The effect of temperature on the kinetic constants of human lactate dehydrogenase 1 and 5.
PMID 199378 · Clinica chimica acta; international journal of clinical chemistry · 1977 · DOI 10.1016/0009-8981(77)90033-x
Authors: S N Buhl; K Y Jackson; R E Vanderlinde
Abstract
The kinetic constants of human lactate dehydrogenase 1 and 5 (L-lactate: NAD+ oxidoreductase, EC 1.1.1.27), assayed lactate-to-pyruvate increase with temperature. The reaction mechanism is ordered sequential as has been found with lactate dehydrogenase from other sources. The KM values for each substrate are larger for isoenzyme 5 than for 1. For lactate dehydrogenase 1 the KM(lactate) increases from 1.07 mM at 25 degrees C to 3.95 mM at 37 degrees C and for lactate dehydrogenase 5 it increases from 5.37 mM at 25 degrees C to 6.88 mM at 37 degrees C. The KM(NAD+) for lactate dehydrogenase 5 is 0.14 mM at 25 degrees C and 0.29 mM at 37 degrees C. The increase in the KM for each substrate with increasing temperature confirms that additional substrate is required for optimal reaction conditions at higher temperatures.
Humans; In Vitro Techniques; Isoenzymes; Kinetics; L-Lactate Dehydrogenase; Lactates; NAD; Temperature
Cite
S N Buhl; K Y Jackson; R E Vanderlinde. The effect of temperature on the kinetic constants of human lactate dehydrogenase 1 and 5. Clinica chimica acta; international journal of clinical chemistry (1977). PMID 199378. DOI 10.1016/0009-8981(77)90033-x.