Anomalous phase behaviour of glycolipid self-assembly tuned by sugar headgroup surface arrangement
Abstract
Data di Pubblicazione:
2007
Citazione:
Anomalous phase behaviour of glycolipid self-assembly tuned by sugar headgroup surface arrangement / E. del Favero, P. Brocca, L.F. Cantù, M. Corti, A. Raudino. - In: EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS. - ISSN 0175-7571. - 36:Suppl. 1(2007 Jul), pp. S111-S111. [10.1007/s00249-007-0178-7]
Abstract:
We present anomalous mesophase behavior of single component,
non-added salt solutions of a family of membrane glycolipid bearing
large headgroups: the gangliosides. Contrary to one of the
mainstays of the colloid science, that the aggregation number of amphiphile
aggregates grows with concentration, an anomalous region
is found at intermediate concentrations of several of those glycolipid
solutions, where a sharp decrease of the aggregation number
occurs. The conventional picture of interacting micelles says that a
reduction in the molecular surface area (increase of aggregate size)
is paid to reduce intermicellar interactions when the solution is concentrated.
Furthermore we present data on a bilayer forming glycolipid
able to spontaneously vesiculate at high dilution and to concentrate
in a more curved aggregate shapes (ribbons) opposite to usual
paradigm telling that curvature can only decrease as concentration
increases. The common point at the base of this rich phenomenology
is that the amphiphilic surfaces made of bulky headgroups of
more or less complex sugar chains, is able of modifying molecular
surface area and protrusion from the aggregate, contributing to the
energy balance between inter- and intra-aggregate interaction. This
capability in the case of GM3 single component solutions have to be
played non-homogeneously on the aggregate surface to account for
edge energy cost of ribbons and finite membrane, and to allow for
asymmetric curvature of the two monolayeres of the vesicles. We
show that the different arrangements can be fine-tuned by physical
condition as, very interestingly, counter-ion substitution.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
E. del Favero, P. Brocca, L.F. Cantù, M. Corti, A. Raudino
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