scholarly journals Embedded Enzyme Nanoclusters Depolymerize Polyesters via Chain-End Mediated Processive Degradation

2020 ◽  
Author(s):  
Christopher DelRe ◽  
Junpyo Kwon ◽  
Philjun Kang ◽  
Le Ma ◽  
Aaron Hall ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Building Blocks ◽  
Polymer Chains ◽  
Poly Lactic Acid ◽  
Polymer Conformation ◽  
Material Development ◽  
Metal Filler ◽  
Segmental Dynamic ◽  
And Function ◽  
Poly Caprolactone

AbstractMany bioactive elements, long perceived as non-viable for material development, are now emerging as viable building blocks to encode material lifecycle and to ensure our harmonious existence with nature. Yet, there is a significant knowledge gap on how bio-elements interface with synthetic counterparts and function outside of their native environments. Here, we show that when enzymes are dispersed as nanoclusters confined within macromolecular matrices, their reaction kinetics, pathway, and substrate selectivity can be modulated to achieve programmable polymer degradation down to repolymerizable small molecules. Specifically, when enzyme nanoclusters are dispersed in trace amount (~0.02 wt%) in polyesters, i.e. poly(caprolactone) (PCL) and poly(lactic acid) (PLA), chain-end mediated processive depolymerization can be realized, leading to scalable bioactive plastics for efficient sorting, such as recovery of precious metal filler from flexible electronics. Present studies demonstrate that when the enzyme is confined at dimensions similar to that of polymer chains, their behaviors are governed by the polymer conformation, segmental dynamic and thermal history, highlighting the importance to consider bioactive plastics differently from solution enzymology.

scholarly journals Wine By-Products as Raw Materials for the Production of Biopolymers and of Natural Reinforcing Fillers: A Critical Review

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 381
Author(s):  
Alessandro Nanni ◽  
Mariafederica Parisi ◽  
Martino Colonna
Keyword(s):  
Critical Review ◽  
Raw Materials ◽  
Green Revolution ◽  
Building Blocks ◽  
Poly Lactic Acid ◽  
Butylene Succinate ◽  
Reinforcing Fillers ◽  
Plastic Industry ◽  
Review Reports ◽  
By Products

The plastic industry is today facing a green revolution; however, biopolymers, produced in low amounts, expensive, and food competitive do not represent an efficient solution. The use of wine waste as second-generation feedstock for the synthesis of polymer building blocks or as reinforcing fillers could represent a solution to reduce biopolymer costs and to boost the biopolymer presence in the market. The present critical review reports the state of the art of the scientific studies concerning the use of wine by-products as substrate for the synthesis of polymer building blocks and as reinforcing fillers for polymers. The review has been mainly focused on the most used bio-based and biodegradable polymers present in the market (i.e., poly(lactic acid), poly(butylene succinate), and poly(hydroxyalkanoates)). The results present in the literature have been reviewed and elaborated in order to suggest new possibilities of development based on the chemical and physical characteristics of wine by-products.

scholarly journals Assembly of multicomponent structures from hundreds of micron-scale building blocks using optical tweezers

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jeffrey E. Melzer ◽  
Euan McLeod
Keyword(s):  
Optical Tweezers ◽  
Three Dimensional ◽  
Building Blocks ◽  
Optical Tweezer ◽  
Device Fabrication ◽  
Positional Accuracy ◽  
Component Structure ◽  
Material Development ◽  
Critical Process Parameters ◽  
Optical Positioning

AbstractThe fabrication of three-dimensional (3D) microscale structures is critical for many applications, including strong and lightweight material development, medical device fabrication, microrobotics, and photonic applications. While 3D microfabrication has seen progress over the past decades, complex multicomponent integration with small or hierarchical feature sizes is still a challenge. In this study, an optical positioning and linking (OPAL) platform based on optical tweezers is used to precisely fabricate 3D microstructures from two types of micron-scale building blocks linked by biochemical interactions. A computer-controlled interface with rapid on-the-fly automated recalibration routines maintains accuracy even after placing many building blocks. OPAL achieves a 60-nm positional accuracy by optimizing the molecular functionalization and laser power. A two-component structure consisting of 448 1-µm building blocks is assembled, representing the largest number of building blocks used to date in 3D optical tweezer microassembly. Although optical tweezers have previously been used for microfabrication, those results were generally restricted to single-material structures composed of a relatively small number of larger-sized building blocks, with little discussion of critical process parameters. It is anticipated that OPAL will enable the assembly, augmentation, and repair of microstructures composed of specialty micro/nanomaterial building blocks to be used in new photonic, microfluidic, and biomedical devices.

scholarly journals Bioelectrocatalytic hydrogels from electron-conducting metallopolypeptides coassembled with bifunctional enzymatic building blocks

2008 ◽  
Vol 105 (40) ◽  
pp. 15275-15280 ◽  
Author(s):  
Ian R. Wheeldon ◽  
Joshua W. Gallaway ◽  
Scott Calabrese Barton ◽  
Scott Banta
Keyword(s):  
Polyphenol Oxidase ◽  
Building Block ◽  
Leucine Zipper ◽  
Electrical Contact ◽  
Building Blocks ◽  
Coiled Coils ◽  
Biofuel Cell ◽  
Random Coil ◽  
Catalytic Current ◽  
And Function

Here, we present two bifunctional protein building blocks that coassemble to form a bioelectrocatalytic hydrogel that catalyzes the reduction of dioxygen to water. One building block, a metallopolypeptide based on a previously designed triblock polypeptide, is electron-conducting. A second building block is a chimera of artificial α-helical leucine zipper and random coil domains fused to a polyphenol oxidase, small laccase (SLAC). The metallopolypeptide has a helix–random-helix secondary structure and forms a hydrogel via tetrameric coiled coils. The helical and random domains are identical to those fused to the polyphenol oxidase. Electron-conducting functionality is derived from the divalent attachment of an osmium bis-bipyrdine complex to histidine residues within the peptide. Attachment of the osmium moiety is demonstrated by mass spectroscopy (MS-MALDI-TOF) and cyclic voltammetry. The structure and function of the α-helical domains are confirmed by circular dichroism spectroscopy and by rheological measurements. The metallopolypeptide shows the ability to make electrical contact to a solid-state electrode and to the redox centers of modified SLAC. Neat samples of the modified SLAC form hydrogels, indicating that the fused α-helical domain functions as a physical cross-linker. The fusion does not disrupt dimer formation, a necessity for catalytic activity. Mixtures of the two building blocks coassemble to form a continuous supramolecular hydrogel that, when polarized, generates a catalytic current in the presence of oxygen. The specific application of the system is a biofuel cell cathode, but this protein-engineering approach to advanced functional hydrogel design is general and broadly applicable to biocatalytic, biosensing, and tissue-engineering applications.

A Molecular Artisans Guide to Supramolecular Coordination Complexes and Metal Organic Frameworks

2015 ◽  
Vol 03 (01n02) ◽  
pp. 1540004 ◽  
Author(s):  
Xialu Wu ◽  
David J. Young ◽  
T. S. Andy Hor
Keyword(s):  
Chemical Reactivity ◽  
Metal Organic Frameworks ◽  
Building Blocks ◽  
Coordination Complexes ◽  
Large Molecules ◽  
Molecular Building Blocks ◽  
Supramolecular Coordination ◽  
Metal Organic ◽  
Molecular Synthesis ◽  
And Function

As molecular synthesis advances, we are beginning to learn control of not only the chemical reactivity (and function) of molecules, but also of their interactions with other molecules. It is this basic idea that has led to the current explosion of supramolecular science and engineering. Parallel to this development, chemists have been actively pursuing the design of very large molecules using basic molecular building blocks. Herein, we review the general development of supramolecular chemistry and particularly of two new branches: supramolecular coordination complexes (SCCs) and metal organic frameworks (MOFs). These two fields are discussed in detail with typical examples to illustrate what is now possible and what challenges lie ahead for tomorrow's molecular artisans.

A Dynamic Route to Structure and Function: Recent Advances in Imine-Based Organic Nanostructured Materials

2013 ◽  
Vol 66 (1) ◽  
pp. 9 ◽  
Author(s):  
Yi Liu ◽  
Zhan-Ting Li
Keyword(s):  
Self Assembly ◽  
Reaction System ◽  
Functional Materials ◽  
Building Blocks ◽  
The Self ◽  
Interlocked Molecules ◽  
Functional Aspects ◽  
Imine Bond ◽  
And Function ◽  
Dynamic Route

The chemistry of imine bond formation from simple aldehyde and amine precursors is among the most powerful dynamic covalent chemistries employed for the construction of discrete molecular objects and extended molecular frameworks. The reversible nature of the C=N bond confers error-checking and proof-reading capabilities in the self-assembly process within a multi-component reaction system. This review highlights recent progress in the self-assembly of complex organic molecular architectures that are enabled by dynamic imine chemistry, including molecular containers with defined geometry and size, mechanically interlocked molecules, and extended frameworks and polymers, from building blocks with preprogrammed steric and electronic information. The functional aspects associated with the nanometer-scale features not only place these dynamically constructed nanostructures at the frontier of materials sciences, but also bring unprecedented opportunities for the discovery of new functional materials.

scholarly journals Large-area display textiles integrated with functional systems

2020 ◽  
Author(s):  
Huisheng Peng ◽  
Xiang Shi ◽  
Yong Zuo ◽  
Peng Zhai ◽  
Jiahao Shen ◽  
...  
Keyword(s):  
Building Blocks ◽  
Speech Disorders ◽  
Communication Tool ◽  
Electronic Textiles ◽  
Large Area ◽  
Practical Applications ◽  
Contact Points ◽  
Luminescent Coating ◽  
And Function ◽  
The Internet Of Things

Abstract Displays are basic building blocks of modern electronics1,2. Integrating displays into textiles offers exciting opportunities for smart electronic textiles – the ultimate form of wearables poised to change the way we interact with electronic devices3-6. Display textiles serve to bridge human-machine interactions7-9, offering for instance, a real-time communication tool for individuals with voice or speech disorders. Electronic textiles capable of communicating10, sensing11,12 and supplying electricity13,14 have been reported previously. However, textiles with functional, large-area displays have not been achieved so far because obtaining small illuminating units that are both durable and easy to assemble over a wide area is challenging. Here, we report a 6 m (L) * 25 cm (W) display textile containing 500000 electroluminescent (EL) units narrowly spaced to ~800 μm. Weaving conductive weft and luminescent warp fibres forms micron-scale EL units at the weft-warp contact points. Brightness between EL units deviates by < 6.3% and remains stable even when the textile is bent, stretched or pressed. We attribute this uniform and stable lighting to the smooth luminescent coating around the warp fibres and homogenous electric field distribution at the contact points. Our display textile is flexible and breathable and withstands repeatable machine-washing, making them suitable for practical applications. We show an integrated textile system consisting of display, keyboard and power supply can serve as a communication tool, which could potentially drive the Internet of Things in various areas including healthcare. Our approach unifies the fabrication and function of electronic devices with textiles, and we expect weaving fibre materials to shape the next-generation electronics.

scholarly journals Microhydration of ionized building blocks of DNA/RNA: infrared spectra of pyrimidine$$^{+}$$-$$(\hbox {H}_{2}\hbox {O})_{\text {1-3}}$$ clusters

2021 ◽  
Vol 75 (3) ◽  
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional ◽  
Size Range ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Ion Solvation ◽  
Structure Stability ◽  
Consistent Picture ◽  
Three Body ◽  
And Function ◽  
Stable Structures

Abstract Hydration of biomolecules is an important physiological process that governs their structure, stability, and function. Herein, we probe the microhydration structure of cationic pyrimidine (Pym), a common building block of DNA/RNA bases, by infrared photodissociation spectroscopy (IRPD) of mass-selected microhydrated clusters, $$\hbox {Pym}^{+}$$ Pym + -$$\hbox {W}_{n}$$ W n (W=$$\hbox {H}_{2}\hbox {O}$$ H 2 O ), in the size range $$n=1$$ n = 1 –3. The IRPD spectra recorded in the OH and CH stretch range are sensitive to the evolution of the hydration network. Analysis with density functional theory calculations at the dispersion-corrected B3LYP-D3/aug-cc-pVTZ level provides a consistent picture of the most stable structures and their energetic and vibrational properties. The global minima of $$\hbox {Pym}^{+}$$ Pym + -$$\hbox {W}_{n}$$ W n predicted by the calculations are characterized by H-bonded structures, in which the H-bonded $$\hbox {W}_{n}$$ W n solvent cluster is attached to the most acidic C4–H proton of $$\hbox {Pym}^{+}$$ Pym + via a single CH...O ionic H-bond. These isomers are identified as predominant carrier of the IRPD spectra, although less stable local minima provide minor contributions. In general, the formation of the H-bonded solvent network (exterior ion solvation) is energetically preferred to less stable structures with interior ion solvation because of cooperative nonadditive three-body polarization effects. Progressive hydration activates the C4–H bond, along with increasing charge transfer from $$\hbox {Pym}^{+}$$ Pym + to $$\hbox {W}_{n}$$ W n , although no proton transfer is observed in the size range $$n\leqslant $$ n ⩽ 3. The solvation with protic, dipolar, and hydrophilic W ligands is qualitative different from solvation with aprotic, quadrupolar, and hydrophobic $$\hbox {N}_{2}$$ N 2 ligands, which strongly prefer interior ion solvation by $$\uppi $$ π stacking interactions. Comparison of $$\hbox {Pym}^{+}$$ Pym + -W with Pym-W and $$\hbox {H}^{+}$$ H + Pym-W reveals the drastic effect of ionization and protonation on the Pym...W interaction. Graphic Abstract

scholarly journals Lamin B1 and lamin B2 are long-lived proteins with distinct functions in retinal development

2016 ◽  
Vol 27 (12) ◽  
pp. 1928-1937 ◽  
Author(s):  
David Razafsky ◽  
Candace Ward ◽  
Chloe Potter ◽  
Wanqiu Zhu ◽  
Yunlu Xue ◽  
...  
Keyword(s):  
Nuclear Lamina ◽  
Building Blocks ◽  
Postnatal Life ◽  
Cone Photoreceptors ◽  
Obvious Effect ◽  
Lamin B1 ◽  
Embryonic Neurogenesis ◽  
And Function ◽  
Embryonic Retina ◽  
Rod And Cone Photoreceptors

Lamin B1 and lamin B2 are essential building blocks of the nuclear lamina, a filamentous meshwork lining the nucleoplasmic side of the inner nuclear membrane. Deficiencies in lamin B1 and lamin B2 impair neurodevelopment, but distinct functions for the two proteins in the development and homeostasis of the CNS have been elusive. Here we show that embryonic depletion of lamin B1 in retinal progenitors and postmitotic neurons affects nuclear integrity, leads to the collapse of the laminB2 meshwork, impairs neuronal survival, and markedly reduces the cellularity of adult retinas. In stark contrast, a deficiency of lamin B2 in the embryonic retina has no obvious effect on lamin B1 localization or nuclear integrity in embryonic retinas, suggesting that lamin B1, but not lamin B2, is strictly required for nucleokinesis during embryonic neurogenesis. However, the absence of lamin B2 prevents proper lamination of adult retinal neurons, impairs synaptogenesis, and reduces cone photoreceptor survival. We also show that lamin B1 and lamin B2 are extremely long-lived proteins in rod and cone photoreceptors. OF interest, a complete absence of both proteins during postnatal life has little or no effect on the survival and function of cone photoreceptors.

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