Biophysical approaches in the study of biomembrane solubilization: quantitative assessment and the role of lateral inhomogeneity

Abstract

Detergents are amphiphilic molecules widely used to solubilize biological membranes and/or extract their components. Nevertheless, because of the complex composition of biomembranes, their solubilization by detergents has not been systematically studied. In this review, we address the solubilization of erythrocytes, which provide a relatively simple, robust and easy to handle biomembrane, and of biomimetic models, to stress the role of the lipid composition on the solubilization process. First, results of a systematic study on the solubilization of human erythrocyte membranes by different series of non-ionic (Triton, CxEy, Brij, Renex, Tween), anionic (bile salts) and zwitterionic (ASB, CHAPS) detergents are shown. Such quantitative approach allowed us to propose R e sat -the effective detergent/lipid molar ratio in the membrane for the onset of hemolysis as a new parameter to classify the solubilization efficiency of detergents. Second, detergent-resistant membranes (DRMs) obtained as a result of the partial solubilization of erythrocytes by TX-100, C 12 E 8 and Brij detergents are examined. DRMs were characterized by their cholesterol, sphingolipid and specific proteins content, as well as lipid packing. Finally, lipid bilayers of tuned lipid composition forming liposomes were used to investigate the solubilization process of membranes of different compositions/phases induced by Triton X-100. Optical microscopy of giant unilamellar vesicles revealed that pure phospholipid membranes are fully solubilized, whereas the presence of cholesterol renders the mixture partially or even fully insoluble, depending on the composition. Additionally, Triton X-100 induced phase separation in raft-like mixtures, and selective solubilization of the fluid phase only.

Proteomic and Bioinformatics Analysis of Membrane Lipid Domains after Brij 98 Solubilization of Uninduced and Phenobarbital-Induced Rat Liver Microsomes: Defining the Membrane Localization of the P450 Enzyme System

“…Originally researchers used the non-polar, Triton X-100 to solubilize the membrane, and the ordered microdomains were isolated on a discontinuous sucrose gradient after ultracentrifugation (Brown and London, 1997;London and Brown, 2000). Subsequently, other detergents have been used for this purpose (Riske et al, 2017). One of the limitations of many of the detergents used to isolate ordered lipid microdomains is that the microdomains are only resistant to solubilization at 4°C.…”

Structural Insights into Escherichia coli Shiga Toxin (Stx) Glycosphingolipid Receptors of Porcine Renal Epithelial Cells and Inhibition of Stx-Mediated Cellular Injury Using Neoglycolipid-Spiked Glycovesicles

“…A precise analysis of the lipid environment of Stx-binding GSLs of LLC-PK1 and PK-15 cells is, therefore, pending using, for example, lipid raft-analog detergent-resistant membranes resembling the liquid-ordered membrane phase [93,94]. Detergent-resistant membranes can readily be isolated which have many properties expected of lipid rafts [95] and represent useful biophysical approaches in the study of biomembrane lateral inhomogeneity [96]. The employment of this procedure for characterization of the lipid composition of such lipid raft-resembling membrane microdomains prepared from Stx-sensitive endothelial cells has been recently reviewed [97].…”

Soap, water, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): an ancient handwashing strategy for preventing dissemination of a novel virus

“…This disruption allows the contents of the bacteria/virus to be released or may allow nucleases/proteases or additional formulation components to enter the bacterium/viral capsid. This process may be hindered by the presence of cholesterol in the cell membrane ( Riske et al, 2017 ). The cell wall composition may also influence the rate at which the process of lipid disruption occurs ( Lete et al, 2019 ).…”