ZfN: Search Results

1	Author	Alfred Gieren, Viktor Lamm, Dieter Oesterhelt, Hans-Jörg Schlude	Requires cookie*
	Title	Röntgenstrukturanalyse des 4-Keto-a//-*rcms-retinals X-ray Structure Analysis of the 4-Keto-aW-/rafts-retinal
	Abstract	The title compound (C20H26Ü2) crystallizes in the monoclinic space group P2i/n with a = 14.761(2), 6 = 8.292(1), c = 15.210(2) Ä, /S= 102.40(1)°; Z = 4. The structure was solved by direct methods and refined by least squares to a final R-value of 0.038 for 1211 observed reflections. The crystal structure is isomorphous with that of all-trans-retinal. The cyclohexenone ring shows a half-boat conformation. The connection of the cyclo-hexenone ring and the conjugated polyene chain via a formal single C-C bond is s-cis. The torsion angle C(5)-C(6)-C(7)-C(8) amounts to 56°. For the polyene side chain the typical curvature is evident. A comparison with analogous compounds shows that details in conformation, especially at the ring side-chain connection, are induced by crystal matrix. It seems that the differences in biological activity between retinal analogous compounds are not reflected by conformational differences of the free molecules.
	Reference	Z. Naturforsch. 37b, 1612—1622 (1982); eingegangen am 1. Juni 1982
	Published	1982
	Keywords	N-ray, Retinal, Conformation
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	TEI-XML for	default:Reihe_B/37/ZNB-1982-37b-1612.pdf
	Identifier	ZNB-1982-37b-1612
	Volume	37

2	Author	N. Yckowski, S. S. Brody	Requires cookie*
	Title	Interactions of Monomolecular Films of Retinal at Alkaline pH
	Abstract	The surface properties of mixed monomolecular films of retinal and phospholipids were studied at a nitrogen/water interface. The subphase was glycine buffer pH 10.5 with an ionic strength of 0.1. Monomolecular films of retinal in the presence of amino acids were also measured. The area per molecule, at a surface pressure of 10 dyn/cm, A 10, in the dark for 9-cis retinal and 11-ci's retinal are 42 A 2 and 47 A 2, respectively. After irradiation A 10 for 9-cis retinal and 11-cts retinal dcerease to 40 A 2 and 43 A2, respectively. The surface potentials, AV, at a surface pressure of 10 dyn/cm, in the dark for 9-cis retinal and 11-cis retinal are 470 mV and 445 mV, respectively. After irradiation, AV for 9-cis retinal decreases to 435 mV and 11-cis retinal increases to 490 mV. Interaction was observed between retinal and phospholipids and amino acids. The A 10 and AV 10 of mixed films of retinal and phospholipid were measured as a function of the mole fraction of phospholipid. Maximum interaction is observed at mole ratios of; phosphatidylserine/9-ct's = 1; phosphatidylethanolamine/9-m = 2, phosphatidylserine/ll-cis = 3; phosphatidylethanolamine/ H-CJ5 = 3. It is shown that mixing and interaction between phosphatidylethanolamine and retinal is spontaneous. The A 10 and A V 10 of films of retinal were measured as a function of the molar concentration of amino acid in the subphase. The nature of the interaction between retinal and phospholipid and amino acid are discussed.
	Reference	(Z. Naturforsch. 29c, 327 [1974]; received April 1 1974)
	Published	1974
	Keywords	) Vision, Retinal, Monolayers, Membranes, Model systems
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	TEI-XML for	default:Reihe_C/29/ZNC-1974-29c-0327.pdf
	Identifier	ZNC-1974-29c-0327
	Volume	29

3	Author	N. Puppala, S. S. Brody	Requires cookie*
	Title	Interactions between Retinal and Phospholipids in Monomolecular Films at Acid pH
	Abstract	The surface properties of mixed monomolecular films of retinal and phospholipids (p. lipids) are measured as a function of mole fraction at a nitrogen-water interface. An acid pH of 6.0 is maintained in the aqueous phase. Before irradiation the surface potential A V for 9-cis retinal, 11-cis retinal, phosphatidyl serine (PS) and phosphatidyl ethanolamine (PE), at j t = 12 dyn/cm, are 490 mV, 645 mV, 548 mV and 375 mV, respectively. Before irradiation, A 0 for 9-cis and 11-ds are 58 Ä2 and 48 A2, respectively. Experimentally measured isotherms are compared with theo retically calculated isotherms. In case of mixed films of retinal and PS the experimental isotherms are greater than theoretical, while mixed films of retinal and PE are smaller than theoretical. A maximum value for the difference between theoretical and experimental areas are obtained at (retinal) / (p. lipid) = 0 .1 . Retinal and p. lipid do not appear to form a Schiff base, charge transfer or any other type of complex at pH 6. A eutectic type mixture between retinal and p. lipid may occur on the surface. A light induced change in A V of —130 mV is observed in the case of 11-cis and PE. The significance of these findings with respect to visual excitation is considered.
	Reference	(Z. Naturforsch. 30c, 478—483 [1975]; received October 4 1973/October 21 1974)
	Published	1975
	Keywords	) Vision, Retinal, Monolayers, Photobiology, Membranes
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	TEI-XML for	default:Reihe_C/30/ZNC-1975-30c-0478.pdf
	Identifier	ZNC-1975-30c-0478
	Volume	30

4	Author	T. Zvetana, R. L. Azarova An, M. Aya, Y. V. Elitchkova	Requires cookie*
	Title	Spin Label Study of Apomembranes and Purple Membranes
	Abstract	Three spin-labelled fatty acids were used to detect the dynamics of lipid bilayer o f apomem branes and purple membranes. It was found that ESR spectra of spin labels bound to apo membranes showed a temperature-induced changes rather similar to those seen with purple membranes. At the same time, however, the values of hyperfine splitting parameter 2Tm were lower as compared to purple membranes. The results pointed out that the removal of the retinal from purple membranes affects the dynamics of lipid bilayer and apomembranes were more rigid structure than those of purple membranes.
	Reference	Z. Naturforsch. 48c, 500—503 (1993); received July 3/September 16 1992
	Published	1993
	Keywords	Purple Membranes, Apomembranes, Retinal, Membrane Fluidity, Spin Label
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	TEI-XML for	default:Reihe_C/48/ZNC-1993-48c-0500.pdf
	Identifier	ZNC-1993-48c-0500
	Volume	48