Single-molecule conformational dynamics of viroporin ion channels regulated by lipid-protein interactions

Abstract

Highlights p7 viroporin forms pH and membrane dependent nanometer-size ion channels. AFM also shows much wider pH regulated channels (tens of nanometers). CSFV p7-induced pores are ruled by equilibrium conformational dynamics. Dynamics of crowded biomembrane systems were seen depending on lipid composition. Sub-nanometric channels may be involved in virus propagation. Virus pathogenicity may be related to the larger pores (1 ~ 10 nm in diameter).

The P. aeruginosa Type VI Secretion System Effector Tse5 Forms Ion-Selective Membrane Pores that Disrupt the Membrane Potential of Intoxicated Cells

“…4a shows representative PSDs obtained from Tse5-CTinduced currents. PSDs for all experiments display characteristic 1/f type spectra similar to those found in other proteolipidic pore assemblies 59 . Notably, for all conditions studied, PSDs at low frequencies (5-15 Hz band) follow a parabolic dependence with the applied voltage (Supplementary Fig.…”

“…3b). Such voltage-independent conductance has been reported in proteolipidic channels like the protein E of SARS-CoV-1 67,68 or the classical swine fever virus p7 59 , in total contrast with other channels that show strong voltage-dependent conductance, such as the antibiotic peptide alamethicin 69 , the antimicrobial peptide Syr-E 70 or melittin peptide from bee venom 71 . Furthermore, the minimal conductive unit obtained (G ~ 0.6 nS; Supplementary Table 1) is similar to that of wellknown protein channels, like the mitochondrial VDAC 72,73 , which forms 14-Å pores in the mitochondrial outer membrane.…”

Transport mechanisms of SARS-CoV-E viroporin in calcium solutions: Lipid-dependent Anomalous Mole Fraction Effect and regulation of pore conductance

“…In the so-called “barrel stave” pores the lipids are located only in the pore mouths while the hydrophilic regions of the protein are the ones forming the channel walls across the membrane in parallel to the membrane normal (Alamethicin seems to be the only peptide of this category) [ 12 , 13 ]. Alternatively, if the length of proteins does not match the hydrophobic length of the bilayer, arrangements in form of “toroidal” pores should appear involving either protein tilting or membrane deformation [ 12 , [14] , [15] , [16] , [17] ]. This could provoke that lipid head groups may be interspersed between the proteins as shown in Fig.…”

Dynorphin A induces membrane permeabilization by formation of proteolipidic pores. Insights from electrophysiology and computational simulations

“…1 A and Fig. 1 B, but might also represent the evolution of much larger dynamical structures that change their pore size with the addition or subtraction of DynA peptides [32] . In contrast to Fig.…”

“…2 B. Antibiotic lipopeptide Syryngomicyn- E (Syr-E) [57] is considerably less conductive (by one order of magnitude) than DynA, which is, in contrast, comparable to the pores formed by hydrophobic proteins SP-B and SP-C of the pulmonary surfactant (PM-B-C) [31] , the SARS Coronavirus Envelope Protein (SARS-E) [58] , the p7 protein of the Classical Swine Fever Virus (CSFV-p7) [32] , [59] , [60] and the bacterial peptide Tis-B [61] . Although the actual architecture of the pores formed by proteins in Fig.…”