Linked Life Data

12081487

Source:http://linkedlifedata.com/resource/pubmed/id/12081487

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
2002-6-25
pubmed:abstractText
Pulmonary surfactant, a thin lipid/protein film lining mammalian lungs, functions in vivo to reduce the work of breathing and to prevent alveolar collapse. Analogues of two hydrophobic surfactant proteins, SP-B and SP-C, have been incorporated into therapeutic agents for respiratory distress syndrome, a pathological condition resulting from deficiency in surfactant. To facilitate rational design of therapeutic agents, a molecular level understanding of lipid interaction with surfactant proteins or their analogues in aqueous monolayer films is necessary. The current work uses infrared reflection-absorption spectroscopy (IRRAS) to determine peptide conformation and the effects of S-palmitoylation on the lipid interactions of a synthetic 13 residue N-terminal peptide [SP-C13(palm)(2)] of SP-C, in mixtures with 1,2-dipalmitoylphosphatidylcholine (DPPC) or 1,2-dipalmitoylphosphatidylglycerol (DPPG). Two Amide I' features, at approximately 1655 and approximately 1639 cm(-1) in the peptide IRRAS spectra, are assigned to alpha-helical peptide bonds in hydrophobic and aqueous environments, respectively. In binary DPPC/SP-C13(palm)(2) films, the proportion of hydrated/hydrophobic helix increases reversibly with surface pressure (pi), suggestive of the peptide being squeezed out from hydrophobic regions of the monolayer. No such effect was observed for DPPG/peptide monolayers, indicative of stronger, probably electrostatic, interactions. Depalmitoylation produced a weakened interaction with either phospholipid as deduced from IRRAS spectra and from pi-area isotherms. S-Palmitoylation may modulate peptide hydration and conformation in the N-terminal region of SP-C and may thus permit the peptide to remain in the film at the high surface pressures present during lung compression. The unique capability of IRRAS to detect the surface pressure dependence of protein or peptide structure/interactions in a physiologically relevant model for surfactant is clearly demonstrated.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8385-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Secondary structure and lipid interactions of the N-terminal segment of pulmonary surfactant SP-C in Langmuir films: IR reflection-absorption spectroscopy and surface pressure studies.
pubmed:affiliation
Department of Chemistry, Newark College of Arts and Science, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't