scholarly journals Antagonistic effects of hexose 1,6-bisphosphates and fructose 2,6-bisphosphate on the activity of 6-phosphofructokinase purified from honey-bee flight muscle

1986 ◽  
Vol 236 (3) ◽  
pp. 925-928 ◽  
Author(s):  
G Wegener ◽  
H Schmidt ◽  
A R Leech ◽  
E A Newsholme
Keyword(s):  
Honey Bee ◽  
Adenylate Kinase ◽  
Flight Muscle ◽  
Antagonistic Effects ◽  
Fructose 1,6 Bisphosphate ◽  
Low Activity

6-Phosphofructokinase purified from honey-bee flight muscle is inhibited by ATP and, unusually, by glucose 1,6-bisphosphate and fructose 1,6-bisphosphate. The inhibition by either of the bisphosphates is not relieved by AMP, but is relieved by fructose 6-phosphate and especially by fructose 2,6-bisphosphate. Lack of effect by AMP is consistent with a low activity of adenylate kinase in this muscle.

scholarly journals The contents of adenine nucleotides, phosphagens and some glycolytic intermediates in resting muscles from vertebrates and invertebrates

1975 ◽  
Vol 152 (1) ◽  
pp. 23-32 ◽  
Author(s):  
I Beis ◽  
E A Newsholme
Keyword(s):  
Honey Bee ◽  
Adenylate Kinase ◽  
Flight Muscle ◽  
Insect Flight ◽  
Adenine Nucleotides ◽  
Equilibrium Constants ◽  
Pectoral Muscle ◽  
Energy Utilization ◽  
Mass Action ◽  
Concentration Ratios

1. The lowest contents of ATP and the lowest ATP/AMP concentration ratios are observed in the molluscan muscles that have very low rates of energy expenditure during contraction. The highest contents of ATP are observed in the extremely aerobic insect flight muscle and the extremely anaerobic pectoral muscle of the pheasant and domestic fowl. In general, the lowest ATP/AMP concentration ratios are observed for muscle in which the variation in the rate of energy utilization is small (e.g. some molluscan muscles, heart muscle); the highest ratios are observed in muscles in which this variation is large (lobster abdominal muscle, pheasant pectoral muscle, some insect flight muscles). This finding is consistent with the proposed role of AMP and the adenylate kinase reaction in the regulation of glycolysis. However, in the flight muscle of the honey-bee the ATP/AMP ratio is very low, so that glycolysis may be regulated by factors other than the variation in AMP concentration. The variation in the contents of arginine phosphate in muscle from the invertebrates is much larger than the variation in creatine phosphate in muscle from the vertebrates. The contents of hexose monophosphates and pyruvate are, in general, higher in the muscles of vertebrates than in those of the invertebrates. The contents of phosphoenolpyruvate are similar in all the muscles investigated, except for the honey-bee in which it is about 4-10-fold higher. The mass-action ratios for the reactions catalysed by phosphoglucoisomerase and adenylate kinase are very similar to the equilibrium constants for these reactions. Further, the variation in the mass-action ratios between muscles is small. It is concluded that these enzymes catalyse reactions close to equilibrium. However, the mass-action ratios for the reactions catalysed by phosphofructokinase and pyruvate kinase are much smaller than the equilibrium constants. The variation in the ratios between different muscles is large. It is concluded that these enzymes catalyse nonequilibrium reactions. Since the variation in the mass-action ratios for the reactions catalysed by the phosphagen kinases (i.e. creatine and arginine phosphokinases) is small, it is suggested that these reactions are close to equilibrium.

scholarly journals Functional cross-talk between allosteric effects of activating and inhibiting ligands underlies PKM2 regulation

2018 ◽  
Author(s):  
Jamie A. Macpherson ◽  
Alina Theisen ◽  
Laura Masino ◽  
Louise Fets ◽  
Paul C. Driscoll ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
High Activity ◽  
Pyruvate Kinase ◽  
Cross Talk ◽  
Glycolytic Enzyme ◽  
Computational Framework ◽  
Allosteric Inhibitor ◽  
Fructose 1,6 Bisphosphate ◽  
Low Activity

ABSTRACTAllosteric regulation is central to the role of the glycolytic enzyme pyruvate kinase M2 (PKM2) in cellular metabolism. Multiple activating and inhibitory allosteric ligands regulate PKM2 activity by controlling the equilibrium between high activity tetramers and low activity dimers and monomers. However, it remains elusive how allosteric inputs upon simultaneous binding of different ligands are integrated to regulate PKM2 activity. Here, we show that, in the presence of the allosteric inhibitor L-phenylalanine (Phe), the activator fructose 1,6-bisphosphate (FBP) can induce PKM2 tetramerisation, but fails to maximally increase enzymatic activity. Guided by a new computational framework we developed to identify residues that mediate FBP-induced allostery, we generated two PKM2 mutants, A327S and C358A, in which activation by FBP remains intact but cannot be attenuated by Phe. Our findings demonstrate a role for residues involved in FBP-induced allostery in enabling the integration of allosteric input from Phe and reveal a mechanism that underlies the co-ordinate regulation of PKM2 activity by multiple allosteric ligands.

scholarly journals Effects of Flight on Gene Expression and Aging in the Honey Bee Brain and Flight Muscle

Insects ◽  
2012 ◽  
Vol 4 (1) ◽  
pp. 9-30 ◽  
Author(s):  
Joseph Margotta ◽  
Georgina Mancinelli ◽  
Azucena Benito ◽  
Andrew Ammons ◽  
Stephen Roberts ◽  
...  
Keyword(s):  
Gene Expression ◽  
Honey Bee ◽  
Flight Muscle

The continuity of thick filaments between sarcomeres in honey bee flight muscle

Nature ◽  
1979 ◽  
Vol 281 (5729) ◽  
pp. 319-320 ◽  
Author(s):  
K. Trombitas ◽  
A. Tigyi-Sebes
Keyword(s):  
Honey Bee ◽  
Flight Muscle ◽  
Thick Filaments

Cytochrome changes during honey bee flight muscle development

1963 ◽  
Vol 8 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Richard C. Herold ◽  
Hans Borei
Keyword(s):  
Honey Bee ◽  
Muscle Development ◽  
Flight Muscle

scholarly journals The activities of fructose diphosphatase in flight muscles from the bumble-bee and role of this enzyme in heat generation

1972 ◽  
Vol 128 (1) ◽  
pp. 89-97 ◽  
Author(s):  
E. A. Newsholme ◽  
B. Crabtree ◽  
S. J. Higgins ◽  
S. D. Thornton ◽  
Carole Start
Keyword(s):  
Flight Muscle ◽  
Maximum Activity ◽  
The Body ◽  
Bumble Bee ◽  
Rest Periods ◽  
Flight Muscles ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Hydrolysis Of ◽  
Low Activity

1. The maximum catalytic activities of fructose diphosphatase from flight muscles of bumble-bees (Bombus spp.) are at least 30-fold those reported for the enzyme from other tissues. The maximum activity of fructose diphosphatase in the flight muscle of any particular bee is similar to that of phosphofructokinase in the same muscle, and the activity of hexokinase is similar to or greater than the activity of phosphofructokinase. There is no detectable activity of glucose 6-phosphatase and only a very low activity of glucose 6-phosphate dehydrogenase in these muscles. The activities of both fructose diphosphatase and phosphofructokinase vary inversely with the body weight of the bee, whereas that of hexokinase is relatively constant. 2. There is no significant hydrolysis of fructose 1-phosphate, fructose 6-phosphate, glucose 1,6-diphosphate and glycerol 3-phosphate by extracts of bumble-bee flight muscle. 3. Fructose 1,6-diphosphatase from bumble-bee flight muscle and from other muscles is inhibited by Mn2+and univalent cations; the potency of inhibition by the latter varies in the order Li+>Na+>K+. However, the fructose diphosphatase from bumble-bee flight muscle is different from the enzyme from other tissues in that it is not inhibited by AMP. 4. The contents of ATP, hexose monophosphates, fructose diphosphate and triose phosphates in bumble-bee flight muscle showed no significant changes between rest and flight. 5. It is proposed that both fructose diphosphatase and phosphofructokinase are simultaneously active and catalyse a cycle between fructose 6-phosphate and fructose diphosphate in resting bumble-bee flight muscle. Such a cycle would produce continuous hydrolysis of ATP, with the release of energy as heat, which would help to maintain the thoracic temperature during rest periods at a level adequate for flight.

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