Biomaterial Database

Partial purification and characterization of two phosvitin phosphatases from rat brain. 1996

T P Geladopoulos, and T G Sotiroudis, and A E Evangelopoulos

Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, Athens, Greece.

The mechanism of dephosphorylation of multiphosphorylated proteins in the brain is not well understood. We have used the multiphosphorylated protein, phosvitin as a model substrate and undertaken the purification and characterization of brain phosphatases that preferentially dephosphorylate multiphosphorylated proteins. Two phosvitin phosphatase activities, termed Phosvitin Phosphatase 1 and 2 (PvP1, PvP2), which show acidic pH optima were resolved from the 33,000g supernatant fraction from rat brain by a procedure employing successive DEAE-cellulose, Sepharose 6B, second DEAE-cellulose and FPLC/Superose 6 chromatography steps. Following FPLC/Superose 6 size exclusion chromatography of PvP1 and PvP2, single peaks of phosvitin phosphatase activities were eluted in the range of 160-220 kDa with acidic pH optima. When FPLC/Sepharose 6 chromatography was performed in the presence of 0.5 M NaCl and 0.1% Triton X-100, low molecular mass protein phosphatase forms were produced in addition to the high-M, activity peak, ranging from 25 to 35 kDa (PvP1) and from 15 to 25 kDa (PvP2). Under these conditions, both high- and low-M, forms of PvP1 and PvP2 exhibited neutral pH optima. Both phosphatases dephosphorylate also (i) phosphorylase a, (ii) the alpha and beta subunits of phosphorylase kinase, and (iii) the microtubule-associated protein tau, phosphorylated by cAMP-dependent protein kinase. The present results suggest that two forms of protein phosphatases, displayed molecular and biochemical characteristics both similar and distinct from type 1 and type 2A protein phosphatases, are present in rat brain.

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009419	Nerve Tissue Proteins		Proteins, Nerve Tissue,Tissue Proteins, Nerve
D010749	Phosphoprotein Phosphatases	A group of enzymes removing the SERINE- or THREONINE-bound phosphate groups from a wide range of phosphoproteins, including a number of enzymes which have been phosphorylated under the action of a kinase. (Enzyme Nomenclature, 1992)	Phosphoprotein Phosphatase,Phosphoprotein Phosphohydrolase,Protein Phosphatase,Protein Phosphatases,Casein Phosphatase,Ecto-Phosphoprotein Phosphatase,Nuclear Protein Phosphatase,Phosphohistone Phosphatase,Phosphoprotein Phosphatase-2C,Phosphoseryl-Protein Phosphatase,Protein Phosphatase C,Protein Phosphatase C-I,Protein Phosphatase C-II,Protein Phosphatase H-II,Protein-Serine-Threonine Phosphatase,Protein-Threonine Phosphatase,Serine-Threonine Phosphatase,Threonine Phosphatase,Ecto Phosphoprotein Phosphatase,Phosphatase C, Protein,Phosphatase C-I, Protein,Phosphatase C-II, Protein,Phosphatase H-II, Protein,Phosphatase, Casein,Phosphatase, Ecto-Phosphoprotein,Phosphatase, Nuclear Protein,Phosphatase, Phosphohistone,Phosphatase, Phosphoprotein,Phosphatase, Phosphoseryl-Protein,Phosphatase, Protein,Phosphatase, Protein-Serine-Threonine,Phosphatase, Protein-Threonine,Phosphatase, Serine-Threonine,Phosphatase, Threonine,Phosphatase-2C, Phosphoprotein,Phosphatases, Phosphoprotein,Phosphatases, Protein,Phosphohydrolase, Phosphoprotein,Phosphoprotein Phosphatase 2C,Phosphoseryl Protein Phosphatase,Protein Phosphatase C I,Protein Phosphatase C II,Protein Phosphatase H II,Protein Phosphatase, Nuclear,Protein Serine Threonine Phosphatase,Protein Threonine Phosphatase,Serine Threonine Phosphatase
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D003124	Colorimetry	Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D004396	Coloring Agents	Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.	Coloring Agent,Dye,Dyes,Organic Pigment,Stain,Stains,Tissue Stain,Tissue Stains,Organic Pigments,Pigments, Inorganic,Agent, Coloring,Inorganic Pigments,Pigment, Organic,Pigments, Organic,Stain, Tissue,Stains, Tissue
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012394	Rosaniline Dyes	Compounds that contain the triphenylmethane aniline structure found in rosaniline. Many of them have a characteristic magenta color and are used as COLORING AGENTS.	Fuchsins,Magentas,Fuchsin,Triphenylmethane Aniline Compounds,Aniline Compounds, Triphenylmethane,Compounds, Triphenylmethane Aniline,Dyes, Rosaniline