Linked Life Data

16286459

Source:http://linkedlifedata.com/resource/pubmed/id/16286459

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-1-12
pubmed:abstractText
ADAMTS13 is a metalloproteinase that cleaves von Willebrand factor (VWF) multimers. The metal ion dependence of ADAMTS13 activity was examined with multimeric VWF and a fluorescent peptide substrate based on Asp(1596)-Arg(1668) of the VWF A2 domain, FRETS-VWF73. ADAMTS13 activity in citrate-anticoagulated plasma was enhanced approximately 2-fold by zinc ions, approximately 3-fold by calcium ions, and approximately 6-fold by both ions, suggesting cooperative activation. Cleavage of VWF by recombinant ADAMTS13 was activated up to approximately 200-fold by zinc ions (K(D) (app) approximately 0.5 microM), calcium ions (K(D) (app) approximately 4.8 microM), and barium ions (K(D) (app) approximately 1.7 mM). Barium ions stimulated ADAMTS13 activity in citrated plasma but not in citrate-free plasma. Therefore, the stimulation by barium ions of ADAMTS13 in citrated plasma appears to reflect the release of chelated calcium and zinc ions from complexes with citrate. At optimal zinc and calcium concentrations, ADAMTS13 cleaved VWF with a K(m) (app) of 3.7 +/- 1.4 microg/ml (approximately 15 nM for VWF subunits), which is comparable with the plasma VWF concentration of 5-10 microg/ml. ADAMTS13 could cleave approximately 14% of VWF pretreated with guanidine HCl, suggesting that this substrate is heterogeneous in susceptibility to proteolysis. ADAMTS13 cleaved FRETS-VWF73 with a K(m) (app) of 3.2 +/- 1.1 microM, consistent with an approximately 200-fold decrease in affinity compared with VWF. ADAMTS13 cleaved VWF and FRETS-VWF73 with roughly comparable catalytic efficiency of 55 microM(-1) min(-1) and 18 microM(-1) min(-1), respectively. The striking preference of ADAMTS13 for VWF suggests that substrate recognition depends on structural features or exosites on multimeric VWF that are missing from FRETS-VWF73.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
850-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:16286459-ADAM Proteins, pubmed-meshheading:16286459-Barium, pubmed-meshheading:16286459-Calcium, pubmed-meshheading:16286459-Catalysis, pubmed-meshheading:16286459-Chelating Agents, pubmed-meshheading:16286459-Citric Acid, pubmed-meshheading:16286459-Crystallography, X-Ray, pubmed-meshheading:16286459-DNA, Complementary, pubmed-meshheading:16286459-Dose-Response Relationship, Drug, pubmed-meshheading:16286459-Enzyme Activation, pubmed-meshheading:16286459-Guanidine, pubmed-meshheading:16286459-Humans, pubmed-meshheading:16286459-Hydrogen-Ion Concentration, pubmed-meshheading:16286459-Ions, pubmed-meshheading:16286459-Kinetics, pubmed-meshheading:16286459-Protein Binding, pubmed-meshheading:16286459-Protein Structure, Tertiary, pubmed-meshheading:16286459-Recombinant Proteins, pubmed-meshheading:16286459-Substrate Specificity, pubmed-meshheading:16286459-Time Factors, pubmed-meshheading:16286459-Zinc, pubmed-meshheading:16286459-von Willebrand Factor
pubmed:year
2006
pubmed:articleTitle
Zinc and calcium ions cooperatively modulate ADAMTS13 activity.
pubmed:affiliation
Howard Hughes Medical Institute, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural