Circular dichroism and the interactions of water soluble porphyrins with DNA?A minireview

Chirality ◽  
2003 ◽  
Vol 15 (4) ◽  
pp. 329-332 ◽  
Author(s):  
Robert F. Pasternack
1977 ◽  
Vol 55 (24) ◽  
pp. 4257-4266 ◽  
Author(s):  
Lewis A. Slotin ◽  
Denis R. Lauren ◽  
Ross E. Williams

Several polypeptides have been synthesized which contain the alternating sequence lysyl-X, where X = gly, L-ala, D-ala, L-val, L-leu, and L-phe. The polypeptides have been characterized by gel filtration (molecular weight) and by circular dichroism spectroscopy (secondary structure).


2015 ◽  
Vol 22 (3) ◽  
pp. 844-852 ◽  
Author(s):  
Jochen Bürck ◽  
Siegmar Roth ◽  
Dirk Windisch ◽  
Parvesh Wadhwani ◽  
David Moss ◽  
...  

Synchrotron radiation circular dichroism (SRCD) is a rapidly growing technique for structure analysis of proteins and other chiral biomaterials. UV-CD12 is a high-flux SRCD beamline installed at the ANKA synchrotron, to which it had been transferred after the closure of the SRS Daresbury. The beamline covers an extended vacuum-UV to near-UV spectral range and has been open for users since October 2011. The current end-station allows for temperature-controlled steady-state SRCD spectroscopy, including routine automated thermal scans of microlitre volumes of water-soluble proteins down to 170 nm. It offers an excellent signal-to-noise ratio over the whole accessible spectral range. The technique of oriented circular dichroism (OCD) was recently implemented for determining the membrane alignment of α-helical peptides and proteins in macroscopically oriented lipid bilayers as mimics of cellular membranes. It offers improved spectral quality <200 nm compared with an OCD setup adapted to a bench-top instrument, and accelerated data collection by a factor of ∼3. In addition, it permits investigations of low hydrated protein films down to 130 nm using a rotatable sample cell that avoids linear dichroism artifacts.


1988 ◽  
Vol 53 (11) ◽  
pp. 2825-2832 ◽  
Author(s):  
Bernard Barbier ◽  
Margarita Perello ◽  
André Brack

Alternating poly(Leu-Lys) and its isopolypeptide poly(Leu-Lys-Lys-Leu) were synthesized via polycondensation of p-nitrophenyl esters of the corresponding protected peptides. Addition of one equivalent of 1-hydroxybenzotriazole and varying amounts of a tertiary base allowed to control the molecular weights of the samples. The conformation of the water soluble polypeptides was investigated by circular dichroism. Poly(Leu-Lys) adopts a β-sheet conformation in the presence of salt while poly(Leu-Lys-Lys-Leu) adopts an α-helical conformation. For polypeptides based on a 1 : 1 composition of hydrophobic (A) and hydrophilic (B) residues, the shortest repeat for the formation of a β-sheet is -AB- whereas -AABB- represents the shortest repeat for an α-helix formation.


ACS Omega ◽  
2020 ◽  
Vol 5 (8) ◽  
pp. 4293-4301 ◽  
Author(s):  
Claudia Honisch ◽  
Viola Donadello ◽  
Rohanah Hussain ◽  
Daniele Peterle ◽  
Vincenzo De Filippis ◽  
...  

1978 ◽  
Vol 56 (20) ◽  
pp. 2650-2656 ◽  
Author(s):  
Sandra L. Kielland ◽  
Lewis A. Slotin ◽  
Ross E. Williams

Turbidity measurements, circular dichroism spectra, electron micrographs and thermal denaturation profiles of complexes between sonicated DNA and either poly(L-lysyl-L-alanine) or poly(L-lysyl-D-alanine) show significant differences which might be related to the primary or secondary structure of the polypeptides.


2010 ◽  
Vol 10 (3) ◽  
pp. 1315-1327 ◽  
Author(s):  
I. Salma ◽  
T. Mészáros ◽  
W. Maenhaut ◽  
E. Vass ◽  
Z. Majer

Abstract. Aerosol water extracts and atmospheric humic-like substances (HULIS) obtained from PM2.5-fraction aerosol samples collected in a rural/continental background environment and in an urban environment in spring and summer, and at a tropical site that was heavily impacted by biomass burning were studied. HULIS was obtained as the water-soluble, methanol-elutable material isolated from a solid-phase extraction procedure. The mean organic matter-to-organic carbon mass conversion factor and the standard deviation of 2.04±0.06 were derived for HULIS from biomass burning. Mean atmospheric concentrations of HULIS for the rural and urban environments and for the biomass burning during daylight periods and nights, were 1.65, 2.2, 43, and 60 μg m−3, respectively. This and other abundances indicate that intense emission sources and/or formation mechanisms of HULIS operate in biomass burning. Mean contributions of C in HULIS (HULIS-C) to water-soluble organic carbon (WSOC) were 35, 48, 63, and 76%, respectively, for the sample set listed. HULIS-C is the major component of the WSOC in tropical biomass burning. The data also suggest that HULIS most likely do not share common origin in the three environments studied. Differentiation among the possible formation processes was attempted by investigating the optical activity of HULIS through their (electronic and vibrational) circular dichroism properties. The urban HULIS did not show optical activity, which is in line with the concept of their major airborne formation from anthropogenic aromatics. The rural HULIS revealed weak optical activity, which may be associated with one of their important formation pathways by photo-oxidation and oligomerisation, i.e., with the formation from chiral biogenic precursors with one of the enantiomers slightly enriched. The The biomass burning of HULIS exhibited a strong effect in the vibrational circular dichroism as a clear distinction from the other two types. This was related to the contribution of the thermal degradation products of lignins and cellulose. The biomass burning of HULIS resemble Suwannee River Fulvic Acid standard more closely in some aspects than the urban and rural types of HULIS, which may be related to their common origin from plant material.


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