title: On a fully closed state of native human type-1 VDAC enriched in Nonidet P40.
abstract: There is indication that human type-1 VDAC/Porin31HL complexes, when purified from highly enriched cell membrane preparations of human B-lymphocytes by classical ion-exchange chromatography in the detergent Nonidet P40, rest in fully closed state, its N-terminus being accessible for mAbs. Cholesterol appears to be involved as a channel modulator. The channel switches to anion-selective or "open state" while being incorporated into black membranes at zero transmembrane potential. In this case, its N-terminus is hidden in the channel lumen. The cation-selective or "closed state" can be induced by transmembrane potentials beyond 30 mV, the N-terminus putatively now being positioned outside the channel lumen. The latter situation might allow one to decide if type-1 VDAC, preincubated with adequate antibodies against its N-terminal part, would enter black membranes in fully closed state or stay in the application medium, respectively, may be complexed to dimers.
authors.forename: Friedrich P
authors.initials: FP
authors.lastname: Thinnes
authors.forename: Gerhard
authors.initials: G
authors.lastname: Burckhardt
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D001402:B-Lymphocytes / Q000737:chemistry; D002458:Cell Fractionation; D002852:Chromatography, Ion Exchange; D006801:Humans; D008564:Membrane Potentials; D008567:Membranes, Artificial; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000737:chemistry*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D050995:Voltage-Dependent Anion Channel 1 / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000911:Antibodies, Monoclonal; D008567:Membranes, Artificial; C494762:VDAC1 protein, human; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40; D050995:Voltage-Dependent Anion Channel 1