TY - JOUR

T1 - Structural Organization of Cardiolipin-Containing Vesicles as Models of the Bacterial Cytoplasmic Membrane

AU - Luchini, Alessandra

AU - Cavasso, Domenico

AU - Radulescu, Aurel

AU - D'Errico, Gerardino

AU - Paduano, Luigi

AU - Vitiello, Giuseppe

PY - 2021/7/20

Y1 - 2021/7/20

N2 - The bacterial cytoplasmic membrane is the innermost bacterial membrane and is mainly composed of three different phospholipid species, i.e., phosphoethanolamine (PE), phosphoglycerol (PG), and cardiolipin (CL). In particular, PG and CL are responsible for the negative charge of the membrane and are often the targets of cationic antimicrobial agents. The growing resistance of bacteria toward the available antibiotics requires the development of new and more efficient antibacterial drugs. In this context, studying the physicochemical properties of the bacterial cytoplasmic membrane is pivotal for understanding drug-membrane interactions at the molecular level as well as for designing drug-testing platforms. Here, we discuss the preparation and characterization of PE/PG/CL vesicle suspensions, which contain all of the main lipid components of the bacterial cytoplasmic membrane. The vesicle suspensions were characterized by means of small-angle neutron scattering, dynamic light scattering, and electron paramagnetic spectroscopy. By combining solution scattering and spectroscopy techniques, we propose a detailed description of the impact of different CL concentrations on the structure and dynamics of the PE/PG bilayer. CL induces the formation of thicker bilayers, which exhibit higher curvature and are overall more fluid. The experimental results contribute to shed light on the structure and dynamics of relevant model systems of the bacterial cytoplasmic membrane.

AB - The bacterial cytoplasmic membrane is the innermost bacterial membrane and is mainly composed of three different phospholipid species, i.e., phosphoethanolamine (PE), phosphoglycerol (PG), and cardiolipin (CL). In particular, PG and CL are responsible for the negative charge of the membrane and are often the targets of cationic antimicrobial agents. The growing resistance of bacteria toward the available antibiotics requires the development of new and more efficient antibacterial drugs. In this context, studying the physicochemical properties of the bacterial cytoplasmic membrane is pivotal for understanding drug-membrane interactions at the molecular level as well as for designing drug-testing platforms. Here, we discuss the preparation and characterization of PE/PG/CL vesicle suspensions, which contain all of the main lipid components of the bacterial cytoplasmic membrane. The vesicle suspensions were characterized by means of small-angle neutron scattering, dynamic light scattering, and electron paramagnetic spectroscopy. By combining solution scattering and spectroscopy techniques, we propose a detailed description of the impact of different CL concentrations on the structure and dynamics of the PE/PG bilayer. CL induces the formation of thicker bilayers, which exhibit higher curvature and are overall more fluid. The experimental results contribute to shed light on the structure and dynamics of relevant model systems of the bacterial cytoplasmic membrane.

KW - ANIONIC PHOSPHOLIPIDS

KW - LIPID-MEMBRANES

KW - CHOLESTEROL

KW - BILAYERS

KW - PHOSPHATIDYLETHANOLAMINE

KW - MIXTURES

KW - BEHAVIOR

KW - SPECTRA

KW - FUSION

KW - VIRUS

U2 - 10.1021/acs.langmuir.1c00981

DO - 10.1021/acs.langmuir.1c00981

M3 - Journal article

C2 - 34213914

VL - 37

SP - 8508

EP - 8516

JO - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 28

ER -