Linked Life Data

17419725

Source:http://linkedlifedata.com/resource/pubmed/id/17419725

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2007-5-1
pubmed:abstractText
We report here the characterization of the first mammalian-like purine nucleoside phosphorylase from the hyperthermophilic archaeon Pyrococcus furiosus (PfPNP). The gene PF0853 encoding PfPNP was cloned and expressed in Escherichia coli and the recombinant protein was purified to homogeneity. PfPNP is a homohexamer of 180 kDa which shows a much higher similarity with 5'-deoxy-5'-methylthioadenosine phosphorylase (MTAP) than with purine nucleoside phosphorylase (PNP) family members. Like human PNP, PfPNP shows an absolute specificity for inosine and guanosine. PfPNP shares 50% identity with MTAP from P. furiosus (PfMTAP). The alignment of the protein sequences of PfPNP and PfMTAP indicates that only four residue changes are able to switch the specificity of PfPNP from a 6-oxo to a 6-amino purine nucleoside phosphorylase still maintaining the same overall active site organization. PfPNP is highly thermophilic with an optimum temperature of 120 degrees C and is characterized by extreme thermodynamic stability (T(m), 110 degrees C that increases to 120 degrees C in the presence of 100 mm phosphate), kinetic stability (100% residual activity after 4 h incubation at 100 degrees C), and remarkable SDS-resistance. Limited proteolysis indicated that the only proteolytic cleavage site is localized in the C-terminal region and that the C-terminal peptide is not necessary for the integrity of the active site. By integrating biochemical methodologies with mass spectrometry we assigned three pairs of intrasubunit disulfide bridges that play a role in the stability of the enzyme against thermal inactivation. The characterization of the thermal properties of the C254S/C256S mutant suggests that the CXC motif in the C-terminal region may also account for the extreme enzyme thermostability.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1742-464X
pubmed:author
pubmed:issnType
Print
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2482-95
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:17419725-Amino Acid Sequence, pubmed-meshheading:17419725-Cloning, Molecular, pubmed-meshheading:17419725-Disulfides, pubmed-meshheading:17419725-Dithiothreitol, pubmed-meshheading:17419725-Enzyme Stability, pubmed-meshheading:17419725-Escherichia coli, pubmed-meshheading:17419725-Hot Temperature, pubmed-meshheading:17419725-Kinetics, pubmed-meshheading:17419725-Molecular Sequence Data, pubmed-meshheading:17419725-Phosphates, pubmed-meshheading:17419725-Purine-Nucleoside Phosphorylase, pubmed-meshheading:17419725-Pyrococcus furiosus, pubmed-meshheading:17419725-Sequence Alignment, pubmed-meshheading:17419725-Spectrometry, Mass, Electrospray Ionization, pubmed-meshheading:17419725-Spectrometry, Mass, Matrix-Assisted Laser..., pubmed-meshheading:17419725-Substrate Specificity, pubmed-meshheading:17419725-Tandem Mass Spectrometry
pubmed:year
2007
pubmed:articleTitle
Biochemical and structural characterization of mammalian-like purine nucleoside phosphorylase from the Archaeon Pyrococcus furiosus.
pubmed:affiliation
Dipartimento di Biochimica e Biofisica F. Cedrangolo, Seconda Università di Napoli, Napoli, Italy. giovanna.cacciapuoti@unina2.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't