Biology Reference
In-Depth Information
5
Myelin: A One-Dimensional Biological
“Crystal” for X-Ray and Neutron
Scattering
Hideyo Inouye and Daniel A. Kirschner*
The periodic nature of the myelin sheath makes it well-suited for examination of
its molecular organization by diffraction techniques. Diffraction provides a means
not only of monitoring the separation between membranes, but also of analyzing
the forces and interactions between them. The diffraction technique is non-
perturbing, and is uniquely suited to analyzing myelin structure and stability in
physiologically intact, unfixed tissue. In principle, changes in structure can be fol-
lowed in real time during physiological events or experimental treatments. The cor-
relation of results from diffraction with results from electron microscopy and
chemical analysis has led to a description of the distribution of lipid, protein, and
water in the membrane array and to the localization of specific proteins and lipids
within the membrane. Such studies are providing the foundation for understanding
the molecular roles of particular myelin lipids and of specific myelin proteins —
both native and mutated — in membrane-membrane adhesion and myelin stability.
Keywords: Myelin; electron density; paracrystalline; neutron scattering ampli-
tude; electron microscopy; Fourier transform; lipid; protein; membranes.
Introduction
The nerve myelin sheath, which is responsible for rapid, saltatory con-
duction in the vertebrate nervous system, is a closely-packed, concentric
*Biology Department, Boston College, Chestnut Hill, MA 02467-3811, USA. E-mail:
inouyeh@bc.edu and kirschnd@bc.edu.
We dedicate this article to the memories of our colleagues, myelin structural biologists,
Dr Allen E. Blaurock (1940-2007) and Dr Leonardo Mateu (1939-2008).
Search WWH ::




Custom Search