Non specific effector-induced enzyme modulation in isolated plasma membranes

Phosphatidylinositol phosphodiesterase in isolated plasma membranes of rodent skeletal muscle

Phosphoinositide metabolism follows cell activation in a variety of excitable tissues (for a recent review, see Hawthorne, 1984). Previous work (Harborne et al., 1978, 1983, 1984) has shown that purified phospholipase C preparations or muscle fractions which exhibited soluble PtdIns phosphodiesterase activity increased the acetylcholine-sensitivity of intact skeletal muscles of the rat and incr...

Non-allosteric enzyme switches possess larger effector-induced changes in thermodynamic stability than their non-switch analogs.

The ability to regulate cellular protein activity offers a broad range of biotechnological and biomedical applications. Such protein regulation can be achieved by modulating the specific protein activity or through processes that regulate the amount of protein in the cell. We have previously demonstrated that the nonhomologous recombination of the genes encoding maltose binding protein (MBP) an...

Vectorial synthesis of a polysaccharide by isolated plasma membranes.

To ascertain the directionality of chitin synthesis by yeast plasma membranes, the external surface of Saccharomyces cerevisiae protoplasts was labeled with ferritin--concanavalin A. After protoplast lysis, plasma membranes were isolated and treated with trypsin to activate chitin synthase (UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamidodeoxy-D-glucosyl-transferase, EC 2.4.1.16). The ...

Lipoproteins isolated from plasma membranes of Morris hepatoma 5123.

Dynamic domain formation in membranes: thickness-modulation-induced phase separation.

A simple model investigates the amplification of fluctuations on membranes constituted of two lipids having different lengths. Van der Waals and electrostatic interactions across the lipid bilayer result in a destabilization favoring thickness variations of the membrane. Close to spontaneous demixing of the two components, the additional gain in free energy due to thickness undulations shifts t...