Secondary Structure of Decorin-Derived Peptides in Solution

MRS Advances ◽  
2016 ◽  
Vol 1 (27) ◽  
pp. 1965-1970
Author(s):  
Axel T. Neffe ◽  
Stefania Federico ◽  
Andreas Lendlein
Keyword(s):  
Crystal Structure ◽  
Outer Surface ◽  
Cd Spectroscopy ◽  
Helical Conformation ◽  
Structural Elements ◽  
Original Sequence ◽  
X Ray ◽  
Inner Surface ◽  
Β Sheet ◽  
Secondary Structural Elements

ABSTRACTDecorin is a small leucine-rich repeat proteoglycan supporting collagen fibril formation by controlling the rate of collagen fibrillogenesis and fibril dimensions. Peptides derived from the inner surface of decorin have been shown to bind to collagen, while peptides derived from the outer surface do not display such binding affinity. As typical secondary structural elements such as β-sheets and α-helical regions were found in the decorin X-ray crystal structure, here it was investigated by Circular Dichroism (CD) spectroscopy in solution, whether the same structural elements can be found in the derived peptides. Here it is shown that the peptide derived from decorin’s outer surface has the propensity to adopt helical conformation, as it was found in the crystal structure. The results were more pronounced in 80 vol% TFE solution, which led to an increase in the number as well as the length of helices. In contrast, peptides derived from the inner surface had a higher tendency to adopt β-sheet conformation, also in TFE, which corresponds to the conformation of the original sequence in the crystal structure of decorin. This suggests that the peptides derived from decorin adopt the structures present in the native protein.

Crystal structure of coalingite

1971 ◽  
Vol 38 (295) ◽  
pp. 286-294 ◽  
Author(s):  
J. Pastor-Rodriguez ◽  
H. F. W. Taylor
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Water Molecules ◽  
Structural Elements ◽  
Structural Element ◽  
X Ray ◽  
Octahedral Sites ◽  
Carbonate Ions ◽  
Disordered Layer ◽  
Ray Methods

SummaryThe crystal structure of coalingite (Mg10Fe2(OH)24(CO3)·2H2O) has been determined using single-crystal X-ray methods. The mineral is trigonal, with space group Rm, aH = 3·12, cH = 37·4 Å, Z = ½, and (0001) cleavage. The structure is of a layer type, and is based on a structural element about 12·5 Å thick in the c-direction and consisting of two brucite-like layers and one disordered layer containing carbonate ions and water molecules and resembling those in sjögrenite and pyroaurite. The unit cell comprises three of these structural elements stacked together in the c-direction. The Mg2+ and Fe3+ ions are randomly distributed among all the octahedral sites of the brucite-like layers. The structure closely resembles those of sjögrenite and pyroaurite, but has two brucite-like layers between each CO32−−H2O layer where these have one. There is a tendency to random interstratification, and the crystals appear to contain intergrown regions of brucite and of sjögrenite or pyroaurite. Coalingite-K probably has a similar structure, but with three brucite-like layers between each -H2O layer; its idealized formula is probably Mg16Fe2(OH)36(CO3).2H2O.

TEXTURE EVOLUTION OF BT20 ALLOY IN BACKWARD TUBE SPINNING

2009 ◽  
Vol 23 (06n07) ◽  
pp. 914-919 ◽  
Author(s):  
GUOPING YANG ◽  
WENCHEN XU ◽  
DEBIN SHAN
Keyword(s):  
Outer Surface ◽  
Texture Evolution ◽  
Basal Texture ◽  
X Ray Diffraction ◽  
Tube Spinning ◽  
X Ray ◽  
Inner Surface ◽  
Medium Level ◽  
Spinning Process ◽  
History Of

Backward tube spinning experiment of BT20 ( Ti -6 Al -2 Zr -1 Mo -1 V ) alloy was carried out with an aim to examine texture evolution of titanium alloy in spinning process. The initial texture and the spinning texture were investigated by X-ray diffraction, and deformation history of a single-pass spinning was analyzed using finite element method. Tilt basal texture occurs when thickness reduction reaches a medium level (~ 49% for the outer surface and ~ 58% for the inner surface in the present study) and that further deformation promotes the formation of central basal texture. During early several passes basal texture in the outer surface develops more rapidly and intensely than that in the inner surface due to much larger deformation. However, the maximum intensity of texture in the inner surface reaches a higher level in subsequent passes for the following two reasons: (1) the discrepancy between equivalent deformation in the internal layer and that in the external layer reduces with increasing deformation; (2) material in the inner surface undergoes much smaller transverse shear deformation. Spinning texture is characterized by its asymmetry, which results from asymmetric spinning deformation investigated by analyzing deformation histories of material particles located in the inner and outer surface.

Study on One Acrylic Ester of Cytosine

2014 ◽  
Vol 912-914 ◽  
pp. 509-512
Author(s):  
Li Li Geng ◽  
Xue Min Ren ◽  
Wei Xi Mao ◽  
Xiao Ming Song ◽  
Yong Feng Ji ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Acrylic Ester ◽  
Adjacent Molecule ◽  
Β Sheet

One acrylic ester of cytosine was synthesized by a facile method, and its molecular structure was characterized by NMR, HRMS, and X-ray crystallography. In this paper, the crystal structure of the analog is described and the available data of cytosine. The X-ray crystallography showed that the adjacent molecule of cytosine Derivatives was tied to form analogous antiparallel β-sheet arrangement.

scholarly journals Crystal structure of rhodopsin bound to arrestin by femtosecond X-ray laser

2014 ◽  
Vol 70 (a1) ◽  
pp. C567-C567
Author(s):  
H. Eric Xu
Keyword(s):  
Crystal Structure ◽  
G Protein ◽  
Conformational Changes ◽  
Molten Globule ◽  
Active Form ◽  
New Paradigm ◽  
X Ray ◽  
Biased Signaling ◽  
G Protein Coupled ◽  
Β Sheet

G protein-coupled receptors (GPCRs) signal primarily through G proteins or arrestins. Arrestin binding to GPCRs blocks G protein interaction and redirects signaling to numerous G protein-independent pathways. One structure of a GPCR bound to a G protein was solved, but the structure of a GPCR-arrestin complex has remained unknown despite its central role in GPCR biology. Here we report the crystal structure of a constitutively active form of human rhodopsin bound to a pre-activated form of the mouse visual arrestin, determined by serial femtosecond X-ray laser crystallography. The structure reveals that arrestin binding induces large and unexpected conformational changes at both the extracellular and intracellular sides of rhodopsin. Arrestin also undergoes dramatic rearrangements from its inactive well-ordered β-sheet structure into a more flexible molten globule-type state, allowing a snake-like movement of the first 77 arrestin residues that shortens its central crest finger loop by seven residues to accommodate the concave surface of rhodopsin. This structure provides a basis for understanding GPCR-mediated arrestin-biased signaling, reveals a new paradigm of signal transduction by a molten globule, and demonstrates the extraordinary power of X-ray lasers for advancing the frontiers of structural biology.

scholarly journals Synthetic putative transmembrane region of minimal potassium channel protein (minK) adopts an α-helical conformation in phospholipid membranes

1997 ◽  
Vol 325 (2) ◽  
pp. 475-479 ◽  
Author(s):  
Eric A. J. MERCER ◽  
Geoffrey W. ABBOTT ◽  
Stephen P. BRAZIER ◽  
Bala RAMESH ◽  
Parvez I. HARIS ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Potassium Channel ◽  
Transmembrane Domain ◽  
Cd Spectroscopy ◽  
Helical Conformation ◽  
Phospholipid Membranes ◽  
Transmembrane Region ◽  
Aqueous Buffer ◽  
Channel Protein ◽  
Β Sheet

Minimal potassium channel protein (minK) is a potassium channel protein consisting of 130 amino acids, possessing just one putative transmembrane domain. In this study we have synthesized a peptide with the amino acid sequence RDDSKLEALYILMVLGFFGFFTLGIMLSYI, containing the putative transmembrane region of minK, and analysed its secondary structure by using Fourier-transform IR and CD spectroscopy. The peptide was virtually insoluble in aqueous buffer, forming intermolecular β-sheet aggregates. On attempted incorporation of the peptide into phospholipid membranes with a method involving dialysis, the peptide adopted a predominantly intermolecular β-sheet conformation identical with that of the peptide in aqueous buffer, in agreement with a previous report [Horvàth, Heimburg, Kovachev, Findlay, Hideg and Marsh, (1995) Biochemistry 34, 3893–3898]. However, by using an alternative method of incorporating the peptide into phospholipid membranes we found that the peptide adopted a predominantly α-helical conformation, a finding consistent with various proposed structural models. These observed differences in secondary structure are due to artifacts of aggregation of the peptide before incorporation into lipid.

scholarly journals Effect of temperature on the secondary structure of β-lactoglobulin at pH 6.7, as determined by CD and IR spectroscopy: a test of the molten globule hypothesis

1997 ◽  
Vol 324 (1) ◽  
pp. 341-346 ◽  
Author(s):  
Xiao Lin QI ◽  
Carl HOLT ◽  
David MCNULTY ◽  
David T. CLARKE ◽  
Sharon BROWNLOW ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Molten Globule ◽  
Cd Spectroscopy ◽  
Helical Conformation ◽  
Effect Of Temperature ◽  
Sheet Structure ◽  
Good Signal ◽  
Increasing Temperature ◽  
Β Lactoglobulin ◽  
Β Sheet

Previous CD measurements of changes in the conformation of β-lactoglobulin at neutral pH as a function of temperature indicated the formation of a molten globule state above approx. 70 °C. New CD measurements are reported at temperatures up to 80 °C with an instrument on the Daresbury synchrotron radiation source which gives spectra of good signal-to-noise ratio down to 170 nm. IR spectra were recorded up to 94.8 °C with a ZnSe circle cell and a single simplified model of the substructure of the amide I′ band was used to give the fractional contents of β-sheet structure unambiguously and independently of the CD spectroscopy. The results of both techniques, however, were in agreement in showing a progressive loss of β-sheet structure with increasing temperature, beginning below the denaturation temperature. Nevertheless, the CD spectroscopy showed a fairly abrupt loss of virtually all the helical conformation at approx. 65 °C. Comparison of the present results with other studies on the molten globule formed at acid pH in the lipocalin family suggests that above 65 °C a partly unfolded state is formed, possibly by destabilization of the intermolecular β-strand I and the loss of the main helix, but it is not a classical molten globule transition.

Crystal Structure of a Type-II Cohesin Module from the Bacteroides cellulosolvens Cellulosome Reveals Novel and Distinctive Secondary Structural Elements

2005 ◽  
Vol 348 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Ilit Noach ◽  
Felix Frolow ◽  
Hilla Jakoby ◽  
Sonia Rosenheck ◽  
LindaJ.W. Shimon ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Type Ii ◽  
Structural Elements ◽  
Secondary Structural Elements

scholarly journals Structural evidence for a latch mechanism regulating access to the active site of SufS-family cysteine desulfurases

2020 ◽  
Vol 76 (3) ◽  
pp. 291-301 ◽  
Author(s):  
Jack A. Dunkle ◽  
Michael R. Bruno ◽  
Patrick A. Frantom
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Sequence Analysis ◽  
Active Site ◽  
Resting State ◽  
Sulfur Source ◽  
Structural Elements ◽  
Cysteine Desulfurase ◽  
X Ray

Cysteine serves as the sulfur source for the biosynthesis of Fe–S clusters and thio-cofactors, molecules that are required for core metabolic processes in all organisms. Therefore, cysteine desulfurases, which mobilize sulfur for its incorporation into thio-cofactors by cleaving the Cα—S bond of cysteine, are ubiquitous in nature. SufS, a type 2 cysteine desulfurase that is present in plants and microorganisms, mobilizes sulfur from cysteine to the transpersulfurase SufE to initiate Fe–S biosynthesis. Here, a 1.5 Å resolution X-ray crystal structure of the Escherichia coli SufS homodimer is reported which adopts a state in which the two monomers are rotated relative to their resting state, displacing a β-hairpin from its typical position blocking transpersulfurase access to the SufS active site. A global structure and sequence analysis of SufS family members indicates that the active-site β-hairpin is likely to require adjacent structural elements to function as a β-latch regulating access to the SufS active site.

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