scholarly journals High-power Terahertz Waves for a Recycle System of Amyloid Fibrils

Author(s):  
Takayasu Kawasaki ◽  
Yuusuke Yamaguchi ◽  
Hideaki Kitahara ◽  
Akinori Irizawa ◽  
Masahiko Tani

Abstract Recycling of persistent materials is one of most important subjects to be addressed towards the sustainable society. Amyloid fibril is such a tough biomaterial that can be designed for various industrial applications, and it is usually difficult to dissociate the once made fibrous conformation due to the cross β-sheet stacks. We propose here a unique but versatile approach to handle the fibril formation by using two-kinds of high-power terahertz waves. Lysozyme and β2-microglobulin peptide fragment were employed as model samples, and those fibrils were clearly disaggregated accompanied by decrease of β-sheets and increase of α-helices by the irradiation of 5.3 THz free electron laser tuned to 56 μm, as shown by infrared (IR) microscopy and scanning-electron microscopy (SEM). In contrast, those fibrous conformations were reversely self-associated by the irradiation of 0.42 THz wave tuned to 720 μm from gyrotron, as shown by optical and IR microscopies, SEM, and small-angle X-ray scattering. The overall reaction is performed at room temperature within 30 min without external heating and high-pressures. Therefore, amyloid fibrils can be dissociated and associated under the proper far-infrared radiation conditions, which inspires a sustainable recycling system of fibrous biomaterials.

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4239
Author(s):  
Pezhman Mohammadi ◽  
Fabian Zemke ◽  
Wolfgang Wagermaier ◽  
Markus B. Linder

Macromolecular assembly into complex morphologies and architectural shapes is an area of fundamental research and technological innovation. In this work, we investigate the self-assembly process of recombinantly produced protein inspired by spider silk (spidroin). To elucidate the first steps of the assembly process, we examined highly concentrated and viscous pendant droplets of this protein in air. We show how the protein self-assembles and crystallizes at the water–air interface into a relatively thick and highly elastic skin. Using time-resolved in situ synchrotron X-ray scattering measurements during the drying process, we showed that the skin evolved to contain a high β-sheet amount over time. We also found that β-sheet formation strongly depended on protein concentration and relative humidity. These had a strong influence not only on the amount, but also on the ordering of these structures during the β-sheet formation process. We also showed how the skin around pendant droplets can serve as a reservoir for attaining liquid–liquid phase separation and coacervation from the dilute protein solution. Essentially, this study shows a new assembly route which could be optimized for the synthesis of new materials from a dilute protein solution and determine the properties of the final products.


2003 ◽  
Vol 11 (2) ◽  
pp. 115-122
Author(s):  
Kálmán Marossy ◽  
Pál Bárczy

Blends of high density polyethylene (HDPE) and chlorinated polyethylene (CPE) have been tested across the whole concentration range. Polyethylene is used to modify the properties of CPE in the elastomer industry, but modification of the properties of polyethylene with CPE is still not usual. Conventional mechanical tests and dynamic mechanical tests were carried out. The blends were found to be multiphase systems of excellent technological compatibility. Between 10 and 15% by weight CPE increased the modulus of polyethylene. X-ray scattering studies showed that the blends contained structural units not present either in the polyethylene or in the CPE. The blends were melt processable and may have industrial applications, too.


1998 ◽  
Author(s):  
Shunichi Sato ◽  
Kouki Shimizu ◽  
Yi-Wei Shi ◽  
Mitsunobu Miyagi

2004 ◽  
Vol 377 (3) ◽  
pp. 709-716 ◽  
Author(s):  
Emma T. A. S. JAIKARAN ◽  
Melanie R. NILSSON ◽  
Anne CLARK

Islet amyloid polypeptide (IAPP), or ‘amylin’, is co-stored with insulin in secretory granules of pancreatic islet β-cells. In Type 2 diabetes, IAPP converts into a β-sheet conformation and oligomerizes to form amyloid fibrils and islet deposits. Granule components, including insulin, inhibit spontaneous IAPP fibril formation in vitro. To determine the mechanism of this inhibition, molecular interactions of insulin with human IAPP (hIAPP), rat IAPP (rIAPP) and other peptides were examined using surface plasmon resonance (BIAcore), CD and transmission electron microscopy (EM). hIAPP and rIAPP complexed with insulin, and this reaction was concentration-dependent. rIAPP and insulin, but not pro-insulin, bound to hIAPP. Insulin with a truncated B-chain, to prevent dimerization, also bound hIAPP. In the presence of insulin, hIAPP did not spontaneously develop β-sheet secondary structure or form fibrils. Insulin interacted with pre-formed IAPP fibrils in a regular repeating pattern, as demonstrated by immunoEM, suggesting that the binding sites for insulin remain exposed in hIAPP fibrils. Since rIAPP and hIAPP form complexes with insulin (and each other), this could explain the lack of amyloid fibrils in transgenic mice expressing hIAPP. It is likely that IAPP fibrillogenesis is inhibited in secretory granules (where the hIAPP concentration is in the millimolar range) by heteromolecular complex formation with insulin. Alterations in the proportions of insulin and IAPP in granules could disrupt the stability of the peptide. The increase in the proportion of unprocessed pro-insulin produced in Type 2 diabetes could be a major factor in destabilization of hIAPP and induction of fibril formation.


2022 ◽  
Vol 17 (01) ◽  
pp. C01049
Author(s):  
G. Costa ◽  
M.P. Anania ◽  
A. Biagioni ◽  
F.G. Bisesto ◽  
M. Del Franco ◽  
...  

Abstract Plasma-based technology promises a tremendous reduction in size of accelerators used for research, medical, and industrial applications, making it possible to develop tabletop machines accessible for a broader scientific community. The use of high-power laser pulses on gaseous targets is a promising method for the generation of accelerated electron beams at energies on the GeV scale, in extremely small sizes, typically millimetres. The gaseous target in question can be a collimated supersonic gasjet from a nozzle. In this work, a technique for optimising the so generated plasma channel is presented. In detail, a study on the influence of the nozzle throat shape in relation to the uniformity and density of the generated plasma profile is reported. These considerations are discussed first of all from a theoretical point of view, by means of a stationary one-dimensional mathematical model of the neutral gas, thus exploiting the possibility of comparing the properties of the output flow for different nozzle geometries. This is combined with an experimental approach using interferometric longitudinal density measurements of the plasma channel. The latter is generated by a high-power laser pulse focused on a helium gasjet, in the SPARC_LAB laboratories.


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