title: Ambiquitous behavior of rabbit liver lactate dehydrogenase.
abstract: Rabbit liver mitochondrial fraction shows lactate dehydrogenase activity. The enzyme can be released from particles by increasing the pH and the ionic strength of the medium. There is a narrow range of pH (6.8-7.4) and ionic strength (20-50 mM NaCl) in which the solubilization sharply increases. It has been shown that divalent anions (SO4(2-) and cations (Mg2+, Ca2+) are highly effective specific solubilizing agents. NADH (1.5 mM) and ATP (1.0 mM) were effective in solubilizing 50% of the enzyme bound, whereas the same concentrations of the analogs NAD+ and ADP had little effect. Cytosolic lactate dehydrogenase bound to the mitochondrial fraction and a saturation of particles by enzyme was observed in all experiments performed. The in vitro binding requires a short period of incubation between the enzyme and particles and the binding is independent of the temperature in the 0-37 degrees C range. Binding was prevented by 0.15 M NaCl. The bound enzyme is approximately 20% less active than the soluble one. The results described give support to the proposal that rabbit liver lactate dehydrogenase has an ambiquitous behavior, like other glycolytic enzymes, which have not a fixed intracellular localization.
authors.affiliation: Department of Biochemistry and Physiology, Faculty of Chemistry University of Barcelona, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Sanz
authors.forename: C
authors.initials: C
authors.lastname: Lluis
mesh_terms: D000818:Animals; D002451:Cell Compartmentation; D006019:Glycolysis; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000201:enzymology*; D009994:Osmolar Concentration; D011817:Rabbits; D012995:Solubility
chemical_list: D007770:L-Lactate Dehydrogenase