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Biomedical subjects

R E Beyer

Publications and source records attributed to R E Beyer.

36 records · Page 2Linked to original sources
PubMed1968

Oxido-Reduction States and Natural Homologue of Ubiquinone (Coenzyme Q) in Submitochondrial Particles From Etiolated Mung Bean (Phaseolus aureus) Seedlings.

A procedure for the isolation of submitochondrial particles in quantity from etiolated Mung bean (Phaseolus aureus) seedlings is described. Using a combination of acetone extraction and 2 systems of thin layer chromatography ubiquinone has been isolated. The isolated ubiquinone migrates coincident with authentic ubiquinone-10 in reversed phase thin layer partition chromatography, gives a positive Craven's test, and has oxidized and reduced spectra characteristic of ubiquinone. The quinone is partially reduced under steady-state electron transfer conditions with both succinate and NADH as substrates and is almost completely reduced under anaerobic conditions with either substrate. The concentration of ubiquinone in the particle is of the order of 4.4 mmumoles per mg particle protein, approximately equal to that found in similar submitochondrial particles from beef heart. It is tentatively concluded that ubiquinone-10 is a functional member of the mitochondrial electron transfer chain of Phaseolus aureus.

Journal Article↗
PubMedDate not supplied

The anticancer enzyme DT diaphorase is induced selectively in liver during ascites hepatoma growth.

DT diaphorase catalyzes the transfer of two electrons to quinones to form relatively stable hydroquinones, thus protecting cells from damage by semiquinone production and subsequent superoxide radical formation. A rapid and substantial increase in the activity of DT diaphorase occurs in the cytosolic and microsomal fractions of livers of rats with Zajdela ascites hepatoma under conditions which generally depress the activity of other xenobiotic-metabolizing enzymes. The increase is time-dependent, parallels the increase in the specific activity of DT diaphorase of the growing hepatoma cells, and is limited to the liver. Treatment of rats with hepatoma cytosol results in a rapid increase in liver cytosolic DT diaphorase activity in a dose-dependent manner.

Animals↗