Papers by Manuel Garcia Ruiz
Geochimica Et Cosmochimica Acta, 2003
Several mechanisms have been proposed to explain the interactions between proteins and mineral su... more Several mechanisms have been proposed to explain the interactions between proteins and mineral surfaces, among them a combination of electrostatic, stereochemical interactions and molecular recognition between the protein and the crystal surface. To identify the mechanisms of interaction in the lysozymecalcium carbonate model system, the effect of this protein on the precipitation kinetics and morphology of calcite crystals was examined. The solution chemistry and morphology of the solid were monitored over time in a set of time-series free-drift experiments in which CaCO 3 was precipitated from solution in a closed system at 25°C and 1 atm total pressure, in the presence and absence of lysozyme. The precipitation of calcite was preceded by the precipitation of a metastable phase that later dissolved and gave rise to calcite as the sole phase. With increasing lysozyme concentration, the nucleation of both the metastable phase and calcite occurred at lower ⍀ calcite , indicating that lysozyme favored the nucleation of both phases. Calcite growth rate was not affected by the presence of lysozyme, at least at protein concentrations ranging from 0 mg/mL to 10 mg/mL.
Worlds Poultry Science Journal, 2001
A full-length cDNA for a novel isoform of the human receptor tyrosine phosphatase y gene d'I l'IÂ... more A full-length cDNA for a novel isoform of the human receptor tyrosine phosphatase y gene d'I l'I«,\ was overexpressed in Sf9 insect cells, and the gene product. PTPy, was purified and characterized. The protein was expressed as a Mr~185,000 protein accompanied by a Mr â€"¿ 120,000 putative cleavage product on SDS-PAGE analysis. The protein undergoes jV-linked glycosylation and constitutive phosphorylation of serine resi dues. When assayed for tyrosine-specific phosphatase activity, PTPy dephosphorylatcd myelin basic protein at a pH optimum of 7.5 and a A,„ of 12.6 UM; reduced carboxyamidomethylated and maleylated lysozyme (RCM-lysozyme) at a pH optimum of 6.0 and a k,,, of 12 UM; and p-nitrophenylphosphate with a pH optimum of 5.5 and a A,,, of 3.5 HIM.
Journal of Chemical Education, 1998
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Papers by Manuel Garcia Ruiz