Linked Life Data

16453153

Source:http://linkedlifedata.com/resource/pubmed/id/16453153

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2006-4-28
pubmed:abstractText
Hanatoxin (HaTx) is an ellipsoidal-shaped peptide that binds to the voltage sensor of voltage-dependent channels. Of physicochemical interest, HaTx has a "ring" of charged residues around its periphery and a hydrophobic protrusion. It has previously been postulated that HaTx binds to and functions on the surface of membranes, but a recent fluorescent-quenching study has implied a fairly deep positioning of HaTx in the lipid bilayer membrane. We carried out numerous molecular dynamic simulations of HaTx1, a well-studied variant of HaTx, in fully hydrated phospholipid bilayers. The system reproduced the surface-binding mode of HaTx1, in which HaTx1 resided in the extracellular side (outer) of the water/membrane interface with the hydrophobic patch of HaTx1 facing the membrane interior. On the other hand, analyses with various parameter settings suggested that the surface-binding mode was unstable because of the substantial attractive electrostatic force between HaTx1 and the lipid head groups of the inner (opposite) leaflet. Compared with this electrostatic force, the energetic cost for membrane deformation involving meniscus formation appeared to be small. In an attempt to interpret the quenching data, we consider the possibility of dimpling (meniscus formation) that brings HaTx1 inward (only ~0.7-0.8 nm above the bilayer center), while accounting for the flexibility of both leaflets of the membrane and the long-range interaction between positively charged residues of the membrane-bound peptide and the polar head groups of the opposite leaflet of the membrane. It is suggested that molecular dynamics simulations taking into account the flexibility of the membrane surface is potentially useful in interpreting the fluorescence-quenching data.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0175-7571
pubmed:author
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
373-81
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Interaction between K+ channel gate modifier hanatoxin and lipid bilayer membranes analyzed by molecular dynamics simulation.
pubmed:affiliation
Department of Biochemistry, Teikyo University School of Medicine, Kaga, Itabashi, 173-8605, Tokyo, Japan. kazunet@med.teikyo-u.ac.jp.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't