Linked Life Data

10889041

Source:http://linkedlifedata.com/resource/pubmed/id/10889041

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
2000-8-16
pubmed:databankReference
pubmed:abstractText
We report here the purification, cloning, expression, and characterization of a novel phosphatase, MDP-1. In the course of investigating the reported acid phosphatase activity of carbonic anhydrase III preparations, several discrete phosphatases were discerned. One of these, a magnesium-dependent species of 18.6 kDa, was purified to homogeneity and yielded several peptide sequences from which the parent gene was identified by database searching. Although orthologous genes were identified in fungi and plants as well as mammalian species, there was no apparent homology to any known family of phosphatases. The enzyme was expressed in Escherichia coli with a fusion tag and purified by affinity methods. The recombinant enzyme showed magnesium-dependent acid phosphatase activity comparable to the originally isolated rabbit protein. The enzyme catalyzes the rapid hydrolysis of p-nitrophenyl phosphate, ribose-5-phosphate, and phosphotyrosine. The selectivity for phosphotyrosine over phosphoserine or phosphothreonine is considerable, but the enzyme did not show activity toward five phosphotyrosine-containing peptides. None of the various substrates assayed (including various nucleotide, sugar, amino acid and peptide phosphates, phosphoinositides, and phosphodiesters) exhibited K(M) values lower than 1 mM, and many showed negligible rates of hydrolysis. The enzyme is inhibited by vanadate and fluoride but not by azide, cyanide, calcium, lithium, or tartaric acid. Chemical labeling, refolding, dialysis, and mutagenesis experiments suggest that the enzymatic mechanism is not dependent on cysteine, histidine, or nonmagnesium metal ions. In recognition of these observations, the enzyme has been given the name magnesium-dependent phosphatase-1 (MDP-1).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8315-24
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:10889041-Amino Acid Sequence, pubmed-meshheading:10889041-Animals, pubmed-meshheading:10889041-Catalysis, pubmed-meshheading:10889041-Cations, pubmed-meshheading:10889041-Chromatography, Affinity, pubmed-meshheading:10889041-Cloning, Molecular, pubmed-meshheading:10889041-Cysteine, pubmed-meshheading:10889041-Enzyme Inhibitors, pubmed-meshheading:10889041-Histidine, pubmed-meshheading:10889041-Hydrogen-Ion Concentration, pubmed-meshheading:10889041-Magnesium, pubmed-meshheading:10889041-Mice, pubmed-meshheading:10889041-Molecular Sequence Data, pubmed-meshheading:10889041-Phosphoprotein Phosphatases, pubmed-meshheading:10889041-Protein Phosphatase 1, pubmed-meshheading:10889041-Rabbits, pubmed-meshheading:10889041-Sequence Analysis, Protein, pubmed-meshheading:10889041-Sequence Homology, Amino Acid, pubmed-meshheading:10889041-Substrate Specificity
pubmed:year
2000
pubmed:articleTitle
MDP-1: A novel eukaryotic magnesium-dependent phosphatase.
pubmed:affiliation
Laboratory of Biochemistry, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-0320, USA. selengut@nih.gov
pubmed:publicationType
Journal Article