Membrane composition influence on the hypotonic hemolysis protection induced by arginine-based surfactants

HERMET, M.; FAIT, M.E.; VÁZQUEZ, R.F.; MATÉ, S.; HERLAX, V.; MORCELLE, S.R.; BAKÁS, L.

San Miguel de Tucumán

Congreso; III Latin American Federation of Biophysical Societies (LAFeBS) ? IX IberoAmerican Congress of Biophysics ? XLV Reunion Anual SAB 2016; 2016

Sociedad Argentina de Biofísica

Bz-Arg-NHC10 and Bz-Arg-NHC12, two novel arginine-based cationic surfactants, were synthesized in our laboratory using papain adsorbed onto polyamide as biocatalyst. Hemolytic and antihemolytic assays were performed using sheep (SRBC) and human (HRBC) erythrocytes in order to clarify the lytic mechanism of Bz-Arg-NHCn and the possible relationship between their effect and the lipid membrane composition. Results showed that the hemolytic effect of Bz-Arg-NHC10 was almost 50% lower than that of Bz-Arg-NHC12. A biphasic behavior was also observed for both surfactants in hypotonic media, showing a wide range of protective concentrations in the case of HRBC. Moreover, the protective effect on SRBC was 50% lower than that observed on HRBC. Although no general correlation was found between the erythrocyte volume expansion and the antihemolytic potency, a 15% increment in the critical hemolytic volume was evidenced for SBRC treated with Bz-Arg-NHC12. Generalized polarization (GP) measurements using Laurdan were aim to analyze this differential interaction between Bz-Arg-NHCn and the erythrocyte membranes. A GP increment was observed in all cases except for SRBC treated with Bz-Arg-NHC12, revealing that the protective mechanism in this case does not involve changes in the membrane packing density. Inorganic phosphorus assays evidenced that the amount of solubilized phospholipids (PLs) in the supernatant of HRBC incubated with Bz-Arg-NHCn at sublytic concentrations was higher than that for SRBC. In the case of HRBC treated with Bz-Arg-NHCn, the presence of microvesicles in the supernatant was observed using Transmission Electronic Microscopy (TEM), whereas no microvesicles were found for SRBC. Results suggest that Bz-Arg-NHCn showed a differential lytic/protective mechanism depending crucially on the lipid membrane composition, and therefore in its biophysical properties.