Conserved and unique thermodynamic properties of lactate dehydrogenases in an ectothermic organism, the teleost Microstomus achne, and an endothermic organism, bovine.
It is widely believed that enzymatic activities in ectothermic organisms adapt to environmental temperatures. However, to date, no study has thoroughly compared multiple thermodynamic enzymatic characteristics across species living in dramatically different environments. To start to address this gap, we compared the characteristics of lactate dehydrogenase (LDH) purified from the muscles from slime flounder Microstomus achne white muscle and bovine skeletal muscle (bM4) and heart. The Kmand Vmaxfor pyruvate reduction were about three times higher for M. achne LDH than bM4Surprisingly, maximum LDH activity was observed at ∼30 °C and ∼50 °C for M. achne and bovine LDHs, respectively, suggesting that the maximum enzymatic activity of LDH is set at a temperature ∼20 °C higher than environmental or body temperature across species. Although Kmand Vmaxvalues of these LDHs increased with temperature, the Vmax/Kmratio for M. achne LDH and bM4was independent. Differential scanning calorimetry and enthalpy change measurements confirmed that M. achne and bovine muscle-specific LDHs shared similar properties. Based on the present findings and previous reports, we hypothesize that the function and thermodynamic properties of muscle LDH are highly conserved between a teleost adapted to cold, M. achne, and bovine.
Department of Life Science, Graduate School of Engineering Science, Akita University, Akita 010-8502, Japan.
Mika
M
Yonezawa
Department of Life Science, Graduate School of Engineering Science, Akita University, Akita 010-8502, Japan.
Mizuki
M
Nakagawa
Department of Bioengineering, Graduate School of Engineering, Nagaôka University of Technology, Nagaôka 940-2188, Japan.
Shigeyoshi
S
Nakamura
Department of Life Science, Graduate School of Engineering Science, Akita University, Akita 010-8502, Japan.
Tatsufumi
T
Goto
Department of Hematology, Nephrology, and Rheumatology, Master Course of Graduate School of Medicine, Akita University, Akita 010-8543, Japan.
Kotomi
K
Sugawara
Department of Bioengineering, Graduate School of Engineering, Nagaôka University of Technology, Nagaôka 940-2188, Japan.
Shun-Ichi
SI
Kidokoro
Department of Life Science, Graduate School of Engineering Science, Akita University, Akita 010-8502, Japan.
Hideki
H
Wakui
Department of Life Science, Graduate School of Engineering Science, Akita University, Akita 010-8502, Japan nunomura@gipc.akita-u.ac.jp.|Research Center for Engineering Science, Graduate School of Engineering Science, Akita University, Akita 010-8502, Japan.
Wataru
W
Nunomura
D000064:Acclimatization / Q000502:physiology*; D000818:Animals; D002417:Cattle; D029941:Fish Proteins / Q000737:chemistry / Q000378:metabolism; D005432:Flounder / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D009124:Muscle Proteins / Q000737:chemistry / Q000378:metabolism; D013045:Species Specificity
D029941:Fish Proteins; D009124:Muscle Proteins; D007770:L-Lactate Dehydrogenase
ectothermy; endothermy; heat capacity; kinetics; lactate dehydrogenase; temperature