INVESTIGADORES
MORCELLE DEL VALLE Susana Raquel
congresos y reuniones científicas
Título:
Membrane composition influence on the hypotonic hemolysis protection.
Autor/es:
HERMET, M.; FAIT, M.E.; VÁZQUEZ, R.F.; MATÉ, S.; HERLAX, V.; MORCELLE, S.R.; BAKÁS, L.
Reunión:
Congreso; III LAFeBS-IX Iberoamerican Congress of Biophysics-XLV SAB; 2016
Resumen:
Bz-Arg-NHC10 and Bz-Arg-NHC12, two novel arginine-based cationicsurfactants, were synthesized in our laboratory using papain adsorbedonto polyamide as biocatalyst. Hemolytic and antihemolytic assays were performed using sheep (SRBC) and human (HRBC) erythrocytesin order to clarify the lytic mechanism of Bz-Arg-NHCn and the possiblerelationship between their effect and the lipid membrane composition.Results showed that the hemolytic effect of Bz-Arg-NHC10 wasalmost 50% lower than that of Bz-Arg-NHC12. A biphasic behaviorwas also observed for both surfactants in hypotonic media, showing awide range of protective concentrations in the case of HRBC. Moreover,the protective effect on SRBC was 50% lower than that observedon HRBC. Although no general correlation was found between the erythrocytevolume expansion and the antihemolytic potency, a 15% incrementin the critical hemolytic volume was evidenced for SBRC treatedwith Bz-Arg-NHC12. Generalized polarization (GP) measurements usingLaurdan were aim to analyze this differential interaction betweenBz-Arg-NHCn and the erythrocyte membranes. A GP increment wasobserved in all cases except for SRBC treated with Bz-Arg-NHC12,revealing that the protective mechanism in this case does not involvechanges in the membrane packing density. Inorganic phosphorus assaysevidenced that the amount of solubilized phospholipids (PLs) inthe supernatant of HRBC incubated with Bz-Arg-NHCn at sublyticconcentrations was higher than that for SRBC. In the case of HRBCtreated with Bz-Arg-NHCn, the presence of microvesicles in the supernatantwas observed using Transmission Electronic Microscopy (TEM),whereas no microvesicles were found for SRBC. Results suggest thatBz-Arg-NHCn showed a differential lytic/protective mechanism dependingcrucially on the lipid membrane composition, and therefore in its biophysical properties.