Publication Date:
1996-08-09
Description:
The diphtheria toxin transmembrane (T) domain was spin-labeled at consecutive residues in a helical segment, TH9. After binding of the T domain to membranes at low pH, the nitroxide side chains generated by spin labeling were measured with respect to their frequency of collision with polar and nonpolar reagents. The data showed that the helical structure of TH9 in solution is conserved, with one face exposed to water and the other to the hydrophobic interior of the bilayer. Measurement of the depth of the nitroxide side chains from the membrane surfaces revealed an incremental change of about 5 angstroms per turn, which is consistent with a transmembrane orientation of an alpha helix. These results indicate that the helix forms the lining of a transmembrane water-filled channel.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Oh, K J -- Zhan, H -- Cui, C -- Hideg, K -- Collier, R J -- Hubbell, W L -- AI-22021/AI/NIAID NIH HHS/ -- AI-22848/AI/NIAID NIH HHS/ -- EY-05216/EY/NEI NIH HHS/ -- New York, N.Y. -- Science. 1996 Aug 9;273(5276):810-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-7008, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8670424" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Diphtheria Toxin/*chemistry/genetics
;
Edetic Acid/analogs & derivatives
;
Electron Spin Resonance Spectroscopy
;
Hydrogen-Ion Concentration
;
*Lipid Bilayers
;
Models, Molecular
;
Molecular Sequence Data
;
Mutation
;
Nickel
;
Oxygen
;
Phospholipids
;
*Protein Structure, Secondary
;
*Protein Structure, Tertiary
;
Spin Labels
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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