title: Spontaneous and protein-mediated intermembrane transfer of the antiretroviral liponucleotide 3'-deoxythymidine diphosphate diglyceride.
abstract: Phospholipid conjugates of antiretroviral nucleosides show activity against the human immunodeficiency virus in vitro [Hostetler, K. Y., Stuhmiller, L. M., Lenting, H. B. M., Van den Bosch, H., & Richman, D. D. (1990) J. Biol. Chem. 265, 6112-6117]. In order to gain insight into the membrane association and the spontaneous and protein-mediated intermembrane transfer of these compounds, we have synthesized the fluorescent analog 3'-deoxythymidine diphosphate 1-myristoyl-2-(10-pyren-1-yl-decanoyl)glycerol. The compound readily incorporated into ethanol-injection vesicles, but the stability of the fluorescent probe (10% of total lipid) in the lipid bilayer was less than that of 1-myristoyl-2-(10-pyren-1-yldecanoyl)phosphatidylcholine. Using a donor-acceptor vesicle assay system, half-times for spontaneous transfer at 25 and 37 degrees C were 20 and 100 min, respectively. The liponucleotide was rapidly transferred between membranes by the nonspecific lipid-transfer protein at a rate at least 10-fold that of the corresponding phosphatidylcholine. Depletion of the liponucleotide from the outer monolayer of vesicles by a large excess of nonspecific lipid-transfer protein indicated a transbilayer distribution similar to the mass distribution of phospholipids. Essentially no flip-flop of the inner monolayer liponucleotide was observed.
authors.affiliation: Centre for Biomembranes and Lipid Enzymology, University of Utrecht, The Netherlands.
authors.forename: G M
authors.initials: GM
authors.lastname: van Wijk
authors.forename: T W
authors.initials: TW
authors.lastname: Gadella
authors.forename: K W
authors.initials: KW
authors.lastname: Wirtz
authors.forename: K Y
authors.initials: KY
authors.lastname: Hostetler
authors.forename: H
authors.initials: H
authors.lastname: van den Bosch
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism*; D004075:Diglycerides / Q000378:metabolism*; D004355:Drug Stability; D005456:Fluorescent Dyes; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008099:Liver / Q000737:chemistry; D015394:Molecular Structure; D010713:Phosphatidylcholines / Q000378:metabolism; D010743:Phospholipids / Q000138:chemical synthesis / Q000378:metabolism*; D011355:Prodrugs / Q000378:metabolism*; D011721:Pyrenes; D013050:Spectrometry, Fluorescence; D013942:Thymine Nucleotides / Q000138:chemical synthesis / Q000378:metabolism*
chemical_list: C071867:3'-deoxythymidine diphosphate diglyceride; D000998:Antiviral Agents; D002352:Carrier Proteins; D004075:Diglycerides; D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D010743:Phospholipids; D011355:Prodrugs; D011721:Pyrenes; D013942:Thymine Nucleotides; C030363:lipid transfer protein; C075305:3'-deoxythymidine diphosphate 1-myristoyl-2-(10-pyren-1-yl-decanoyl)glycerol; C030984:pyrene