Dynamics of membrane penetration of the fluorescent 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) group attached to an acyl chain of phosphatidylcholine - PubMed (original) (raw)

Dynamics of membrane penetration of the fluorescent 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) group attached to an acyl chain of phosphatidylcholine

D Huster et al. Biophys J. 2001 Feb.

Abstract

Location and dynamic reorientation of the fluorophore 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) covalently attached to a short (C6) or a long (C12) sn2 acyl chain of a phosphatidylcholine molecule was investigated by fluorescence and solid-state NMR spectroscopy. 2H NMR lipid chain order parameters indicate a perturbation of the phospholipid packing density in the presence of NBD. Specifically, a decrease of molecular order was found for acyl chain segments of the lower, more hydrophobic region. Molecular collision probabilities determined by 1H magic angle spinning nuclear Overhauser enhancement spectroscopy indicate a highly dynamic reorientation of the probe in the membrane due to thermal fluctuations. A broad distribution of the fluorophore in the lipid bilayer is observed with a preferential location in the upper acyl chain/glycerol region. The distribution of the NBD group in the membrane is quite similar for both the long- and the short-chain analog. However, a slight preference of the NBD group for the lipid-water interface is found for C12-NBD-PC in comparison with C6-NBD-PC. Indeed, as shown by dithionite fluorescence assay, the long-chain analog reacts more favorably with dithionite, indicating a better accessibility of the probe by dithionite present in the aqueous phase. Forces determining the location of the fluorophore in the lipid water interface are discussed.

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References

    1. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Sep;62(3 Pt B):4000-9 - PubMed
    1. Annu Rev Biophys Biomol Struct. 1999;28:319-65 - PubMed
    1. J Mol Biol. 1982 Mar 5;155(3):347-66 - PubMed
    1. Biochem Biophys Res Commun. 1983 Dec 16;117(2):479-85 - PubMed
    1. Biochim Biophys Acta. 1985 Jul 11;817(1):193-6 - PubMed

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