Location and dynamics of a membrane-bound fluorescent hapten. A spectroscopic study

Stanton, Susan G.; Kantor, Aaron B.; Petrossian, Ashot; Owicki, John C.

doi:10.1016/0005-2736(84)90212-8

Cited by 36 publications

(31 citation statements)

References 22 publications

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“…The choice of the fluorescein/rhodamine probe pair was made because their distance-dependent transfer efficiency falls intermediate between the two different models. Thus for this acceptor/donor probe pair, one would predict approximately 50% transfer efficiency (R 0 ) between 45 and 50Å (35)(36)(37)(38)(39). Therefore, when the donor and acceptor probes are configured in the belt orientation, nearly 100% transfer efficiency would be observed, whereas, if the donor and acceptor probes are configured in the picket fence, nearly 0% transfer efficiency would be observed.…”

Section: Figmentioning

confidence: 95%

“…Comparison of these spectra with previously published spectra (36) indicated that 50% of the donor probes in DMPC rHDL were protonated at pH 7.4. This is typical of fluorescein probes that interact with the head group region of phospholipid bilayers, such as those attached to head groups of membrane phospholipids (37) or those attached close to the membrane anchor sequence of transmembrane proteins (36). The less polar environment of the phospholipid head groups raises the pK a of fluorescein, favoring the less charged monoanionic form.…”

Section: Hypothetical Models Of Lipid-bound Apoa-i Conformation-mentioning

confidence: 96%

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Structural Determination of Lipid-bound ApoA-I Using Fluorescence Resonance Energy Transfer

Lyles

Thomas

et al. 2000

Journal of Biological Chemistry

107

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Based on the x-ray crystal structure of lipid-free ⌬43 apoA-I, two monomers of apoA-I were suggested to bind to a phospholipid bilayer in an antiparallel paired dimer, or "belt orientation." This hypothesis challenges the currently held model in which each of the two apoA-I monomers fold as antiparallel ␣-helices or "picket fence orientation." When apoA-I is bound to a phospholipid disc, the first model predicts that the glutamine at position 132 on one apoA-I molecule lies within 16 Å of glutamine 132 in the second monomer, whereas, the second model predicts glutamines at position 132 to be 104 Å apart. To distinguish between these models, glutamine at position 132 was mutated to cysteine in wild-type apoA-I to produce Q132C apoA-I, which were labeled with thiol-reactive fluorescent probes. Q132C apoA-I was labeled with either fluorescein (donor probe) or tetramethylrhodamine (acceptor probe) and then used to make recombinant phospholipid discs (recombinant high density lipoprotein (rHDL)). The rHDL containing donor-and acceptor-labeled Q132C apoA-I were of similar size, composition, and lecithin:cholesterol acyltransferase reactivity when compared to rHDL-containing human plasma apoA-I. Analysis of donor probe fluorescence showed highly efficient quenching in rHDL containing one donor-and one acceptorlabeled Q132C apoA-I. rHDL containing only acceptor probe-labeled Q132C apoA-I showed rhodamine selfquenching. Both of these observations demonstrate that position 132 in two lipid-bound apoA-I monomers were in close proximity, supporting the "belt conformation" hypothesis for apoA-I on rHDL.

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Section: Figmentioning

confidence: 95%

Section: Hypothetical Models Of Lipid-bound Apoa-i Conformation-mentioning

confidence: 96%

Structural Determination of Lipid-bound ApoA-I Using Fluorescence Resonance Energy Transfer

Lyles

Thomas

et al. 2000

Journal of Biological Chemistry

107

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“…[26][27][28]30 A model described for the effect of a spacer on the binding of the biotinylated liposome to streptavidin has been purposed. [30][31][32] According to this model, equilibrium exists between two states of hapten residues on the surface of liposomes, Hm and Hs. Hm represents a physical state of the hapten group that interacts with lipid membrane, and is not available for binding.…”

Section: The Effect Of Spacers Between Biotin and Phospholipid On Thementioning

confidence: 99%

Luminol Encapsulated Liposome as a Signal Generator for the Detection of Specific Antigen-antibody Reactions and Nucleotide Hybridization

Rakthong¹,

Intaramat

Ratanabanangkoon

2010

ANAL. SCI.

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Liposomes prepared with biotinylated phospholipids and luminol entrapped were shown to be of 187 nm in size, 59% of which were unilamellar and with 43% luminol trapping efficiency. Liposome prepared from biotinylated phospholipids with a longer hydrophilic PEG2000 spacer, but not with the shorter hydrophobic caproyl one, bound efficiently and specifically with immobilized streptavidin in a microplate assay. The interactions of dinitrophenol and tobramycin with their respective antibodies, and the hybridization of 20-mers oligonucleotides were studied using the liposome as a signal generator. These reactions were shown to be specific with limits of detection of 0.58 µM, 0.96 µM and 18 nM, respectively.

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“…1). The pK a of the monoanion-dianion transition is 6.3 in water (1) but is substantially increased when the chromophore is present in media of lower polarity (4)(5)(6)(7)(8), at the lipid-water interface of micelles and bilayers (7)(8)(9)(10)(11) or conjugated to macromolecules (12)(13)(14)(15). As a result, the monoanion contributes significantly to the spectroscopic signal in these instances.…”

Section: Introductionmentioning

confidence: 99%

Effect of Solvent-Water Mixtures on the Prototropic Equilibria of Fluorescein and on the Spectral Properties of the Monoanion¶

Klonis

Sawyer

2007

Photochemistry and Photobiology

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A spectral resolution procedure was used to resolve the absorption, excitation and emission spectra of the fluorescein monoanion in a number of solvent-water mix- tures. This permitted an analysis of the effect of the solvent environment on the spectral properties of the monoanion and on the lactone/monoanion/dianion transitions of fluorescein. The monoanion excitation and emission spectra show relatively small changes with changing environment, a behavior that is related to the hydrogenbonding environment of the solvent-water mixtures.There is also a general increase in the quantum yield of the monoanion from 0.36 in water to values up to 0.49 in the solvent-water mixtures. The presence of solvent also results in a general increase in the lactone content and in the monoanion:dianion and lactone:monoanion ratios. General polarity effects alone cannot account for the observed effects on the prototropic transitions indicating that specific solute-solvent effects involving hydrogen bonding perturb the prototropic equilibria of fluorescein.

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Location and dynamics of a membrane-bound fluorescent hapten. A spectroscopic study

Cited by 36 publications

References 22 publications

Structural Determination of Lipid-bound ApoA-I Using Fluorescence Resonance Energy Transfer

Structural Determination of Lipid-bound ApoA-I Using Fluorescence Resonance Energy Transfer

Luminol Encapsulated Liposome as a Signal Generator for the Detection of Specific Antigen-antibody Reactions and Nucleotide Hybridization

Effect of Solvent-Water Mixtures on the Prototropic Equilibria of Fluorescein and on the Spectral Properties of the Monoanion¶

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