Spectroscopic Methods

Vetter, Walter; Englert, Gerhard; Rigassi, N.; Schwieter, Ulrich

doi:10.1007/978-3-0348-5831-1_4

Cited by 150 publications

(100 citation statements)

References 49 publications

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“…19) or Section 467-18-5 exhibited an inflection at 425 or 438 nm and maxima at 449 or 462 nm and 478 or 489 nm, depending on the solvent (petroleum ether or benzene, respectively). The bathochromic shift in the position of absorption maxima between petroleum ether and benzene solutions is quite characteristic of these polyene pigments (cf., Vetter et al, 1971). Because of the presence of minor amounts of impurities absorbing in the near ultraviolet, valid spectra could not be obtained below ca.…”

Section: Carotenoidsmentioning

confidence: 99%

See 1 more Smart Citation

Geochemistry of Tetrapyrrole, Carotenoid, and Perylene Pigments in Sediments from the San Miguel Gap (Site 467) and Baja California Borderland (Site 471), Deep Sea Drilling Project Leg 63

Louda¹,

Baker²

1981

Initial Reports of the Deep Sea Drilling Project

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Section: Carotenoidsmentioning

confidence: 99%

“…Because of the presence of minor amounts of impurities absorbing in the near ultraviolet, valid spectra could not be obtained below ca. 360 nm; thus the presence of the characteristic cis-peak at 338 nm in the electronic spectrum of ß-carotene (cf., Vetter et al, 1971;Zechmeister, 1958) is unknown.…”

Section: Carotenoidsmentioning

confidence: 99%

Geochemistry of Tetrapyrrole, Carotenoid, and Perylene Pigments in Sediments from the San Miguel Gap (Site 467) and Baja California Borderland (Site 471), Deep Sea Drilling Project Leg 63

Louda¹,

Baker²

1981

Initial Reports of the Deep Sea Drilling Project

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“…Both the loss in fine structure and the blue shift of the absorption maximum can be explained by steric hindrance: the two parts of the molecule are not completely free to rotate around the 6-7 single bond but are held preferentially in a position in which the cyclohexene ring is not coplanar with the side chain [20]. The comparison of the spectra of p-carotene and lycopene nicely illustrates this case of steric hindrance (discussed in [21]). …”

Section: Some Definitions and General Considerationsmentioning

confidence: 99%

Studies on the Retinal-Protein Interaction in Bacteriorhodopsin

1977

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1. Different types of bacteriorhodopsin chromophores and their reactions are described. This includes intermediates of the reconstitution reaction of the purple complex, intermediates of the photochemical cycle and a photochemically active 500-nm chromophore. In contrast to the native chromophore (purple complex) some of these species are reducible by borohydride yielding stable retinyl proteins.2. Hydrolysis and/or extraction of the retinyl proteins reveals that in the corresponding non reduced parent chromophores the retinal is bound either noncovalently or covalently to lysyl residues of the polypeptide chain.3. Retinol, retinyl lysine and their retro isomers isolated from the various reduced chromophores are identified by thin-layer chromatography and mass spectrometry.4. The absorption spectra of the retinyl proteins and binding studies with retinol and retinal indicate that the cyclohexene ring and the side chain of the retinyl moiety are forced into a coplanar conformation by interaction with the protein. The three peaked absorption band of the reduced chromophores is due to this planarized conformation and not to a retro configuration of the retinyl moiety.5. Isomerization to retro compounds can be achieved by HCl as is known to be the case for retinyl compounds in solution. In addition photochemical isomerization is observed in the case of planarized retinyl moieties. Thus the native protein structure is responsible not only for a specific conformation of the retinyl moiety but also for its specific reactivity.The retinal-protein complex bacteriorhodopsin has been shown to mediate light-energy conversion in halobacteria. Its properties and its function have recently been reviewed [l]. Light absorption by the chromophore (purple complex) of bacteriorhodopsin results in a series of spectral changes composing a photochemical cycle which is accompanied by a vectorial release and uptake of protons. As a result an electrochemical proton gradient across the cell membrane is established [2,3], which can drive ATP synthesis [4-61 and transport processes [7,8].The purple complex absorbs maximally around 560 nm, whereas retinal in solution has a A, , , value around 370 nm. The strong bathochromic shift 190 nm) apparently is due to a specific retinal-protein interaction. The exact chemical structure of the purple complex, however, is not known. One is reminded of the futile attempts to elucidate the chemical structure of the chromophores in other retinalprotein complexes (e.g. the rhodopsins), even though many suggestions for their structure have been made over the years [9]. The importance of a precise knowledge of the chromophore structure and its changes upon light absorption is evident because the chromophore mediates the physiological function of all retinal-protein complexes as photoreceptors. In the special case of bacteriorhodopsin the understanding of the chromophore structure and its lightinduced changes will be the basis for our understanding of the active proton transport process coupled to it. Unfortun...

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“…Most carotenoids have a typical spectrum with three strong absorbance maxima in the region 400-550 nm and weak maxima in the 260-280 and 320-350 nm regions [22]. The spectrum of purified chicken TTR shows this pattern and is identical to that of lutein.…”

Section: Yellow Component In Chicken Ttrmentioning

confidence: 84%

“…while preliminary NMR studies indicate structural similarities to lutein, suggesting that many of the components extracted from chicken TTR could be oxidized carotenoid products [22]. The extent oflutein saturation of chicken TTR was estimated to be about 50%, assuming a molar ratio of one lutein per protein tetramer as the maximum binding.…”

Section: Yellow Component In Chicken Ttrmentioning

confidence: 95%

Lutein associated with a transthyretin indicates carotenoid derivation and novel multiplicity of transthyretin ligands

et al. 1995

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Transthyretins isolated from different species bind hydrophobic compounds and are often obtained in a yellow form. Such a transthyretin from chicken serum was purified by chromatography using Sepharose-coupled human retinol-binding protein. The yellow chromophore was extracted with methanol and purified by reverse phase HPLC followed by normal-phase chromatography on a nitrile column. Ultraviolet-visible absorbance and mass spectrometry identified the yellow compound as iutein, i.e. xanthophyll, (all-trans)-~,e-carotene-3,3"-diol, estimated to constitute 10-30% of associated eolourless compounds. These components are different from the yellow component isolated from human transthyretin and establish that carotenoidderived pigments can be associated with transthyretins.

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Spectroscopic Methods

Cited by 150 publications

References 49 publications

Geochemistry of Tetrapyrrole, Carotenoid, and Perylene Pigments in Sediments from the San Miguel Gap (Site 467) and Baja California Borderland (Site 471), Deep Sea Drilling Project Leg 63

Geochemistry of Tetrapyrrole, Carotenoid, and Perylene Pigments in Sediments from the San Miguel Gap (Site 467) and Baja California Borderland (Site 471), Deep Sea Drilling Project Leg 63

Studies on the Retinal-Protein Interaction in Bacteriorhodopsin

Lutein associated with a transthyretin indicates carotenoid derivation and novel multiplicity of transthyretin ligands

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