Synaptic plasma membranes from rat brain synaptosomes: Isolation and partial characterization

摘要: Abstract We have isolated a highly purified plasma membrane fraction directly from synaptosomes prepared by centrifugation on Ficoll-sucrose gradient. A critical feature of the preparation method is use alkaline conditions to achieve effective osmotic shock so that membranes effectively resolve mitochondria. If carried out at pH, 70 % (Na + -K )-activated-ouabain-sensitive ATPase (EC 3.6.1.4) can be recovered with only 7 total cytochrome oxidase 1.9.3.1) in synaptosomal fractions. In contrast, if neutral 50 mitochondria overlays 85 membranes. enriched synaptic (SPM fraction) simple discontinuous gradient relatively good yield. The SPM bands between 25–32.5 sucrose; yield about 1.5 mg protein per g tissue wet wt. An phosphatase 3.1.3.1) found fraction. distribution pattern parallels Na )-ATPase . 5′-Nucleotidase 3.1.3.5) and acetylcholinesterase 3.1.1.7) sediment lighter densities than or although there considerable overlap. contains β-N- acetylglucosaminidase This enzyme not completely washed salt treatment but released low concentrations Triton X-100.