Abortive Enzyme-Substrate Ternary Complexes Formed by the Fructose 1,6-Diphosphate-Activated Pyruvate Kinase from the Hepatopancreas of Carcinus maenas

1976 ◽  
Vol 4 (3) ◽  
pp. 481-484 ◽  
Author(s):  
IAN G. GILES ◽  
PETER C. POAT ◽  
KENNETH A. MUNDAY
Keyword(s):  
Pyruvate Kinase ◽  
Carcinus Maenas ◽  
Ternary Complexes ◽  
Enzyme Substrate

scholarly journals The stereochemical course of phosphoryl transfer catalysed by Bacillus stearothermophilus and rabbit skeletal-muscle phosphofructokinase with a chiral [16O,17O,18O]phosphate ester

1981 ◽  
Vol 199 (2) ◽  
pp. 427-432 ◽  
Author(s):  
R L Jarvest ◽  
G Lowe ◽  
B V L Potter
Keyword(s):  
Skeletal Muscle ◽  
Phosphorus Atom ◽  
Bacillus Stearothermophilus ◽  
Ternary Complexes ◽  
Rabbit Skeletal Muscle ◽  
Phosphoryl Group ◽  
Phosphate Ester ◽  
Phosphoryl Transfer ◽  
Enzyme Substrate

Bacillus stearothermophilus and rabbit skeletal-muscle phosphofructokinases catalyse the transfer of the chiral [16O,17O,18O]phosphoryl group from D-fructose 1[(S)-16O,17O,18O],6-bisphosphate to ADP with inversion of configuration at the phosphorus atom. D-Fructose 1[(S)-16O,17O,18O],-bisphosphate was synthesized in situ from sn-glycerol 3[(S)-16O,17O,18O]phosphate. The simplest interpretation of these results is that the phosphoryl group is transferred between substrates in the enzyme substrate ternary complexes by an ‘in-line’ mechanism.

Substrate Inhibition of Pyruvate Kinase Isolated from the Leg Muscle of Carcinus maenas

1976 ◽  
Vol 4 (6) ◽  
pp. 1158-1160 ◽  
Author(s):  
COLIN J. NEWTON ◽  
PETER C. POAT ◽  
KENNETH A. MUNDAY
Keyword(s):  
Pyruvate Kinase ◽  
Substrate Inhibition ◽  
Carcinus Maenas ◽  
Leg Muscle

Crystallization and preliminary analysis of enzyme-substrate complexes of pyruvate kinase from rabbit muscle

1991 ◽  
Vol 11 (2) ◽  
pp. 153-157 ◽  
Author(s):  
Karen Schmidt-Bäse ◽  
Jenny L. Buchbinder ◽  
George H. Reed ◽  
Ivan Rayment
Keyword(s):  
Pyruvate Kinase ◽  
Preliminary Analysis ◽  
Rabbit Muscle ◽  
Enzyme Substrate

Regulation of Pyruvate Kinase from the Hepatopancreas of the Crab Carcinus maenas

1975 ◽  
Vol 3 (3) ◽  
pp. 400-402 ◽  
Author(s):  
IAN G. GILES ◽  
PETER C. POAT ◽  
KENNETH A. MUNDAY
Keyword(s):  
Pyruvate Kinase ◽  
Carcinus Maenas

scholarly journals An investigation of the interactions of the allosteric modifiers of pyruvate kinase with the enzyme from Carcinus maenas hepatopancreas

1977 ◽  
Vol 165 (1) ◽  
pp. 97-105 ◽  
Author(s):  
I G Giles ◽  
P C Poat ◽  
K A Munday
Keyword(s):  
Enzyme Activity ◽  
Pyruvate Kinase ◽  
Enzyme Preparation ◽  
Carcinus Maenas ◽  
Maximal Activity ◽  
Initial Increase ◽  
Low Concentration ◽  
Saturation Kinetics ◽  
Fructose 1,6 Bisphosphate ◽  
Allosteric Activator

1. Pyruvate kinase purified from the hepatopancrease of Carcinus maenas exhibited sigmoidal saturation kinetics with respect to the substrate phosphoenolpyruvate in the absence of the allosteric activator fructose 1,6-bisphosphate, but normal hyperbolic saturation was seen in the presence of this activator. The activation appears to be the result of a decrease in the s0.5 (phosphoenolpyruvate) and not to a change in Vmax. 2. In the presence of ADP and ATP at a constant nucleotide-pool size the results indicate that phosphoenolpyruvate co-operativity is lost on increasing the [ATP]/[ADP] ratio. 3. Paralleling this change is the observation that the fructose 1,6-bisphosphate activation became less at the [ATP]/[ATP] ratio was increased. This was due to the enzyme exhibiting a near-maximal activity in the absence of activator. 4. L-Alanine inhibited the enzyme, but homotropic co-operative interactions were only seen with a cruder (1000000g supernatant) enzyme preparation. The inhibition by alanine could be overcome by increasing the concentration of either phosphoenolpyruvate or fructose 1,6-bisphosphate, although increasing the L-alanine concentration did not appear to be able to reverse the activation by fructose 1,6-bisphosphate. 5. In the presence of a low concentration of phosphoenolpyruvate, increasing the concentration of the product, ATP, caused an initial increase in enzyme activity, followed by an inhibitory phase. In the presence of either fructose 1,6-bisphosphate or L-alanine only inhibition was seen. 6. The inhibition by ATP could not be completely reversed by fructose 1,6-bisphosphate.

A Kinetic Study of Muscle Pyruvate Kinase from Carcinus maenas

1976 ◽  
Vol 4 (3) ◽  
pp. 479-481 ◽  
Author(s):  
COLIN J. NEWTON ◽  
PETER C. POAT ◽  
KENNETH A. MUNDAY
Keyword(s):  
Kinetic Study ◽  
Pyruvate Kinase ◽  
Carcinus Maenas ◽  
Muscle Pyruvate Kinase
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