Lytic Agents, Cell Permeability, and Monolayer Penetrability

Abstract

Cell lysis induced by lytic agents is the terminal phase of a series of events leading to membrane disorganization and breadkdown with the release of cellular macromolecules. Permeability changes following exposure to lytic systems may range from selective effects on ion fluxes to gross membrane damage and cell leakage. Lysis can be conceived as an interfacial phenomenon, and the action of surface-active agents on erythrocytes has provided a model in which to investigate relationships between hemolysis and chemical structure, ionic charge, surface tension lowering, and ability to penetrate monolayers of membrane lipid components. Evidence suggests that lysis follows the attainment of surface pressures exceeding a "critical collapse" level and could involve membrane cholesterol or phospholipid. Similarities of chemical composition of membranes from various cell types could account for lytic responses observed on interaction with surface-active agents. Cell membranes usually contain about 20-30 % lipid and 50-75 % protein. One or two major phospholipids are present in all cell membranes, but sterols are not detectable in bacterial membranes other than those of the Mycoplasma group. The rigid cell wall in bacteria has an important bearing on their response to treatment with lytic agents. Removal of the wall renders the protoplast membrane sensitive to rapid lysis with surfactants. Isolated membranes of erythrocytes and bacteria are rapidly dissociated by surface-active agents. Products of dissociation of bacterial membranes have uniform behavior in the ultracentrifuge (sedimentation coefficients 2-3S). Dissociation of membrane proteins from lipids and the isolation and characterization of these proteins will provide a basis for investigating the specificity of interaction of lytic agents with biomembranes.The lysis or clearing of cell suspensions by lytic agents and lytic systems is the terminal phase of what has long been regarded as an interfacial phenomenon and has been the subject of intensive investigations for many decades. Much valuable information about the nature of cell surfaces had been deduced from these studies, at a time when the cellular membranes and walls were not amenable to the techniques of isolation now commonly employed. With the tremendous growth of our knowledge of the chemistry and structural organization of cell surfaces during the past 10 years, we are in a position to 227 s

Identification of a Binding Motif in the S5 Helix That Confers Cholesterol Sensitivity to the TRPV1 Ion Channel

“…1). Cholesterol is a major component of plasma membranes where it increases bilayer mechanical strength, thereby helping to prevent cell lysis (12). Importantly, cholesterol has been shown to modify the function of many classes of ion channels (for review, see Ref.…”

Comparative Transcriptomic and Phenotypic Analysis of the Responses ofBacillus cereusto Various Disinfectant Treatments

“…It belongs to the quaternary ammonium compounds (QACs), which are membrane-active agents (36). Their antibacterial activity has been suggested to be associated with the loss of integrity of the cytoplasmic membrane and subsequent leakage of intracellular material upon adsorption by bacterial cells (49). SH is extensively used in the food processing industry (66).…”

Effects of Quaternary-Ammonium-Based Formulations on Bacterial Community Dynamics and Antimicrobial Susceptibility

“…The hydrophobic tail subsequently interacts with the hydrophobic membrane core. At concentrations normally used for application to inanimate surfaces, QACs form mixed-micelle aggregates with hydrophobic membrane components that solubilize membrane and lyse the cells (41). Lethality occurs through generalized and progressive leakage of cytoplasmic materials (21).…”