MYOKINASE AND ADENOSINETRIPHOSPHATASE IN OXIDATIVE PHOSPHORYLATION

The Role of Myokinase in Transphosphorylations* I. the Enzymatic Phosphorylation of Hexoses by Adenyl

The enzyme which catalyzes the phosphorylation of glucose and fructose was described in 1927 by Meyerhof (1). He found that muscle extracts which split polysaccharides and hexose phosphates to lactic acid but were unable to ferment hexoses could be enabled to ferment glucose and fructose by addition of a protein fraction from bakers’ yeast. The same protein fraction activated the aerobic oxidat...

Barbiturates and oxidative phosphorylation.

It has been claimed that barbiturates uncouple oxidative phosphorylations (Brody & Bain, 1954; Brody, 1955). These authors have demonstrated that during the oxidation of pyruvate by liver and brain mitochondria, phosphate uptake was lowered proportionately more than oxygen uptake. Support for the uncoupling theory was derived from certain similarities between the barbiturates and 2:4dinitrophen...

Myokinase activity of coronary arteries.

In exploring the mechanism of action of vasodilating drugs an attempt has been made to study the enzyme systems of the blood vessels. A transphosphatase of the myokinase type has been found to be present in the coronary arteries of the steer. The activity has been studied under the optimal conditions for this enzyme system. Coronary arterial tissue may be maintained at the temperature of dry ic...

Kinetic studies on rabbitmuscle myokinase.

Vitamin K and oxidative phosphorylation.

1. Oxidative phosphorylation was studied in a cell-free preparation of Mycobacterium phlei and in rat-liver mitochondria. Phosphorylation was destroyed in both systems by long-wave ultraviolet radiation and restored by the addition of small amounts of [2-Me-(14)C,(3)H]phylloquinone. When the radioactive quinones were recovered from the phosphorylating system and chromatographed with carrier phy...