Biomaterial Database

Effects of ZnCl2 on membrane interactions in myelin of normal and shiverer mice. 1984

H Inouye, and D A Kirschner

X-ray diffraction was used to record the effects of metal cations on the structure of peripheral nerve myelin. Acidic saline (pH 5.0) either with or without added metal cations caused myelin to swell by 10-20 A from its native period of 178 A. The X-ray patterns usually showed broad reflections, and higher orders were either weak or unobserved. With added ZnCl2, however, the swollen myelin gave diffraction patterns that retained sharp reflections to approx. 15 A spacing. Alkaline saline (pH 9.7) containing ZnCl2 produced a reduction of the myelin period by approx. 5 A which was at least twice as much as that produced by other metals. To examine the underlying chemical basis for these unique interactions of Zn2+ with myelin, we carried out parallel X-ray experiments on sciatic nerve from the shiverer mutant mouse, which lacks the major myelin basic proteins. Shiverer myelin responded like normal myelin to ZnCl2 in acidic saline; however, in alkaline saline shiverer myelin showed broadened X-ray reflections which indicated disordering of the regularity of the membrane arrays, and additional reflections were recorded which indicated lipid phase separation. This breakdown may come about by the binding of Zn2+ to negatively-charged lipids which could be more exposed due to the absence of myelin basic proteins. Electron density profiles were calculated on the assumption that, except for changes in their packing, the myelin membranes were minimally altered in structure. For both normal and shiverer myelins, treatments under acidic conditions resulted in swelling at the extracellular apposition and a slight narrowing of the cytoplasmic space. This swelling is likely due to adsorption of protons and divalent cations. Interaction between Zn2+ and myelin P0 glycoprotein could preserve an ordered arrangement of the apposed membrane surfaces. Alkaline saline containing ZnCl2 produced compaction at the cytoplasmic apposition in both normal and shiverer myelins possibly through interactions with a portion of P0 glycoprotein which extends into the cytoplasmic space between membranes.

UI	MeSH Term	Description	Entries
D008818	Mice, Neurologic Mutants	Mice which carry mutant genes for neurologic defects or abnormalities.	Lurcher Mice,Nervous Mice,Reeler Mice,Staggerer Mice,Weaver Mice,Chakragati Mice,Chakragati Mouse,Lurcher Mouse,Mice, Neurological Mutants,Mouse, Neurologic Mutant,Mouse, Neurological Mutant,Nervous Mouse,Neurologic Mutant Mice,Neurological Mutant Mouse,Reeler Mouse,Staggerer Mouse,Weaver Mouse,ckr Mutant Mice,Mice, Chakragati,Mice, Lurcher,Mice, Nervous,Mice, Neurologic Mutant,Mice, Reeler,Mice, Staggerer,Mice, Weaver,Mice, ckr Mutant,Mouse, Chakragati,Mouse, Lurcher,Mouse, Nervous,Mouse, Reeler,Mouse, Staggerer,Mouse, Weaver,Mutant Mice, Neurologic,Mutant Mice, ckr,Mutant Mouse, Neurologic,Neurologic Mutant Mouse
D009186	Myelin Sheath	The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem.	Myelin,Myelin Sheaths,Sheath, Myelin,Sheaths, Myelin
D002413	Cations, Divalent	Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.	Divalent Cations
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D004676	Myelin Basic Protein	An abundant cytosolic protein that plays a critical role in the structure of multilamellar myelin. Myelin basic protein binds to the cytosolic sides of myelin cell membranes and causes a tight adhesion between opposing cell membranes.	Golli-MBP1 Protein,Golli-MBP2 Protein,HOG5 Protein,HOG7 Protein,MBP1 Protein,MBP2 Protein,MBP3 Protein,MBP4 Protein,Myelin Basic Protein, 17.2 kDa Isoform,Myelin Basic Protein, 18.5 kDa Isoform,Myelin Basic Protein, 20.2 kDa Isoform,Myelin Basic Protein, 21.5 kDa Isoform,Myelin Basic Protein, Isoform 1,Myelin Basic Protein, Isoform 2,Myelin Basic Protein, Isoform 3,Myelin Basic Protein, Isoform 4,Myelin Basic Protein, Isoform 5,Myelin Basic Protein, Isoform 6,Myelin Basic Protein, Isoform 7,Golli MBP1 Protein,Golli MBP2 Protein
D005110	Extracellular Space	Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.	Intercellular Space,Extracellular Spaces,Intercellular Spaces,Space, Extracellular,Space, Intercellular,Spaces, Extracellular,Spaces, Intercellular
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012584	Sciatic Nerve	A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.	Nerve, Sciatic,Nerves, Sciatic,Sciatic Nerves
D015032	Zinc	A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.