Is (9Z)‐“<i>meso</i>”‐zeaxanthin optically active?

Lutnæs, Bjart Frode; Gautun, Odd R.; Liaaen‐Jensen, Synnøve

doi:10.1002/chir.1023

Cited by 6 publications

(3 citation statements)

References 21 publications

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“…This difference leads to a decoupling of the C‚C bond in the e-ring from the rest of the conjugated chain, resulting in a conjugation length of 10 for lutein and 11 for zeaxanthin. Because of the conjugation length is a key factor to determine many spectroscopic properties of carotenoids (7,10), the stereoisomer (3R,39S-meso)-zeaxanthin is spectroscopically indistinguishable from (3R,39R)-zeaxanthin except under specialized conditions using polarized light, such as circular dichroism spectroscopy (45). We found that XBP complexes with exogenous (3R,39R)-zeaxanthin were considerably more unstable than complexes with the other two xanthophylls, especially after freezing; therefore, the studies reported below generally focused on the interactions of (3R,39R,69R)-lutein and (3R,39S-meso)-zeaxanthin with XBP.…”

Section: Resultsmentioning

confidence: 99%

Photophysical Properties of Xanthophylls in Carotenoproteins from Human Retina¶

Billsten

Bhosale

Yemelyanov

et al. 2003

Photochem Photobiol

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The macula of the human retina contains high amounts of the xanthophyll carotenoids lutein and zeaxanthin [a mixture of (3R,3'R)-zeaxanthin and (3R,3'S-meso)-zeaxanthin]. Recently, it was shown that the uptake and the stabilization of zeaxanthin and lutein into the retina are likely to be mediated by specific xanthophyll-binding proteins (XBP). Here, we have used femtosecond pump-probe spectroscopy to study the dynamics of the S1 state of these xanthophylls in xanthophyll-enriched and native XBP. The results from the native XBP and the enriched XBP were then compared with those for carotenoids in organic solvents and in detergent micelles. Steady-state and transient absorption spectra show that the incorporation of xanthophylls into the protein causes a redshift of the spectra, which is stronger for lutein than for zeaxanthin. The transient absorption spectra further indicate that a part of the xanthophylls remains unbound in the xanthophyll-enriched XBP. The transient absorption spectra of the native XBP prove the presence of both xanthophylls in native XBP. Although the S1 lifetime of lutein does not exhibit any changes when measured in solution, micelles or XBP, we have observed the influence of the environment on the S1 lifetime of meso-zeaxanthin, which has a longer (12 ps) lifetime in XBP than in solution (9 ps). The most pronounced effect was found for vibrational relaxation in the S1 state, which is significantly slower for xanthophylls in XBP compared with micelles and solution. This effect is more pronounced for meso-zeaxanthin, suggesting a specific site of binding of this carotenoid to XBP.

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Section: Resultsmentioning

confidence: 99%

Photophysical Properties of Xanthophylls in Carotenoproteins from Human Retina¶

Billsten

Bhosale

Yemelyanov

et al. 2003

Photochem Photobiol

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“…In THF, its CD spectrum is strongest in the UV range (Fig. 6), and the weak signals in the visible range are usually considered to be artifactual (28,29). When dissolved in CHAPS, the UV CD of (3R,3ЈR)-zeaxanthin is no longer detectable, whereas a negative Cotton peak is present at 410 nm, and a biphasic positive Cotton peak is present at 480 and 500 nm.…”

Section: Xanthophyll Binding and Spectral Studies With Gstp1 And Xbp-mentioning

confidence: 99%

Identification and Characterization of a Pi Isoform of Glutathione S-Transferase (GSTP1) as a Zeaxanthin-binding Protein in the Macula of the Human Eye

Bhosale

Larson

Frederick

et al. 2004

Journal of Biological Chemistry

249

211

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Uptake, metabolism, and stabilization of xanthophyll carotenoids in the retina are thought to be mediated by specific xanthophyll-binding proteins (XBPs). A membrane-associated XBP was purified from human macula using ion-exchange chromatography followed by gel-exclusion chromatography. Two-dimensional gel electrophoresis showed a prominent spot of 23 kDa and an isoelectric point of 5.7. Using mass spectral sequencing methods and the public NCBI database, it was identified as a Pi isoform of human glutathione S-transferase (GSTP1). Dietary (3R,3 R)-zeaxanthin displayed the highest affinity with an apparent K d of 0. Other mammalian xanthophyll carrier proteins such as tubulin, high-density lipoprotein, low-density lipoprotein, albumin, and ␤-lactoglobulin did not bind zeaxanthins with high affinity, and they failed to induce or alter xanthophyll CD spectra to any significant extent. Immunocytochemistry with an antibody to GSTP1 on human macula sections showed highest labeling in the outer and inner plexiform layers. These results indicate that GSTP1 is a specific XBP in human macula that interacts with (3R,3 S-meso)-zeaxanthin and dietary (3R,3 R)-zeaxanthin in contrast to apparently weaker interactions with (3R,3 R,6 R)-lutein.

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“…This difference leads to a decoupling of the C=C bond in the ε‐ring from the rest of the conjugated chain, resulting in a conjugation length of 10 for lutein and 11 for zeaxanthin. Because of the conjugation length is a key factor to determine many spectroscopic properties of carotenoids (7,10), the stereoisomer (3 R ,3′ S ‐meso)‐zeaxanthin is spectroscopically indistinguishable from (3 R ,3′ R )‐zeaxanthin except under specialized conditions using polarized light, such as circular dichroism spectroscopy (45). We found that XBP complexes with exogenous (3 R ,3′ R )‐zeaxanthin were considerably more unstable than complexes with the other two xanthophylls, especially after freezing; therefore, the studies reported below generally focused on the interactions of (3 R ,3′ R ,6′ R )‐lutein and (3 R ,3′ S ‐meso)‐zeaxanthin with XBP.…”

Section: Resultsmentioning

confidence: 99%

Photophysical Properties of Xanthophylls in Carotenoproteins from Human Retina¶

Billsten¹,

Bhosale²,

Yemelyanov³

et al. 2007

Photochemistry and Photobiology

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The macula of the human retina contains high amounts of the xanthophyll carotenoids lutein and zeaxanthin [a mixture of (3R,3′R)‐zeaxanthin and (3R,3′S‐meso)‐zeaxanthin]. Recently, it was shown that the uptake and the stabilization of zeaxanthin and lutein into the retina are likely to be mediated by specific xanthophyll‐binding proteins (XBP). Here, we have used femtosecond pump–probe spectroscopy to study the dynamics of the S1 state of these xanthophylls in xanthophyll‐enriched and native XBP. The results from the native XBP and the enriched XBP were then compared with those for carotenoids in organic solvents and in detergent micelles. Steady‐state and transient absorption spectra show that the incorporation of xanthophylls into the protein causes a redshift of the spectra, which is stronger for lutein than for zeaxanthin. The transient absorption spectra further indicate that a part of the xanthophylls remains unbound in the xanthophyll‐enriched XBP. The transient absorption spectra of the native XBP prove the presence of both xanthophylls in native XBP. Although the S1 lifetime of lutein does not exhibit any changes when measured in solution, micelles or XBP, we have observed the influence of the environment on the S1 lifetime of meso‐zeaxanthin, which has a longer (12 ps) lifetime in XBP than in solution (9 ps). The most pronounced effect was found for vibrational relaxation in the S1 state, which is significantly slower for xanthophylls in XBP compared with micelles and solution. This effect is more pronounced for meso‐zeaxanthin, suggesting a specific site of binding of this carotenoid to XBP.

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Is (9Z)‐“meso”‐zeaxanthin optically active?

Cited by 6 publications

References 21 publications

Photophysical Properties of Xanthophylls in Carotenoproteins from Human Retina¶

Photophysical Properties of Xanthophylls in Carotenoproteins from Human Retina¶

Identification and Characterization of a Pi Isoform of Glutathione S-Transferase (GSTP1) as a Zeaxanthin-binding Protein in the Macula of the Human Eye

Photophysical Properties of Xanthophylls in Carotenoproteins from Human Retina¶

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