Membranes fluorescent probes

Lipid-protein interactions are of major importance in the structural and dynamic properties of biological membranes. Fluorescent probes can provide much information on these interactions. For example, van Paridon et al.a) used a synthetic derivative of phosphatidylinositol (PI) with a ris-parinaric acid (see formula in Figure 8.4) covalently linked on the sn-2 position for probing phospholipid vesicles and biological membranes. The emission anisotropy decays of this 2-parinaroyl-phosphatidylinositol (PPI) probe incorporated into vesicles consisting of phosphatidylcholine (PC) (with a fraction of 5 mol % of PI) and into acetylcholine receptor rich membranes from Torpedo marmorata are shown in Figure B8.3.1. 

Baumgard, T, Hunt, G., Farkas, E. R., Webb, W. W. and Feigenson, G. W. (2007) Fluorescence probe partitioning between Lo/Ld phases in lipid membranes. Biochim. Biophys. Acta,... 

DD can be monitored by a variety of experimental techniques. They involve thermodynamic, dilatometric, and spectroscopic procedures. Molecular dynamics (MD) simulations also become applicable to self-assembled systems to some extent see the review in Ref. 2. Spectroscopic methods provide us with molecular parameters, as compared with thermodynamic ones on the macroscopic level. The fluorescence probing method is very sensitive (pM to nM M = moldm ) and informs us of the molecular environment around the probes. However, fluorescent molecules are a kind of drug and the membrane... 

Clarke RJ, Zouni A, Holzwarth JF (1995) Voltage sensitivity of the fluorescent probe RH421 in a model membrane system. Biophys J 68 1406-1415... 

Dialkylanthracene-containing squaraine dyes 17 show intense absorption and emission in the NIR region (720-810 nm) [74]. They are compatible with aqueous environments and show substantial enhancement of quantum yields and fluorescence lifetimes in hydrophobic and micellar media, suggesting that these dyes can be potentially useful as fluorescent probes in biological applications, e.g., for imaging of hydrophobic domains such as cell membranes. 

DiVittorio KM, Leevy WM, O Neil EJ, Johnson JR, Vakulenko S, Morris JD, Rosek KD, Serazin N, Hilkert S, Hurley S, Marquez M, Smith BD (2008) Zinc(II) coordination complexes as membrane-active fluorescent probes and antibiotics. Chembiochem 9 286-293... 

Dobretsov GE (1989) Fluorescent probes in study of cells. Membranes and lipoproteins. Nauka, Moscow (in Rus)... 

Haidekker MA, Ling T, Anglo M, Stevens HY, Frangos JA, Theodorakis EA (2001) New fluorescent probes for the measurement of cell membrane viscosity. Chem Biol 8(2) 123-131... 

The aim of this Chapter is to review a method by which fluorescence properties of organic dyes can, in general, be predicted and understood at a microscopic (nm scale) by interfacing quantum methods with classical molecular dynamics (MD) methods. Some review of our extensive applications [1] of this method to the widely exploited intrinsic fluorescence probe in proteins, the amino acid tryptophan (Trp) will be followed by a discussion of electrochromic membrane voltagesensing dyes. 

Grinvald A, Hildesheim R, Farber IC, Anglister L (1982) Improved fluorescent-probes for the measurement of rapid changes in membrane-potential. Biophys J 39(3) 301—308... 

Ira ASR, Koti GK, Periasamy N (2003) TRANES spectra of fluorescence probes in lipid bilayer membranes an assessment of population heterogeneity and dynamics. J Fluoresc 13(1) 95—103... 

Demchenko AP, Mely Y, Duportail G, Klymchenko AS (2009) Monitoring biophysical properties of lipid membranes by environment-sensitive fluorescent probes. Biophys J 96 3461-3470... 

Klymchenko AS, Duportail G, Mely Y et al (2003) Ultrasensitive two-colour fluorescence probes for dipole potential in phospholipid membranes. PNAS 100 11219-11224... 

Shynkar VV, Klymchenko AS, Duportial G et al (2005) Two-colour fluorescent probes for imaging the dipole potential of cell plasma membranes. Biochim Biophys Acta Biomem 1712 128-136... 

Pal, R., Barenholz, Y. and Wagner, R. R. (1988). Pyrene Phospholipid as a biological fluorescent-probe for studying fusion of virus membrane with liposomes. Biochemistry (Mosc). 27, 30-36. 

Sklar, L. A., Hudson, B. S. and Simoni, R. D. (1977). Conjugated polyene fatty-acids as fluorescent-probes - Synthetic phospholipid membrane studies. Biochemistry (Mosc). 16, 819-828. 

P. S. Uster and R. E. Pagano, Resonance energy transfer microscopy Observations of membrane-bound fluorescent probes in model membranes and in living cells, J. Cell. Biol. 103, 1221-1234 (1986). 

Iu. A. Vladimorov and G. E. Dobretsov, Fluorescence Probes in the Studies of Biological Membranes, Nauka, Moscow (1980). 

A. P. Demchenko and N. V. Shcherbatska, Nanosecond dynamics of the charged fluorescent probes at the polar interface of the membrane phospholipid bilayer, Biophys. Chem. 22, 131-143 (1985). 

The properties of membranes commonly studied by fluorescence techniques include motional, structural, and organizational aspects. Motional aspects include the rate of motion of fatty acyl chains, the head-group region of the phospholipids, and other lipid components and membrane proteins. The structural aspects of membranes would cover the orientational aspects of the lipid components. Organizational aspects include the distribution of lipids both laterally, in the plane of the membrane (e.g., phase separations), and across the membrane bilayer (phospholipid asymmetry) and distances from the surface or depth in the bilayer. Finally, there are properties of membranes pertaining to the surface such as the surface charge and dielectric properties. Fluorescence techniques have been widely used in the studies of membranes mainly since the time scale of the fluorescence lifetime coincides with the time scale of interest for lipid motion and since there are a wide number of fluorescence probes available which can be used to yield very specific information on membrane properties. 

The polarization properties of light in combination with fluorescence can be used as a powerful tool for determining motional properties of membranes. This is possible due to the fact that the time scale of interest for membrane lipids falls within the time frame of the fluorescence decay phenomena (0-100+ ns). This, coupled with high sensitivity, low perturbing properties of fluorescent probes, and the large number of available probes, makes the fluorescence approach the method of choice for membrane motional studies. 

Table 5.3. Alteration of Membrane Lipid Properties and the Resultant Approximate Directions of Changes of Fluorescence Parameters of a Typical Membrane Fluorophore Probe of the Fatty Acyl Chain Region0...

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