards for Determination of Chlorophyll Concentrations

1982 ◽  
Vol 36 (4) ◽  
pp. 430-435 ◽  
Author(s):  
David K. Lavallee ◽  
Thomas J. McDonough ◽  
Lisa Cioffi
Keyword(s):  
Chlorophyll A ◽  
Organic Solvents ◽  
Fluorescence Spectra ◽  
Emission Spectra ◽  
Quantum Yields ◽  
Polar Organic Solvents ◽  
Solvent Systems ◽  
Nonpolar Organic ◽  
Chlorophyll Concentrations

As part of an ongoing study of the chemistry and properties of N-methylporphyrins and their metal complexes, we have observed that the excitation and emission spectra of N-methyltetraphenylporphyrin and N-methyltetra( p-sulfophenyl)porphyrin and their zinc complexes closely resemble corresponding spectra of chlorophyll a. We have characterized fluorescence spectra for these species in a variety of solvents commonly used for quantitative determination of chlorophylls. Quantum yields for the N-methylporphyrins are lower by approximately a factor of 10 than yields for chlorophyll a in such solvents as acetone, ethanol, and mixed aqueous/organic solvent systems. The yields are quite sufficient, however, for these species to be used as fluorescence standards. Solution of N-methylporphyrins are stable and the compounds can be inexpensively synthesized in high purity. The tetra( p-sulfophenyl) species are soluble in aqueous and highly polar organic solvents, whereas the tetraphenyl species are soluble in nonpolar organic solvents.

Photo-oxidation of water in phospholipid bilayer membranes containing chlorophyll a

Nature ◽  
1977 ◽  
Vol 265 (5590) ◽  
pp. 187-189 ◽  
Author(s):  
Y. TOYOSHIMA ◽  
M. MORINO ◽  
H. MOTOKI ◽  
M. SUKIGARA
Keyword(s):  
Chlorophyll A ◽  
Phospholipid Bilayer ◽  
Bilayer Membranes ◽  
Photo Oxidation

SPECTROSCOPIC STUDY OF CHLOROPHYLL a IN ORGANIC SOLVENTS AND POLYMERIZED ANHYDROUS POLYVINYL MATRIX

1993 ◽  
Vol 58 (4) ◽  
pp. 600-606 ◽  
Author(s):  
Marc A. M. J. van Zandvoort ◽  
Danuta Wroabel ◽  
Andries J. Scholten ◽  
Dries de Jager ◽  
Glis van Ginkel ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Chlorophyll A ◽  
Organic Solvents

High-Resolution electron crystallography of the light-harvesting chlorophyll-a/b protein complex from chloroplast membranes

1990 ◽  
Vol 48 (1) ◽  
pp. 610-610
Author(s):  
Werner Kühlbrandt ◽  
Da Neng Wang ◽  
K.H. Downing
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Chlorophyll A ◽  
Protein Complex ◽  
Structural Integrity ◽  
Light Harvesting ◽  
Lhc Ii ◽  
Diffraction Patterns ◽  
Difference Fourier ◽  
2D Crystals

The light-harvesting chlorophyll-a/b protein complex (LHC-II) is the most abundant membrane protein in the chloroplasts of green plants where it functions as a molecular antenna of solar energy for photosynthesis. We have grown two-dimensional (2d) crystals of the purified, detergent-solubilized LHC-II . The crystals which measured 5 to 10 μm in diameter were stabilized for electron microscopy by washing with a 0.5% solution of tannin. Electron diffraction patterns of untilted 2d crystals cooled to 130 K showed sharp spots to 3.1 Å resolution. Spot-scan images of 2d crystals were recorded at 160 K with the Berkeley microscope . Images of untilted crystals were processed, using the unbending procedure by Henderson et al . A projection map of the complex at 3.7Å resolution was generated from electron diffraction amplitudes and high-resolution phases obtained by image processing .A difference Fourier analysis with the same image phases and electron diffraction amplitudes recorded of frozen, hydrated specimens showed no significant differences in the 3.7Å projection map. Our tannin treatment therefore does not affect the structural integrity of the complex.

Identification of a single-copy gene encoding a Type I chlorophyll a/b-binding polypeptide of photosystem I in Arabidopsis thaliana

1992 ◽  
Vol 84 (4) ◽  
pp. 561-567 ◽  
Author(s):  
Poul E. Jensen ◽  
Michael Kristensen ◽  
Tine Hoff ◽  
Jan Lehmbeck ◽  
Bjarne M. Stummann ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Chlorophyll A ◽  
Photosystem I ◽  
Single Copy ◽  
Type I ◽  
Single Copy Gene ◽  
Gene Encoding ◽  
Copy Gene
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