ZfN: Search Results

1	Author	M. Suwalsky, M. A. Espinoza, M. Bagnara, C. P. Sotomayor	Requires cookie*
	Title	X-Ray and Fluorescence Studies on Phospholipid Bilayers. IX. Interactions with Pentachlorophenol
	Abstract	Pentachlorophenol (PCP) is a widely used and highly toxic fungicide. Its toxicity is mainly expressed at the cell membrane level. It is, therefore, o f interest to test its ability to alter the lipid bilayer organization. The present study was performed by X-ray diffraction techniques on dimyristoylphosphatidylethanolam ine (D M PE) and dim yristoylphosphatidylcholine (D M P C) bilayers and by fluorescence on DM PC liposomes. These two phospholipids are re spectively found at the inner and outer monolayers o f human erythrocyte membranes. Each type o f phospholipid was made to interact with different concentrations o f the sodium form o f PCP in absence and in presence o f water. It was found that PCP significatively affected the structure o f both phospholipids, being the damage much higher in DM PC bilayers.
	Reference	Z. Naturforsch. 45c, 265 (1990); received September 18 1989
	Published	1990
	Keywords	X -R ay Diffraction, Fluorescence, Phospholipid Bilayers, Pentachlorophenol, Toxicity
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	TEI-XML for	default:Reihe_C/45/ZNC-1990-45c-0265.pdf
	Identifier	ZNC-1990-45c-0265
	Volume	45

2	Author	MarcelA K Jansen3, Shmuel Malkinb, Marvin Edelmana	Requires cookie*
	Title	Differential Sensitivity of 32 kDa-D 1 Protein Degradation and Photosynthetic Electron Flow to Photosystem II Herbicides
	Abstract	Degradation of the 32 kDa-D 1 protein, a photosystem II reaction centre component, was studied as a function of linear electron flow in visible light in the presence of various photosys tem II herbicides. Under these conditions, herbicide specific effects on protein degradation were clearly evident. 32 kDa-D 1 protein degradation and electron flow between Q a and Q b proved to be only partially correlated. We conclude that inhibition of protein degradation by PS II herbicides in visible light is not simply correlated to displacement of Q b.
	Reference	Z. Naturforsch. 45c, 408—411 (1990); received December 12 1989
	Published	1990
	Keywords	Diuron, Bromoxynil, Dinoseb, Oxygen, Evolution, Chlorophyll, Fluorescence
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	TEI-XML for	default:Reihe_C/45/ZNC-1990-45c-0408.pdf
	Identifier	ZNC-1990-45c-0408
	Volume	45

3	Author	Shan-Yuan Yang, S. S. Brody	Requires cookie*
	Title	Effect of ß-Carotene on Delayed Light Emission from Aggregated Chlorophyll
	Abstract	Delayed light emission (DLE) from aggregated chlorophyll is used to probe energy transfer between aggre gated chlorophyll and ß-carotene. Preilluminated ß-carotene when injected into a dark chamber containing aggregated chlorophyll, induces DLE from aggregated chlorophyll. If the dark chamber contains only monomeric chlorophyll, there is no DLE. The intensity of DLE is de pendent on the time of illumination of ß-carotene. The decay of energy stored by the carotene is not a first order process. The first half life is about 2 min, the next about 1 0 min.
	Reference	Z. Naturforsch. 45c, 132—134 (1990); received February 6 /August 15 1989
	Published	1990
	Keywords	ß-Carotene, Delayed Light Emission, Chlorophyll Aggre gates, Fluorescence, Phosphorescence
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	TEI-XML for	default:Reihe_C/45/ZNC-1990-45c-0132_n.pdf
	Identifier	ZNC-1990-45c-0132_n
	Volume	45

4	Author	U. Eberl, A. Ogrodnik, M. E. Michel-Beyerle	Requires cookie*
	Title	Access to Primary Charge Separation Mechanism in Photosynthetic Reaction Centers: Anisotropic Excitation Spectra of Electric Field Modulated Fluorescence Yields
	Abstract	Two-step sequential and unistep, superexchange primary electron transfer form primary radical pair states which differ in the direction and magnitude of their dipole moments as revealed in the X-ray structure analysis. The direction can be measured by the excitation anisotropy of electric field induced changes of the fluorescence yield. This method determines angles between the dipole of the primary radical pair and photoselected transition moments (in absorption and emission) of cofactors in the reaction centers. Transitions particularly favourable for discrimination between the two models of primary electron transfer are discussed.
	Reference	Z. Naturforsch. 45a, 763—770 (1990); received March 17 1990
	Published	1990
	Keywords	Electric field effect, Anisotropy, Fluorescence, Photosynthesis, Reaction center, Pri-mary charge separation
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	TEI-XML for	default:Reihe_A/45/ZNA-1990-45a-0763.pdf
	Identifier	ZNA-1990-45a-0763
	Volume	45