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Xanthophyll spectral forms and efficiency of energy transfer to Chl a in LHCII monomeric preparations purified by non-denaturing IEF from WT and lut2.1 thylakoids. |
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| Site |
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| L1 |
L2 |
N1 |
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| LHCII WT |
Spectral form |
Lutein1 (489 nm) |
Lutein2 (495 nm) |
Viola1 (492 nm) |
Neoxanthin (486.5 nm) |
| Efficiency |
81.0% |
79.0% |
60.0% |
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| LHCII lut2.1 |
Spectral form |
Viola2 (505 nm) |
Viola1 (493.5 nm) |
Neoxanthin (486.5 nm) |
|
| Efficiency |
93.8% |
79.0% |
60.0% |
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Spectral deconvolution analysis and calculation of energy transfer efficiency were as in Croce et al.,, 1999 [18]. The data, normalized to the WT, are relative to a 100% Chl a-to-Chl a ET efficiency. The error in the ET efficiency was <4%, with the exception of Viola1 in WT (>10%). Xanthophyll absorption maxima in ethanol are 477.2, 472.8 and 468.4 nm, respectively, for violaxanthin, lutein and neoxanthin. Binding to sites L2 and L1 shifts violaxanthin absorption from 477.2 to 492 and 505 nm respectively; lutein is shifted from 472.8 to 489 and 495 nm, respectively. Binding to site N1 shifts neoxanthin from 468.4 to 486.5 nm. | |||||
Dall'Osto et al. BMC Plant Biology 2006 6:32 doi:10.1186/1471-2229-6-32 |
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