Succinate thiokinase in pigeon breast muscle mitochondria

Abstract
Succinate thiokinase has been purified from pigeon breast muscle. It has been confirmed that the enzyme is entirely specific for ATP, and the Km is very high (0.8 mM). Activity in mitochondrial sonicates is low enough for it to be doubtful whether the enzyme can support citric acid cycle flux in the tissue. The enzyme appears to have an Mr of 80000–100000, and to have two unequal subunits. As determined by SDS gel electrophoresis one subunit certainly has an Mr of 40000