Conformation of self-assembled porphyrin dimers in liposome vesicles by phase-modulation 2D fluorescence spectroscopy

@article{Lott2011ConformationOS,
  title={Conformation of self-assembled porphyrin dimers in liposome vesicles by phase-modulation 2D fluorescence spectroscopy},
  author={Geoffrey A. Lott and Alejandro Perdomo-Ortiz and James K. Utterback and Julia R. Widom and Al{\'a}n Aspuru-Guzik and Andrew H. Marcus},
  journal={Proceedings of the National Academy of Sciences},
  year={2011},
  volume={108},
  pages={16521 - 16526}
}
By applying a phase-modulation fluorescence approach to 2D electronic spectroscopy, we studied the conformation-dependent exciton coupling of a porphyrin dimer embedded in a phospholipid bilayer membrane. Our measurements specify the relative angle and separation between interacting electronic transition dipole moments and thus provide a detailed characterization of dimer conformation. Phase-modulation 2D fluorescence spectroscopy (PM-2D FS) produces 2D spectra with distinct optical features… 

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References

SHOWING 1-10 OF 43 REFERENCES
Excitonic Interactions in Covalently Linked Porphyrin Dimers with Rotational Freedom
Experimental and calculated absorption spectra are compared for four different porphyrin dimers covalently linked by alkyl- or phenyl bridges. The spectra of the corresponding monomers were used as a
Structural Studies by Exciton Coupled Circular Dichroism over a Large Distance: Porphyrin Derivatives of Steroids, Dimeric Steroids, and Brevetoxin B⊥
The present study (see ref 1) delineates the scope and limitations of porphyrin chromophores for structural studies by the exciton coupled circular dichroic (CD) method. A distance dependency of the
Visualization of excitonic structure in the Fenna-Matthews-Olson photosynthetic complex by polarization-dependent two-dimensional electronic spectroscopy.
TLDR
It is demonstrated that coarse-grained, excitonic, structural information in the form of projection angles between transition dipole moments can be obtained from the polarization-dependent, two-dimensional electronic spectroscopy of an isotropic sample, particularly when the nonrephasing or free polarization decay signal, rather than the photon echo signal, is considered.
Two-dimensional electronic spectra of symmetric dimers: Intermolecular coupling and conformational states.
TLDR
In the framework of this model, the highly readable 2D PE spectra can unambiguously identify spectral doublets, by relating peak heights and positions with mutual orientations of site-localized transition dipoles.
Two-dimensional electronic spectroscopy of molecular aggregates.
TLDR
Each of the probed systems described offers insights that have both increased the utility of 2D electronic spectroscopy and led to discoveries about the molecular aggregates' dynamics and underlying structure.
Effect of temperature, pressure and lipid acyl chain length on the structure and phase behaviour of phospholipid–gramicidin bilayers
TLDR
Investigating the effect of incorporation of gramicidin D (GD) on the structure and phase behaviour of aqueous dispersions of fully hydrated neutral phospholipid bilayers of different chain lengths found a molecular sorting mechanism seems to be very likely in these regions.
Cross-peak-specific two-dimensional electronic spectroscopy
TLDR
2D electronic spectroscopy is developed using cross-peak-specific pulse polarization conditions in an investigation of the Fenna–Matthews–Olson light harvesting complex from green photosynthetic bacteria, providing insight into the interchromophore couplings, as well as into the energetic pathways giving rise to the signal.
Two-dimensional infrared spectra reveal relaxation of the nonnucleoside inhibitor TMC278 complexed with HIV-1 reverse transcriptase
TLDR
The results show that the inhibitor cyano modes lose memory of their structural configurations relative to the hydrophobic pocket within tens of picoseconds.
Spectroscopic elucidation of uncoupled transition energies in the major photosynthetic light-harvesting complex, LHCII
TLDR
In an investigation of the major light-harvesting complex of photosystem II (LHCII), a method based on polarized 2D electronic spectroscopy is developed to experimentally access the energies of the S0–S1 transitions in the chromophore site basis and shows that rotating the linear polarization of the incident laser pulses reveals previously hidden off-diagonal features.
Exciton interactions in synthetic porphyrin dimers
TLDR
The Soret absorption spectra of six synthetic rigid porphyrin dimers whose crystal structures have been determined are simulated using simple exciton theory, and electronic interaction parameters are calculated using data obtained from the monomer spectra, with no adjustable parameters.
...
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