Determination of membrane immersion depth with O-2: A high-pressure F-19 NMR study

Title

Determination of membrane immersion depth with O-2: A high-pressure F-19 NMR study

Creator

Prosser R S; Luchette P A; Westerman P W; Rozek A; Hancock R E W

Publisher

Biophysical Journal

Date

2001
2001-03

Description

Oxygen is known to partition with an increasing concentration gradient toward the hydrophobic membrane interior. At partial pressures (P-O2) of 100 Atm or more, this concentration gradient is sufficient to induce paramagnetic effects that depend sensitively on membrane immersion depth. This effect is demonstrated for the fluorine nucleus by depth-dependent: paramagnetic shifts and spin-lattice relaxation rates, using a fluorinated detergent, CF3(CF2)(5)C2H4-O-maltose (TFOM), reconstituted into a lipid bilayer model membrane system, To interpret the spin-lattice relaxation rates (R-1(P)) in terms of a precise immersion depth, two specifically fluorinated cholesterol species (6-fluorocholesterol and 25-fluorocholesterol), whose membrane immersion depths were independently estimated, were studied by F-19 NMR. The paramagnetic relaxation rates, R-1(P), of the cholesterol species were then used to parameterize a Gaussian profile that directly relates R-1(P) to immersion depth z.: This same Gaussian curve could then be used to determine the membrane immersion depth of all six fluorinated chain positions of TFOM and of two adjacent residues of specifically fluorinated analogs of the antibacterial peptide indolicidin. The potential of this method for determination of immersion depth and topology of membrane proteins is discussed.

Subject

Biophysics; cholesterol; conformational-changes; dynamics; lipid bilayers; micelles; nuclear magnetic-resonance; phospholipid-bilayers; protein-structure; solid-state nmr; x-ray-diffraction

Format

Journal Article

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Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

1406-1416

Issue

3

Volume

80

Citation

Prosser R S; Luchette P A; Westerman P W; Rozek A; Hancock R E W, “Determination of membrane immersion depth with O-2: A high-pressure F-19 NMR study,” NEOMED Bibliography Database, accessed September 21, 2021, https://neomed.omeka.net/items/show/6829.

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