풀망둑(Acanthogobius hasta) 신경조직 젖산탈수소효소의 역학적 특성 = Kinetic Properties of Lactate Dehydrogenase in Neural Tissues from Acanthogobius hasta

다국어 초록 (Multilingual Abstract)

In order to evaluate the effectiveness of lactate dehydrogenase(EC .1.1.27, LDH) in eye and brain tissues from Acanthogobius hasta as a catalyst, the kinetics were studied and the suitable condition for measuring the activity of LDH in fishes was proposed. The LDH inhibition by pyruvate was observed to reduce activity at concentrations greater than 0.2 mM in eye tissue, and 0.3 mM in brain and skeletal muscle, while substrate inhibition by lactate was significant above 60 mM in eye and brain tissues. And the activities of LDH in eye and brain remained at 48.89% and, 63.25% as a result of the inhibition by 1.5 mM of pyruvate. The corresponding value of KmNADH for eye was 0.147 mM, and those of KmPYR and KmLAC for eye, brain and skeletal muscle were 0.028, 0.067, 0.069 mM, and 2.787, 11.986, 8.786 mM, respectively. Therefore, it was found that the activity of LDH in fish had to be measured with 0.5 mM pyruvate and 0.14 mM NADH, or 40 mM lactate and 0.91 mM NAD+ in Tris-HCl buffer of pH 7.5. Conclusively, the LDH in eye tissue had a high affinity for pyruvate. And LDH in eye and brain tissues exhibited higher activity than that of skeletal muscle at lower concentration of lactate. So it was found that the energy produced rapidly by LDH eye-specific C4 isozyme in neural tissues was used for the predatory and defense behavior and lactate played an important role in metabolism of brain.