1,720,971 research outputs found
Conformational modeling of elastin tetrapeptide Boc-Gly-Leu-Gly-Gly-NMe by molecular dynamics simulations with improvements to the thermalization procedure.
No full textSite directed spin labeling of the mitochondrial membrane. Synthesis and utilization of the adenosine triphosphatase inhibitor (N (2,2,6,6 tetramethyl piperidyl 1 oxyl) N' (cyclohexyl) carbodiimide)
No full textSynthetic fragments and analogues of elastin. I. The synthesis
No full textThe synthesis of some repetitive sequences of elastin and their simplified analogues, all comprising the structural unit Gly-X-Gly (X = Val, Leu, Ala), is described. In particular, the following peptides and polypeptides were synthesized and characterized: Boc-Gly-Val-Gly-Gly-Leu-OMe, Boc-Gly-Leu-Gly-Gly-Val-OMe, Boc-(Gly-Val-Gly-Gly-Leu)2-OMe, Boc-(Gly-Val-Gly-Gly-Leu)3-OMe, Boc-Gly-Val-Gly-Gly-OEt, Boc-Leu-Gly-Gly-Leu-OMe, Boc-Val-Gly-Gly-Val-OMe, poly(Ala-Gly-Gly), poly(Val-Gly-Gly), and poly (Leu-Gly-Gly).
In every case, the synthesis was accomplished by classical procedures in solution, by using the p-nitrophenyl ester method for the polycondensation step, and the mixed anhydride or the azide methods for the coupling steps
Conformational studies on particles of turnip yellow mosaic virus
No full textCircular dichroism studies (CD) of turnip yellow mosaic virus (TYMV) nucleoprotein and of its isolated RNA and capsid revealed that: (i) the nucleic acid structure, which comprises a considerable amount of base pairing and/or stacking, remains essentially unchanged irrespective of whether the RNA is encapsidated or free; (ii) the secondary structure of the protein component is mainly accounted for by β- and irregular forms without appreciable amounts of α-helix; (iii) the interaction of capsid protein and RNA induces some conformational changes in the protein probably involving a decrease of β-structure and a perturbation of the microenvironment of some aromatic residues. The influence of temperature on the CD spectra of virus nucleoprotein, RNA and capsid was also investigated. The results are discussed in connection with particle stability
‘Transformation of amyloid-like fibres, formed from an elastin-based biopolymer, into hydrogel: an XPS and AFM study’
No full textPrevious studies have revealed the propensity of elastin-based biopolymers to form amyloid-like fibers when dissolved in water. These are of interest when considered as "ancestral units" of elastin in which they represent the simplest sequences in the hydrophobic regions of the general type XxxGlyGlyZzzGly (Xxx, Zzz = Val, Leu). We normally refer to these biopolymers based on elastin or related to elastin units as "elastin-like polypeptides". The requirement of water for the formation of amyloids seems quite interesting and deserves investigation, the water representing the natural transport medium in human cells. As a matter of fact, the "natural" supramolecular organization of elastin is in the form of beaded-string-like filaments and not in the form of amyloids whose "in vivo" deposition is associated with some important human diseases. Our work is directed, therefore, to understanding the mechanism by which such hydrophobic sequences form amyloids and any conditions by which they might regress to a non-amyloid filament. The elastin-like sequence here under investigation is the ValGlyGly ValGly pentapeptide that has been previously analyzed both in its monomer and polymer form. In particular, we have focused our investigation on the apparent stability of amyloids formed from poly(ValGlyGlyValGly), and we have observed these fibers evolving to a hydrogel after prolonged aging in water. We will show how atomic force microscopy can be combined with X-ray photoelectron spectroscopy to gain an insight into the spontaneous organization of an elastin-like polypeptide driven by interfacial interactions. The results are discussed also in light of fractal-like assembly and their implications from a biomedical point of view
Molecular dynamics study of the conformational behavior of a representative elastin building block: Boc-Gly-Val-Gly-Gly-Leu-OMe.
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