Purification and Properties of White Muscle Lactate Dehydrogenase from the Anoxia-Tolerant Turtle, the Red-Eared Slider, Trachemys scripta elegans

Table 2

Control and 20 h anoxic T. s. elegans purified skeletal muscle LDH kinetics.

	Control	20 h anoxic
𝐾𝑚 lactate (mM)	17 ± 2	8 ± 1*
𝐾𝑚 NAD^+ (mM)	0.38 ± 0.06	0.5 ± 0.1
𝑉max (U/mg)	0.19 ± 0.01	0.75 ± 0.02*
𝐾𝑚 pyruvate (mM)	0.15 ± 0.03	0.140 ± 0.003
𝑉max (U/mg)	0.52 ± 0.03	3.8 ± 0.2*

Data are means ± SEM, 𝑛=4 individual determinations. 𝐾_𝑚 values were determined at optimal cosubstrate concentrations (defined in Materials and Methods). *Significantly different from the corresponding control value using a two-tailed Student’s t-test, 𝑃<0.05.