Parallel measurement of oxoglutarate dehydrogenase activity and matrix free Ca2+ in fura‐2‐loaded heart mitochondria

FEBS Letters

Lukács, Gergely L.¹  Fonyó, Attila¹  Kapus, András¹ 

[1] Department of Physiology, Semmelweis University of Medicine, PO Box 259, H-1444 Budapest 8, Hungary

关键词: Ca2+;    Oxoglutarate dehydrogenase;    Fura-2;    (Mitochondria);    OGDH;    oxoglutarate dehydrogenase;    CCCP;    carbonyl cyanide p-trifluoromethoxyphenylhydrazone;    [Ca2+]m;    intramitochondrial (matrix) free [Ca2+];    fura-2/AM;    acetoxymethylester of fura-2;   

DOI  :  10.1016/0014-5793(88)80831-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The entrapment of the Ca²⁺ -sensitive fluorescence indicators fura-2 or quin2 in the matrix space of isolated heart mitochondria renders possible the direct monitoring of the matrix free Ca²⁺ ([Ca²⁺]_m) [(1987) Biochem. J. 248, 609–613]. In this paper the correlation between the [Ca²⁺]_m and the in situ activity of oxoglutarate dehydrogenase (OGDH) in fura-2-loaded mitochondria is shown. At the initial value of [Ca²⁺]_m, 64 nM, which corresponded to 0.36 nmol/mg mitochondrial Ca content, the OGDH activity was 12% of the maximal. Half-maximal and maximal activation were attained at 0.8 and 1.6 μM [Ca²⁺]_m, respectively. The results indicate that an increase of the mitochondrial Ca content in the physiological range enhances the OGDH activity by means of elevation of [Ca²⁺]_m.

【 授权许可】

Unknown