Linked Life Data

8844651

Source:http://linkedlifedata.com/resource/pubmed/id/8844651

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-12-17
pubmed:abstractText
When 30 clinical isolates of Streptococcus pneumoniae, representing 16 capsular serotypes, were analysed by Western blot for production of the haemolytic toxin pneumolysin (Ply), all strains produced an immunoreactive band of similar intensity. However, six isolates of serotype 8 and two of type 7F expressed Ply whose mobility on SDS-PAGE was anomalously slow. Culture lysates from these strains also had low haemolytic activities compared with those for clinical isolates of other serotypes, suggesting the possibility of mutations affecting specific activity. Genes encoding Ply from one type 8 isolate and one type 7F isolate were cloned into Escherichia coli and sequenced. Compared with the published sequence for Ply, the deduced amino acid sequence for the type 8 Ply variant contained three amino acid substitutions, and the type 7F variant four amino acid substitutions. Both variants also had Val270 and Lys271 deleted. The variant Ply proteins were purified from recombinant E. coli expressing the cloned genes, and shown to have substantially reduced specific haemolytic activities [6.8 x 10(4) haemolytic units (HU)/mg and 2.3 x 10(4) HU/mg for type 8 Ply and type 7F Ply respectively] compared with Ply itself (1.2 x 10(6) HU/mg). Studies with chimeric toxin gene constructs indicated that both the reduced haemolytic specific activity and the anomalous electrophoretic mobility of the variant Plys were attributable to a single amino acid substitution (Thr172-->Ile).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0882-4010
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
71-83
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8844651-Amino Acid Sequence, pubmed-meshheading:8844651-Bacterial Proteins, pubmed-meshheading:8844651-Bacterial Vaccines, pubmed-meshheading:8844651-Cloning, Molecular, pubmed-meshheading:8844651-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:8844651-Escherichia coli, pubmed-meshheading:8844651-Genes, Bacterial, pubmed-meshheading:8844651-Genetic Variation, pubmed-meshheading:8844651-Hemolysis, pubmed-meshheading:8844651-Molecular Sequence Data, pubmed-meshheading:8844651-Pneumococcal Infections, pubmed-meshheading:8844651-Recombinant Fusion Proteins, pubmed-meshheading:8844651-Sequence Analysis, DNA, pubmed-meshheading:8844651-Sequence Homology, Amino Acid, pubmed-meshheading:8844651-Streptococcus pneumoniae, pubmed-meshheading:8844651-Streptolysins, pubmed-meshheading:8844651-Virulence
pubmed:year
1996
pubmed:articleTitle
Sequence variation in the Streptococcus pneumoniae pneumolysin gene affecting haemolytic activity and electrophoretic mobility of the toxin.
pubmed:affiliation
Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, Australia.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't