Pyrene-labelled

Okamoto A, Ichiba T, Saito I (2004) Pyrene-labeled oligodeoxynucleotide probe for detecting base insertion by excimer fluorescence emission. J Am Chem Soc 126 8364—8365... 

Somerharju, P. (2002). Pyrene-labeled lipids as tools in membrane biophysics and cell biology. Chem. Phys. Lipids 116, 57-74. 

The serious drawback of the methods of evaluation of fluidity based on intermolecular quenching or excimer formation is that the translational diffusion can be perturbed in constrained media. It should be emphasized that, in the case of biological membranes, problems in the estimation of fluidity arise from the presence of proteins and possible additives (e.g. cholesterol). Nevertheless, excimer formation with pyrene or pyrene-labeled phospholipids can provide interesting in-... 

Hresko R. C., Sugar I. P., Barenhoiz Y. and Thompson T. E. (1986) Lateral Diffusion of a Pyrene-Labeled Phosphatidylcholine in Phosphatidylcholine Bilayers/Fluorescence Phase and Modulation Study, Biochemistry 25, 3813-3823. 

Highly selective fluorometric determination of polyamines based on intramolecular excimer-forming derivatization with a pyrene-labeling reagent. Anal Chem 72 ... 

Figure 3. Critical concentration behavior of actin self-assembly. For the top diagram depicting the macroscopic critical concentration curve, one determines the total amount of polymerized actin by methods that measure the sum of addition and release processes occurring at both ends. Examples of such methods are sedimentation, light scattering, fluorescence assays with pyrene-labeled actin, and viscosity measurements. Forthe bottom curves, the polymerization behavior is typically determined by fluorescence assays conducted under conditions where one of the ends is blocked by the presence of molecules such as gelsolin (a barbed-end capping protein) or spectrin-band 4.1 -actin (a complex prepared from erythrocyte membranes, such that only barbed-end growth occurs). Note further that the barbed end (or (+)-end) has a lower critical concentration than the pointed end (or (-)-end). This differential stabilization requires the occurrence of ATP hydrolysis to supply the free energy that drives subunit addition to the (+)-end at the expense of the subunit loss from the (-)-end.

Analysis of the pyrene-labeled homoduplex 5 5 (Eig. 9.3b) by NMR, mass spectrometry, and TLC suggested that 5 5 had a stability similar to that of 3 4. NOESY spectra revealed cross-strand NOEs consistent with the formation of the self-dimer 5 5 (Zeng et al. 2003). Based on a fluorescence method described in the literature (Sontjens et al. 2000), the dimerization constant of the pyrene-labeled duplex 5 5 was found to be (6.77 + 4.12) x 10 M. The studies on duplexes 3 4 and 5 5 clearly demonstrated that the stabilities of our duplexes are indeed only determined by the number of intermolecular H bonds, and both hetero- and homoduplexes can be easily designed and constructed. 

Our group [124] has used pyrene and pyrene labeled poly(acrylic acid) as a fluorescent probe to investigate the interaction between poly(acrylic acid) (PAA) and dodecyltrimethylammonium bromide (DTAB) in water. We have measured the Is /1 ratio of pyrene as a function of DTAB in the presence of 1 g/L PAA. A sharp decrease in polarity is found well below the CMC of DTAB (1.3 X 10 M, Fig. 17). The onset of this polymer-induced association is referred to as the critical aggregation concentration. The CAC has been measured at various pH and NaCl levels (Fig. 18). It was observed that the... 

Fig. 19 Excimer to monomer ratio, le/Im of pyrene-labeled poly(acrylic acid), py-PAA, as a function of DTAB concentration in 1 g/L sodium polyacrylate and 0.03 M NaCl...

Fig. 23 Schematic representation of the formation of polymer surfactant complexes for the pyrene-labeled (polyacrylic acid)-dodecyltrimethylammonium bromide system for high (high pH) and low (low pH) degrees of ionization...

Fig. 43 Schematic representation of the adsorption process of pyrene labeled polyacrylic acid on alumina at different pH...

The formation of a compact structure accompanying the complexation of PMMA with PEO and the lower flexibility of the PMMA chain in the complex than that of the PAA chain have been confirmed by viscometry [ 16], membrane contraction [2], and polarized luminescence techniques [3]. In addition, comparison of the dynamic light-scattering behavior of PMAA/PEO and PMAA/PEO" in solution shows that the pyrene label, which acts as a hydrophobic species, allows the labeled PEO to aggregate intermolecularly much faster than unlabeled PEO does [30]. 

As Fig. 15b illustrates, the graphical relation appears to be linear for an interaction number of 3 to 4, if A 1. Alternatively, for A = 1, linearity is evident (Fig. 15c) when the interaction number is 5 to 6. Thus a large value of A is compatible with the smallest interaction number. Excimer formation occurs within the fluorescence lifetime, about 8 nsec. Within that time the pyrene-labeled amine side chains must approach within about 4 A of each other. For the 5.3% pyrenylpolyethylenimine derivative in ethanol, where no ground-state association occurs, the effective local concentration of pyrene on the polymer matrix is about 10-2 M, as calculated from excimer fluorescence. In aqueous solution, where clusters form within the polymer matrix, the effective local concentration of pyrene adduct must be even greater. The quantitative assessment of fluorescence intensities (Fig. 15) points to a minimum interaction number of 3 to 4 pyrenyl-labeled amine side chains, within the 8 nsec lifetime. Since A 1, it appears from (12) that kDM(A) kMD + kD. Thus excimer formation must be very rapid in the polymer environment. We can conclude, therefore, that the primary-amine side chains of poly-ethylenimine are very flexible and mobile. 

Wnnik, F.M., A. Adronov, and H. Kitann. 1995. Pyrene-labeled amphiphilic pblyisfopropylacrylamides)... 

Yamana et al. [67] used bis-pyrene-labeled DNA aptamer for detection of ATP. The pyrene excimer was incorporated into several nucleotide positions. Addition of ATP resulted in an increase in fluorescence only for aptamers labeled by fluorescence probe between residues that were responsible for ATP binding. Using this sensor it was possible to detect ATP with mmol/L sensitivity. 

Studies of the pyrene label on actin indicate that the ATP-induced dissociation of actin occurs via a three-step process (steps 1, 2, and c, Scheme 1 Millar and Geeves, 1983). Initial fast equilibrium binding of ATP (controlled by and probably diffusion limited) is followed by an isomerization that alters the environment of the pyrene label on actin. This isomerization is fast in myosin II and much slower for some non-muscle myosins (-500 s-1 for Dictyostelium myosin II Kurzawa et al., 1997 >1000 s-1 for rabbit skeletal myosin II, Geeves andjeffries, 1988 100 s-1 for myosin lb at 20°C Coluccio and Geeves, 1999) and is accompanied by a very rapid... 

Pyrene-labeled SA mixed monolayers were prepared by adsorption from solutions of the desired concentration of a particular fatty acid, along with a small fraction (1-5%) of the probe Py-C16. All solutions used were of total acid concentration of 5xl0 3M. 

Fluorescence Of Monolayers Containing Pyrene-Labeled Probes. A fluorescence probe method was also used as a complementary technique to study the thermodynamics of SA film formation. Mixed monolayers containing the fluorescence probe pyrene hexadecanoic acid, Py-C16, in host fatty acids of different lengths were prepared by adsoiption from solutions containing mostly the host fatty acid and a small fraction of Py-C16 (approximately 1 to 5 mol %). All monolayers were prepared under equilibrium adsoiption conditions. For fluorescence measurements only A1 substrate was used because when glass is used an impurity fluorescence from glass interferes with the pyrene fluorescence. 

Several papers compare the properties of sulfobetaine (meth)acrylic polymers. NMR spectra and solution properties of 23a and 23b [59,60] are correlated with data from the corresponding polycarbobetaines [26]. The photophysical and solution properties of pyrene-labeled 23c were studied in terms of fluorescence emission. Addition of surfactants induces the formation of mixed micelles in aqueous solution [61]. Excluded volume effects of the unlabeled polymer were measured by light scattering [62], its adsorption on silica was studied by adsorbance measurement and ellipsometry [62,63], and the electrostimulated shift of the precipitation temperature was followed at various electric held intensities [64]. Polysulfobetaines may accelerate interionic reactions, e.g., oxidation of ferrocyanide by persulfate [65]. The thermal and dielectric properties of polysulfobetaines 23d were investigated. The flexible lateral chain of the polymers decreased Tg, for which a linear relationship with the number of C atoms was shown [66,67]. 

An important factor for in vivo studies is the auto fluorescent cellular background. To overcome this problem, pyrene-labeled binary probes have been used to take advantage of the long fluorescence lifetime (>40ns) of the pyrene excimer, compared with that of the cellular extracts (7 ns), that allows selective detection of the excimer using time-resolved spectroscopy (35). 

Repakova J, Holopainen JM, Karttunen M, Vattulainen I. Influence of pyrene-labeling on fluid lipid membranes. J. Phys. Chem. B 2007 110 15403-15410. 

In order to study the segmental mobility in dendrimers, solutions of compound (118) with twelve pyrene labels have been investigated by Fluorescent Spectroscopy and compared to the model molecule (119) having two labels. It turned out that that the interior of the dendrimer contains solvent molecules adjacent to the pyrene-labeled side chains. The movement of the pyrene groups is influenced by the solvent molecules but not by the dendrimer core. ... 

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