scholarly journals Amyloid Self‐Assembly of hIAPP8‐20 via the Accumulation of Helical Oligomers, α‐Helix to β‐Sheet Transition, and Formation of β‐Barrel Intermediates

Small ◽  
2019 ◽  
Vol 15 (18) ◽  
pp. 1805166 ◽  
Author(s):  
Yunxiang Sun ◽  
Aleksandr Kakinen ◽  
Yanting Xing ◽  
Pouya Faridi ◽  
Aparna Nandakumar ◽  
...  
Keyword(s):  
Α Helix ◽  
2009 ◽  
Vol 121 (9) ◽  
pp. 1629-1633 ◽  
Author(s):  
Yong-beom Lim ◽  
Kyung-Soo Moon ◽  
Myongsoo Lee

2017 ◽  
Vol 114 (14) ◽  
pp. 3601-3606 ◽  
Author(s):  
Haiyan Zhao ◽  
Kunpeng Li ◽  
Anna Y. Lynn ◽  
Keith E. Aron ◽  
Guimei Yu ◽  
...  

The enormous prevalence of tailed DNA bacteriophages on this planet is enabled by highly efficient self-assembly of hundreds of protein subunits into highly stable capsids. These capsids can stand with an internal pressure as high as ∼50 atmospheres as a result of the phage DNA-packaging process. Here we report the complete atomic model of the headful DNA-packaging bacteriophage Sf6 at 2.9 Å resolution determined by electron cryo-microscopy. The structure reveals the DNA-inflated, tensed state of a robust protein shell assembled via noncovalent interactions. Remarkable global conformational polymorphism of capsid proteins, a network formed by extended N arms, mortise-and-tenon–like intercapsomer joints, and abundant β-sheet–like mainchain:mainchain intermolecular interactions, confers significant strength yet also flexibility required for capsid assembly and DNA packaging. Differential formations of the hexon and penton are mediated by a drastic α–helix-to-β–strand structural transition. The assembly scheme revealed here may be common among tailed DNA phages and herpesviruses.


2015 ◽  
Vol 16 (8) ◽  
pp. 2327-2339 ◽  
Author(s):  
Jing Fu ◽  
Paul A. Guerette ◽  
Ali Miserez
Keyword(s):  
Α Helix ◽  

Soft Matter ◽  
2009 ◽  
Vol 5 (1) ◽  
pp. 193-202 ◽  
Author(s):  
A. Saiani ◽  
A. Mohammed ◽  
H. Frielinghaus ◽  
R. Collins ◽  
N. Hodson ◽  
...  

Small ◽  
2019 ◽  
Vol 15 (18) ◽  
pp. 1970093 ◽  
Author(s):  
Yunxiang Sun ◽  
Aleksandr Kakinen ◽  
Yanting Xing ◽  
Pouya Faridi ◽  
Aparna Nandakumar ◽  
...  
Keyword(s):  
Α Helix ◽  

2009 ◽  
Vol 48 (9) ◽  
pp. 1601-1605 ◽  
Author(s):  
Yong-beom Lim ◽  
Kyung-Soo Moon ◽  
Myongsoo Lee

2020 ◽  
Vol 01 ◽  
Author(s):  
Zheng Zuo ◽  
Zongyun Chen ◽  
Zhijian Cao ◽  
Wenxin Li ◽  
Yingliang Wu

: The scorpion toxins are the largest potassium channel-blocking peptide family. The understanding of toxin binding interfaces is usually restricted by two classical binding interfaces: one is the toxin α-helix motif, the other is the antiparallel β-sheet motif. In this review, such traditional knowledge was updated by another two different binding interfaces: one is BmKTX toxin using the turn motif between the α-helix and antiparallel β-sheet domains as the binding interface, the other is Ts toxin using turn motif between the β-sheet in the N-terminal and α-helix domains as the binding interface. Their interaction analysis indicated that the scarce negatively charged residues in the scorpion toxins played a critical role in orientating the toxin binding interface. In view of the toxin negatively charged amino acids as “binding interface regulator”, the law of scorpion toxin-potassium channel interaction was proposed, that is, the polymorphism of negatively charged residue distribution determines the diversity of toxin binding interfaces. Such law was used to develop scorpion toxin-potassium channel recognition control technique. According to this technique, three Kv1.3 channel-targeted peptides, using BmKTX as the template, were designed with the distinct binding interfaces from that of BmKTX through modulating the distribution of toxin negatively charged residues. In view of the potassium channel as the common targets of different animal toxins, the proposed law was also shown to helpfully orientate the binding interfaces of other animal toxins. Clearly, the toxin-potassium channel interaction law would strongly accelerate the research and development of different potassium channelblocking animal toxins in the future.


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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ukrit Thamma ◽  
Tia J. Kowal ◽  
Matthias M. Falk ◽  
Himanshu Jain

AbstractThe nanostructure of engineered bioscaffolds has a profound impact on cell response, yet its understanding remains incomplete as cells interact with a highly complex interfacial layer rather than the material itself. For bioactive glass scaffolds, this layer comprises of silica gel, hydroxyapatite (HA)/carbonated hydroxyapatite (CHA), and absorbed proteins—all in varying micro/nano structure, composition, and concentration. Here, we examined the response of MC3T3-E1 pre-osteoblast cells to 30 mol% CaO–70 mol% SiO2 porous bioactive glass monoliths that differed only in nanopore size (6–44 nm) yet resulted in the formation of HA/CHA layers with significantly different microstructures. We report that cell response, as quantified by cell attachment and morphology, does not correlate with nanopore size, nor HA/CHO layer micro/nano morphology, or absorbed protein amount (bovine serum albumin, BSA), but with BSA’s secondary conformation as indicated by its β-sheet/α-helix ratio. Our results suggest that the β-sheet structure in BSA interacts electrostatically with the HA/CHA interfacial layer and activates the RGD sequence of absorbed adhesion proteins, such as fibronectin and vitronectin, thus significantly enhancing the attachment of cells. These findings provide new insight into the interaction of cells with the scaffolds’ interfacial layer, which is vital for the continued development of engineered tissue scaffolds.


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