scholarly journals NADH dehydrogenase activity of Pediococcus halophilus as a factor determining its reducing force.

1987 ◽  
Vol 51 (2) ◽  
pp. 507-514 ◽  
Author(s):  
Chiyuki KANBE ◽  
Kinji UCHIDA
Keyword(s):  
Dehydrogenase Activity ◽  
Nadh Dehydrogenase ◽  
Pediococcus Halophilus

scholarly journals Biochemical heterogeneity of rat liver mitochondria separated by rate zonal centrifugation

1972 ◽  
Vol 129 (1) ◽  
pp. 209-218 ◽  
Author(s):  
M. A. Wilson ◽  
J. Cascarano
Keyword(s):  
Cytochrome C ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Cytochrome B ◽  
Rat Liver ◽  
Nadh Dehydrogenase ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Osmotic Gradient ◽  
Glycerophosphate Dehydrogenase

1. Rat liver mitochondria were separated on the basis of their sedimentation coefficients in an iso-osmotic gradient of Ficoll–sucrose by rate zonal centrifugation. The fractions (33, each of 40ml) were collected in order of decreasing density. Fractions were analysed by spectral analysis to determine any differences in the concentrations of the cytochromes and by enzyme analyses to ascertain any differences in the activities of NADH dehydrogenase, succinate dehydrogenase and α-glycerophosphate dehydrogenase. 2. When plotted as% of the highest specific concentration, the contents of cytochrome a+a3 and cytochrome c+c1 were constant in all fractions but cytochrome b was only 65% of its maximal concentration in fraction 7 and increased with subsequent fractions. As a result, the cytochrome b/cytochrome a+a3 ratio almost doubled between fractions 7 and 25 whereas the cytochrome c+c1/cytochrome a+a3 ratio was unchanged. 3. Expression of the dehydrogenase activities as% of highest specific activity showed the following for fractions 6–26: NADH dehydrogenase activity remained fairly constant in all fractions; succinate dehydrogenase activity was 62% in fraction 6 and increased steadily to its maximum in fraction 18 and then decreased; the activity of α-glycerophosphate dehydrogenase was only 53% in fraction 6 and increased slowly to its peak in fractions 22 and 24. 4. These differences did not result from damaged or fragmented mitochondria or from microsomal contamination. 5. These results demonstrate that isolated liver mitochondria are biochemically heterogeneous. The importance of using a system for separating biochemically different mitochondria in studies of mitochondrial biogenesis is discussed.

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