Conformations of calf thymus and rye histones H3 and H4 in aqueous solution by laser Raman spectroscopy

1980 ◽  
Vol 58 (8) ◽  
pp. 633-640 ◽  
Author(s):  
M. Pézolet ◽  
R. Savoie ◽  
J.-G. Guillot ◽  
M. Pigeon-Gosselin ◽  
D. Pallotta
Keyword(s):  
Laser Raman Spectroscopy ◽  
Carboxylate Group ◽  
Weakly Bound ◽  
Tyrosine Residues ◽  
Laser Raman ◽  
Calf Thymus ◽  
Sheet Structure ◽  
High Degree ◽  
Β Sheet ◽  
Positively Charged

The Raman spectra of aqueous solutions of histones H3 and H4 from calf thymus and from rye reflect the high degree of conservation from species to species of the primary and secondary structures of these proteins. The amount of β-sheet structure is estimated at 40 ± 5% in H4 and at 33 ± 5% in H3 from the intensities of the amide I and amide III bands at 1663 and 1241 cm−1, respectively, in the spectra. These values are independent of the salt concentration of the solutions, most likely because of the high histone concentration (~3 mM) required to obtain the spectra, which results in some aggregation of the proteins. The intensity ratio of the tyrosine doublet at 852 and 826 cm−1 indicates that the four tyrosine residues in H4 are relatively exposed to the solvent or weakly bound to positively charged groups of basic amino acids, whereas in H3 at least one tyrosine is buried inside the protein and tightly bound to a carboxylate group. The results also show that the secondary structure of H3 is slightly influenced by the state of oxidation of the two cysteine residues it contains.

Laser Raman Spectroscopic Study Of The β-Sheet Structure Of Fibrinx

1981 ◽  
Author(s):  
J Marx ◽  
G Hudry-Clergeon ◽  
L Bernard
Keyword(s):  
Protein Conformation ◽  
Protein Concentration ◽  
Structural Changes ◽  
Fibre Diameter ◽  
Enzymatic Conversion ◽  
Raman Spectroscopic ◽  
Laser Raman ◽  
Sheet Structure ◽  
Two Parameters ◽  
Β Sheet

Raman spectroscopy has proved to be a useful tool in the study of protein conformation in aqueous solution. Structural changes have been observed by this technique during the enzymatic conversion of fibrinogen into fibrin (J. Marx and col. (1979) Biochim. Biophys. Acta., 578, 107-115), particularly by the study of the Amide I and Amide III regions an important increase in the β-sheet form has been shown to occur. This variation is investigated under various conditions of ionic strength (μ) and protein concentration (c), two parameters which are known to change the fibre diameter (low values of μ and c favor an increase in the fibre diameter). The amount of β-sheet structure in fibrinogen is approximately 10 % and is unaffected by μ or c. In fibrin, the amount of β-sheet increases progressively from 20 % in fine clots (low diameter fibres) to more than 30 % in coarse clots (high diameter fibres). This correlation between the percentage of β-sheet structure and fibre diameter in fibrin indicates that numerous intermonomer hydrogen bonds are formed in the equatorial direction of the fibre. These bonds would greatly consolidate the association between monomers which is probably initiated at a few highly specific sites.

Laser Raman Spectroscopy of Fibrinogen and Fibrin

1979 ◽  
Author(s):  
J Marx ◽  
G Hudry-Clergeon ◽  
L Bernard
Keyword(s):  
Raman Spectroscopy ◽  
Secondary Structure ◽  
Laser Raman Spectroscopy ◽  
Laser Raman ◽  
Secondary Structure Of Proteins ◽  
Β Sheet ◽  
Structure Of Proteins

Raman spectroscopy is now a useful mean of estimating the secondary structure of proteins. The study of the Amide I and Amide III bands revealed an important increase in the β-sheet form of fibrin, compared with that of fibrinogen. This effect is accompanied by significant variations in the bands characteristic of aromatic chromophores. These observations favour the hypothesis (Hudry-Clergeon et al. 1975, Thromb. Res. 6, 533) that important structural events occur during the fibrinogenfibrin transition.

Laser Raman Spectroscopy of Fibrinogen and Fibrin

1979 ◽  
Author(s):  
J. Marx ◽  
G. Hudry-Clergeon ◽  
L. Bernard
Keyword(s):  
Raman Spectroscopy ◽  
Secondary Structure ◽  
Laser Raman Spectroscopy ◽  
Laser Raman ◽  
Secondary Structure Of Proteins ◽  
Β Sheet ◽  
Structure Of Proteins

Raman spectroscopy is now a useful mean of estimating the secondary structure of proteins. The study of the Amide I and Amide III bands revealed an important increase in the β-sheet form of fibrin, compared with that of fibrinogen. This effect is accompanied by significant variations in the bands characteristic of aromatic chromophores. These observations favour the hypothesis (Hudry-Clergeon et al.1975, Thromb. Res. 6, 533) that important structural events occur during the fibrinogenfibrin transition.

POLYMERIZATION OF DIACETYLENE USING β-SHEET AS A TEMPLATE

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3872-3877 ◽  
Author(s):  
TAKESHI MORI ◽  
YOICHI FUKAWA ◽  
KENJI SHIMOYAMA ◽  
KEIJI MINAGAWA ◽  
MASAMI TANAKA
Keyword(s):  
Hydrogen Bonding ◽  
Amino Acid ◽  
Degree Of Polymerization ◽  
The Other ◽  
Unit Distance ◽  
Amide Bonds ◽  
Cleavage Process ◽  
Sheet Structure ◽  
High Degree ◽  
Β Sheet

In the parallel and anti-parallel β-sheet structures, hydrogen bonding arises between the amide bonds of the peptide chains to arrange them with a distance of ca. 5 Å. That distance matched with the repeating unit distance of polydiacetylene. In this study, the effectiveness of the β-sheet as a template for the polymerization of diacetylene was examined by using diacetylene-introduced oligopeptides. The diacetylene-introduced amino acid (Thr(DA)) was synthesized from L-threonine. Though peptides Ac-Thr(DA)-NHMe and Ac -[ Thr(DA) ]2- NHMe formed anti-parallel β-sheet, they showed slight or no polymerization in both of the solid and the solution states. On the other hand, Ac -[ Thr(DA) ]5- NHMe and 11mer peptide with a Thr(DA) in the center of the sequence contained anti-parallel β-sheet structure and formed polydiacetylene of high degree of polymerization with high conversion during the cleavage process of the peptide from resin in the solution. This result indicated that the preorganization of the peptide through the β-sheet formation was necessary for the polymerization of diacetylene group. Thus, the β-sheet motif was effective template for the polymerization of diacetylene.

Tuning of Electronic Properties in Conducting Polymers

2001 ◽  
Vol 66 (8) ◽  
pp. 1208-1218 ◽  
Author(s):  
Guofeng Li ◽  
Mira Josowicz ◽  
Jiří Janata
Keyword(s):  
Hydrogen Bonding ◽  
Binding Site ◽  
Binding Sites ◽  
Polymer Chains ◽  
Electronic Transitions ◽  
Weakly Bound ◽  
Ordered Structures ◽  
Doped Polymer ◽  
Positively Charged ◽  
Repeated Cycling

Structural and electronic transitions in poly(thiophenyleneiminophenylene), usually referred to as poly(phenylenesulfidephenyleneamine) (PPSA) upon electrochemical doping with LiClO4 have been investigated. The unusual electrochemical behavior of PPSA indicates that the dopant anions are bound in two energetically different sites. In the so-called "binding site", the ClO4- anion is Coulombically attracted to the positively charged S or N sites on one chain and simultaneously hydrogen-bonded with the N-H group on a neighboring polymer chain. This strong interaction causes a re-organization of the polymer chains, resulting in the formation of a networked structure linked together by these ClO4- Coulombic/hydrogen bonding "bridges". However, in the "non-binding site", the ClO4- anion is very weakly bound, involves only the electrostatic interaction and can be reversibly exchanged when the doped polymer is reduced. In the repeated cycling, the continuous and alternating influx and expulsion of ClO4- ions serves as a self-organizing process for such networked structures, giving rise to a diminishing number of available "non-binding" sites. The occurrence of these ordered structures has a major impact on the electrochemical activity and the morphology of the doped polymer. Also due to stabilization of the dopant ions, the doped polymer can be kept in a stable and desirable oxidation state, thus both work function and conductivity of the polymer can be electrochemically controlled.

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