Allemann N, Schneider A
Department of Biology, Institute of Zoology, University of Fribourg, Pérolles, CH-1700 Fribourg, Switzerland.
Mol Biochem Parasitol. 2000 Nov;111(1):87-94. doi: 10.1016/s0166-6851(00)00303-0.
Membrane potential-dependent ATP production was measured in mitochondrial fractions of procyclic Trypanosoma brucei using a luciferase based assay. Mitochondria isolated under hypotonic conditions were able to produce ATP using succinate as substrate. The same was observed with mitochondria isolated under isotonic conditions, however, in this case a 6-7-fold higher amount of ATP was produced with glycerol-3-phosphate as substrate. Disruption of the outer membrane of isotonically prepared mitochondria lead to a selective loss of the glycerol-3 phosphate induced ATP production, indicating that glycerol-3-phosphate dehydrogenase is a soluble enzyme of the intermembrane space. Isolation of mitochondria under hypotonic conditions, therefore, results in disruption of the outer membrane, whereas in the organelles isolated under isotonic conditions both the membranes remain intact.
利用基于荧光素酶的检测方法，在布氏锥虫前循环期的线粒体组分中测量了膜电位依赖性ATP的产生。在低渗条件下分离得到的线粒体能够利用琥珀酸作为底物产生ATP。在等渗条件下分离得到的线粒体也观察到了同样的情况，然而，在这种情况下，以3-磷酸甘油为底物时产生的ATP量要高出6-7倍。等渗条件下制备的线粒体的外膜被破坏会导致3-磷酸甘油诱导的ATP产生选择性丧失，这表明3-磷酸甘油脱氢酶是膜间隙的一种可溶性酶。因此，在低渗条件下分离线粒体导致外膜被破坏，而在等渗条件下分离得到的细胞器中，两层膜都保持完整。
