Linked Life Data

7093289

Source:http://linkedlifedata.com/resource/pubmed/id/7093289

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1982-9-24
pubmed:abstractText
Steady-state kinetic studies were made on the very efficient enzyme hydrolysis of acetylthiocholine by electric eel acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) in glycerol/water solvents of increased viscosity. Determinations of the very fast minimum substrate association rate constants kmin, (2 . 10(8) M-1 . s-1 at I approximately 0.1 M and 25 degrees C) from the Michaelis parameters, V/(Km[E0]), were made at low substrate concentrations in order to obtain kmin directly. kmin was shown to be strongly dependent upon viscosity, which is characteristic of a diffusion-controlled reaction. kmin is as large or larger than plausible models for a simple diffusion-controlled reaction between a charged enzyme and substrate would suggest. Enhancement of the diffusion-controlled reaction through nonspecific binding of substrate to the highly negatively charged acetylcholinesterase followed by two-dimensional surface diffusion in a random walk to the active site may be a factor in this enzyme mechanism. Evidence for this comes from the viscosity dependence of kmin. Using the surface diffusion model it is estimated that the binding-site target area on acetylcholinesterase is effectively increased a minimum of 8-fold.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
704
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
52-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Kinetics of acetylthiocholine binding to electric eel acetylcholinesterase in glycerol/water solvents of increased viscosity. Evidence for a diffusion-controlled reaction.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't