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Biomedical subjects

R A Butow

Publications and source records attributed to R A Butow.

107 records · Page 6Linked to original sources
PubMed1971

Euglena gracilis: formation of giant mitochondria.

The addition of antimycin A (0.5 microgram per milliliter) to cultures of a bleached strain of Euglena gracilis in the logarithmic phase of growth on succinate as a carbon source results in (i) an interruption of growth for 24 hours and (ii) an increase in whole-cell respiration and the emergence of a novel succinoxidase activity within 2 to 4 hours. After 3 to 5 hours, the mitochondria enlarge, fuse, and form a sheathlike structure situated close to the periphery of the cell.

Adenosine Monophosphate↗
PubMed1970

Low temperature and chloramphenicol induction of respiratory deficiency in a cold-sensitive mutant of Saccharomyces cerevisiae.

A cold-sensitive mutant of a haploid strain of Saccharomyces cerevisiae has been isolated by selection for impaired growth at 18 degrees on nonfermentable carbon sources. Growth of the mutant on glucose or galactose at either 28 or 18 degrees is similar to that of the parental strain. The cold-sensitive strain is highly mutable to a cytoplasmic petite when grown at 18 degrees , or when grown at 28 degrees in the presence of 4 mg/ml of chloramphenicol. Cold sensitivity is not observed in the conversion of promitochondria to mitochondria. We conclude that mitochondrial protein synthesis is required for maintaining the stability of the mitochondrial genome.

Chloramphenicol↗
PubMed1965

On the mechanism of respiratory control.

Control of oxidation is the key mechanism in the regulation of energy metabolism. In glycolysis the oxidation of glyceraldehyde-3-phosphate is controlled by DPNH, which inhibits glyceraldehyde-3-phosphate dehydrogenase. In oxidative phosphorylation the inhibition of electron flow from DPNH to oxygen, called "respiratory control," is the subject of this paper. After a discussion of the physiological significance of the "tight coupling" between phosphorylation and oxidation, studies on "loosely coupled" submitochondrial particles are reported. These particles are capable of oxidative phosphorylation in the presence of a suitable phosphate acceptor system, but in contrast to controlled, intact mitochondria they oxidize DPNH in the absence of phosphate and ADP. The addition of o-phenanthroline to submitochondrial particles gives rise to an inhibition of respiration, which is partly reversed by phosphate and ADP or by dinitrophenol. The properties of this model system of respiratory control will be described.

Adenine Nucleotides↗