Subunits, composition, and related properties of succinyl coenzyme A synthetase

Biochemistry ◽  
1970 ◽  
Vol 9 (11) ◽  
pp. 2338-2346 ◽  
Author(s):  
Claus Leitzmann ◽  
Jang-Yen Wu ◽  
Paul D. Boyer
Keyword(s):  
Coenzyme A ◽  
Succinyl Coenzyme A Synthetase

scholarly journals Succinyl Coenzyme A Synthetase from Escherichia coli

1967 ◽  
Vol 242 (15) ◽  
pp. 3531-3537
Author(s):  
John A. Grunau ◽  
Ernest Knight ◽  
Emily S. Hart ◽  
I.C. Gunsalus
Keyword(s):  
Escherichia Coli ◽  
Coenzyme A ◽  
Succinyl Coenzyme A Synthetase

Succinyl Coenzyme A Synthetase of Escherichia coli: Initial Rate Kinetics of Succinyl-CoA Cleavage and Isotope Exchange Studies

1973 ◽  
Vol 51 (1) ◽  
pp. 44-55 ◽  
Author(s):  
Frank J. Moffet ◽  
W. A. Bridger
Keyword(s):  
Isotope Exchange ◽  
Coenzyme A ◽  
Initial Rate ◽  
Substrate Inhibition ◽  
Kinetic Studies ◽  
Kinetic Mechanism ◽  
Constant Ratio ◽  
Rate Kinetics ◽  
Kinetics Of ◽  
Succinyl Coenzyme A Synthetase

Initial rate kinetic studies of succinyl coenzyme A synthetase of E. coli in the direction of succinyl-CoA cleavage are consistent with the operation of a partially random sequential kinetic mechanism with initial binding of ADP followed by random association of succinyl-CoA and Pi. The mechanism is analogous to that proposed previously for the succinyl-CoA formation reaction, and thus the kinetic mechanism of the overall reversible succinyl-CoA synthetase reaction appears to be symmetrical.Studies of the kinetics of [Formula: see text] isotope exchange at equilibrium show that this partially random sequential kinetic mechanism is not an exclusive pathway. [Formula: see text] isotope exchange rates did not show complete substrate inhibition when CoA or succinate was varied in constant ratio with Pi. However, when CoA or succinate was varied in constant ratio with succinyl-CoA, nearly complete substrate inhibition was observed. These results can be interpreted in terms of a wide variety of minor pathways of substrate binding and product release available to the enzyme under various conditions.

Some Physical Parameters of Succinyl-Coenzyme A Synthetase of Escherichia coli

1974 ◽  
Vol 52 (7) ◽  
pp. 594-598 ◽  
Author(s):  
Anita Krebs ◽  
William A. Bridger
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Coenzyme A ◽  
Apparent Molecular Weight ◽  
Random Coil ◽  
Sedimentation Equilibrium ◽  
Physical Parameters ◽  
Equilibrium Studies ◽  
Α Helix ◽  
Succinyl Coenzyme A Synthetase

A physical study of succinyl-coenzyme A synthetase of Escherichia coli has been conducted. The extinction coefficient for the enzyme at 280 nm [Formula: see text] has been evaluated by two independent methods and found to be equal to 4.9 ± 0.2. Sedimentation equilibrium studies show that there is a marked dependence of the apparent molecular weight upon the concentration of the enzyme. At concentrations above 1 mg/ml, the enzyme exists predominantly as an α2β2 tetramer of overall molecular weight near 140 000; at lower concentrations, a significant fraction of the enzyme dissociates to an αβ dimer. The circular dichroism spectrum of the enzyme suggests a high proportion of random coil structure, with small contributions of α-helix and β-structure.

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