Assignment of lectins specific for D-galactose or N-acetyl-D-galactosamine to two groups, based on their circular dichroism

1985 ◽  
Vol 63 (4) ◽  
pp. 268-271 ◽  
Author(s):  
N. Martin Young ◽  
Ross E. Williams
Keyword(s):  
Circular Dichroism ◽  
Ultraviolet Region ◽  
Cd Spectra ◽  
Difference Spectra ◽  
Sophora Japonica ◽  
Vicia Villosa ◽  
Near Ultraviolet ◽  
Caragana Arborescens ◽  
Wisteria Floribunda ◽  
Circular Dichroïsm

The circular dichroism (CD) spectra of thirteen lectins, most being specific for D-galactose or N-acetyl-D-galactosamine, were compared. Two groupings are proposed on the basis of the CD in the near-ultraviolet region. Group one comprises the lectins from Arachis hypogaea, Glycine max, Phaseolus coccineus, P. lunatus, P. vulgaris, and Vicia villosa, and group two comprises lectins from Caragana arborescens, Cytisus sessilifolius, Dolichos biflorus, Griffonia simplicifolia, and Wisteria floribunda. The CD spectra of lectins from Bauhinia purpurea and Sophora japonica were different from any of the other lectins. CD difference spectra produced by the two sugars were distinctive for each protein, suggesting that the combining sites of these lectins are not homologous despite similarities in specificity and that the CD spectral similarities arise from residues in other, more homologous regions of the proteins.

scholarly journals Messung und Berechnung der CD-Spektren der Biaryl-Alkaloide Ancistrocladein und Dioncophyllein A [1] / Detection and Calculation of the CD Spectra from the Biaryl Alkaloids Ancistrocladeine and Dioncophylleine A [1]

1993 ◽  
Vol 48 (2) ◽  
pp. 140-148 ◽  
Author(s):  
J. Fleischhauer ◽  
A. Koslowski ◽  
B. Kramer ◽  
E. Zobel ◽  
G. Bringmann ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Cd Spectra ◽  
Circular Dichroïsm

AbstractThe circular dichroism (CD) of the biaryls ancistrocladeine and dioncophylleine A has been studied. The CNDO/S method in combination with a Boltzmann weighting o f different structures using AM 1 energies has been applied to reproduce the experimental CD spectra o f the two alkaloids with known absolute configuration at with those o f the exciton chirality method.

scholarly journals Water-Mediated Electronic Structure of Oligopeptides Probed by Their UV Circular Dichroism, Absorption Spectra, and Time-Dependent DFT Calculations

2020 ◽  
Author(s):  
Anshuman Kumar ◽  
Siobhan E. Toal ◽  
David DiGuiseppi ◽  
Reinhard Schweitzer-Stenner ◽  
Bryan Wong
Keyword(s):  
Circular Dichroism ◽  
Absorption Spectra ◽  
Density Functional ◽  
Time Dependent ◽  
Water Model ◽  
Cd Spectra ◽  
Influence Of Water ◽  
Explicit Consideration ◽  
A Charge ◽  
Circular Dichroïsm

<p>We investigate the UV absorption spectra of a series of cationic GxG (where x denotes a guest residue) peptides in aqueous solution and find that the spectra of a subset of peptides with x = A, L, I, K, N, and R (and, to a lesser extent, peptides with x = D and V) vary as a function of temperature. To explore whether or not this observation reflects conformational dependencies, we carry out time-dependent density functional calculations for the polyproline II (pPII) and β-strand conformations of a limited set of tripeptides (x = A, V, I, L, and R) in implicit and explicit water. We find that the calculated CD spectra for pPII can qualitatively account for the experimental spectra irrespective of the water model. The reproduction of the <i>β</i>-strand UV-CD spectra, however, requires the explicit consideration of water. Based on the calculated absorption spectra, we explain the observed temperature dependence of the experimental spectra as being caused by a reduced dispersion (larger spectral density) of the overlapping NV<sub>2</sub> band and the influence of water on electronic transitions in the β-strand conformation. Contrary to conventional wisdom, we find that both the NV<sub>1</sub> and NV<sub>2</sub> band are the envelopes of contributions from multiple transitions that involve more than just the HOMOs and LUMOs of the peptide groups. A natural transition orbital analysis reveals that some of the transitions with significant oscillator strength have a charge-transfer character. The overall manifold of transitions, in conjunction with their strengths and characters, depends on the peptide’s backbone conformation, peptide hydration, and also on the side chain of the guest residue. It is particularly noteworthy that molecular orbitals of water contribute significantly to transitions in <i>β</i>-strand conformations. Our results reveal that peptide groups, side chains, and hydration shells must be considered as an entity for a physically valid characterization of UV absorbance and circular dichroism. </p>

scholarly journals BeStSel: From Secondary Structure Analysis to Protein Fold Prediction by Circular Dichroism Spectroscopy

2020 ◽  
pp. 175-189
Author(s):  
András Micsonai ◽  
Éva Bulyáki ◽  
József Kardos
Keyword(s):  
Circular Dichroism ◽  
Secondary Structure ◽  
Classical Method ◽  
Cd Spectroscopy ◽  
Protein Fold ◽  
Cd Spectra ◽  
Secondary Structure Analysis ◽  
Β Sheets ◽  
Α Helix ◽  
Circular Dichroïsm

Abstract Far-UV circular dichroism (CD) spectroscopy is a classical method for the study of the secondary structure of polypeptides in solution. It has been the general view that the α-helix content can be estimated accurately from the CD spectra. However, the technique was less reliable to estimate the β-sheet contents as a consequence of the structural variety of the β-sheets, which is reflected in a large spectral diversity of the CD spectra of proteins containing this secondary structure component. By taking into account the parallel or antiparallel orientation and the twist of the β-sheets, the Beta Structure Selection (BeStSel) method provides an improved β-structure determination and its performance is more accurate for any of the secondary structure types compared to previous CD spectrum analysis algorithms. Moreover, BeStSel provides extra information on the orientation and twist of the β-sheets which is sufficient for the prediction of the protein fold. The advantage of CD spectroscopy is that it is a fast and inexpensive technique with easy data processing which can be used in a wide protein concentration range and under various buffer conditions. It is especially useful when the atomic resolution structure is not available, such as the case of protein aggregates, membrane proteins or natively disordered chains, for studying conformational transitions, testing the effect of the environmental conditions on the protein structure, for verifying the correct fold of recombinant proteins in every scientific fields working on proteins from basic protein science to biotechnology and pharmaceutical industry. Here, we provide a brief step-by-step guide to record the CD spectra of proteins and their analysis with the BeStSel method.

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