in this article, the immobilization of microsomal membranes on fractosil and hexadecylfractosil by hydrophobic adsorption is reported. microsomes were prepared from rat brain and thecatalytic activity of antimycin a insensitive nadh-cytochrome c reductase (nccr), one of themembrane bound enzymes in the microsomal electron transport chain, was chosen as a representative ofthe microsomal membrane...

Phospholipase A, lyophospholipase, acyl CoA hydrolase, and palmitoyl CoA synthetase are present in the plasma membrane of Acanthamoeba castellanii. The first three of these enzymes also occur in other cell fractions but in concentrations too low for the activities in the plasma membrane fraction to be accounted for by contamination by any other cell fraction. Palmitoyl CoA synthetase is restric...

Rat liver rough microsomes were labeled enzymatically with (125)I using lactoperoxidase and glucose oxidase. In intact microsomes only proteins exposed on the outside face of the microsomal membrane were iodinated. Low concentrations of detergent (0.049% deoxycholate) were used to allow entrance of the iodination system into the vesicles without disassembling the membranes. This led to iodinati...

Glutathione S-transferase activity has been shown to be firmly associated with microsomal fractions. This activity could not be removed by repeated washing, by sonication, or by treatment of the microsomal fractions with high salt concentrations or urea. Treatment of the microsomal fraction with puromycin and MgCls to remove the ribosomes with any associated newly synthesized proteins did not d...

The p34 protein is a non-glycosylated, integral membrane protein characteristic of rough microsomes and is believed to play a role in the ribosome-membrane association. Here, antibodies directed against p34 were examined as to their inhibitory effect on ribosome binding to and protein translocation across the microsomal membrane. Preincubation of the stripped (ribosome-depleted) membrane with a...

A membrane-integrated , core-glycosylated form of bovine opsin was synthesized in vitro when bovine retina mRNA was translated in a wheat germ cell-free system supplemented with dog pancreas microsomal vesicles; glycosylation and integration of opsin into membranes were coupled to translation. Proteolysis with themolysin was used to probe the orientation of opsin within the dog pancreas microso...

Isolation of a microsomal membrane fraction is a common procedure in studies involving membrane proteins. By conventional definition, microsomal membranes are collected by centrifugation of a postmitochondrial fraction at 100,000g in an ultracentrifuge, a method originally developed for large amounts of mammalian tissue. We present a method for isolating microsomal-type membranes from small amo...

We have found opiate receptors enriched in two distinct subcellular fractions obtained from rat brain cellfree homogenates. By several criteria, one fraction contains synaptic plasma membranes, while the other represents predominantly smooth microsomes. Using marker enzyme analysis, we determined that the occurrence of opiate receptors in the smooth microsomal fraction cannot be attributed to ...