Linked Life Data

7569776

Source:http://linkedlifedata.com/resource/pubmed/id/7569776

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-11-22
pubmed:abstractText
Most group A streptococcal strains bind immunoglobulins (Ig) and fibrinogen to their cell walls. It is shown in this paper that the Ig-binding of three different strains was much weaker at 37 degrees C than at room temperature (20 degrees C), whereas the fibrinogen binding was unaffected by temperature. The binding properties and molecular sizes of two purified group A streptococcal cell surface proteins from the M protein family were studied at various temperatures, M1 protein with affinity for IgG, fibrinogen and albumin, and protein Sir22 with affinity for IgA and IgG. Both proteins appeared as monomers which bound all their ligands, including fibrinogen, very weakly at 37 degrees C, and as strongly binding dimers at 10 and 20 degrees C. Furthermore, the results demonstrated that the plasma protein binding of the bacterial proteins was allosterically regulated, i.e. the binding of a ligand to one site modulated the binding of a ligand to a second site. For example, the binding of albumin or IgG to purified M1 protein at 10 and 20 degrees C strongly enhanced the binding of fibrinogen at 37 degrees C. This indicates that the high affinity dimer form of the bacterial proteins can be stabilized at 37 degrees C, a possible explanation for the strong fibrinogen binding of whole bacteria. Finally, the sizes and binding properties of three M1 protein fragments were studied and the results indicated that the centrally located C-repeats, which are conserved among the members of the M protein family, are important for the formation of the high-affinity dimers of the bacterial proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0300-9475
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
433-41
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Allosteric and temperature effects on the plasma protein binding by streptococcal M protein family members.
pubmed:affiliation
Department of Cell and Molecular Biology, Lund University, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't