Linear dichroism spectroscopy

Bloemendal, M. and van Grondelle, R., Linear-dichroism spectroscopy for the study of structural properties of proteins. Mol. Biol. Rep., 18, 49, 1993. 

Rhenium(I) pyrazolyl-diamine complexes appended with an anthracen-9-yl group (21) have been isolated and characterised [59], The binding of these complexes to double-stranded calf-thymus DNA has been investigated with absorption, fluorescence, circular dichroism, and linear dichroism spectroscopy. The results indicate that the complexes bind to the DNA molecules by intercalation of the... 

Marcott, C. and Noda, 1. (2001) Dynamic linear dichroism spectroscopy, in Handbook of Vibrational Spectroscopy,... 

On a different note, anisotropic molecules, once extracted fully or partly into the membrane, become selectively oriented. By itself, the inside of the membrane is a highly anisotropic, hairbrush-like, lipophilic solvent. Any anisotropic lipophilic molecule selectively extracted into the membrane must therefore automatically become oriented to avoid the unfavorable energetics of disrupting this ordered state. Indeed, it has been shown experimentally (by specific labeling with a transmembrane photosensitive probe) that cholesterol is oriented perpendicularly to the membrane in closed vesicles (Nakatani et al., 1996). By contrast, the linear hydrocarbon p-carotene has been shown (by linear dichroism spectroscopy on flat bilayer stacks) to lie parallel to the surface (Norden... 

Norden, B., Lindblom, G. and Jonas, I. (1977). Linear dichroism spectroscopy as a tool for studying molecular orientation in model membrane systems. Journal of Physical Chemistry, 81, 2086-93. 

Jonsson, M. Akerman, B. Norden, B. Orientation of DNA during gel electrophoresis studied with linear dichroism spectroscopy. Biopolymers 1988 27 381-414. 

I. Jonas, K. Fontell, G. Lindblom, and B. Norden, Linear Dichroism Spectroscopy, Proceedings of the Nobel Workshop on Molecular Optical Dichroism and Chemical Applications of Polarization Spectroscopy 1976, ed. B. Norden, Lund University Press, Lund, Sweden, 1977, p. 217. 

Six symmetrically disubstituted derivatives of r-tetrazine have been studied by linear dichroism spectroscopy in the UV-Vis region, magnetic circular dichroism spectroscopy, and theoretical calculations of structures and spectra <1995CPH(200)201>. A detailed discussion of the sensitivity and of the optothermal detection scheme for the study of nonfluorescing excited states of the r-tetrazine-argon van der Waals complex has been presented <2000MI183>. 

Electronic spectroscopy, including ultraviolet (UV) and visible absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) and linear dichroism spectroscopy. 

In this chapter, electrochemical properties of ET proteins at electrode interfaces studied by spectroelectrochem-ical techniques are described. In situ spectroelectrochemical techniques at well-defined electrode surfaces are sufficiently selective and sensitive to distinguish not only steady state structures and oxidation states of adsorbed species but also dynamics of reactants, products, and intermediates at electrode surfaces on a monolayer level. The spectroelectrochemical techniques used in studies of ET proteins include IR reflection-absorption, potential-modulated UV-vis reflectance (electroreflectance), surface-enhanced Raman scattering (SERS) and surface plasmon resonance, total internal reflection fluorescence, (TIRE) and absorbance linear dichroism spectroscopies. 

Marcott, C. and Noda, I. (2002) Dynamic infrared linear dichroism spectroscopy. In Handbook of Vibrational Spectroscopy, Vol. 4 (eds J.M. Chalmers and PR. Griffiths), John Wiley Sons, Ltd, Chichester, pp. 2576-2591. 

Abstract In the first part of this chapter we will illustrate circular dichroism and we will discuss the optical activity of chemical compounds with respect to light absorption which is at the basis of this technique. Moreover, we will introduce the phenomena that lie behind the technique of optical rotatory dispersion. We thought appropriate to include a brief description of linear dichroism spectroscopy, although this technique has nothing to do with optical activity. In the final part of the chapter we will introduce the basic principles of the luminescence teehniques based on polarized (either circularly or linearly) excitation. The experimental approach to the determination of steady-state and time resolved fluorescence anisotropy will be illustrated. For all the teehniques examined in this chapter the required instrumentation will be schematieally deseribed. A few examples of application of these techniques to molecular and supramolecular systems will also be presented. 

Linear dichroism spectroscopy is used to study the orientation of molecules in an anisotropic sample. It is usually performed in the UV-visible (LD of electronic transitions) and in the infrared (vibrational LD) spectral regions. 

I. Noda, A.E. Dowrey and C. Marcott, Characterization of polymers using polarization-modulation infrared techniques Dynamic infrared linear dichroism (DIRLD) spectroscopy. 

On the other hand, these conclusions seem difficult to reconcile, a priori, with those from linear dichroism (entry 5), NMR spectroscopy (entry 7), and viscosity measurements (entry 10), which strongly suggest a surface binding. A new mode of interaction should thus be proposed which fits all the results. 

Probing Metalloproteins Electronic absorption spectroscopy of copper proteins, 226, 1 electronic absorption spectroscopy of nonheme iron proteins, 226, 33 cobalt as probe and label of proteins, 226, 52 biochemical and spectroscopic probes of mercury(ii) coordination environments in proteins, 226, 71 low-temperature optical spectroscopy metalloprotein structure and dynamics, 226, 97 nanosecond transient absorption spectroscopy, 226, 119 nanosecond time-resolved absorption and polarization dichroism spectroscopies, 226, 147 real-time spectroscopic techniques for probing conformational dynamics of heme proteins, 226, 177 variable-temperature magnetic circular dichroism, 226, 199 linear dichroism, 226, 232 infrared spectroscopy, 226, 259 Fourier transform infrared spectroscopy, 226, 289 infrared circular dichroism, 226, 306 Raman and resonance Raman spectroscopy, 226, 319 protein structure from ultraviolet resonance Raman spectroscopy, 226, 374 single-crystal micro-Raman spectroscopy, 226, 397 nanosecond time-resolved resonance Raman spectroscopy, 226, 409 techniques for obtaining resonance Raman spectra of metalloproteins, 226, 431 Raman optical activity, 226, 470 surface-enhanced resonance Raman scattering, 226, 482 luminescence... 

More recently, the PCM has been amply extended to the treatment of vibrational spectroscopies, by taking into account not only solvent-induced vibrational frequency shifts, but also vibrational intensities in a unified and coherent formulation. Thus, models to treat IR [8], Raman [9], IR linear dichroism [10], VCD [11] and VROA [12] have been proposed and tested, by including in the formulation local field effects, as well as an incomplete solute-solvent regime (nonequilibrium) and, when necessary, by extending the model to the treatment of specific solute-solvent (or solute-solute) effects. 

Finally, we remark that the problem of the calculation of molecular quantities directly comparable with the outcome of experiments in the liquid phase is not limited to the realm of the NLO processes. All experiments involving the interaction of light with molecules in condensed matter are plagued by this problem. The methodology reviewed here has been applied (with appropriate modifications) to various spectroscopies, IR [23], Raman [24], Surface Enhanced Raman Scattering (SERS) [25], vibrational circular dichroism (VCD) [26] and linear dichroism [27] with equal reliability, and other extensions will come. 

Nafie LA, Diem M (1979) Theory of high-frequency differential interferometry - application to the measurement of infrared circular and linear dichroism via Fourier-transform spectroscopy. Appl Spectrosc 33 130-135... 

Nafie LA, Buijs H, Rilling A et al (2004) Dual source Fourier transform polarization modulation spectroscopy an improved method for the measurement of circular and linear dichroism. Appl Spectrosc 58 647-654... 

When chirality is involved, information on solid-state structures and supra-molecular properties must be obtained by solid-state circular dichroism (CDf spectroscopy, as certain characteristics may be lost upon dissolution. However extreme care is required to obtain artifact-free solid-state CD spectra. This is because CD spectra in the solid state (except for special homogeneous cases [9,10]) are inevitably accompanied by parasitic signals that originate from thd macroscopic anisotropies of a sample such as LD (linear dichroism) and LB (linear birefringence) [11-16]. We have been working in the field of solid-state chirality for the last 30 years and recently developed a novel universal chiroptical spectrophotometer, UCS J-800KCM, for the measurement of true CD and circular birefringence (CB) spectra in the solid state [17]. 

As to infrared spectroscopy - and the same holds good for other spectral ranges -the orientational order is readily observable in form of dichroism Being related to the molecular shape, the molecular polarizability is anisotropic as well. By the alignment of the molecules this anisotropy is transferred to the sample, however damped due to the imperfect order as described by the order parameters. As a consequence, the dielectric function and furthermore the (complex) refractive index are anisotropic, so that eventually (linear) dichroism and birefringence occur. 

Electronic spectroscopy (see Electronic Spectroscopy), in one form or another, has been the principal method used for the detection of short-lived intermediates. UV-visible absorption was the initial spectroscopic method used with flash photolysis and flow systems, and for each of these methods it remains the most commonly used approach. For species in low-temperature matrices, many varieties of electronic spectroscopy have been used. These include UV-visible absorption and emission, fluorescence, magnetic circular dichroism (MCD) and magnetic linear dichroism, and photoelectron spectroscopy. It is unfortunate, therefore, that in many cases electronic spectroscopy yields little or no stractnral information. The exceptions are high-resolution spectra, where vibrational or rotational flne structure may be seen. 

Other Spectroscopic Techniques. Photoacoustic spectroscopy has been used to investigate the carotenoproteins of lobster shell.Visual pigments and bacteriorhodopsin have been studied by linear dichroism/ neutron diffraction/ and emission spectroscopy. ... 

Two methods have been used to determine the secondary structure and orientation of membrane proteins in supported bilayers polarized ATR-FTIR spectroscopy and oriented CD spectroscopy. SFVS may also be applied to study peptide and protein structures in supported bilayers. Polarized ATR-FTIR spectroscopy is sensitive enough that high-quality spectra can be obtained from a single bilayer. Beta-sheet structures are readily distinguished from a-helical and random stmctures, and the orientations of a-helices are determined from the linear dichroism of the peptide amide 1 bands (20). Multiple stacks of supported bilayers have to be used to gain enough sensitivity to determine the stmcture and orientation of a-helices in lipid bilayers by oriented CD spectroscopy (60, 93). 

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