Chlorophyll-Binding Proteins (CAB, chlorophyll A and B binding proteins, light-harvesting chlorophyll protein complex, LHCP)

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.

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The N-terminal domain of the light-harvesting chlorophyll a/b -binding protein complex (LHCII) is essential for its acclimative proteolysis

FEBS Letters ◽

10.1016/s0014-5793(00)01107-8 ◽

2000 ◽

Vol 466 (2-3) ◽

pp. 385-388 ◽

Cited By ~ 46

Author(s):

Dan-Hui Yang ◽

Harald Paulsen ◽

Bertil Andersson

Keyword(s):

Chlorophyll A ◽

Protein Complex ◽

Light Harvesting ◽

Binding Protein ◽

Terminal Domain

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PIGMENT ORGANIZATION IN THE LIGHT-HARVESTING CHLOROPHYLL-a/b PROTEIN COMPLEX OF LETTUCE CHLOROPLASTS. EVIDENCE OBTAINED FROM PROTECTION OF THE CHLOROPHYLLS AGAINST PROTON ATTACK and FROM EXCITATION ENERGY TRANSFER

Photochemistry and Photobiology ◽

10.1111/j.1751-1097.1982.tb02636.x ◽

1982 ◽

Vol 35 (5) ◽

pp. 719-731 ◽

Cited By ~ 64

Author(s):

Dorothea Siefermann-Harms ◽

Helga Ninnemann

Keyword(s):

Energy Transfer ◽

Excitation Energy ◽

Chlorophyll A ◽

Protein Complex ◽

Light Harvesting ◽

Excitation Energy Transfer

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Light-Induced Accumulation and Stability of Chlorophylls and Chlorophyll-Proteins during Chloroplast Development in Radish Seedlings

Zeitschrift für Naturforschung C ◽

10.1515/znc-1981-5-614 ◽

1981 ◽

Vol 36 (5-6) ◽

pp. 421-430 ◽

Cited By ~ 37

Author(s):

H. K. Lichtenthaler ◽

G. Burkard ◽

G. Kuhn ◽

U. Prenzel

Keyword(s):

Chlorophyll A ◽

Early Stage ◽

Continuous Darkness ◽

Suitable Parameter ◽

Chlorophyll Accumulation ◽

Chlorophylls A And B ◽

Sds Page ◽

Chlorophyll Protein ◽

Chlorophyll A And B ◽

Radish Seedlings

Abstract Illumination of 3 day old etiolated radish seedlings with continuous white light results in a progressive accumulation of chlorophyll a and b. Both pigments are bound in a different way to the thylakoid chlorophyll-proteins, which appear parallel to the formation of chlorophylls. By applying the SDS-PAGE method to SDS-digested chloroplasts, it was possible to show that the chloroplasts of radish cotyledons contain the typical chlorophyll proteins LHCP1-3, CPa, CPI and CPIa which have been found in other plants. Between LHCP1 and CPI an additional chlorophyll protein is detected with the spectral properties of a LHCP; it is termed here LHCPy. When the green plants are transferred to continuous darkness, chlorophylls and the chlorophyll-proteins are progressively degraded. At an early stage of greening chlorophyll b is destroyed at a much higher rate in darkness than chlorophyll a, which yields high chlorophyll a/b ratios. This is paralleled by a faster decrease in the level of the corresponding chlorophyll a/b-protein LHCP3 than of CPI. At a later stage of greening, after the end of the logarithmic chlorophyll accumulation, the chlorophylls a and b and also the LHCP3 and CPI are destroyed in continuous darkness at equal rates; the a/b ratios and the LHCP3/CPI ratios are then little different from the light control. The data indicate that at an early stage of greening the light-harvesting chlorophyll a/b-protein LHCP3 is less stable than the other chlorophyll-proteins (CPI, CPIa, CPa), which contain pre dominantly chlorophyll a. The ratio chlorophyll a to β-carotene (a/c ratio) of CPIa, CPI and CPa is about 10, while that of the LHCP1-3 is found to be between 150 to 300. We therefore propose using the a/c ratio to define the chlorophyll-proteins which, besides the absorption spectra, is the most suitable parameter.

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