Journal article
Nano-scale morphology of melanosomes revealed by small-angle X-ray scattering
PloS one, Vol.9(3), e90884
2014
DOI: 10.1371/journal.pone.0090884
PMCID: PMC3951238
PMID: 24621581
Abstract
Melanosomes are highly specialized organelles that produce and store the pigment melanin, thereby fulfilling essential functions within their host organism. Besides having obvious cosmetic consequences – determining the color of skin, hair and the iris – they contribute to photochemical protection from ultraviolet radiation, as well as to vision (by defining how much light enters the eye). Though melanosomes can be beneficial for health, abnormalities in their structure can lead to adverse effects. Knowledge of their ultrastructure will be crucial to gaining insight into the mechanisms that ultimately lead to melanosome-related diseases. However, due to their small size and electron-dense content, physiologically intact melanosomes are recalcitrant to study by common imaging techniques such as light and transmission electron microscopy. In contrast, X-ray-based methodologies offer both high spatial resolution and powerful penetrating capabilities, and thus are well suited to study the ultrastructure of electron-dense organelles in their natural, hydrated form. Here, we report on the application of small-angle X-ray scattering – a method effective in determining the three-dimensional structures of biomolecules – to whole, hydrated murine melanosomes. The use of complementary information from the scattering signal of a large ensemble of suspended organelles and from single, vitrified specimens revealed a melanosomal sub-structure whose surface and bulk properties differ in two commonly used inbred strains of laboratory mice. Whereas melanosomes in C57BL/6J mice have a well-defined surface and are densely packed with 40-nm units, their counterparts in DBA/2J mice feature a rough surface, are more granular and consist of 60-nm building blocks. The fact that these strains have different coat colors and distinct susceptibilities to pigment-related eye disease suggest that these differences in size and packing are of biological significance.
Details
- Title: Subtitle
- Nano-scale morphology of melanosomes revealed by small-angle X-ray scattering
- Creators
- Thomas Gorniak - Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany; Applied Physical Chemistry, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany; Analytical Chemistry - Biointerfaces, Ruhr-University Bochum, Bochum, GermanyTamas Haraszti - Applied Physical Chemistry, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany; Max-Planck-Institute for Intelligent Systems, Stuttgart, GermanyVasyl M Garamus - Helmholtz-Zentrum Geesthacht, Zentrum für Material- und Küstenforschung GmbH, Geesthacht, GermanyAndreas R Buck - Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany; Applied Physical Chemistry, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany; Analytical Chemistry - Biointerfaces, Ruhr-University Bochum, Bochum, GermanyTobias Senkbeil - Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany; Applied Physical Chemistry, Ruprecht-Karls-University Heidelberg, Heidelberg, GermanyMarius Priebe - Institute for X-Ray Physics, University of Göttingen, Göttingen, GermanyAdam Hedberg-Buenz - University of Iowa, Molecular Physiology and BiophysicsDemelza Koehn - Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, Iowa, United States of AmericaTim Salditt - Institute for X-Ray Physics, University of Göttingen, Göttingen, GermanyMichael Grunze - Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany; Applied Physical Chemistry, Ruprecht-Karls-University Heidelberg, Heidelberg, GermanyMichael G Anderson - University of Iowa, Molecular Physiology and BiophysicsAxel Rosenhahn - Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany; Applied Physical Chemistry, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany; Analytical Chemistry - Biointerfaces, Ruhr-University Bochum, Bochum, Germany
- Resource Type
- Journal article
- Publication Details
- PloS one, Vol.9(3), e90884
- DOI
- 10.1371/journal.pone.0090884
- PMID
- 24621581
- PMCID
- PMC3951238
- NLM abbreviation
- PLoS One
- ISSN
- 1932-6203
- eISSN
- 1932-6203
- Publisher
- United States
- Grant note
- EY017673 / NEI NIH HHS R01 EY017673 / NEI NIH HHS
- Language
- English
- Date published
- 2014
- Academic Unit
- Molecular Physiology and Biophysics; Ophthalmology and Visual Sciences
- Record Identifier
- 9984043800302771
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