Biomaterial Database

The sodium channel from rat brain. Purification and subunit composition. 1984

R P Hartshorne, and W A Catterall

A procedure is described for purification of the sodium channel 1380-fold from rat brain to essential homogeneity. The channel is solubilized in Triton X-100 and stabilized by addition of phosphatidylcholine and 10 mM CaCl2. It is purified by sequential chromatography on DEAE-Sephadex, hydroxylapatite, and wheat germ agglutinin/Sepharose followed by sedimentation through sucrose gradients. The final preparation binds 2910 pmol of saxitoxin (STX)/mg of protein or 0.9 mol of STX/mol of sodium channel of Mr approximately 316,000. Three polypeptide subunits comprise 90% of the silver stain intensity on sodium dodecyl sulfatepolyacrylamide gels of the pure protein and migrate as a stoichiometric complex coincident with STX-binding activity in sucrose gradient sedimentation: alpha with Mr approximately 260,000, beta 1 with Mr approximately 39,000, and beta 2 with Mr approximately 37,000. The alpha subunit, both purified and in intact synaptosomes, is shown to behave anomalously during sodium dodecyl sulfate-polyacrylamide gel electrophoresis exhibiting an unusually high extrapolated electrophoretic free mobility. A subunit stoichiometry of alpha 1(beta 1)1(beta 2)1 is proposed.

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
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
D012530	Saxitoxin	A compound that contains a reduced purine ring system but is not biosynthetically related to the purine alkaloids. It is a poison found in certain edible mollusks at certain times; elaborated by GONYAULAX and consumed by mollusks, fishes, etc. without ill effects. It is neurotoxic and causes RESPIRATORY PARALYSIS and other effects in MAMMALS, known as paralytic SHELLFISH poisoning.	Gonyaulax Toxin,Mitilotoxin,Saxitonin,Toxin, Gonyaulax
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D046911	Macromolecular Substances	Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.	Macromolecular Complexes,Macromolecular Compounds,Macromolecular Compounds and Complexes,Complexes, Macromolecular,Compounds, Macromolecular,Substances, Macromolecular