scholarly journals A rhythmically pulsing leaf-spring nanoengine that drives a passive follower

2021 ◽  
Author(s):  
Mathias Centola ◽  
Erik Poppleton ◽  
Martin Centola ◽  
Julian Valero ◽  
Petr Sulc ◽  
...  
Keyword(s):  
Brownian Motion ◽  
Molecular Motors ◽  
Molecular Engineering ◽  
Dna Origami ◽  
Chemical Energy ◽  
Leaf Spring ◽  
Bottom Up ◽  
Second Tier ◽  
Dna Nanomachine ◽  
Efficient Transfer

Molecular engineering seeks to create functional entities for the modular use in the bottom-up design of nanoassemblies that can perform complex tasks. Such systems require fuel-consuming nanomotors that can actively drive downstream passive followers. Most molecular motors are driven by Brownian motion, but the generated forces are scattered and insufficient for efficient transfer to passive second-tier components, which is why nanoscale driver-follower systems have not been realized. Here, we describe bottom-up construction of a DNA-nanomachine that engages in an active, autonomous and rhythmical pulsing motion of two rigid DNA-origami arms, driven by chemical energy. We show the straightforward coupling of the active nanomachine to a passive follower unit, to which it then transmits its own motion, thus constituting a genuine driver-follower pair. Our work introduces a versatile fuel-consuming nanomachine that can be coupled with passive modules in nanoassemblies, the function of which depends on downstream sequences of motion.

scholarly journals Positional isomers of a non-nucleoside substrate differentially affect myosin function

2019 ◽  
Author(s):  
M. Woodward ◽  
E. Ostrander ◽  
S.P. Jeong ◽  
X. Liu ◽  
B. Scott ◽  
...  
Keyword(s):  
Energy Source ◽  
Muscle Contraction ◽  
Motor Function ◽  
Molecular Motors ◽  
Molecular Motor ◽  
Vesicular Transport ◽  
Gain Control ◽  
Mechanical Work ◽  
Chemical Energy ◽  
Muscle Myosin

AbstractMolecular motors have evolved to transduce chemical energy from adenosine triphosphate into mechanical work to drive essential cellular processes, from muscle contraction to vesicular transport. Dysfunction of these motors is a root cause of many pathologies necessitating the need for intrinsic control over molecular motor function. Herein, we demonstrate that positional isomerism can be used as a simple and powerful tool to control the molecular motor of muscle, myosin. Using three isomers of a synthetic non-nucleoside triphosphate we demonstrate that myosin’s force and motion generating capacity can be dramatically altered at both the ensemble and single molecule levels. By correlating our experimental results with computation, we show that each isomer exerts intrinsic control by affecting distinct steps in myosin’s mechano-chemical cycle. Our studies demonstrate that subtle variations in the structure of an abiotic energy source can be used to control the force and motility of myosin without altering myosin’s structure.Statement of SignificanceMolecular motors transduce chemical energy from ATP into the mechanical work inside a cell, powering everything from muscle contraction to vesicular transport. While ATP is the preferred source of energy, there is growing interest in developing alternative sources of energy to gain control over molecular motors. We synthesized a series of synthetic compounds to serve as alternative energy sources for muscle myosin. Myosin was able to use this energy source to generate force and velocity. And by using different isomers of this compound we were able to modulate, and even inhibit, the activity of myosin. This suggests that changing the isomer of the substrate could provide a simple, yet powerful, approach to gain control over molecular motor function.

scholarly journals TOP-DOWN OR BOTTOM-UP? EMPLOYING A MIDDLE-GROUND APPROACH IN DESIGNING A UK ACADEMIC WRITING COURSE FOR ADVANCED CHINESE GRADUATES

2020 ◽  
pp. 095
Author(s):  
Ivo Ganchev
Keyword(s):  
Design Process ◽  
Academic Writing ◽  
Course Design ◽  
Middle Ground ◽  
Top Down ◽  
Bottom Up ◽  
Postgraduate Study ◽  
Writing Course ◽  
Second Tier ◽  
The Uk

This article documents the academic writing course design process for advanced Chinese learners aiming to pursue postgraduate degrees in business-related fields at their respective target universities in the UK. Four holders of BA degrees in the social sciences from second tier universities in Beijing were tested, surveyed and observed in detail to design a non-terminal twenty-hour pre-sessional writing course (ten two-hour sessions) to assist in their preparation for postgraduate study. All students held offers from Russell Group universities in the UK and had covered the IELTS requirement (6.5-7.0) for admission there prior to signing up for the EAP course discussed in this paper. The aim of the course is to enhance the students’ academic skills and improve their performance in the following year when they attend UK universities. The course design process is informed by two sets of principles, incorporating both a top-down and a bottom-up perspective. The former is framed within an understanding of EAP as academic, rather than language training. The latter is based on needs analysis of student-specific weaknesses explored through the use of a questionnaire, a diagnostic writing test and in-class observations. Both perspectives feed into the course goals and objectives which serve as a basis for the course rationale. Aiming to bridge the gap between Chinese undergraduate and UK postgraduate study, the course combines textbooks with authentic materials and formative with summative assessment. Reflections on major constraints and limitations are provided throughout the process. This documented case of academic writing course design aims to reveal challenges faced by EAP practitioners working with UK and Chinese institutions, and to present a middle ground approach to resolving tensions between top-down and bottom-up pressures in the context of course design for advanced Chinese graduates.

scholarly journals DNA Origami Nanomachines

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1766 ◽  
Author(s):  
Masayuki Endo ◽  
Hiroshi Sugiyama
Keyword(s):  
Dna Sequences ◽  
Molecular Motors ◽  
Molecular Machines ◽  
Dna Origami ◽  
Dna Nanostructures ◽  
Molecular Systems ◽  
Nanoscale Structures ◽  
Research Fields ◽  
Dna Strands ◽  
External Stimuli

DNA can assemble various molecules and nanomaterials in a programmed fashion and is a powerful tool in the nanotechnology and biology research fields. DNA also allows the construction of desired nanoscale structures via the design of DNA sequences. Structural nanotechnology, especially DNA origami, is widely used to design and create functionalized nanostructures and devices. In addition, DNA molecular machines have been created and are operated by specific DNA strands and external stimuli to perform linear, rotational, and reciprocating movements. Furthermore, complicated molecular systems have been created on DNA nanostructures by arranging multiple molecules and molecular machines precisely to mimic biological systems. Currently, DNA nanomachines, such as molecular motors, are operated on DNA nanostructures. Dynamic DNA nanostructures that have a mechanically controllable system have also been developed. In this review, we describe recent research on new DNA nanomachines and nanosystems that were built on designed DNA nanostructures.

Molecular engineering of the bio/nano-interface for enzymatic electrocatalysis in fuel cells

2018 ◽  
Vol 2 (12) ◽  
pp. 2555-2566 ◽  
Author(s):  
Alan Le Goff ◽  
Michael Holzinger
Keyword(s):  
Fuel Cells ◽  
Electric Power ◽  
Molecular Engineering ◽  
Chemical Energy ◽  
Large Community ◽  
Sustainable Fuels

The fascinating topic of converting chemical energy into electric power using biological catalysts, called enzymes, and sustainable fuels motivates a large community of scientists to develop enzymatic fuel cells.

Artificial Molecular Motors Powered by Light

2006 ◽  
Vol 59 (3) ◽  
pp. 157 ◽  
Author(s):  
Alberto Credi
Keyword(s):  
Molecular Motors ◽  
Energy Supply ◽  
Molecular Size ◽  
Design Principles ◽  
Light Energy ◽  
Bottom Up ◽  
Waste Products ◽  
Photochemical Processes ◽  
Autonomous Operation

The bottom-up construction and operation of machines and motors of molecular size is a topic of great interest in nanoscience, and a fascinating challenge of nanotechnology. The problem of the energy supply to make molecular motors work is of the greatest importance. Research in the last ten years has demonstrated that light energy can indeed be used to power artificial nanomotors by exploiting photochemical processes in appropriately designed systems. More recently, it has become clear that under many aspects light is the best choice to power molecular motors; for example, systems that show autonomous operation and do not generate waste products can be obtained. This review is intended to discuss the design principles at the basis of light-driven artificial nanomotors, and provide an up-to-date overview on the prototype systems that have been developed.

scholarly journals A nanoscale reciprocating rotary mechanism with coordinated mobility control

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Bertosin ◽  
Christopher M. Maffeo ◽  
Thomas Drexler ◽  
Maximilian N. Honemann ◽  
Aleksei Aksimentiev ◽  
...  
Keyword(s):  
Molecular Motors ◽  
Large Scale ◽  
Mechanical Deformation ◽  
Dna Origami ◽  
Mobility Control ◽  
Mechanical Stiffness ◽  
Allosteric Coupling ◽  
Brownian Rotation ◽  
Cryo Electron Microscopy ◽  
Dynamics Simulations

AbstractBiological molecular motors transform chemical energy into mechanical work by coupling cyclic catalytic reactions to large-scale structural transitions. Mechanical deformation can be surprisingly efficient in realizing such coupling, as demonstrated by the F1FO ATP synthase. Here, we describe a synthetic molecular mechanism that transforms a rotary motion of an asymmetric camshaft into reciprocating large-scale transitions in a surrounding stator orchestrated by mechanical deformation. We design the mechanism using DNA origami, characterize its structure via cryo-electron microscopy, and examine its dynamic behavior using single-particle fluorescence microscopy and molecular dynamics simulations. While the camshaft can rotate inside the stator by diffusion, the stator’s mechanics makes the camshaft pause at preferred orientations. By changing the stator’s mechanical stiffness, we accelerate or suppress the Brownian rotation, demonstrating an allosteric coupling between the camshaft and the stator. Our mechanism provides a framework for manufacturing artificial nanomachines that function because of coordinated movements of their components.

scholarly journals Molecular engineering of chiral colloidal liquid crystals using DNA origami

2017 ◽  
Vol 16 (8) ◽  
pp. 849-856 ◽  
Author(s):  
Mahsa Siavashpouri ◽  
Christian H. Wachauf ◽  
Mark J. Zakhary ◽  
Florian Praetorius ◽  
Hendrik Dietz ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Molecular Engineering ◽  
Dna Origami

Track-walking molecular motors: a new generation beyond bridge-burning designs

Nanoscale ◽  
2019 ◽  
Vol 11 (19) ◽  
pp. 9240-9263 ◽  
Author(s):  
Zhisong Wang ◽  
Ruizheng Hou ◽  
Iong Ying Loh
Keyword(s):  
Chemical Synthesis ◽  
Molecular Motors ◽  
Technological Capability ◽  
Assembly Lines ◽  
Bottom Up ◽  
The Core ◽  
New Generation ◽  
Molecular Robots ◽  
Nanoscale Assembly

Track-walking molecular motors are the core bottom-up mechanism for nanometre-resolved translational movements – a fundamental technological capability at the root of numerous applications ranging from nanoscale assembly lines and chemical synthesis to molecular robots and shape-changing materials.

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