Linked Life Data

3607056

Source:http://linkedlifedata.com/resource/pubmed/id/3607056

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1987-9-21
pubmed:abstractText
The insertion of the A domain of diphtheria toxin into model membranes has been shown to be both pH- and temperature-dependent (Hu and Holmes (1984) J. Biol. Chem. 259, 12226-12233). In this report, the insertion behavior of two mutant proteins of diphtheria toxin, CRM197 and CRM9, was studied and compared to that of wild-type toxin. Results indicated that both CRM197 and CRM9 resembled toxin with respect to the pH-dependence of binding to negatively-charged liposomes at room temperature. However, CRM197 differed from toxin with respect to both the pH- and temperature-dependence of fragment A insertion; fragment A197 inserts more readily into the bilayer at 0 degrees C and low pH or at neutral pH and room temperature than does wild type fragment A under these same conditions. This result indicates that the single amino acid substitution in the A domain of CRM197 facilitates entry of fragment A197 into the membrane, suggesting that CRM197 may be conformationally distinct from native toxin. In fact, the fluorescence spectra of CRM197 and wild-type toxin as well as their respective tryptic peptide patterns indicate that, at pH 7, CRM197 more closely resembles the acid form of wild-type toxin than the native form of toxin. These data suggest that CRM197 may be naturally in a more 'insertion-competent' conformation. In contrast, the mutation in the B domain of CRM9 which results in a 1000-fold decrease in binding affinity for plasma membrane receptors apparently does not cause a change in either the insertion of fragment A9 or the lipid-binding properties of CRM9 relative to toxin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins, http://linkedlifedata.com/resource/pubmed/chemical/CRM197 (non-toxic variant of..., http://linkedlifedata.com/resource/pubmed/chemical/Diphtheria Toxin, http://linkedlifedata.com/resource/pubmed/chemical/Intercellular Signaling Peptides..., http://linkedlifedata.com/resource/pubmed/chemical/Lipid Bilayers, http://linkedlifedata.com/resource/pubmed/chemical/Liposomes, http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cell Surface, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cholinergic, http://linkedlifedata.com/resource/pubmed/chemical/Trypsin, http://linkedlifedata.com/resource/pubmed/chemical/heparin-binding EGF-like growth...
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
902
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24-30
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Single mutation in the A domain of diphtheria toxin results in a protein with altered membrane insertion behavior.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.