The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform

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

  • Prediction of signal peptide functional properties: a study of the Orientation and Angle of insertion of yeast invertase mutants and human apolipoprotein B signal peptide variants
    "Protein Engineering Design and Selection", 1996
    Co-Authors: Philippa J. Talmud, Laurence Lins, Robert Brasseur
    Abstract:

    A number of studies have introduced mutations into the yeast invertase signal peptide, using it as a model system to elucidate features for targeting, translocation and intracellular transport. Using molecular modelling of the invertase signal peptide we have analysed the hydrophobicity potential and the change in the dielectric constant of the energy transfer, when the molecule moves from a hydrophobic to a hydrophilic phase at the simulated hydrophobic-hydrophilic interface. This modelling has been carried out on wild type and mutant invertase signal peptides of altered function, previously reported in the literature, While the predicted Angle of insertion correlates with the measured extent of invertase secretion, with an optimum Angle of 45 degrees, mutations that change the Angle of Orientation reduce the extent of invertase secretion, We have applied these same molecular modelling principles to the naturally occurring variants of the human apolipoprotein B (apoB) signal peptide, that confer a secretion defective phenotype when fused to yeast invertase and expressed in yeast, Our modelling thus identifies a strong correlation between the predicted Angle of insertion of the signal peptide into the membrane and its ability to direct secretion.

Philippa J. Talmud - One of the best experts on this subject based on the ideXlab platform.

  • Prediction of signal peptide functional properties: a study of the Orientation and Angle of insertion of yeast invertase mutants and human apolipoprotein B signal peptide variants
    "Protein Engineering Design and Selection", 1996
    Co-Authors: Philippa J. Talmud, Laurence Lins, Robert Brasseur
    Abstract:

    A number of studies have introduced mutations into the yeast invertase signal peptide, using it as a model system to elucidate features for targeting, translocation and intracellular transport. Using molecular modelling of the invertase signal peptide we have analysed the hydrophobicity potential and the change in the dielectric constant of the energy transfer, when the molecule moves from a hydrophobic to a hydrophilic phase at the simulated hydrophobic-hydrophilic interface. This modelling has been carried out on wild type and mutant invertase signal peptides of altered function, previously reported in the literature, While the predicted Angle of insertion correlates with the measured extent of invertase secretion, with an optimum Angle of 45 degrees, mutations that change the Angle of Orientation reduce the extent of invertase secretion, We have applied these same molecular modelling principles to the naturally occurring variants of the human apolipoprotein B (apoB) signal peptide, that confer a secretion defective phenotype when fused to yeast invertase and expressed in yeast, Our modelling thus identifies a strong correlation between the predicted Angle of insertion of the signal peptide into the membrane and its ability to direct secretion.

Tomáš Mareš - One of the best experts on this subject based on the ideXlab platform.

  • Elastic Properties of Human Osteon and Osteonal Lamella Computed by a Bidirectional Micromechanical Model and Validated by Nanoindentation
    Journal of biomechanical engineering, 2015
    Co-Authors: Radim Korsa, Jaroslav Lukes, Josef Sepitka, Tomáš Mareš
    Abstract:

    Knowledge of the anisotropic elastic properties of osteon and osteonal lamellae provides a better understanding of various pathophysiological conditions, such as aging, osteoporosis, osteoarthritis, and other degenerative diseases. For this reason, it is important to investigate and understand the elasticity of cortical bone. We created a bidirectional micromechanical model based on inverse homogenization for predicting the elastic properties of osteon and osteonal lamellae of cortical bone. The shape, the dimensions, and the curvature of osteon and osteonal lamellae are described by appropriately chosen curvilinear coordinate systems, so that the model operates close to the real morphology of these bone components. The model was used to calculate nine orthotropic elastic constants of osteonal lamellae. The input values have the elastic properties of a single osteon. We also expressed the dependence of the elastic properties of the lamellae on the Angle of Orientation. To validate the model, we performed nanoindentation tests on several osteonal lamellae. We compared the experimental results with the calculated results, and there was good agreement between them. The inverted model was used to calculate the elastic properties of a single osteon, where the input values are the elastic constants of osteonal lamellae. These calculations reveal that the model can be used in both directions of homogenization, i.e., direct homogenization and also inverse homogenization. The model described here can provide either the unknown elastic properties of a single lamella from the known elastic properties at the level of a single osteon, or the unknown elastic properties of a single osteon from the known elastic properties at the level of a single lamella.

Laurence Lins - One of the best experts on this subject based on the ideXlab platform.

  • Prediction of signal peptide functional properties: a study of the Orientation and Angle of insertion of yeast invertase mutants and human apolipoprotein B signal peptide variants
    "Protein Engineering Design and Selection", 1996
    Co-Authors: Philippa J. Talmud, Laurence Lins, Robert Brasseur
    Abstract:

    A number of studies have introduced mutations into the yeast invertase signal peptide, using it as a model system to elucidate features for targeting, translocation and intracellular transport. Using molecular modelling of the invertase signal peptide we have analysed the hydrophobicity potential and the change in the dielectric constant of the energy transfer, when the molecule moves from a hydrophobic to a hydrophilic phase at the simulated hydrophobic-hydrophilic interface. This modelling has been carried out on wild type and mutant invertase signal peptides of altered function, previously reported in the literature, While the predicted Angle of insertion correlates with the measured extent of invertase secretion, with an optimum Angle of 45 degrees, mutations that change the Angle of Orientation reduce the extent of invertase secretion, We have applied these same molecular modelling principles to the naturally occurring variants of the human apolipoprotein B (apoB) signal peptide, that confer a secretion defective phenotype when fused to yeast invertase and expressed in yeast, Our modelling thus identifies a strong correlation between the predicted Angle of insertion of the signal peptide into the membrane and its ability to direct secretion.

Radim Korsa - One of the best experts on this subject based on the ideXlab platform.

  • Elastic Properties of Human Osteon and Osteonal Lamella Computed by a Bidirectional Micromechanical Model and Validated by Nanoindentation
    Journal of biomechanical engineering, 2015
    Co-Authors: Radim Korsa, Jaroslav Lukes, Josef Sepitka, Tomáš Mareš
    Abstract:

    Knowledge of the anisotropic elastic properties of osteon and osteonal lamellae provides a better understanding of various pathophysiological conditions, such as aging, osteoporosis, osteoarthritis, and other degenerative diseases. For this reason, it is important to investigate and understand the elasticity of cortical bone. We created a bidirectional micromechanical model based on inverse homogenization for predicting the elastic properties of osteon and osteonal lamellae of cortical bone. The shape, the dimensions, and the curvature of osteon and osteonal lamellae are described by appropriately chosen curvilinear coordinate systems, so that the model operates close to the real morphology of these bone components. The model was used to calculate nine orthotropic elastic constants of osteonal lamellae. The input values have the elastic properties of a single osteon. We also expressed the dependence of the elastic properties of the lamellae on the Angle of Orientation. To validate the model, we performed nanoindentation tests on several osteonal lamellae. We compared the experimental results with the calculated results, and there was good agreement between them. The inverted model was used to calculate the elastic properties of a single osteon, where the input values are the elastic constants of osteonal lamellae. These calculations reveal that the model can be used in both directions of homogenization, i.e., direct homogenization and also inverse homogenization. The model described here can provide either the unknown elastic properties of a single lamella from the known elastic properties at the level of a single osteon, or the unknown elastic properties of a single osteon from the known elastic properties at the level of a single lamella.