Subsynaptosomal localization and biochemical characterization of serotonin binding sites in the brain.
The subsynaptosomal distribution of the borohydride stabilizable binding of serotonin (5-HT) in the brain was investigated using various enzyme markers, such as NAD glycohydrolase (NADase), Na+, K+-activated ATPase for synaptic membranes, and monoamine oxidase (MAO) for outer mitochondrial membranes. The gross distribution of the activity of NADase and Na+, K+-activated ATPase in various membrane fractions was found to parallel the distribution of 5-HT binding in these fractions. Radioactivity bound to brain fractions was extractable with chloroform-methanol (2:1). The membranous material was solubilized by chloroform-methanol (2:1) and the recovered material, suspended in 0.32 M sucrose was found to retain its 5-HT binding capacity. The protein-phospholipid nature of the binding subcellular macromolecule was demonstrated with proteolytic and lipolytic enzymes.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D001894:Borohydrides / Q000494:pharmacology; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D002417:Cattle; D002499:Centrifugation, Density Gradient; D066298:In Vitro Techniques; D008049:Lipase / Q000494:pharmacology; D008995:Monoamine Oxidase / Q000378:metabolism; D009244:NAD+ Nucleosidase / Q000378:metabolism; D010206:Papain / Q000494:pharmacology; D010740:Phospholipases / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D013570:Synaptic Membranes / Q000201:enzymology / Q000378:metabolism*; D013788:Thalamus / Q000648:ultrastructure; D014357:Trypsin / Q000494:pharmacology; D014363:Tryptamines / Q000378:metabolism
D001894:Borohydrides; D010743:Phospholipids; D014363:Tryptamines; D012701:Serotonin; D008995:Monoamine Oxidase; D010740:Phospholipases; D008049:Lipase; D009244:NAD+ Nucleosidase; D014357:Trypsin; D010206:Papain; D000251:Adenosine Triphosphatases