The calcium sensitivity of ATP ase activity of myofibrils and actomyosins from insect flight and leg muscles

1968 ◽  
Vol 169 (1016) ◽  
pp. 229-240 ◽  
Keyword(s):  
Flight Muscle ◽  
Insect Flight ◽  
Locusta Migratoria ◽  
Calcium Sensitivity ◽  
Mechanical Activity ◽  
Rabbit Muscle ◽  
Leg Muscles ◽  
Structural Peculiarities ◽  
Flight Muscles ◽  
Leg Muscle

Myofibrils and actomyosin suspension were prepared from the fibrillar flight and non-fibrillar leg muscles of the water-bug, Lethocerus maximus , and their ATP ase activity measured in solutions of various ionic strength containing Mg ATP . Leg muscle showed a low ATP ase in the absence of Ca 2+ , and a large increase of ATPase over a narrow range of Ca 2+ concentration. Flight muscle had a greater ATPase in the absence of Ca 2+ but showed a much smaller increase over a wider range of Ca 2+ concentration. A similar difference between flight and leg muscle was found in the honey-bee, Apis mellifera , and the beetle, Oryctes rhinoceros , both of which have fibrillar flight muscles, but was not found in the locust, Locusta migratoria , which has non-fibrillar flight muscle. Tryptic digestion raised the ATP ase in the absence of Ca 2+ , and abolished the Ca 2+ -activation, in both flight and leg-muscle preparations from the water-bug; addition of ‘native tropomyosin5 prepared from rabbit muscle partially reversed the effect. These results are discussed in relation to the structural peculiarities and oscillatory mechanical activity of fibrillar flight muscle.

scholarly journals Regulation of muscle phosphorylase b kinase activity by inorganic phosphate and calcium ions

1974 ◽  
Vol 137 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Bertram Sacktor ◽  
Niou-Ching Wu ◽  
Ono Lescure ◽  
W. Douglas Reed
Keyword(s):  
Kinase Activity ◽  
Flight Muscle ◽  
Insect Flight ◽  
Narrow Range ◽  
Leg Muscles ◽  
Wide Range ◽  
Maximal Activation ◽  
Muscle Phosphorylase ◽  
Leg Muscle ◽  
Increased Activity

The regulation of the activity of blowfly flight-muscle phosphorylase b kinase by Pi and Ca2+ was studied, and the actions of these effectors on the kinases from insect flight and rabbit leg muscles were compared. Preincubation of blowfly kinase with Pi increased activity severalfold. The effect was concentration-dependent, with an apparent Km of about 20mm, and time-dependent, requiring at least 10min for maximal activation. Neither ATP nor cyclic AMP was needed, suggesting that a protein kinase may not be involved. Maximal activation of the insect kinase required Mg2+ in addition to Pi. The apparent Km for Mg2+ was 3mm. Rabbit leg-muscle phosphorylase b kinase was slightly inhibited, rather than stimulated, by Pi, and was strongly inhibited by K+, Na+ and Li+. At physiological concentrations, Ca2+ activated the phosphorylase b kinases from both blowfly flight and rabbit leg muscles. However, the responses to Ca2+ of the enzymes from the two tissues were different. The mammalian kinase had virtually no activity in the absence of Ca2+, and showed a large increase in activity over a narrow range of Ca2+ concentrations. Flight-muscle kinase had appreciable activity in the absence of Ca2+, and had a smaller increase over a wide range of Ca2+ concentration. The concentrations of Ca2+ required for half-activation were 0.1 and 1μm for the blowfly and rabbit enzymes respectively. The pH–activity profiles of the non-activated, phosphate- and Ca2+-activated kinase revealed considerable enhancement of activity with little, if any, increase in the ratio of activities at pH6.8 to those at 8.2. These results are discussed in relation to the mechanism coupling contraction to glycogenolysis and to the biochemical distinction between asynchronous and synchronous types of muscle.

Cytoskeletal proteins of insect muscle: location of zeelins in Lethocerus flight and leg muscle

1994 ◽  
Vol 107 (5) ◽  
pp. 1115-1129 ◽  
Author(s):  
C. Ferguson ◽  
A. Lakey ◽  
A. Hutchings ◽  
G.W. Butcher ◽  
K.R. Leonard ◽  
...  
Keyword(s):  
Insect Flight ◽  
Regular Structure ◽  
Thick Filament ◽  
Cytoskeletal Proteins ◽  
Stretch Activation ◽  
Insect Muscle ◽  
Thick Filaments ◽  
Flight Muscles ◽  
Leg Muscle ◽  
Low Ionic Strength

Asynchronous insect flight muscles produce oscillatory contractions and can contract at high frequency because they are activated by stretch as well as by Ca2+. Stretch activation depends on the high stiffness of the fibres and the regular structure of the filament lattice. Cytoskeletal proteins may be important in stabilising the lattice. Two proteins, zeelin 1 (35 kDa) and zeelin 2 (23 kDa), have been isolated from the cytoskeletal fraction of Lethocerus flight muscle. Both zeelins have multiple isoforms of the same molecular mass and different charge. Zeelin 1 forms micelles and zeelin 2 forms filaments when renatured in low ionic strength solutions. Filaments of zeelin 2 are ribbons 10 nm wide and 3 nm thick. The position of zeelins in fibres from Lethocerus flight and leg muscle was determined by immunofluorescence and immunoelectron microscopy. Zeelin 1 is found in flight and leg fibres and zeelin 2 only in flight fibres. In flight myofibrils, both zeelins are in discrete regions of the A-band in each half sarcomere. Zeelin 1 is across the whole A-band in leg myofibrils. Zeelins are not in the Z-disc, as was thought previously, but migrate to the Z-disc in glycerinated fibres. Zeelins are associated with thick filaments and analysis of oblique sections showed that zeelin 1 is closer to the filament shaft than zeelin 2. The antibody labelling pattern is consistent with zeelin molecules associated with myosin near the end of the rod region. Alternatively, the position of zeelins may be determined by other A-band proteins. There are about 2.0 to 2.5 moles of myosin per mole of each zeelin. The function of these cytoskeletal proteins may be to maintain the ordered structure of the thick filament.

scholarly journals Activities of citrate synthase and NAD+-linked and NADP+-linked isocitrate dehydrogenase in muscle from vertebrates and invertebrates

1976 ◽  
Vol 154 (3) ◽  
pp. 689-700 ◽  
Author(s):  
P R. Alp ◽  
E A. Newsholme ◽  
V A. Zammit
Keyword(s):  
Citric Acid ◽  
Isocitrate Dehydrogenase ◽  
Citric Acid Cycle ◽  
Citrate Synthase ◽  
Insect Flight ◽  
Mechanical Activity ◽  
Activity Data ◽  
Acid Cycle ◽  
Equilibrium Reaction ◽  
Flight Muscles

1. The activities of citrate synthase, NAD+-linked and NADP+-linked isocitrate dehydrogenase were measured in muscles from a large number of animals, in order to provide some indication of the importance of the citric acid cycle in these muscles. According to the differences in enzyme activities, the muscles can be divided into three classes. First, in a number of both vertebrate and invertebrate muscles, the activities of all three enzymes are very low. It is suggested that either the muscles use energy at a very low rate or they rely largely on anaerobic glycolysis for higher rates of energy formation. Second, most insect flight muscles contain high activities of citrate synthase and NAD+-linked isocitrate dehydrogenase, but the activities of the NADP+-linked enzyme are very low. The high activities indicate the dependence of insect flight on energy generated via the citric acid cycle. The flight muscles of the beetles investigated contain high activities of both isocitrate dehydrogenases. Third, other muscles of both vertebrates and invertebrates contain high activities of citrate synthase and NADP+-liniked isocitrate dehydrogenase. Many, if not all, of these muscles are capable of sustained periods of mechanical activity (e.g. heart muscle, pectoral muscles of some birds). Consequently, to support this activity fuel must be supplied continually to the muscle via the circulatory system which, in most animals, also transports oxygen so that energy can be generated by complete oxidation of the fuel. It is suggested that the low activities of NAD+-linked isocitrate dehydrogenase in these muscles may be involved in oxidation of isocitrate in the cycle when the muscles are at rest. 2. A comparison of the maximal activities of the enzymes with the maximal flux through the cycle suggests that, in insect flight muscle, NAD+-linked isocitrate dehydrogenase catalyses a non-equilibrium reaction and citrate synthease catalyses a near-equilibrium reaction. In other muscles, the enzyme-activity data suggest that both citrate synthase and the isocitrate dehydrogenase reactions are near-equilibrium.

scholarly journals THE FILAMENT LATTICE OF COCKROACH THORACIC MUSCLE

1968 ◽  
Vol 36 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Martin Hagopian ◽  
David Spiro
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Flight Muscle ◽  
Insect Flight ◽  
Thick Filament ◽  
Leucophaea Maderae ◽  
Thick Filaments ◽  
Femoral Muscle ◽  
Flight Muscles ◽  
Characteristic 3

The fine structure of the tergo-coxal muscle of the cockroach, Leucophaea maderae, has been studied with the electron microscope. This muscle differs from some other types of insect flight muscles inasmuch as the ratio of thin to thick filaments is 4 instead of the characteristic 3. The cockroach flight muscle also differs from the cockroach femoral muscle in thin to thick filament ratios and diameters and in lengths of thick filaments. A comparison of these latter three parameters in a number of vertebrate and invertebrate muscles suggests in general that the diameters and lengths of the thick filaments and thin to thick filament ratios are related.

Differential activation of octopaminergic (DUM) neurones via proprioceptors responding to flight muscle contractions in the locust

1999 ◽  
Vol 202 (24) ◽  
pp. 3555-3564
Author(s):  
O.T. Morris ◽  
C. Duch ◽  
P.A. Stevenson
Keyword(s):  
Sensory Feedback ◽  
Flight Muscle ◽  
Sensory Nerve ◽  
Direct Stimulation ◽  
Differential Activation ◽  
Leg Muscles ◽  
Flight Muscles ◽  
Stimulation Of Nerve ◽  
Dorsal Unpaired Median ◽  
Stimulation Of

The synaptic potentials generated in neuromodulatory octopaminergic dorsal unpaired median (DUM) neurones by afferents excited by twitch contractions of a dorso-ventral flight muscle were investigated in the locust. Responses to stimulation of the metathoracic wing elevator muscle 113 were obtained in locusts in which all sensory feedback from the thorax had been removed, except for feedback from the thoracic chordotonal organs, the axons of which enter via the purely sensory nerve 2. Afferents in nerve 2C, which originates from two chordotonal organs, responded reliably to twitch contractions of this flight muscle. Octopaminergic neurones innervating leg muscles (DUM5 neurones) received depolarising inputs and often spiked following stimulation of the muscle. In contrast, those innervating the wing muscles themselves (DUM3 and DUM3,4 neurones) received inhibitory inputs. The responses of DUM3,4,5 neurones, which project mainly to leg muscles, were more complex: most were excited by twitch contractions of M113 but some were inhibited. DUMDL, which innervates the dorsal longitudinal indirect flight muscles, showed no clear response. Direct stimulation of nerve 2C evoked depolarising inputs and spikes in DUM5 neurones and hyperpolarising inputs in DUM3 and DUM3,4 neurones. Our data suggest that sensory feedback from thoracic chordotonal organs, which are known to be activated rhythmically during flight, contributes to the differential activation of efferent DUM neurones observed during flight.

scholarly journals Myofibril and mitochondria morphogenesis are coordinated by a mechanical feedback mechanism in muscle

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jerome Avellaneda ◽  
Clement Rodier ◽  
Fabrice Daian ◽  
Nicolas Brouilly ◽  
Thomas Rival ◽  
...  
Keyword(s):  
Striated Muscle ◽  
Flight Muscle ◽  
Mitochondrial Dynamics ◽  
Feedback Mechanism ◽  
Mitochondrial Fusion ◽  
Sarcomeric Proteins ◽  
Muscle Type ◽  
Leg Muscles ◽  
Flight Muscles ◽  
Mechanical Feedback

AbstractComplex animals build specialised muscles to match specific biomechanical and energetic needs. Hence, composition and architecture of sarcomeres and mitochondria are muscle type specific. However, mechanisms coordinating mitochondria with sarcomere morphogenesis are elusive. Here we use Drosophila muscles to demonstrate that myofibril and mitochondria morphogenesis are intimately linked. In flight muscles, the muscle selector spalt instructs mitochondria to intercalate between myofibrils, which in turn mechanically constrain mitochondria into elongated shapes. Conversely in cross-striated leg muscles, mitochondria networks surround myofibril bundles, contacting myofibrils only with thin extensions. To investigate the mechanism causing these differences, we manipulated mitochondrial dynamics and found that increased mitochondrial fusion during myofibril assembly prevents mitochondrial intercalation in flight muscles. Strikingly, this causes the expression of cross-striated muscle specific sarcomeric proteins. Consequently, flight muscle myofibrils convert towards a partially cross-striated architecture. Together, these data suggest a biomechanical feedback mechanism downstream of spalt synchronizing mitochondria with myofibril morphogenesis.

scholarly journals Effects of calcium ions and adenosine diphosphate on the activities of NAD+-linked isocitrate dehydrogenase from the radular muscles of the whelk and flight muscles of insects

1976 ◽  
Vol 154 (3) ◽  
pp. 677-687 ◽  
Author(s):  
V A. Zammit ◽  
E A. Newsholme
Keyword(s):  
Enzyme Activity ◽  
Isocitrate Dehydrogenase ◽  
Flight Muscle ◽  
Schistocerca Gregaria ◽  
Insect Flight ◽  
Maximum Activity ◽  
Glycerol Phosphate ◽  
Energy Formation ◽  
Flight Muscles ◽  
Glycerol Phosphate Dehydrogenase

1. The activity of NAD+-linked isocitrate dehydrogenase from the radular muscle of the whelk is higher than those in many vertebrate muscles and only slightly lower than in the flight muscles of insects. The enzyme activity from the whelk (Buccinum undatum) is stable for several hours after homogenization of the radular muscle, whereas that from insect flight muscle is very unstable. Consequently, the enzyme from the whelk muscle is suitable for a systematic investigation of the effects of Ca2+ and ADP. 2. The sigmoid response of the enzyme activity to isocitrate concentration is markedly increased by raising the Ca2+ concentration from 0.001 to 10 muM, but it is decreased by ADP. The inhibitory effect of Ca2+ is most pronounced at pH7.1; it is not observed at pH 6.5. Similar effects are observed for the enzyme from the flight muscle of the locust (Schistocerca gregaria) and the water bug (Lethocerus cordofanus). The percentage activation by ADP of the enzyme from either the whelk or the insects is greater at 10 muM-Ca2+, and 50% of the maximum activation is obtained at 0.10 and 0.16 mM-ADP for the enzyme from whelk and locust respectively at this Ca2+ concentration. At 10 muM-Ca2+ in the absence of added ADP, the apparent Km for isocitrate is markedly higher than in other conditions. Ca2+ concentrations of 0.01, 0.1 and 0.2 muM cause 50% inhibition of maximum activity of the enzyme from the muscles of the whelk, locust and water bug respectively. 3. Recent work has indicated that mitochondria may play a complementary role to the sarcoplasmic reticulum in the control of the distribution of Ca2+ in muscle. The opposite effects of Ca2+ on the activities of isocitrate dehydrogenase and mitochondrial glycerol phosphate dehydrogenase from muscle tissue are consistent with the hypothesis that changes in the intracellular distribution of Ca2+ control the activities of these two enzymes in order to stimulate energy production for the contraction process in the muscle. Although both enzymes are mitochondrial, glycerol phosphate dehydrogenase resides on the outer surface of the inner membrane and responds to sarcoplasmic changes in Ca2+ concentration (i.e. an increase during contraction), whereas the isocitrate dehydrogenase resides in the matrix of the mitochondria and responds to intramitochondrial concentrations of Ca2+ (i.e. a decrease during contraction). It is suggested that changes in intramitochondrial Ca2+ concentrations are primarily responsible for regulation of the activity of NAD+-isocitrate dehydrogenase in order to control energy formation for the contractile process. However, when the muscle is at rest, changes in intramitochondrial concentrations of ADP may regulate energy formation for non-contractile processes.

scholarly journals The activities of pyruvate carboxylase, phosphoenolpyruvate carboxylase and fructose diphosphatase in muscles from vertebrates and invertebrates

1972 ◽  
Vol 130 (2) ◽  
pp. 391-396 ◽  
Author(s):  
B. Crabtree ◽  
S. J. Higgins ◽  
E. A. Newsholme
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Pyruvate Carboxylase ◽  
Flight Muscle ◽  
Insect Flight ◽  
Tricarboxylic Acid Cycle ◽  
Mitochondrial Fraction ◽  
Bumble Bee ◽  
Insect Flight Muscle ◽  
Carboxylase Activity ◽  
Flight Muscles

1. The activities of pyruvate carboxylase, phosphoenolpyruvate carboxylase and fructose diphosphatase in crude homogenates of vertebrate and invertebrate muscles are reported. 2. Pyruvate carboxylase activity was present in all insect flight muscles that were investigated: in homogenates of bumble-bee flight muscle the activity was inhibited by ADP and activated by acetyl-CoA, and it was distributed mainly in the mitochondrial fraction. This is the first demonstration of pyruvate carboxylase activity in muscle. However, the activity appears to be restricted to insect flight muscle, since it was not found in other invertebrate or vertebrate muscles. 3. Since the three enzymes were never found together in the same muscle, it is concluded that these enzymes cannot provide a pathway for the synthesis of glycogen from lactate or pyruvate in muscle. Other roles for these enzymes in muscle are suggested. In particular, pyruvate carboxylase may be present in insect flight muscle for the provision of oxaloacetate to support the large increase in activity of the tricarboxylic acid cycle which occurs when an insect takes flight.

scholarly journals Power and efficiency of insect flight muscle

1985 ◽  
Vol 115 (1) ◽  
pp. 293-304 ◽  
Author(s):  
C. P. Ellington
Keyword(s):  
Power Output ◽  
Flight Muscle ◽  
Insect Flight ◽  
Power Input ◽  
Mechanical Power ◽  
Insect Flight Muscle ◽  
Muscle Properties ◽  
System A ◽  
Mechanical Power Output ◽  
Flight Muscles

The efficiency and mechanical power output of insect flight muscle have been estimated from a study of hovering flight. The maximum power output, calculated from the muscle properties, is adequate for the aerodynamic power requirements. However, the power output is insufficient to oscillate the wing mass as well unless there is good elastic storage of the inertial energy, and this is consistent with reports of elastic components in the flight system. A comparison of the mechanical power output with the metabolic power input to the flight muscles suggests that the muscle efficiency is quite low: less than 10%.

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