Influence of β-Sheet Structure on the Susceptibility of Proteins to Backbone Oxidative Damage:  Preference forαC-Centered Radical Formation at Glycine Residues of Antiparallel β-Sheets

2000 ◽  
Vol 122 (17) ◽  
pp. 4185-4192 ◽  
Author(s):  
Arvi Rauk ◽  
David A. Armstrong
Keyword(s):  
Oxidative Damage ◽  
Radical Formation ◽  
Sheet Structure ◽  
Β Sheets ◽  
Β Sheet

Amyloid structure

2014 ◽  
Vol 56 ◽  
pp. 1-10 ◽  
Author(s):  
Louise Serpell
Keyword(s):  
Hydrogen Bonding ◽  
Sequence Homology ◽  
Amyloid Fibrils ◽  
Side Chains ◽  
Primary Sequence ◽  
Sheet Structure ◽  
Β Sheets ◽  
The Stability ◽  
Β Sheet ◽  
Proteins And Peptides

Amyloid fibrils are formed by numerous proteins and peptides that share little sequence homology. The structures formed are highly ordered and extremely stable, being composed of β-sheet structure and stabilized along their length by hydrogen bonding. The fibrils are formed by several protofilaments that wind around one another in rope-like structures, lending further strength and stability to the resulting fibres. The fact that so many proteins and peptides form amyloid structures under suitable conditions, seems to suggest that the sequence of the precursor is unimportant. However, it is now clear that side chains play a central role in forming interactions between several β-sheets to further stabilize and regulate the structures. The primary sequence plays a central role in determining the rate of fibril formation, the stability of the resulting structure to degradation and the final morphology of the fibrils. The side chains regulate the elongation and growth, and also the lateral association of the protofilament and fibrils, having a significant impact on the final architecture.

On the roles of the alanine and serine in the β-sheet structure of fibroin

2015 ◽  
Vol 197 ◽  
pp. 10-17 ◽  
Author(s):  
Juan Francisco Carrascoza Mayen ◽  
Alexandru Lupan ◽  
Ciprian Cosar ◽  
Attila-Zsolt Kun ◽  
Radu Silaghi-Dumitrescu
Keyword(s):  
Sheet Structure ◽  
Β Sheet

scholarly journals Factors involved in the stability of isolated β-sheets: Turn sequence, β-sheet twisting, and hydrophobic surface burial

2004 ◽  
Vol 13 (4) ◽  
pp. 1134-1147 ◽  
Author(s):  
Clara M. Santiveri ◽  
Jorge Santoro ◽  
Manuel Rico ◽  
M. Angeles Jiménez
Keyword(s):  
Hydrophobic Surface ◽  
Β Sheets ◽  
The Stability ◽  
Β Sheet

Effect of curcumin on amyloidogenic property of molten globule-like intermediate state of 2,5-diketo-d-gluconate reductase A

2009 ◽  
Vol 390 (10) ◽  
Author(s):  
Nandini Sarkar ◽  
Abhay Narain Singh ◽  
Vikash Kumar Dubey
Keyword(s):  
Protein Concentration ◽  
Molten Globule ◽  
Molar Ratio ◽  
Amyloid Formation ◽  
Molten Globule State ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sheet Structure ◽  
Amyloid Diseases ◽  
Β Sheet

Abstract We identified a molten globule-like intermediate of 2,5-diketo-d-gluconate reductase A (DKGR) at pH 2.5, which has a prominent β-sheet structure. The molten globule state of the protein shows amyloidogenic property >50 μm protein concentration. Interestingly, a 1:1 molar ratio of curcumin prevents amyloid formation as shown by the Thioflavin-T assay and atomic force microscopy. To the best of our knowledge, this is the first report on amyloid formation by an (α/β)8-barrel protein. The results presented here indicate that the molten globule state has an important role in amyloid formation and potential application of curcumin in protein biotechnology as well as therapeutics against amyloid diseases.

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.

NMR structure of bucandin, a neurotoxin from the venom of the Malayan krait (Bungarus candidus)

2001 ◽  
Vol 360 (3) ◽  
pp. 539-548 ◽  
Author(s):  
Allan M. TORRES ◽  
R. Manjunatha KINI ◽  
Nirthanan SELVANAYAGAM ◽  
Philip W. KUCHEL
Keyword(s):  
Solution Structure ◽  
Pharmacological Action ◽  
Nmr Structure ◽  
Side Chains ◽  
X Ray ◽  
Nmr Study ◽  
C Terminus ◽  
Mean Structure ◽  
Β Sheets ◽  
Β Sheet

A high-resolution solution structure of bucandin, a neurotoxin from Malayan krait (Bungarus candidus), was determined by 1H-NMR spectroscopy and molecular dynamics. The average backbone root-mean-square deviation for the 20 calculated structures and the mean structure is 0.47 Å (1 Å = 0.1nm) for all residues and 0.24 Å for the well-defined region that spans residues 23–58. Secondary-structural elements include two antiparallel β-sheets characterized by two and four strands. According to recent X-ray analysis, bucandin adopts a typical three-finger loop motif and yet it has some peculiar characteristics that set it apart from other common α-neurotoxins. The presence of a fourth strand in the second antiparallel β-sheet had not been observed before in three-finger toxins, and this feature was well represented in the NMR structure. Although the overall fold of the NMR structure is similar to that of the X-ray crystal structure, there are significant differences between the two structures that have implications for the pharmacological action of the toxin. These include the extent of the β-sheets, the conformation of the region spanning residues 42–49 and the orientation of some side chains. In comparison with the X-ray structure, the NMR structure shows that the hydrophobic side chains of Trp27 and Trp36 are stacked together and are orientated towards the tip of the middle loop. The NMR study also showed that the two-stranded β-sheet incorporated in the first loop, as defined by residues 1–22, and the C-terminus from Asn59, is probably flexible relative to the rest of the molecule. On the basis of the dispositions of the hydrophobic and hydrophilic side chains, the structure of bucandin is clearly different from those of cytotoxins.

Influence of Strand Number on Antiparallel β-Sheet Stability in Designed Three- and Four-stranded β-Sheets

2003 ◽  
Vol 326 (2) ◽  
pp. 553-568 ◽  
Author(s):  
Faisal A. Syud ◽  
Heather E. Stanger ◽  
Heather Schenck Mortell ◽  
Juan F. Espinosa ◽  
John D. Fisk ◽  
...  
Keyword(s):  
Β Sheets ◽  
Β Sheet
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