Ion Gutiérrez-Aguirre

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Equinatoxin-II is a eukaryotic pore-forming toxin belonging to the family of actinoporins. Its interaction with model membranes is largely modulated by the presence of sphingomyelin. We have used large unilamellar vesicles and lipid monolayers to gain further information about this interaction. The coexistence of gel and liquid-crystal lipid phases in(More)
Amyloid-induced toxicity is a well-known phenomenon but the molecular background remains unclear. One hypothesis relates toxicity to amyloid-membrane interactions, predicting that amyloid oligomers make pores into membranes. Therefore, the toxicity and membrane interaction of prefibrillar aggregates and individual oligomers of a non-pathological yet highly(More)
The genetic variability of Grapevine fanleaf virus (GFLV) was assessed within RNA2 of nine isolates from Vitis vinifera cv. Volovnik in a vineyard in Slovenia by immunocapture (IC)–reverse transcription (RT)–polymerase chain reaction (PCR)–restriction length fragment polymorphism (RFLP), followed by cloning and sequencing. Four, one, and nine distinct StyI(More)
Equinatoxin II (EqtII) belongs to a unique family of 20-kDa pore-forming toxins from sea anemones. These toxins preferentially bind to membranes containing sphingomyelin and create cation-selective pores by oligomerization of 3-4 monomers. In this work we have studied the binding of EqtII to lipid membranes by the use of lipid monolayers and surface plasmon(More)
Sphingomyelin (SM) is abundant in the outer leaflet of the cell plasma membrane, with the ability to concentrate in so-called lipid rafts. These specialized cholesterol-rich microdomains not only are associated with many physiological processes but also are exploited as cell entry points by pathogens and protein toxins. SM binding is thus a widespread and(More)
Protein aggregation is central to most neurodegenerative diseases, as shown by familial case studies and by animal models. A modified 'amyloid cascade' hypothesis for Alzheimer's disease states that prefibrillar oligomers, also called amyloid-beta-derived diffusible ligands or globular oligomers, are the responsible toxic agent. It has been proposed that(More)
Obtaining pure virus suspensions is an essential step in many applications, such as vaccine production, antibody production, sample preparation for procedures requiring enrichment in viruses and other in vitro characterizations. Purification procedures usually consist of complex, long lasting and tedious protocols involving several ultracentrifugation(More)
Human stefin B, from the family of cystatins, is used as a model amyloidogenic protein in studies of the mechanism of amyloid fibril formation and related cytotoxicity. Interaction of the protein's prefibrillar oligomers/aggregates with predominantly acidic phospholipid membranes is known to correlate with cellular toxicity. In the present study, we(More)
Rotaviruses are one of the major causes of diarrhea in infants and children under 5 years old, especially affecting developing countries. In natural disasters, fecal matter and potable waters can mix, allowing low, yet infective, concentrations of rotavirus to be present in water supplies, constituting a risk for the population. Any of the most commonly(More)
Actinoporins are eukaryotic pore-forming proteins that create 2-nm pores in natural and model lipid membranes by the self-association of four monomers. The regions that undergo conformational change and form part of the transmembrane pore are currently being defined. It was shown recently that the N-terminal region (residues 10-28) of equinatoxin, an(More)