Single-molecule studies

Osborne M A, Balasubramanian S, Furey W S and Klenerman D 1998 Optically biased diffusion of single molecules studied by confocal fluorescence microscopy J. Chem. Phys. B 102 3160-7... 

Ishikawa M, Ye J Y, Maruyama Y and Nakatsuka H 1999 Triphenylmethane dyes revealing heterogeneity of their nanoenvironment femtosecond, picosecond, and single-molecule studies J. Chem. Phys. A 103 4319-31... 

I., Beljonne, D., Champagne, B., Mullen, K., Sauer, M., Hofkens, J. andDe Schryver, F. C. (2004) Multichromophoric dendrimers as single-photon sources a single-molecule study. J. Phys. Chem. B., 108, 16686-16696. 

The commercially available dicyanomethylene squaraine dye Seta-670-mono-NHS showed extremely low blinking effects and good photostability when used in single-molecule studies of multiple-fluorophore labeled antibodies [113]. Seta-670-mono-NHS and Seta-635-NH-mono-NHS were covalently labeled to antibodies and used in a surface-enhanced immunoassay [114]. From the fluorescence intensity and lifetime changes determined for a surface that had been coated with silver nanoparticles, both labeled compounds exhibited a 15- to 20-fold... 

E. Mei, A.M. Bardo, M.M. Collinson, and D.A. Higgins, Single-molecule studies of sol-gel-derived silicate films. Microenvironments and film-drying conditions J. Phys. Chem., B 104, 9973-9980 (2000). 

The intersubunit rotation is required for translocation as ribosomes trapped in the nonrotated state by an engineered intersubunit disulfide bridge fail in tRNA-mRNA movement. Real-time observation of intersubunit movement by fluorescence resonance energy transfer (FRET) showed that intersubunit movement occurs concomitantly with hybrid state formation, and that the rotated state can be trapped by the antibiotic viomycin. Similarly to the fluctuation of tRNAs between classical and hybrid states, single-molecule studies have detected spontaneous intersubunit movement where the 3 OS subunit fluctuates between a rotated... 

Even in 1978, it was realized the assembly of nucleosomes in vivo was likely to be a facilitated process. In fact, Laskey et al. [33] had discovered a factor, nucleo-plasmin that assisted in this assembly. Very recently. X-ray diffraction studies have revealed much about this protein, and its probable role in nucleosome assembly [34] or disassembly [35]. At the same time, single-molecule studies (see Zlatanova and Leuba, this volume, p. 369) have provided an insight into the dynamics and energetics of nucleosome formation. This appears likely to be an area in which rapid progress is possible. 

The analysis of single DNA molecules or small self-assemblies is equally important for medical research, e.g., for the understanding of the DNA sequence-dependent and structure-dependent diseases (recently reviewed [48]), as well as for nanoengineering-oriented research, e.g., understanding of the mechanical properties of DNA [49] that are useful for the construction of future nanodevices. In the following section we will refer to the AFM studies concerning DNA molecules and small self-assembhes as single molecule studies . 

In principle, there are two methods for the AFM probing of amorphous layers, namely (i) an active probing, which probes the surface chemistry, and (ii) a passive probing, which probes the surface physics. The active AFM probing, which is essentially an extension of the AFM-based single molecule studies, relies on the measurement of LF by an AFM tip that is fimctionahsed with molecular recognition-active molecules (e.g., a potentially complementary DNA). 

Roland JT, Guan Z. Synthesis and single-molecule studies of a well-defined biomimetic modular multidomain polymer using a peptidomimetic j8-sheet module. J Am Chem Soc 2004 126 14328-14329. 

Tinnefeld, R, Herten, D.P., and Sauer, M. 2001. Photophysical dynamics of single molecules studied by spectrally-resolved fluorescence hfetime imaging microscopy (SFLIM). J. Phys. Chem. A 105 7989. 

Johnson, Daniel S., Lu Bai, Benjamin Y. Smith, Smita S. Patel, and Michelle D. Wang. Single-Molecule Studies Reveal Dynamics of DNA Unwinding by the Ring-Shaped T7 ffelicase. Cell 129 (2007) 1,299-1,309. By using a laser beam, the experimenters made precise measurements of the movement of the bead, observing the forces imposed by helicase enzymes. 

C. Bustamante, S. B. Smith, J. Liphardt, and D. Smith, Single-molecule studies of DNA mechanics. Curr. Opin. Struct. Biol. 10, 279-285 (2000). 

As a result, the site-dependent nonradiative process of individual C molecules is responsible to biexponential fluorescence decay curves of CV observed in the ensemble-averaged measurement. Our single-molecule study presented in this section will open new possibilities in the experimental study of dynamic response of condensed matter, such as polymers and liquid. We further expect that dye molecules with flexible molecular structures like CV are useful to sensitive local probes for microscopic dynamics of various host mediums. 

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