IIBYT   23944
INSTITUTO DE INVESTIGACIONES BIOLOGICAS Y TECNOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
Non-linearity of ionic current dynamics across natural and artificial membranes: an emergent property under stressful conditions
Autor/es:
PERILLO, MARÍA ANGÉLICA; CORVALÁN NATALIA ANDREA
Revista:
Problems of Nonlinear Analysis in Engineering Systems PNAES
Editorial:
International Federation of Nonlinear Analysts and Academy of nonlinear Sciences
Referencias:
Lugar: Kazan; Año: 2020 vol. 53 p. 12 - 24
ISSN:
1727-687X
Resumen:
In our studies, typical complex behavior of critical biological and biophysical systems far from equilibrium was observed for the time series of transmembrane ion currents registered across BLMs in various experimental conditions. The self-similarity parameter (α) was obtained by the detrended fluctuation analysis (DFA) method applied on the fluctuation pattern of ionic currents.This allowed to elucidate different types of dynamic behaviors, observing a strong correlation between the structural variables of the system and the emergence of a self-correlated behavior of the temporal fluctuations pattern.The tendency to exhibit long-range correlations and the appearance of a 1/f type behavior in the temporal pattern of fluctuations increased with the content of cholesterol (CHO) and the intensity of the applied voltage. This behavior is associated with the formation of transient pores that, depending onthe phase state of the membrane, its composition, stability, and the magnitudeof the electric transmembrane potential applied, could precede the rupture ofthe bilayer by electroporation, or, may drive the system towards a fluctuating regime of dissipative character. The emergence and amplification of fluctuations occurred only under certain structural and organizational conditions of the membrane such as at temperatures close to the phase transition. However,in fluid bilayers this phenomenon can emerged at critical concentrations of some of the lipid components (e.g. CHO) allowing asymmetries in the molecular ordering and the adoption of a spatial superlattice pattern This strongly suggested that the existence of long-range correlations in the temporal fluctuations of current must necessarily obey a structural phenomenon(such as the formation of lipid pores) which requires the presence of defects or asymmetries in the molecular packing. Furthermore, we try to raise new questions related with the kind of background that allows protein channels as well as lipid or filter pores to acquire a percolated state allowing them to function as an extended network as well as the external conditions that triggers the different dynamics.