X-ray characterization of melanins--II.
Structural modeling of amorphous eumelanin has been carried out by comparing calculated data, S(q) and RDF(r), in reciprocal and real space, respectively, for limited random network models with the experimental X-ray scattering data of tyrosine melanin (Cheng et al., 1994). A basic picture of the atomic arrangements in amorphous eumelanin, which accounts for the short and intermediate range order, has been formulated. This reveals domains of a fundamental "particle" dimension of R approximately 15 A, consisting of a paracrystalline array of disordered planar networks polymerized by 4-8 DHI monomers with a graphite-like stacking spacing of approximately 3.45 A, 4-5 layers thick.
Department of Physics, University of Houston, Texas 77204-5506.
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Cheng
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Moss
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Eisner
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005583:Fourier Analysis; D008433:Mathematics; D008543:Melanins / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D012542:Scattering, Radiation; D014443:Tyrosine; D014965:X-Rays
D008543:Melanins; C041877:eumelanin; D014443:Tyrosine