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Biomedical subjects

D Charlemagne

Publications and source records attributed to D Charlemagne.

67 records · Page 4Linked to original sources
PubMed1979

Induction of specific anti-actin antibodies and their measurement by ELISA technique.

Using the ELISA technique we have been able to quantify antibodies directed against actin and to follow the kinetics of antibody production. Specific anti-actin antisera have been raised in rabbits by immunization with chemically modified white muscle rabbit actin. Two or three dinitrophenyl groups linked per actin molecule were sufficient to break natural tolerance, while linkage of three phosphorylcholine groups to actin was not.

Actins↗
PubMed1977

Roles of proteins from inner face of plasma membranes in susceptibility of of (Na+ + K+)-stimulated Mg2+ adenosinetriphosphatase to ouabain.

Purified right-side-out (RSO) and inside-out (IO) plasma membrane vesicles release 35% of the total plasma membrane proteins after EDTA treatment. After such a treatment both types of vesicles exhibited the same total activity of (Na+ + K+)-stimulated Mg2+ adenosinetriphosphatase (ATPase; ATP phosphohydrolase, EC 3.6.1.3) as in their native state. The EDTA treatment increases the enzyme sensitivity to ouabain by 350-fold in IO vesicles while being without any effect RSO vesicles. Thus, proteins released only from the IO vesicles led to a change in ouabain sensitivity of the (Na+ + K+)-stimulated Mg2+ ATPase. Moreover, only proteins released from IO vesicles, when added to treated IO vesicles with divalent cations, were able to restore the original resistance of the enzyme to ouabain; released proteins from RSO vesicles failed to make such a reconstitution. Thus, we assume that these proteins detach from the inner face of the plasma membrane upon EDTA treatment and are distinct from the enzyme. Polyacrylamide gel electrophoresis indicates that these inner face plasma membrane proteins are approximately 30,000 daltons.

Adenosine Triphosphatases↗
PubMed1976

Plasma membrane studies on drug-sensitive and -resistant cell lines. II. Ouabain sensitivity of (Na+ +K+)-stimulated Mg2+-ATPase.

Mutant cell lines have been selected from the murine plasmocytoma MOPC 173 for their resistance to ouabain, dibutyryl cyclic AMP, theophyllin and concanavalin A. We have compared three wild-type cell lines with their seven resistant counterparts. All resistant mutants exhibited a (Na+ + K+)-stimulated Mg2+-ATPase resistance to ouabain inhibition when measured in microsomes. The homogeneity of ouabain binding sites has been found in most of the cell lines; however, two different populations of sites have been detected in one wild-type and in one resistant cell lines. These results led us to hypothetise the (Na+ + K+)-ATPase-ouabain interaction being modulated by a non-specific membrane structure.

Adenosine Triphosphatases↗
PubMed1976

[The role of distinct membrane components of the enzyme in the ouabain sensitivity of Na+/K+ ATPase].

Purified plasma membranes from a cell line derived from the murine plasmocytoma MOPC 173 exhibited a 50% inhibition of the Na+K+ ATPase by 120 muM ouabain. EDTA treatment of such membranes induced a drop in the ouabain concentration needed for 50% inhibition to 0.4 muM. Supernatants obtained after EDTA treatment were able to complement with Ca(++) + Mg++ the washed EDTA treated membranes which recover their original resistance.

Adenosine Triphosphatases↗