Mitochondrial porin incorporation into black lipid membranes: ionic and gating contribution to the total current

Micelli, S.; Gallucci, E.; Meleleo, Daniela; Stipani, Valentina; Picciarelli, V.

doi:10.1016/s1567-5394(02)00003-8

Cited by 24 publications

(17 citation statements)

References 49 publications

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“…One characteristic of the cholesterol molecule is the rigid planar ring that probably manages all the interactions with proteins; examples of cholesterol-dependent proteins include prominin, synaptophysin, platelet-derived growth factor receptor, hemolysin, prions (Roper et al, 2000;Thiele et al, 2000;Liu et al, 2000;Song et al, 1996;Sanghera and Pinheiro, 2002), porins (Freitag et al, 1982;Popp et al, 1995;Micelli et al, 2002), magainin-2 (Gallucci et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

Effect of Sterols on β-Amyloid Peptide (AβP 1–40) Channel Formation and their Properties in Planar Lipid Membranes

Micelli

Meleleo

Picciarelli

et al. 2004

Biophysical Journal

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We investigate the role played by membrane composition on the interaction and self-assembly of beta-amyloid peptide (AbetaP1-40) during pore formation in planar lipid membranes (PLMs). Incorporation studies showed that AbetaP does not interact with zwitterionic membranes made up of phosphatidylcholine, whereas the addition of cholesterol or ergosterol to the membranes leads to channel formation. Among the PLMs used, a higher propensity of AbetaP to form channels at low applied potential (+/-20 mV) was observed in 7-dehydrocholesterol and in oxidized cholesterol PLMs. These channels present long lifetimes, high-occurrence frequencies, and are voltage dependent. In particular, the AbetaP channel in oxidized cholesterol showed anion selectivity. Thus cholesterol (and sterols in general) could be considered as targets for AbetaP, which prevents the fibrillation process by increasing incorporation into membranes. Furthermore, by switching the channel selectivity versus anions, cholesterol helps to reduce the imbalance of the cellular ions, calcium included, induced by membrane depolarization, which could be one of the factors responsible for cytotoxicity in Alzheimer's disease.

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Section: Discussionmentioning

confidence: 99%

Effect of Sterols on β-Amyloid Peptide (AβP 1–40) Channel Formation and their Properties in Planar Lipid Membranes

Micelli

Meleleo

Picciarelli

et al. 2004

Biophysical Journal

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“…The values of parameters A and B were used to transform the Vlh value into capacitance data, as described by Micelli et al [23].…”

Section: Discussionmentioning

confidence: 99%

Studies on the Effect of Salts on the Channel Activity of Kissper, a Kiwi Fruit Peptide

Meleleo¹

2012

TONUTRAJ

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Fruits and vegetables are known to possess health benefits: indeed, they contain a large number of bioactive molecules with a positive impact on human health. Dietary proteins possess specific biological properties which make these components potential ingredients of functional or health-promoting foods. Many of these properties are attributed to physiologically-active peptides encrypted in protein molecules.Kissper, a 39-residue peptide isolated from kiwi fruit (Actinidia deliciosa), derives from the processing of kiwellin, a well-represented novel allergenic protein present in the edible part of the fruit. Kissper has six cysteine residues forming three disulfide bridges. This cysteine pattern is similar, but not identical, to those observed in some plant and animal proteins, including toxins involved in defence mechanisms. We show that kissper forms ion channels in DOPS:DOPE:POPC PLMs in different media, such as KCl, potassium gluconate, potassium citrate and potassium phosphate monobasic. Kissper's channels show a strong voltage dependence in all media used, and an estimated pore diameter in the range from 1.9 to 7.6 Å in KCl medium. Finally, kissper's pores shift selectivity from anions to neutral to cations, depending on the nature of the salt solutions. Therefore we propose the kissper as a novel nutraceutical component of kiwi fruit that may have a positive impact on human health due to its channel-like pathways which modulate membrane permeability. The kissper action might promote the adsorption of substances, in particular, within the gastrointestinal tract, helping digestion, preventing constipation and harmful accumulation of metabolites.

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“…However, there are also considerable amounts of Ch in neuronal plasmalemma and in lipid rafts. One interesting aspect of the Ch molecule seems to be its affinity for many proteins such as porins [22, 23], for peptides such as magainin-2 [24], A β P1-40 and A β P1-42 [14], and for peptides associated with myelin; examples of Ch-dependent proteins are prominin, synaptophysin, platelet-derived growth factor receptor, hemolysin, acetylcholine-receptor, peripheral myelin protein 22, and prions [25–31]. In particular, it has been demonstrated that Ch at a concentration of 33% in model membranes and in vesicles can favour the transition of A β P1-40 and human cytoplasmic domain of myelin protein zero into alpha helix [32].…”

Section: Discussionmentioning

confidence: 99%

Choline Modulation of the Aβ P1-40 Channel Reconstituted into a Model Lipid Membrane

Meleleo

Notarachille

Micelli

2010

International Journal of Alzheimer's Disease

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Nicotinic acetylcholine receptors (AChRs), implicated in memory and learning, in subjects affected by Alzheimer's disease result altered. Stimulation of α7-nAChRs inhibits amyloid plaques and increases ACh release. β-amyloid peptide (AβP) forms ion channels in the cell and model phospholipid membranes that are retained responsible in Alzheimer disease. We tested if choline, precursor of ACh, could affect the AβP1-40 channels in oxidized cholesterol (OxCh) and in palmitoyl-oleoyl-phosphatidylcholine (POPC):Ch lipid bilayers. Choline concentrations of 5 × 10−11 M–1.5 × 10−8 M added to the cis- or trans-side of membrane quickly increased AβP1-40 ion channel frequency (events/min) and ion conductance in OxCh membranes, but not in POPC:Ch membranes. Circular Dichroism (CD) spectroscopy shows that after 24 and 48 hours of incubation with AβP1-40, choline stabilizes the random coil conformation of the peptide, making it less prone to fibrillate. These actions seem to be specific in that ACh is ineffective either in solution or on AβP1-40 channel incorporated into PLMs.

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Mitochondrial porin incorporation into black lipid membranes: ionic and gating contribution to the total current

Cited by 24 publications

References 49 publications

Effect of Sterols on β-Amyloid Peptide (AβP 1–40) Channel Formation and their Properties in Planar Lipid Membranes

Effect of Sterols on β-Amyloid Peptide (AβP 1–40) Channel Formation and their Properties in Planar Lipid Membranes

Studies on the Effect of Salts on the Channel Activity of Kissper, a Kiwi Fruit Peptide

Choline Modulation of the Aβ P1-40 Channel Reconstituted into a Model Lipid Membrane

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