Linked Life Data

15568810

Source:http://linkedlifedata.com/resource/pubmed/id/15568810

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
48
pubmed:dateCreated
2004-11-30
pubmed:abstractText
Although the membrane-associated surfactant protein B (SP-B) is an essential component of lung surfactant, which is itself essential for life, the molecular basis for its activity is not understood. SP-B's biophysical functions can be partially mimicked by subfragments of the protein, including the C-terminus. We have used NMR to determine the structure of a C-terminal fragment of human SP-B that includes residues 63-78. Structure determination was performed both in the fluorinated alcohol hexafluoro-2-propanol (HFIP) and in sodium dodecyl sulfate (SDS) micelles. In both solvents, residues 68-78 take on an amphipathic helical structure, in agreement with predictions made by comparison to homologous saposin family proteins. In HFIP, the five N-terminal residues of the peptide are largely unstructured, while in SDS micelles, these residues take on a well-defined compact conformation. Differences in helical residue side chain positioning between the two solvents were also found, with better agreement between the structures for the hydrophobic face than the hydrophilic face. A paramagnetic probe was used to investigate the position of the peptide within the SDS micelles and indicated that the peptide is located at the water interface with the hydrophobic face of the helix oriented inward, the hydrophilic face of the helix oriented outward, and the N-terminal residues even farther from the micelle center than those on the hydrophilic face of the alpha-helix. Interactions of basic residues of SP-B with anionic lipid headgroups are known to have an impact on function, and these studies demonstrate structural ramifications of such interactions via the differences observed between the peptide structures determined in HFIP and SDS.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15187-94
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
NMR structures of the C-terminal segment of surfactant protein B in detergent micelles and hexafluoro-2-propanol.
pubmed:affiliation
Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X9, Canada. valerie@ physics.mun.ca
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't