Comparative study of the membrane-permeabilizing activities of mastoparans and related histamine-releasing agents in bacteria, erythrocytes, and mast cells

Abstract

The membrane-permeabilizing activities of mastoparans and related histamine-releasing agents were compared through measurements of K(+) efflux from bacteria, erythrocytes, and mast cells. Changes in bacterial cell viability, hemolysis, and histamine release, as well as in the shape of erythrocytes were also investigated. The compounds tested were mastoparans (HR1, a mastoparan from Polistes jadwagae, and a mastoparan from Vespula lewisii), granuliberin R, mast cell-degranulating peptide, and compound 48/80, as well as antimicrobial peptides, such as magainin I, magainin II, gramicidin S, and melittin. We used a K(+)-selective electrode to determine changes in the permeability to K(+) of the cytoplasmic membranes of cells. Consistent with the surface of mast cells becoming negatively charged during histamine release, due to the translocation of phosphatidylserine to the outer leaflet of the cytoplasmic membrane, histamine-releasing agents induced K(+) efflux from mast cells, dependent on their ability to increase the permeability of bacterial cytoplasmic membranes rich in negatively charged phospholipids. The present results demonstrated that amphiphilic peptides, possessing both histamine-releasing and antimicrobial capabilities, induced the permeabilization of the cytoplasmic membranes of not only bacteria but mast cells. Mastoparans increased the permeability of membranes in human erythrocytes at higher concentrations, and changed the normal discoid shape to a crenated form. The structural requirement for making the crenated form was determined using compound 48/80 and its constituents (monomer, dimer, and trimer), changing systematically the number of cationic charges of the molecules.

Cationic Antimicrobial Peptides Cytotoxicity on Mammalian Cells: An Analysis Using Therapeutic Index Integrative Concept

“…Our results showed that the toxic effects against mammalian cells are observed at concentrations higher than the one tested before. The toxic effects were observed around 70 lM, a concentration at least seven times higher than the MIC reported in the literature for its family members (Nakao et al 2011).…”

In situ potentiometric method to evaluate bacterial outer membrane-permeabilizing ability of drugs: Example using antiprotozoal diamidines

“…Although outer membranepermeabilizing action is traditionally studied with a microbiological assay using the synergistic effect of a hydrophobic antibiotic, we made potentiometric measurements with a K + -selective electrode coupled with tyrocidine A. The use of an ion-selective electrode for biochemical analysis is attractive, because the measurement is fast, easy, and continuous in a turbid cell suspension (Daugelavičius et al, 2000;Katsu et al, 1986;Komagoe et al, 2011;Nakao et al, 2011;Ohmizo et al, 2004;Yasuda et al, 2003). For the present purposes, it was indispensable to use a phospholipid-sensitive drug, which acted selectively on the cytoplasmic membrane, inducing the leakage of K + from the cytoplasm.…”

“…E. coli cells were grown at 37°C in a minimal salt medium supplemented with 1% polypepton, while S. aureus cells were grown at 37°C in a nutrient broth (Katsu et al, 1989;Nakao et al, 2011). Cells were harvested in the exponential phase of growth, washed twice with buffer (100 mM choline chloride and 50 mM 4-morpholinepropanesulphonic acid (Mops) -Tris, pH 7.2), and suspended in this buffer at a final concentration of 2 × 10 9 CFU/mL.…”

“…Colonies were counted after standing for 20 h at 37°C. The remaining cell suspension was centrifuged (14,000×g for 1 min), and the amount of K + in the supernatant was measured with a K + -selective electrode (Katsu et al, 1986(Katsu et al, , 1989Komagoe et al, 2011;Nakao et al, 2011). The total amount of K + was determined by disrupting the outer and cytoplasmic membranes of cells with polymyxin B .…”

Optimized Mucosal MVA Prime/ Soluble gp120 Boost Vaccination Regimen Induces Similar Antibody Responses as an Intramuscular Regimen

“…However, C48/80, represents a mixture of polymer species (18), and therefore it may not be an ideal adjuvant as regulatory agencies would most likely require a single active compound to provide the described adjuvant activity. To identify a potent adjuvant for nasally administered HIV-1 gp120, we compared the ability of several adjuvants— CT, MPL, C48/80, as well as mastoparan 7 (M7), a cationic antimicrobial mast cell activating peptide (19, 20)— to enhance serum anti-gp120 antibody responses.…”