Hydrophobic mismatch in gramicidin A prime /lecithin systems

Journal Article · Tue Jul 03 04:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00478a015· OSTI ID:6229739

Watnick, P I; Chan, S I ^[1]; Dea, P ^[2]

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1. California Institute of Technology, Pasadena (USA)
2. California State Univ., Los Angeles (USA)

Gramicidin A{prime} (GA{prime}) has been added to three lipid systems of varying hydrophobic thickness: dimyristoyllecithin (DML), dipalmitoyllecithin (DPL), and distearoyllecithin (DSL). The similarity in length between the hydrophobic portion of GA{prime} and the hydrocarbon chains of the lipid bilayers has been studied by using {sup 31}P and {sup 2}H NMR. Hydrophobic mismatch has been found to be most severe in the DML bilayer system and minimal in the case of DSL. In addition, the effects of hydrophobic mismatch on the cooperative properties of the bilayer have been obtained from {sup 2}H NMR relaxation measurements. The results indicate that incorporation of the peptide into the bilayer disrupts the cooperative director fluctuations characteristic of pure multilamellar lipid dispersions. Finally, the GA{prime}/lecithin ratio at which the well-known transformation from bilayer to reverse hexagonal (H{sub II}) phase occurs is shown to depend on the acyl chain length of the phospholipid. A rationale is proposed for this chain length dependence.

• OSTI ID: 6229739
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:26; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANISOTROPY
BACILLUS
BACTERIA
BIOPHYSICS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL SHIFT
DEUTERIUM COMPOUNDS
ESTERS
HYDROGEN COMPOUNDS
ISOTOPES
LECITHINS
LIGHT NUCLEI
LIPIDS
MAGNETIC RESONANCE
MEMBRANE PROTEINS
MEMBRANES
MICELLAR SYSTEMS
MICROORGANISMS
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHASE STUDIES
PHOSPHOLIPIDS
PHOSPHORUS 31
PHOSPHORUS ISOTOPES
PROTEINS
RELAXATION
RESONANCE
STABLE ISOTOPES
STRUCTURE-ACTIVITY RELATIONSHIPS