The effect of
hypoxia and re-oxygenation on the mitochondrial complex F(O)F(1)-ATP synthase was investigated in the whiteleg shrimp Litopenaeus vannamei. A 660 kDa
protein complex isolated from mitochondria of the shrimp muscle was identified as the
ATP synthase complex. After 10h at
hypoxia (1.5-2.0 mg
oxygen/L), the concentration of L-
lactate in plasma increased significantly, but the
ATP amount and the concentration of ATPĪ²
protein remained unaffected. Nevertheless, an increase of 70% in the
ATPase activity was detected, suggesting that the
enzyme may be regulated at a post-translational level. Thus, during
hypoxia shrimp are able to maintain
ATP amounts probably by using some other energy sources as
phosphoarginine when an acute lack of energy occurs. During re-oxygenation, the
ATPase activity decreased significantly and the
ATP production continued via the electron transport chain and oxidative phosphorylation. The results obtained showed that shrimp faces
hypoxia partially by hydrolyzing the
ATP through the reaction catalyzed by the mitochondrial
ATPase which increases its activity.