Spectropolarimeters

The screening was performed in a way similar to that of Welch, except that it involved the use of a spectropolarimeter instead of chiral chromatography to determine the selectivity. Equal amounts of the target racemate 17 were added into each of the 16 wells containing beads and the ellipticity of the supernatant liquid in each well was measured after equilibrating for 24 h at the wavelength of the maximum adsorption (260 nm). Knowing the specific ellipticity of one enantiomerically pure... 

UVSOR storage ring in the Institute for Molecular Science. Circular dichroism for LB films was measured by a JASCO spectropolarimeter (J-600) with rotating the film sample to remove the influence of linear dichroism. 

Corning CS 2-73 high energy (580 nm) cut-off filter. Absorption spectra were obtained with a Cary model 219 spectrophotometer, while MCD spectra were obtained with a JASCO J500C spectropolarimeter controlled by an IBM... 

CD spectra of 20 pM DIMS samples in lx PBS buffer were measured on a Jasco J-720 spectropolarimeter (Jasco Corp., Tokyo, Japan). 

Hiis work was suj rted in part by a contract NOl CP 55675 to the University of New Hanpshire from the National Cancer Institute subcontracted in part to North Texas State University (REL) by a grant from the National Institutes of Environmental Health Sciences, 1-R01-ESO1975 (REL-MJK) and by grants from the Robert A. Welch Foundation to REL (B-702) and MJK (B-633). Hie authors express appreciation for the Faculty Research Grant which provided partial su rt for the Jasco Spectropolarimeter. S. Singh is on leave from the Department of Chemistry, Banaras Hindu University, Varanasi 221005, India H. M. Fribush was Phillips Petroleum Fellow 1977-1978, and R. A. Barton is the Blanche Mary Taxis Cancer Research Scholar. 

The spectropolarimeters for the CD and MCD observations in the vaccuum ultraviolet region use prisms and a Rochon prism made of CaF2 or MgF2 234). 

The author thanks S. Fleischer, J. H. Gibbs, E. S. Pysh, M. E. Tourtel-lotte, and M. J. Grourke for stimulating and helpful discussions. Much of the support came from U. S. Public Health Service Grants FR 07085 and GM 14696. The Cary 60 spectropolarimeter and the Varian A60A NMR spectrometer were purchased with National Science Foundation instrument grants. 

Die meisten der in den nachfolgenden Tabellen angegebenen Dreh-werte wurden mit visuellen Polarimetem bei 589 mp bestimmt. Zur Messung der Rotationsdispersion dienten, soweit es sich aus den zitierten Arbeiten entnehmen laBt, vorwiegend Rudolph-Spectropolarimeter. 

Applied Physics Corp. USA, Cary Recording Spectropolarimeter Modell 60. Bellingham Stanley Ltd., England, Polarmatic 62. Japan Spectroscopic Co., Ltd., Jasco-Model ORD/UV 5. O. C. Rudolph Sons, Inc., USA verschiedene photoelektrische Polarimeter und Spectropolarimeter. 

Automatic spectropolarimeters are available for the measurement of optical rotation as a function of wavelength (in the region 180-700 nm), enabling optical rotatory dispersion (ORD) curves to be recorded. Models are also available (e.g. Japan Spectroscopic Co. Ltd) for the measurement of circular dichroism (CD) curves in the wavelength region of 180-1000 nm, and 700-2000 nm. Authoritative accounts of the value of ORD and CD data in studies on the structure... 

Figure 15.6 Far-UV CD spectra of the odorant-binding proteins from the scarab beetle P. diversa (1) PdivOBPI and (2) PdivOBP2. The spectra of the pure proteins were recorded in 20 mM sodium phosphate buffer, pH 6.8, at 0.4 mg/ml on a JASCO J-720 spectropolarimeter at 25°C in a 0.1 mm pathlength cell.

These results imply that the functional l-RNA and d-RNA sequences are folding into mirror-image shapes this is consistent with the observed circular dichroism (CD) spectra of the functional 58-mer RNA sequences. CD spectra were recorded in 0.1 M NaCI and 10 mM sodium phosphate, pH 7.0, at 4 °C on a Jasco J-600 spectropolarimeter. 

Methods. Measurements of absorption spectra and spectrophoto-metric titrations were carried out on a Cary 15 spectrophotometer equipped with a thermostated cell compartment. Circular dichroic spectra were recorded on a Cary 60 spectropolarimeter equipped with a 6001 CD attachment. Fluorescence spectra were measured on a Hitachi-... 

Tris buffer (pH 7.8). MCD spectra were obtained using a JASCO J-500A spectropolarimeter equipped with a 1.5 T electromagnet. (The data are taken from reference 43.)... 

Fig. 5. Circular dichroism spectroscopy of peptide (120-189) fused to a 6xHis-tag. The circular dichroism spectrum of 6xHis-rCla h6 (120-189) (protein concentration was 27 piMin salt-free water) was recorded on a Jasco spectropolarimeter (J-810) at 185-260nm. Computer-assisted analysis of the data showed that the peptide is folded with 11% helix, 35% (3-sheet, 27% loop and 26% random structural elements.

The easiest way to obtain a CD spectrum is to use a spectropolarimeter. In these instruments the signal is plotted as... 

Most CD spectropolarimeters must be calibrated. A common way is to compare the absorption and CD spectra of ammonium (+)-dlO-camphorsulfonate (ACS) using a solntion nominally ImgmL in a 1mm cell. Using the absorption at 285 nm (e28s mn = 34.5 cm ) to determine... 

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