Linked Life Data

8530480

Source:http://linkedlifedata.com/resource/pubmed/id/8530480

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
1996-1-30
pubmed:abstractText
Mass spectrometry has been used to demonstrate that vitamin K-dependent carboxylation is a processive post-translational modification (i.e. multiple carboxylations occur during a single association between enzyme and substrate). Purified vitamin K-dependent carboxylase can carboxylate as many as 12 glutamate residues in FIXQ/S, a peptide substrate based on amino acids -18 to 41 of the human blood clotting enzyme factor IX. Mass spectrometry was used to determine the number of gamma-carboxyl groups added to FIXQ/S by the carboxylase during an in vitro reaction. Despite the fact that most substrate molecules in a reaction were uncarboxylated, almost all carboxylated FIXQ/S molecules were carboxylated many times. This observation can only be explained by two types of mechanisms. In a processive mechanism, multiple carboxylations could occur during a single substrate binding event. Alternatively, a distributive mechanism could result in the observed behavior if the initial carboxylation event results in a substrate that is additionally carboxylated far more efficiently than the uncarboxylated FIXQ/S. Kinetic experiments and arguments were used to show that the vitamin K-dependent carboxylase is not distributive but rather is one of the first well documented examples of an enzyme that catalyzes a processive post-translation modification.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30491-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8530480-Amino Acid Sequence, pubmed-meshheading:8530480-Carbon-Carbon Ligases, pubmed-meshheading:8530480-Chromatography, High Pressure Liquid, pubmed-meshheading:8530480-Cloning, Molecular, pubmed-meshheading:8530480-Escherichia coli, pubmed-meshheading:8530480-Glutamic Acid, pubmed-meshheading:8530480-Humans, pubmed-meshheading:8530480-Kinetics, pubmed-meshheading:8530480-Ligases, pubmed-meshheading:8530480-Mass Spectrometry, pubmed-meshheading:8530480-Molecular Sequence Data, pubmed-meshheading:8530480-Peptide Biosynthesis, pubmed-meshheading:8530480-Peptide Fragments, pubmed-meshheading:8530480-Peptides, pubmed-meshheading:8530480-Protein Processing, Post-Translational, pubmed-meshheading:8530480-Recombinant Proteins, pubmed-meshheading:8530480-Substrate Specificity
pubmed:year
1995
pubmed:articleTitle
Processive post-translational modification. Vitamin K-dependent carboxylation of a peptide substrate.
pubmed:affiliation
Department of Biology, University of North Carolina, Chapel Hill 27599-3280, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't