Linked Life Data

6952939

Source:http://linkedlifedata.com/resource/pubmed/id/6952939

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1982-8-26
pubmed:abstractText
The active-site sulfhydryl group in the enzyme thiosulfate sulfurtransferase (rhodanese; thiosulfate:cyanide sulfurtransferase; EC 2.8.1.1) is alkylated rapidly by iodoacetic acid in the free enzyme form, E, with complete loss of sulfurtransferase activity. Iodoacetic acid is completely ineffective with the sulfur-substituted form of the enzyme, ES. Iodoacetamide, on the other hand, has no effect on either enzyme form. The competitive enzyme inhibitor, toluenesulfonic acid, protects against inactivation in a strictly competitive way and analysis gives an apparent binding constant for toluenesulfonic acid of 12.5 mM, which is in agreement with studies of its effect on the catalyzed reaction. These results are taken to indicate that iodoacetic acid is an affinity analog for the substrate, thiosulfate, and inactivates because it can use the specific thiosulfate binding interactions, correctly orient its reactive center and displace intraprotein interactions which appear to protect the active-site sulfhydryl group in the E form.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
702
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
173-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
The specificity of active-site alkylation by iodoacetic acid in the enzyme thiosulfate sulfurtransferase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't