Hydrodynamic properties of the purified glutamate-binding protein subunit of the N-methyl-D-aspartate receptor.
The hydrodynamic properties of the previously purified glutamate-binding protein from rat synaptic membranes were determined in order to estimate the molecular size of the protein in its native state. This protein is apparently a subunit of a multisubunit complex that forms the N-methyl-D-aspartate subtype of glutamate receptor and has a molecular size of approximately 70 kDa based on electrophoretic migration under denaturing conditions. On the basis of results obtained from H2O/D2O sucrose density gradient sedimentation and gel filtration chromatography of the purified glutamate-binding protein we calculated the partial specific volume of the protein-detergent complex to be 0.766 cc3/g, the Stokes radius of the complex as 4.9 nm, the Mc of the complex as 203,000 +/- 22,000 and the Mr of the protein as 182,000 +/- 19,000. These results are indicative of stable self-association of the glutamate-binding protein and are in agreement with recent studies indicating that more than one molecule of glutamate may be required to activate the N-methyl-D-aspartate receptor-associated ion channel.
Kumar
K N
KN
Department of Pharmacology and Toxicology, University of Kansas, Lawrence 66045-2505.
Eggeman
K T
KT
Adams
J L
JL
Michaelis
E K
EK
D000818:Animals; D015153:Blotting, Western; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D051381:Rats; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate / Q000737:chemistry*; D017981:Receptors, Neurotransmitter / Q000737:chemistry* / Q000302:isolation & purification
D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter