The physiological functions of proteins depend on their folding into a particular spatial structure (tertiary structure): enzymes and their substrates must fit together like the proverbial lock and key. It has recently been discovered that not only large biomolecules are capable of stable, defined folding; synthetic molecules can do it too. Called foldamers, these molecules can even imitate the biological functions of the proteins they are modeled after. However, until recently their size and complexity was strictly limited. French researchers have now produced an intricately folded molecule exclusively from manmade components. The dimensions of this foldamer correspond to those of the tertiary structures of smaller proteins.
The team led by Ivan Huc did not want to base the design of their foldamer on the structure of proteins, because the synthesis of large chains from small individual building blocks is difficult. The alternative was to use branched structures. They did adopt one important structural element from proteins: the helix. The researchers hooked eight quinoline units (nitrogen-containing aromatic six-membered rings with a shared edge) together into a chain. This type of octamer twists itself into a helix. The researchers then bridged two such octamers together with a special branching link. This linker inserts so well into the two octamers that a continuous, stable helix is formed. The branching linker can then be used to hook two such helical structures together side by side. Once linked, the two helices do not lie in parallel, but rather at right angles to each other.
Helices can be twisted to the left or the right. In peptides, the direction of the helix is uniquely defined by the spatial structure of the individual building blocks. In the synthesis of the quadruple-octamers, however, an equal number of right- and left-handed helices are formed. The preferences demonstrated by the helices on pairing are determined by the solvent: In aromatic solvents, pairing of two helices with the same direction of twist is clearly preferred (70 %), while in chlorinated hydrocarbons up to 93 % of the pairs are formed from helices with opposite directions of twist. When the solvent is changed, the helices change their directionality to match these preferences. “This proves both helices are involved in strong interactions with each other, just like a folded protein,” says Huc. “Our abiotic foldamer is the first of its kind and shows that it is possible to synthesize folded molecules that imitate the size and structural complexity of the tertiary structure of proteins, while consisting entirely of manmade building blocks.” The goal is to produce artificial structures with defined binding sites and uniquely positioned catalytic groups for controlled reactions with specific substrates.
Author: Ivan Huc, Institut Européen de Chimie et Biologie, Pessac (France), http://www.iecb.u-bordeaux.fr/index.php?id=66
Title: Proteomorphous Objects from Abiotic Backbones
Angewandte Chemie International Edition, doi: 10.1002/anie.200603390
Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel
Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences