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Estimation of molar absorptivities and pigment sizes for eumelanin and pheomelanin using femtosecond transient absorption spectroscopy
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1.
1.J. B. Nofsinger, T. Ye, and J. D. Simon, J. Phys. Chem. B 105, 2864 (2001).
http://dx.doi.org/10.1021/jp004045y
2.
2.S. Ito and K. Fujita, Anal. Biochem. 144, 527 (1985).
http://dx.doi.org/10.1016/0003-2697(85)90150-2
3.
3.K. Wakamatsu and S. Ito, Pigment Cell Res. 15, 174 (2002).
http://dx.doi.org/10.1034/j.1600-0749.2002.02017.x
4.
4.J. Cheng, S. C. Moss, and M. Eisner, Pigment Cell Res. 7, 263 (1994);
http://dx.doi.org/10.1111/j.1600-0749.1994.tb00061.x
4.G. W. Zajac, J. M. Gallas, J. Cheng, M. Eisner, S. C. Moss, and A. E. Alvaradoswaisgood, Biochim. Biophys. Acta 1199, 271 (1994).
5.
5.Y. Liu and J. D. Simon, Pigment Cell Res. 16, 606 (2003).
http://dx.doi.org/10.1046/j.1600-0749.2003.00098.x
6.
6.A. Pullman and B. Pullman, Biochim. Biophys. Acta 54, 384 (1961).
http://dx.doi.org/10.1016/0006-3002(61)90389-4
7.
7.M. L. Tran, B. J. Powell, and P. Meredith, Biophys. J. 90, 743 (2006).
http://dx.doi.org/10.1529/biophysj.105.069096
8.
8.G. Zonios, A. Dimou, I. Bassukas, D. Galaris, A. Tsolakidis, and E. Kaxiras, J. Biomed. Opt. 13, 014017 (2008).
http://dx.doi.org/10.1117/1.2844710
9.
9.J. McGinness, P. Corry, and P. Proctor, Science 183, 853 (1974).
http://dx.doi.org/10.1126/science.183.4127.853
10.
10.T. Ye and J. D. Simon, J. Phys. Chem. B 107, 11240 (2003).
http://dx.doi.org/10.1021/jp0352837
11.
11.A. Orstan and J. B. A. Ross, J. Phys. Chem. 91, 2739 (1987);
http://dx.doi.org/10.1021/j100295a019
11.A. Napolitano, P. Di Donato, G. Prota, and E. J. Land, Free Radic Biol. Med. 27, 521 (1999).
http://dx.doi.org/10.1016/S0891-5849(99)00098-2
12.
12.D. Fu, T. E. Matthews, I. R. Piletic, and W. S. Warren, J. Biomed. Opt. 13, 0405031 (2008);
12.D. Fu, T. Ye, T. E. Matthews, J. Grichnik, L. Hong, J. D. Simon, and W. S. Warren, J. Biomed. Opt. 13, 054036 (2008).
http://dx.doi.org/10.1117/1.2976424
13.
13.See EPAPS supplementary material at http://dx.doi.org/10.1063/1.3265861 for a description of the laser apparatus and sample preparation.[Supplementary Material]
14.
14.Y. Liu, L. Hong, K. Wakamatsu, S. Ito, B. Adhyaru, C. Y. Cheng, C. R. Bowers, and J. D. Simon, Photochem. Photobiol. 81, 135 (2005).
http://dx.doi.org/10.1562/2004-08-03-RA-259.1
15.
15.S. Ito, Pigment Cell Res. 2, 53 (1989).
http://dx.doi.org/10.1111/j.1600-0749.1989.tb00158.x
16.
16.J. B. Nofsinger, S. E. Forest, and J. D. Simon, J. Phys. Chem. B 103, 11428 (1999).
http://dx.doi.org/10.1021/jp992640y
17.
17.P. Meredith, B. J. Powell, J. Riesz, S. P. Nighswander-Rempel, M. R. Pederson, and E. G. Moore, Soft Matter 2, 37 (2006).
http://dx.doi.org/10.1039/b511922g
18.
18.G. J. Blanchard and M. J. Wirth, Anal. Chem. 58, 532 (1986).
http://dx.doi.org/10.1021/ac00294a007
19.
19.S. Ito and K. Wakamatsu, Pigment Cell Res. 16, 523 (2003).
http://dx.doi.org/10.1034/j.1600-0749.2003.00072.x
20.
20.A. Napolitano, M. De Lucia, L. Panzella, and M. d’Ischia, Photochem. Photobiol. 84, 593 (2008).
http://dx.doi.org/10.1111/j.1751-1097.2007.00232.x
21.
21.E. Kaxiras, A. Tsolakidis, G. Zonios, and S. Meng, Phys. Rev. Lett. 97, 218102 (2006);
http://dx.doi.org/10.1103/PhysRevLett.97.218102
21.S. Meng and E. Kaxiras, Biophys. J. 94, 2095 (2008).
http://dx.doi.org/10.1529/biophysj.107.121087
22.
22.R. Philip, A. Penzkofer, W. Baumler, R. M. Szeimies, and C. Abels, J. Photochem. Photobiol., A 96, 137 (1996).
http://dx.doi.org/10.1016/1010-6030(95)04292-X
23.
23.M. Albota, D. Beljonne, J. L. Bredas, J. E. Ehrlich, J. Y. Fu, A. A. Heikal, S. E. Hess, T. Kogej, M. D. Levin, S. R. Marder, D. McCord-Maughon, J. W. Perry, H. Rockel, M. Rumi, C. Subramaniam, W. W. Webb, X. L. Wu, and C. Xu, Science 281, 1653 (1998).
http://dx.doi.org/10.1126/science.281.5383.1653
24.
24.T. Ye, L. Hong, J. Garguilo, A. Pawlak, G. S. Edwards, R. J. Nemanich, T. Sarna, and J. D. Simon, Photochem. Photobiol. 82, 733 (2006).
http://dx.doi.org/10.1562/2006-01-02-RA-762
25.
25.J. Riesz, J. Gilmore, and P. Meredith, Biophys. J. 90, 4137 (2006).
http://dx.doi.org/10.1529/biophysj.105.075713
26.
26.Y. Liu and J. D. Simon, Pigment Cell Res. 18, 42 (2005).
http://dx.doi.org/10.1111/j.1600-0749.2004.00197.x
27.
27.E. Vedralova and J. Duchon, Neoplasma 30, 317 (1983).
http://aip.metastore.ingenta.com/content/aip/journal/jcp/131/18/10.1063/1.3265861
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Figures

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FIG. 1.

Monomeric precursors present in the synthesis of eumelanin and pheomelanin. The molar masses of each species were averaged (with equal weighting) in order to determine the average monomer molar masses that were used in subsequent calculations.

Image of FIG. 2.

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FIG. 2.

Transient absorption decays and fits for Sepia eumelanin and synthetic pheomelanin. Convention: negative signal implies ground state depletion. The decays were normalized for laser intensity and pump absorbance. The inset graph shows the transient absorption of an ICG calibration sample which was used to determine melanin molar absorptivities by correlating the extrapolated lock-in signal intensity at time zero with the known molar absorptivity of ICG.

Image of FIG. 3.

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FIG. 3.

Average molar absorptivity spectra for pigments in Sepia eumelanin and synthetic pheomelanin.

Tables

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Table I.

Linear and nonlinear absorption parameters for melanins measured at . Bold/italicized entries were determined by calculations using the calibrated laser spectrometer values from the ICG solution and the Beer–Lambert law

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/content/aip/journal/jcp/131/18/10.1063/1.3265861
2009-11-13
2014-04-20

Abstract

Fundamental optical and structuralproperties of melanins are not well understood due to their poor solubility characteristics and the chemical disorder present during biomolecular synthesis. We apply nonlinear transient absorption spectroscopy to quantify molar absorptivities for eumelanin and pheomelanin and thereby get an estimate for their average pigment sizes. We determine that pheomelanin exhibits a larger molar absorptivity at near IR wavelengths , which may be extended to shorter wavelengths. Using the molar absorptivities, we estimate that melanin pigments contain and 28 monomer units for eumelanin and pheomelanin, respectively. This is considerably larger than the oligomeric species that have been recently proposed to account for the absorptionspectrum of eumelanin and illustrates that larger pigments comprise a significant fraction of the pigment distribution.

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Scitation: Estimation of molar absorptivities and pigment sizes for eumelanin and pheomelanin using femtosecond transient absorption spectroscopy
http://aip.metastore.ingenta.com/content/aip/journal/jcp/131/18/10.1063/1.3265861
10.1063/1.3265861
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