The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform

Akira Hachimori - One of the best experts on this subject based on the ideXlab platform.

  • The role of histidine-118 of Inorganic Pyrophosphatase from thermophilic bacterium PS-3.
    Biochemical Journal, 1991
    Co-Authors: Naoto Hirano, T Ichiba, Akira Hachimori
    Abstract:

    Treatment of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3 with diethyl pyrocarbonate resulted in the almost complete loss of its activity, which followed pseudo-first-order kinetics. The presence of Mg2+ prevented the inactivation. Enzyme inactivated with diethyl pyrocarbonate was re-activated by hydroxylamine. The inactivation parallelled the amount of modified histidine residue, and a plot of the activity remaining against the amount of modified histidine residue suggested that the modification of one of two histidine residues totally inactivated the enzyme. The site involved was found to be located in a single lysyl endopeptidase-digest peptide derived from the ethoxy[14C]carbonylated enzyme. Amino acid analysis and sequence analysis of the peptide revealed that it comprised residues 96-119 of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3. These results, when compared with those reported for the Escherichia coli and yeast enzymes, imply that His-118 of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3 is located near the Mg(2+)-binding site and thus affects the binding of Mg2+.

Naoto Hirano - One of the best experts on this subject based on the ideXlab platform.

  • The role of histidine-118 of Inorganic Pyrophosphatase from thermophilic bacterium PS-3.
    Biochemical Journal, 1991
    Co-Authors: Naoto Hirano, T Ichiba, Akira Hachimori
    Abstract:

    Treatment of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3 with diethyl pyrocarbonate resulted in the almost complete loss of its activity, which followed pseudo-first-order kinetics. The presence of Mg2+ prevented the inactivation. Enzyme inactivated with diethyl pyrocarbonate was re-activated by hydroxylamine. The inactivation parallelled the amount of modified histidine residue, and a plot of the activity remaining against the amount of modified histidine residue suggested that the modification of one of two histidine residues totally inactivated the enzyme. The site involved was found to be located in a single lysyl endopeptidase-digest peptide derived from the ethoxy[14C]carbonylated enzyme. Amino acid analysis and sequence analysis of the peptide revealed that it comprised residues 96-119 of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3. These results, when compared with those reported for the Escherichia coli and yeast enzymes, imply that His-118 of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3 is located near the Mg(2+)-binding site and thus affects the binding of Mg2+.

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

  • The role of histidine-118 of Inorganic Pyrophosphatase from thermophilic bacterium PS-3.
    Biochemical Journal, 1991
    Co-Authors: Naoto Hirano, T Ichiba, Akira Hachimori
    Abstract:

    Treatment of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3 with diethyl pyrocarbonate resulted in the almost complete loss of its activity, which followed pseudo-first-order kinetics. The presence of Mg2+ prevented the inactivation. Enzyme inactivated with diethyl pyrocarbonate was re-activated by hydroxylamine. The inactivation parallelled the amount of modified histidine residue, and a plot of the activity remaining against the amount of modified histidine residue suggested that the modification of one of two histidine residues totally inactivated the enzyme. The site involved was found to be located in a single lysyl endopeptidase-digest peptide derived from the ethoxy[14C]carbonylated enzyme. Amino acid analysis and sequence analysis of the peptide revealed that it comprised residues 96-119 of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3. These results, when compared with those reported for the Escherichia coli and yeast enzymes, imply that His-118 of the Inorganic Pyrophosphatase from thermophilic bacterium PS-3 is located near the Mg(2+)-binding site and thus affects the binding of Mg2+.

Alexei Teplyakov - One of the best experts on this subject based on the ideXlab platform.

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

  • sudden cardiac death due to deficiency of the mitochondrial Inorganic Pyrophosphatase ppa2
    American Journal of Human Genetics, 2016
    Co-Authors: Hannah L Kennedy, Tobias B Haack, Verity Hartill, Lavinija Matakovic, Regula E Baumgartner, Howard C Potter, Richard Mackay, Charlotte L Alston, Siobhan Osullivan, Robert Mcfarland
    Abstract:

    We have used whole-exome sequencing in ten individuals from four unrelated pedigrees to identify biallelic missense mutations in the nuclear-encoded mitochondrial Inorganic Pyrophosphatase (PPA2) that are associated with mitochondrial disease. These individuals show a range of severity, indicating that PPA2 mutations may cause a spectrum of mitochondrial disease phenotypes. Severe symptoms include seizures, lactic acidosis, cardiac arrhythmia, and death within days of birth. In the index family, presentation was milder and manifested as cardiac fibrosis and an exquisite sensitivity to alcohol, leading to sudden arrhythmic cardiac death in the second decade of life. Comparison of normal and mutant PPA2-containing mitochondria from fibroblasts showed that the activity of Inorganic Pyrophosphatase was significantly reduced in affected individuals. Recombinant PPA2 enzymes modeling hypomorphic missense mutations had decreased activity that correlated with disease severity. These findings confirm the pathogenicity of PPA2 mutations and suggest that PPA2 is a cardiomyopathy-associated protein, which has a greater physiological importance in mitochondrial function than previously recognized.