The Experts below are selected from a list of 30 Experts worldwide ranked by ideXlab platform

Robert S Balaban - One of the best experts on this subject based on the ideXlab platform.

  • effect of calcium on the oxidative phosphorylation cascade in skeletal muscle mitochondria
    Biochemistry, 2013
    Co-Authors: Brian Glancy, David J Chess, Wayne T Willis, Robert S Balaban
    Abstract:

    Calcium is believed to regulate mitochondrial oxidative phosphorylation, thereby contributing to the maintenance of cellular energy homeostasis. Skeletal muscle, with an energy conversion dynamic range of up to 100-fold, is an extreme case for evaluating the cellular balance of ATP production and consumption. This study examined the role of Ca2+ in the entire oxidative phosphorylation reaction network in isolated skeletal muscle mitochondria and attempted to extrapolate these results back to the muscle, in vivo. Kinetic analysis was conducted to evaluate the dose–response effect of Ca2+ on the maximal velocity of oxidative phosphorylation (VmaxO) and the ADP affinity. Force-flow analysis evaluated the interplay between energetic driving Forces and Flux to determine the conductance, or effective activity, of individual steps within oxidative phosphorylation. Measured driving Forces [extramitochondrial phosphorylation potential (ΔGATP), membrane potential, and redox states of NADH and cytochromes bH, bL, c1...

  • Effect of Calcium on the Oxidative Phosphorylation Cascade in Skeletal Muscle Mitochondria
    Biochemistry, 2013
    Co-Authors: Brian Glancy, David J Chess, Wayne T Willis, Robert S Balaban
    Abstract:

    Calcium is believed to regulate mitochondrial oxidative phosphorylation, thereby contributing to the maintenance of cellular energy homeostasis. Skeletal muscle, with an energy conversion dynamic range of up to 100-fold, is an extreme case for evaluating the cellular balance of ATP production and consumption. This study examined the role of Ca(2+) in the entire oxidative phosphorylation reaction network in isolated skeletal muscle mitochondria and attempted to extrapolate these results back to the muscle, in vivo. Kinetic analysis was conducted to evaluate the dose-response effect of Ca(2+) on the maximal velocity of oxidative phosphorylation (V(maxO)) and the ADP affinity. Force-flow analysis evaluated the interplay between energetic driving Forces and Flux to determine the conductance, or effective activity, of individual steps within oxidative phosphorylation. Measured driving Forces [extramitochondrial phosphorylation potential (ΔG(ATP)), membrane potential, and redox states of NADH and cytochromes b(H), b(L), c(1), c, and a,a(3)] were compared with Flux (oxygen consumption) at 37 °C; 840 nM Ca(2+) generated an ~2-fold increase in V(maxO) with no change in ADP affinity (~43 μM). Force-flow analysis revealed that Ca(2+) activation of V(maxO) was distributed throughout the oxidative phosphorylation reaction sequence. Specifically, Ca(2+) increased the conductance of Complex IV (2.3-fold), Complexes I and III (2.2-fold), ATP production/transport (2.4-fold), and fuel transport/dehydrogenases (1.7-fold). These data support the notion that Ca(2+) activates the entire muscle oxidative phosphorylation cascade, while extrapolation of these data to the exercising muscle predicts a significant role of Ca(2+) in maintaining cellular energy homeostasis.

Brian Glancy - One of the best experts on this subject based on the ideXlab platform.

  • effect of calcium on the oxidative phosphorylation cascade in skeletal muscle mitochondria
    Biochemistry, 2013
    Co-Authors: Brian Glancy, David J Chess, Wayne T Willis, Robert S Balaban
    Abstract:

    Calcium is believed to regulate mitochondrial oxidative phosphorylation, thereby contributing to the maintenance of cellular energy homeostasis. Skeletal muscle, with an energy conversion dynamic range of up to 100-fold, is an extreme case for evaluating the cellular balance of ATP production and consumption. This study examined the role of Ca2+ in the entire oxidative phosphorylation reaction network in isolated skeletal muscle mitochondria and attempted to extrapolate these results back to the muscle, in vivo. Kinetic analysis was conducted to evaluate the dose–response effect of Ca2+ on the maximal velocity of oxidative phosphorylation (VmaxO) and the ADP affinity. Force-flow analysis evaluated the interplay between energetic driving Forces and Flux to determine the conductance, or effective activity, of individual steps within oxidative phosphorylation. Measured driving Forces [extramitochondrial phosphorylation potential (ΔGATP), membrane potential, and redox states of NADH and cytochromes bH, bL, c1...

  • Effect of Calcium on the Oxidative Phosphorylation Cascade in Skeletal Muscle Mitochondria
    Biochemistry, 2013
    Co-Authors: Brian Glancy, David J Chess, Wayne T Willis, Robert S Balaban
    Abstract:

    Calcium is believed to regulate mitochondrial oxidative phosphorylation, thereby contributing to the maintenance of cellular energy homeostasis. Skeletal muscle, with an energy conversion dynamic range of up to 100-fold, is an extreme case for evaluating the cellular balance of ATP production and consumption. This study examined the role of Ca(2+) in the entire oxidative phosphorylation reaction network in isolated skeletal muscle mitochondria and attempted to extrapolate these results back to the muscle, in vivo. Kinetic analysis was conducted to evaluate the dose-response effect of Ca(2+) on the maximal velocity of oxidative phosphorylation (V(maxO)) and the ADP affinity. Force-flow analysis evaluated the interplay between energetic driving Forces and Flux to determine the conductance, or effective activity, of individual steps within oxidative phosphorylation. Measured driving Forces [extramitochondrial phosphorylation potential (ΔG(ATP)), membrane potential, and redox states of NADH and cytochromes b(H), b(L), c(1), c, and a,a(3)] were compared with Flux (oxygen consumption) at 37 °C; 840 nM Ca(2+) generated an ~2-fold increase in V(maxO) with no change in ADP affinity (~43 μM). Force-flow analysis revealed that Ca(2+) activation of V(maxO) was distributed throughout the oxidative phosphorylation reaction sequence. Specifically, Ca(2+) increased the conductance of Complex IV (2.3-fold), Complexes I and III (2.2-fold), ATP production/transport (2.4-fold), and fuel transport/dehydrogenases (1.7-fold). These data support the notion that Ca(2+) activates the entire muscle oxidative phosphorylation cascade, while extrapolation of these data to the exercising muscle predicts a significant role of Ca(2+) in maintaining cellular energy homeostasis.

Wayne T Willis - One of the best experts on this subject based on the ideXlab platform.

  • effect of calcium on the oxidative phosphorylation cascade in skeletal muscle mitochondria
    Biochemistry, 2013
    Co-Authors: Brian Glancy, David J Chess, Wayne T Willis, Robert S Balaban
    Abstract:

    Calcium is believed to regulate mitochondrial oxidative phosphorylation, thereby contributing to the maintenance of cellular energy homeostasis. Skeletal muscle, with an energy conversion dynamic range of up to 100-fold, is an extreme case for evaluating the cellular balance of ATP production and consumption. This study examined the role of Ca2+ in the entire oxidative phosphorylation reaction network in isolated skeletal muscle mitochondria and attempted to extrapolate these results back to the muscle, in vivo. Kinetic analysis was conducted to evaluate the dose–response effect of Ca2+ on the maximal velocity of oxidative phosphorylation (VmaxO) and the ADP affinity. Force-flow analysis evaluated the interplay between energetic driving Forces and Flux to determine the conductance, or effective activity, of individual steps within oxidative phosphorylation. Measured driving Forces [extramitochondrial phosphorylation potential (ΔGATP), membrane potential, and redox states of NADH and cytochromes bH, bL, c1...

  • Effect of Calcium on the Oxidative Phosphorylation Cascade in Skeletal Muscle Mitochondria
    Biochemistry, 2013
    Co-Authors: Brian Glancy, David J Chess, Wayne T Willis, Robert S Balaban
    Abstract:

    Calcium is believed to regulate mitochondrial oxidative phosphorylation, thereby contributing to the maintenance of cellular energy homeostasis. Skeletal muscle, with an energy conversion dynamic range of up to 100-fold, is an extreme case for evaluating the cellular balance of ATP production and consumption. This study examined the role of Ca(2+) in the entire oxidative phosphorylation reaction network in isolated skeletal muscle mitochondria and attempted to extrapolate these results back to the muscle, in vivo. Kinetic analysis was conducted to evaluate the dose-response effect of Ca(2+) on the maximal velocity of oxidative phosphorylation (V(maxO)) and the ADP affinity. Force-flow analysis evaluated the interplay between energetic driving Forces and Flux to determine the conductance, or effective activity, of individual steps within oxidative phosphorylation. Measured driving Forces [extramitochondrial phosphorylation potential (ΔG(ATP)), membrane potential, and redox states of NADH and cytochromes b(H), b(L), c(1), c, and a,a(3)] were compared with Flux (oxygen consumption) at 37 °C; 840 nM Ca(2+) generated an ~2-fold increase in V(maxO) with no change in ADP affinity (~43 μM). Force-flow analysis revealed that Ca(2+) activation of V(maxO) was distributed throughout the oxidative phosphorylation reaction sequence. Specifically, Ca(2+) increased the conductance of Complex IV (2.3-fold), Complexes I and III (2.2-fold), ATP production/transport (2.4-fold), and fuel transport/dehydrogenases (1.7-fold). These data support the notion that Ca(2+) activates the entire muscle oxidative phosphorylation cascade, while extrapolation of these data to the exercising muscle predicts a significant role of Ca(2+) in maintaining cellular energy homeostasis.

David J Chess - One of the best experts on this subject based on the ideXlab platform.

  • effect of calcium on the oxidative phosphorylation cascade in skeletal muscle mitochondria
    Biochemistry, 2013
    Co-Authors: Brian Glancy, David J Chess, Wayne T Willis, Robert S Balaban
    Abstract:

    Calcium is believed to regulate mitochondrial oxidative phosphorylation, thereby contributing to the maintenance of cellular energy homeostasis. Skeletal muscle, with an energy conversion dynamic range of up to 100-fold, is an extreme case for evaluating the cellular balance of ATP production and consumption. This study examined the role of Ca2+ in the entire oxidative phosphorylation reaction network in isolated skeletal muscle mitochondria and attempted to extrapolate these results back to the muscle, in vivo. Kinetic analysis was conducted to evaluate the dose–response effect of Ca2+ on the maximal velocity of oxidative phosphorylation (VmaxO) and the ADP affinity. Force-flow analysis evaluated the interplay between energetic driving Forces and Flux to determine the conductance, or effective activity, of individual steps within oxidative phosphorylation. Measured driving Forces [extramitochondrial phosphorylation potential (ΔGATP), membrane potential, and redox states of NADH and cytochromes bH, bL, c1...

  • Effect of Calcium on the Oxidative Phosphorylation Cascade in Skeletal Muscle Mitochondria
    Biochemistry, 2013
    Co-Authors: Brian Glancy, David J Chess, Wayne T Willis, Robert S Balaban
    Abstract:

    Calcium is believed to regulate mitochondrial oxidative phosphorylation, thereby contributing to the maintenance of cellular energy homeostasis. Skeletal muscle, with an energy conversion dynamic range of up to 100-fold, is an extreme case for evaluating the cellular balance of ATP production and consumption. This study examined the role of Ca(2+) in the entire oxidative phosphorylation reaction network in isolated skeletal muscle mitochondria and attempted to extrapolate these results back to the muscle, in vivo. Kinetic analysis was conducted to evaluate the dose-response effect of Ca(2+) on the maximal velocity of oxidative phosphorylation (V(maxO)) and the ADP affinity. Force-flow analysis evaluated the interplay between energetic driving Forces and Flux to determine the conductance, or effective activity, of individual steps within oxidative phosphorylation. Measured driving Forces [extramitochondrial phosphorylation potential (ΔG(ATP)), membrane potential, and redox states of NADH and cytochromes b(H), b(L), c(1), c, and a,a(3)] were compared with Flux (oxygen consumption) at 37 °C; 840 nM Ca(2+) generated an ~2-fold increase in V(maxO) with no change in ADP affinity (~43 μM). Force-flow analysis revealed that Ca(2+) activation of V(maxO) was distributed throughout the oxidative phosphorylation reaction sequence. Specifically, Ca(2+) increased the conductance of Complex IV (2.3-fold), Complexes I and III (2.2-fold), ATP production/transport (2.4-fold), and fuel transport/dehydrogenases (1.7-fold). These data support the notion that Ca(2+) activates the entire muscle oxidative phosphorylation cascade, while extrapolation of these data to the exercising muscle predicts a significant role of Ca(2+) in maintaining cellular energy homeostasis.

Xavier Obradors - One of the best experts on this subject based on the ideXlab platform.

  • Flux trapping and levitation Forces in directionally solidified superconducting YBa2Cu3O7 ingots
    Journal of Applied Physics, 1996
    Co-Authors: Javier Mora, M. Carrera, Xavier Granados, Josep Fontcuberta, S. Piñol, Xavier Obradors
    Abstract:

    YBa2Cu3O7 cylinders with 10%–20% of Y2BaCuO5 and 1% CeO2 additions have been directionally solidified under a temperature gradient. It is shown that a steady growth regime of domains, typically 1 cm in diameter, is established after polynucleation at the bottom of the cylinders on the substrate interface. The length of the region where a steady growth proceeds is limited by the liquid loss, which induces an enrichment in unreacted Y2BaCuO5 in the upper part of the cylinder and a polycrystalline structure. The vertical and lateral magnetic levitation Forces and Flux trapping profiles have been measured and a direct correlation with the size and location of the domains has been found.