Linked Life Data

9398245

Source:http://linkedlifedata.com/resource/pubmed/id/9398245

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
1998-1-6
pubmed:abstractText
A question of fundamental importance concerning the biosynthesis of integral membrane proteins is whether transmembrane secondary structure can insert spontaneously into a lipid bilayer. It has proven to be difficult to address this issue experimentally because of the poor solubility in aqueous solution of peptides and proteins containing these extremely hydrophobic sequences. We have identified a system in which the kinetics and thermodynamics of alpha-helix insertion into lipid bilayers can be studied systematically and quantitatively using simple spectroscopic assays. Specifically, we have discovered that a 36-residue polypeptide containing the sequence of the C-helix of the integral membrane protein bacteriorhodopsin exhibits significant solubility in aqueous buffers free of both detergents and denaturants. This helix contains two aspartic acid residues in the membrane-spanning region. At neutral pH, the peptide associates with lipid bilayers in a nonhelical and presumably peripheral conformation. With a pKa of 6.0, the peptide inserts into the bilayer as a transbilayer alpha-helix. The insertion reaction proceeds rapidly at room temperature and is fully reversible.
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
9
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15177-92
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Spontaneous, pH-dependent membrane insertion of a transbilayer alpha-helix.
pubmed:affiliation
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA. hunt@sid.bio.columbia.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.