Singer 1956 J Biol Chem: Difference between revisions
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# AmongĀ theĀ commonĀ electronĀ acceptors,Ā onlyĀ theĀ followingĀ function withĀ theĀ dehydrogenase,Ā atĀ theĀ relativeĀ ratesĀ indicatedĀ inĀ parentheses: phenazineĀ methosulfateĀ (100),Ā ferricyanideĀ (39),Ā O2 (0.02).Ā TheĀ firstĀ two ofĀ theseĀ acceptorsĀ reactĀ viaĀ theĀ ironĀ moieties,Ā whereasĀ O2Ā seemsĀ toĀ react directlyĀ withĀ theĀ flavin. Ā | # AmongĀ theĀ commonĀ electronĀ acceptors,Ā onlyĀ theĀ followingĀ function withĀ theĀ dehydrogenase,Ā atĀ theĀ relativeĀ ratesĀ indicatedĀ inĀ parentheses: phenazineĀ methosulfateĀ (100),Ā ferricyanideĀ (39),Ā O2 (0.02).Ā TheĀ firstĀ two ofĀ theseĀ acceptorsĀ reactĀ viaĀ theĀ ironĀ moieties,Ā whereasĀ O2Ā seemsĀ toĀ react directlyĀ withĀ theĀ flavin. Ā | ||
# TheĀ QO2,Ā hasĀ beenĀ measuredĀ asĀ 20,000 andĀ theĀ turnoverĀ numberĀ as 3000Ā underĀ theĀ standardĀ assayĀ conditions. Ā | # TheĀ QO2,Ā hasĀ beenĀ measuredĀ asĀ 20,000 andĀ theĀ turnoverĀ numberĀ as 3000Ā underĀ theĀ standardĀ assayĀ conditions. Ā | ||
# TheĀ propertiesĀ ofĀ theĀ isolatedĀ dehydrogenaseĀ agreeĀ withĀ thoseĀ previouslyĀ describedĀ forĀ mitochondrialĀ andĀ otherĀ particulateĀ preparationsĀ of theĀ enzyme,Ā exceptĀ forĀ propertiesĀ relatedĀ toĀ theĀ absenceĀ ofĀ contaminating hemoproteins.Ā AtĀ | # TheĀ propertiesĀ ofĀ theĀ isolatedĀ dehydrogenaseĀ agreeĀ withĀ thoseĀ previouslyĀ describedĀ forĀ mitochondrialĀ andĀ otherĀ particulateĀ preparationsĀ of theĀ enzyme,Ā exceptĀ forĀ propertiesĀ relatedĀ toĀ theĀ absenceĀ ofĀ contaminating hemoproteins.Ā AtĀ 38 Ā°C theĀ pHĀ optimumĀ isĀ 7.7;Ā theĀ K,Ā forĀ succinateĀ is 1.3Ā XĀ 10-3 MĀ atĀ 38 Ā°C andĀ 5.2Ā XĀ 10-4 MĀ atĀ 21 Ā°C.Ā Oxalacetate,Ā malonate,Ā and fumarateĀ areĀ competitiveĀ inhibitors.Ā AntimycinĀ AĀ andĀ BALĀ doĀ notĀ inhibitĀ theĀ dehydrogenase.Ā TheĀ dehydrogenaseĀ isĀ highlyĀ sensitiveĀ toĀ sulfhydrylĀ reagents,Ā p-chloromercuribenzoateĀ inhibitingĀ itĀ inĀ aĀ reversibleĀ mannerĀ andĀ theĀ substrateĀ protectingĀ theĀ enzymeĀ fromĀ thisĀ typeĀ ofĀ inhibition. | ||
|keywords=Succinic dehydrogenase, Beef heart mitochondria | |keywords=Succinic dehydrogenase, Beef heart mitochondria | ||
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|organism=Bovines | |organism=Bovines | ||
|tissues=Heart | |tissues=Heart | ||
|preparations=Isolated Mitochondria | |preparations=Isolated Mitochondria, SMP | ||
|enzymes=Complex II; Succinate Dehydrogenase | |enzymes=Complex II; Succinate Dehydrogenase | ||
|kinetics | |topics=Inhibitor kinetics, Temperature | ||
|additional=Made history | |additional=Made history | ||
}} | }} | ||
Revision as of 09:09, 11 August 2013
| Singer TP, Kearney, EB and Bernath P (1956) Studies on succinic dehydrogenase. Isolation and properties of the dehydrogenase from beef heart. J Biol Chem 223: 599-613. |
Singer TP, Kearney, EB and Bernath P (1956) J Biol Chem
Abstract:
- Succinic dehydrogenase has been isolated from beef heart mitochondria as a soluble protein in a state approaching homogeneity by physico-chemical criteria. The overall purification is about 100-fold compared with a mitochondrial acetone powder.
- The enzyme is a ferroflavoprotein cont,aining 4 atoms of ferrous (non-hemin) iron and a mole of flavin per mole of protein (200,000 gm.). The dehydrogenase may be isolated from aged starting material with 2 atoms of iron per mole and half the specific activity.
- Among the common electron acceptors, only the following function with the dehydrogenase, at the relative rates indicated in parentheses: phenazine methosulfate (100), ferricyanide (39), O2 (0.02). The first two of these acceptors react via the iron moieties, whereas O2 seems to react directly with the flavin.
- The QO2, has been measured as 20,000 and the turnover number as 3000 under the standard assay conditions.
- The properties of the isolated dehydrogenase agree with those previously described for mitochondrial and other particulate preparations of the enzyme, except for properties related to the absence of contaminating hemoproteins. At 38 Ā°C the pH optimum is 7.7; the K, for succinate is 1.3 X 10-3 M at 38 Ā°C and 5.2 X 10-4 M at 21 Ā°C. Oxalacetate, malonate, and fumarate are competitive inhibitors. Antimycin A and BAL do not inhibit the dehydrogenase. The dehydrogenase is highly sensitive to sulfhydryl reagents, p-chloromercuribenzoate inhibiting it in a reversible manner and the substrate protecting the enzyme from this type of inhibition.
ā¢ Keywords: Succinic dehydrogenase, Beef heart mitochondria
Labels:
Organism: Bovines
Tissue;cell: Heart
Preparation: Isolated Mitochondria"Isolated Mitochondria" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property., SMP
Enzyme: Complex II; Succinate Dehydrogenase"Complex II; Succinate Dehydrogenase" is not in the list (Adenine nucleotide translocase, Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase, Inner mt-membrane transporter, Marker enzyme, Supercomplex, TCA cycle and matrix dehydrogenases, ...) of allowed values for the "Enzyme" property.
Regulation: Inhibitor kinetics"Inhibitor kinetics" is not in the list (Aerobic glycolysis, ADP, ATP, ATP production, AMP, Calcium, Coupling efficiency;uncoupling, Cyt c, Flux control, Inhibitor, ...) of allowed values for the "Respiration and regulation" property., Temperature
Made history
