Linked Life Data

2084499

Source:http://linkedlifedata.com/resource/pubmed/id/2084499

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-5-16
pubmed:abstractText
A novel enzyme reactor for studying phospholipid-dependent reactions was used to explore the effects of flow on tissue factor (TF)-initiated coagulation. Capillary tubes (0.27 mm i.d.) were coated with a phospholipid bilayer containing TF, a transmembrane protein that is an essential cofactor for factor VII. Production of factor Xa exiting the tube was monitored with time during perfusion of the capillary with factor X (50 to 1500 nM) in the presence of factor VIIa (10 nM). Steady-state production of factor Xa as a function of [FX] was determined by chromogenic assay (Spectrozyme Xa) for a range of wall shear rates (25 to 3000 sec-1). Diffusion was found to play a major limiting role in FXa production for TF:30% phosphatidylserine (PS)/70% phosphatidylcholine (PC) surfaces. In contrast, TF/PC surfaces slowed the reaction sufficiently to enter a kinetically controlled regime where shear fluid had little effect on Km. In contrast with classical enzyme kinetic theory there was a three-fold increase in Vmax as shear increased from 25 to 300 sec-1. This finding implies a direct effect of shear on the kinetics of factor X activation by TF/FVIIa. The perfusion system is simple to use and offers the potential for studying the role of flow on a wide variety of enzymatic reactions related to coagulation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0026-2862
pubmed:author
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
327-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
The effects of shear rate on the enzymatic activity of the tissue factor-factor VIIa complex.
pubmed:affiliation
Mt. Sinai Medical Center, Department of Medicine, New York, New York 10029.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.