Long-wavelength circular dichroism of dithiomides

1988 ◽  
pp. 853-854 ◽  
Author(s):  
Tadeusz Połoński
Keyword(s):  
Circular Dichroism ◽  
Long Wavelength ◽  
Circular Dichroïsm

Circular Dichroism and Ultraviolet Absorbance of Calf Thymus DNA in Presence of CH3HgOH

1979 ◽  
Vol 34 (3-4) ◽  
pp. 259-265 ◽  
Author(s):  
Michael S. Clegg ◽  
Dieter W. Gruenwedel
Keyword(s):  
Circular Dichroism ◽  
Absorption Band ◽  
Calf Thymus Dna ◽  
Absorbance Spectrum ◽  
Absorption Bands ◽  
Long Wavelength ◽  
Ultraviolet Absorbance ◽  
Rotational Strength ◽  
Calf Thymus ◽  
Circular Dichroïsm

Abstract The changes that one observes upon the addition of CH3HgOH in the circular dichroism spec­trum and ultraviolet absorbance spectrum of native calf thymus DNA, dissolved in buffered (pH 6.8) solutions of Na2SO4 at pNa 2.0, 1.5, 1.0, and 0.0, respectively (pNa = - log [Na+]), are shown to be due to denaturation brought about by the organomercurial interacting with the base moieties of the polymer. The changes are characterized by an extensive shift of both spectra to longer wavelengths, by a decrease of the rotational strength of the long-wavelength positive dichroic absorption band, and by an increase in the UV absorbance at λmax . Both the hyperchromicity Hλ of calf thymus DNA and the normalized decrease of the rotational strength of its long-wavelength positive dichromic band, Ω , display cooperativity when plotted against the methylmercury concentration pM (pM = - log [CH3HgOH]added) at a given salt strength. Rotational strength data, evaluated by integration of the area under the positive and negative dichroic absorption bands, have been tabulated for selected values of pNa and pM. They are compared with data available from the literature. In absence of CH3HgOH, and with varying salt strength, native calf thymus DNA exhibits alterations in the long-wavelength positive dichroic absorption band that are interpreted as representing B → C transitions in agreement with currently held views regarding their origin. Similar salt-induced alterations have been noted in the case of denatured DNA; their meaning in terms of DNA geometry remains unclear at this point in time.

Circular Dichroism of Long Wavelength Forms of Chlorophyll a

Nature ◽  
1969 ◽  
Vol 224 (5224) ◽  
pp. 1108-1110 ◽  
Author(s):  
GWENDOLYN M. SHERMAN
Keyword(s):  
Circular Dichroism ◽  
Chlorophyll A ◽  
Long Wavelength ◽  
Circular Dichroïsm

Characterization of Tamm-Horsfall Urinary Glycoprotein

1973 ◽  
Vol 31 ◽  
pp. 420-421
Author(s):  
John P. Robinson ◽  
J. David Puett
Keyword(s):  
Electron Microscopy ◽  
Circular Dichroism ◽  
Secondary Structure ◽  
Quaternary Structure ◽  
Normal Adult ◽  
Morphological Properties ◽  
Adult Males ◽  
Circular Dichroïsm ◽  
Urinary Glycoprotein

Much work has been reported on the chemical, physical and morphological properties of urinary Tamm-Horsfall glycoprotein (THG). Although it was once reported that cystic fibrotic (CF) individuals had a defective THG, more recent data indicate that THG and CF-THG are similar if not identical.No studies on the conformational aspects have been reported on this glycoprotein using circular dichroism (CD). We examined the secondary structure of THG and derivatives under various conditions and have correlated these results with quaternary structure using electron microscopy.THG was prepared from normal adult males and CF-THG from a 16-year old CF female by the method of Tamm and Horsfall. CF female by the method of Tamm and Horsfall.

Circular dichroism spectra of adsorbed dye-aggregates

1968 ◽  
Vol 65 ◽  
pp. 146-151 ◽  
Author(s):  
G. Scheibe ◽  
O. Wörz ◽  
F. Haimerl ◽  
W. Seiffert ◽  
J. Winkler
Keyword(s):  
Circular Dichroism ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm
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