Journal article
Scanning transmission X-ray microscopic analysis of purified melanosomes of the mouse iris
Micron (Oxford, England : 1993), Vol.37(8), pp.689-698
2006
DOI: 10.1016/j.micron.2006.03.008
PMID: 16723235
Abstract
Melanosomes are specialized intracellular membrane bound organelles that produce and store melanin pigment. The composition of melanin and distribution of melanosomes determine the color of many mammalian tissues, including the hair, skin, and iris. However, the presence of melanosomes within a tissue carries potentially detrimental risks related to the cytotoxic indole–quinone intermediates produced during melanin synthesis. In order to study melanosomal molecules, including melanin and melanin-related intermediates, we have refined methods allowing spectromicroscopic analysis of purified melanosomes using scanning transmission X-ray microscopy. Here, we present for the first time absorption data for melanosomes at the carbon absorption edge ranging from 284 to 290
eV. High-resolution images of melanosomes at discrete energies demonstrate that fully melanized mature melanosomes are internally non-homogeneous, suggesting the presence of an organized internal sub-structure. Spectra of purified melanosomes are complex, partially described by a predominating absorption band at 288.4
eV with additional contributions from several minor bands. Differences in these spectra were detectable between samples from two strains of inbred mice known to harbor genetically determined melanosomal differences, DBA/2J and C57BL/6J, and are likely to represent signatures arising from biologically relevant and tractable phenomena.
Details
- Title: Subtitle
- Scanning transmission X-ray microscopic analysis of purified melanosomes of the mouse iris
- Creators
- Michael G Anderson - Department of Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, United StatesTamás Haraszti - Institute for Molecular Biophysics, University of Maine, Orono, ME 04469, United StatesGreg E Petersen - Department of Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, United StatesSue Wirick - National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, United StatesChris Jacobsen - Department of Physics, SUNY at Stony Brook, Stony Brook, NY 11794, United StatesSimon W.M John - The Howard Hughes Medical Institute and The Jackson Laboratory, Bar Harbor, ME 04609, United StatesMichael Grunze - Institute for Molecular Biophysics, University of Maine, Orono, ME 04469, United States
- Resource Type
- Journal article
- Publication Details
- Micron (Oxford, England : 1993), Vol.37(8), pp.689-698
- Publisher
- Elsevier Ltd
- DOI
- 10.1016/j.micron.2006.03.008
- PMID
- 16723235
- ISSN
- 0968-4328
- eISSN
- 1878-4291
- Language
- English
- Date published
- 2006
- Academic Unit
- Molecular Physiology and Biophysics; Ophthalmology and Visual Sciences
- Record Identifier
- 9984025329402771
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