Linked Life Data

3050452

Source:http://linkedlifedata.com/resource/pubmed/id/3050452

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-11-21
pubmed:abstractText
The alkaline pH induced difference spectra (270-310 nm) of three antigenically distinct forms of the botulinum neurotoxin (NT) types A, B and E were examined. When isolated from the cultures of Clostridium botulinum, type A NT is a fully toxic dichain (nicked) protein, type E is a mildly toxic single chain (unnicked) protein, and type B NT is a mixture of single and dichain proteins and near fully toxic. Trypsin nicks the single chain protein to the dichain and increases its toxicity (up to about 100 fold in type E). A strong difference spectrum peak at approximately 296 nm was found when types A, B or E NT were in the alkaline pH region. This peak was not observed at pH 4.0. For types A and B NT plots of difference absorptivity vs. pH were simple sigmoidal curves. The pK of phenolic moieties of tyrosine residues in both proteins were 10.9. Nearly all tyrosine residues in both proteins were ionized. The single chain type E, unlike type A and B NT, yielded a two step titration curve and pK values 11.3 and less than 7.5; about 60% of the total tyrosine residues present were ionized. The two step titration curve was not observed when the single chain protein was nicked with trypsin to the dichain type E NT. The titration curve of dichain type E NT, although complex, was more like those of type A and B NT.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0300-8177
pubmed:author
pubmed:issnType
Print
pubmed:volume
81
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
187-94
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Botulinum neurotoxin types A, B & E: pH induced difference spectra.
pubmed:affiliation
Food Research Institute, University of Wisconsin, Madison 53706.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't