Interactions between magainin 2 and Salmonella typhimurium outer membranes: Effect of lipopolysaccharide structure

Journal Article · Tue Jun 18 00:00:00 EDT 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00238a008· OSTI ID:5029201

Rana, F R; Macias, E A; Sultany, C M; Modzrakowski, M C; Blazyk, J ^[1]

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1. Ohio Univ., Athens (United States)

The role of the outer membrane and lipopolysaccharide (LPS) in the interaction between the small cationic antimicrobial peptide magainin 2 and the Gram-negative cell envelope was studied by FT-IR spectroscopy. Magainin 2 alters the thermotropic properties of the outer membrane-peptidoglycan complexes from wild-type Salmonella typhimurium and a series of LPS mutants which display differential susceptibility to the bactericidal activity of cationic antibiotics. These results are correlated with the LPS phosphorylation pattern and charge (characterized by high-resolution {sup 31}P NMR) and outer membrane lipid composition, and are compared to the bactericidal susceptibility. LPS mutants show a progressive loss of resistance to killing by magainin 2 as the length of the LPS polysaccharide moiety decreases. Disordering of the outer membrane lipid fatty acyl chains by magainin 2, however, depends primarily upon the magnitude of PLS charge rather than the length of the LPS polysaccharide. While disruption of outer membrane structure most likely is not the primary factor leading to cell death, the susceptibility of Gram-negative cells to magainin 2 is associated with factors that facilitate the transport of the peptide across the outer membrane, such as the magnitude and location of LPS charge, and concentration of LPS in the outer membrane, outer membrane molecular architecture, and the presence or absence of the O-antigen side chain.

• OSTI ID: 5029201
• Journal Information: Biochemistry; (United States), Vol. 30:24; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
GLYCOPROTEINS
NUCLEAR MAGNETIC RESONANCE
LIPOPOLYSACCHARIDES
PHOSPHORYLATION
ANTIMICROBIAL AGENTS
PHOSPHORUS 31
SALMONELLA TYPHIMURIUM
TEMPERATURE DEPENDENCE
ANTI-INFECTIVE AGENTS
BACTERIA
CARBOHYDRATES
CHEMICAL REACTIONS
DRUGS
ISOTOPES
LIGHT NUCLEI
LIPIDS
MAGNETIC RESONANCE
MICROORGANISMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
POLYSACCHARIDES
PROTEINS
RESONANCE
SACCHARIDES
SALMONELLA
STABLE ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics