Partially purified plasma membranes were obtained from chick-embryo muscle cells grown in tissue culture. The purification procedure involved homogenization in buffered isotonic sucrose followed by differential and sucrose density gradient centrifugations. The activities of five plasma-membrane markers, as well as microsomal and mitochondrial markers, were followed throughout the purification. ...

In polarized Madin-Darby canine kidney (MDCK) epithelial cells, ankyrin, and the alpha- and beta-subunits of fodrin are components of the basolateral membrane-cytoskeleton and are colocalized with the Na+,K+-ATPase, a marker protein of the basolateral plasma membrane. Recently, we showed with purified proteins that the Na+,K+-ATPase is competent to bind ankyrin with high affinity and specificit...

A bulk fraction enriched with respect to neuronal cell bodies was used as starting material for the isolation of neuronal plasma membrane The cells were gently homogenized in isotonic sucrose and a crude membrane containing fraction sedimented at 3000 g. Subsequently, the membrane fraction was purified on a discontinuous sucrose density gradient between 35% and 25 5% sucrose (w/w). Enzymatic an...

Samples (2ml) of a 605g,,. supernatant were applied to continuous linear gradients of 0.74-2.45 M-sucrose in 16 ml, on a cushion of 2ml of 2.45 M-sucrose. Centrifugation was at 4°C in a 3 x25ml swing-out rotor, and the integrated field-time was 562000g-min at ray. 9.39cm. Fractions (1 ml) were collected by displacement with 2.45~-sucrose. The letters A-D indicate the positions of the four fract...

Preliminary results from differential centrifugation experiments, washing treatments, and enrichment in linear sucrose gradients at a density of 1.09 grams per cubic centimeter all indicated that beta-glucosidase activity in corn root homogenates was associated with a membrane such as tonoplast. A subsequent sucrose density gradient centrifugation time course showed that the beta-glucosidase wa...

To investigate the membrane abnormalities that may play a pathophysiologic role in several hemolytic anemias we determined the density distribution on sucrose density gradients of human red blood cell (RBC) membranes from patients with these disorders, from normal controls, and from incubated normal RBC. We analyzed the fractions for membrane-adsorbed hemoglobin (Hb), globin, and nonglobin cyto...

Sugar metabolism in kernels of starch-deficient endosperm mutants of maize (Zea mays L.) was examined to determine how single locus mutations of carbohydrate metabolism affect carbohydrate metabolism as a whole. Activities of 14 enyzmes were measured in extracts from endosperms from isogenic lines of normal, shrunken, shrunken-2, shrunken-4, brittle-1, and brittle-2 maize in an OH43 background....