scholarly journals Directed Assembly of Multi‐Walled Nanotubes and Nanoribbons of Amino Acid Amphiphiles Using a Layer‐by‐Layer Approach

2021 ◽  
Author(s):  
Kathrin Siegl ◽  
Luba Kolik-Shmuel ◽  
Mingming Zhang ◽  
Sylvain Prévost ◽  
Kalanit Vishnia ◽  
...  
Keyword(s):  
Amino Acid ◽  
Directed Assembly ◽  
Layer By Layer

scholarly journals Electric-Field-Directed Self-Assembly of Active Enzyme-Nanoparticle Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Alexander P. Hsiao ◽  
Michael J. Heller
Keyword(s):  
Electric Field ◽  
Self Assembly ◽  
Microelectrode Array ◽  
Glucose Sensor ◽  
Directed Assembly ◽  
Passive Layer ◽  
Higher Order ◽  
Significant Loss ◽  
Layer By Layer ◽  
Multilayered Structures

A method is presented for the electric-field-directed self-assembly of higher-order structures composed of alternating layers of biotin nanoparticles and streptavidin-/avidin-conjugated enzymes carried out on a microelectrode array device. Enzymes included in the study were glucose oxidase (GOx), horseradish peroxidase (HRP), and alkaline phosphatase (AP); all of which could be used to form a light-emitting microscale glucose sensor. Directed assembly included fabricating multilayer structures with 200 nm or 40 nm GOx-avidin-biotin nanoparticles, with AP-streptavidin-biotin nanoparticles, and with HRP-streptavidin-biotin nanoparticles. Multilayered structures were also fabricated with alternate layering of HRP-streptavidin-biotin nanoparticles and GOx-avidin-biotin nanoparticles. Results showed that enzymatic activity was retained after the assembly process, indicating that substrates could still diffuse into the structures and that the electric-field-based fabrication process itself did not cause any significant loss of enzyme activity. These methods provide a solution to overcome the cumbersome passive layer-by-layer assembly methods to efficiently fabricate higher-order active biological and chemical hybrid structures that can be useful for creating novel biosensors and drug delivery nanostructures, as well as for diagnostic applications.

scholarly journals Non-enzymatic assembly of active chimeric ribozymes from aminoacylated RNA oligonucleotides

2021 ◽  
Author(s):  
Aleksandar Radakovic ◽  
Saurja Dasgupta ◽  
Tom H Wright ◽  
Harry R.M. Aitken ◽  
Jack W Szostak
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Ribosomal Protein ◽  
Rna World ◽  
Directed Assembly ◽  
Enzymatic Function ◽  
Hammerhead Rna ◽  
Rna Backbone ◽  
Ribosomal Protein Synthesis

Aminoacylated tRNAs, which harbor a covalent linkage between amino acids and RNA, are a universally conserved feature of life. Because they are essential substrates for ribosomal translation, aminoacylated oligonucleotides must have been present in the RNA World prior to the evolution of the ribosome. One possibility we are exploring is that the aminoacyl ester linkage served another function before being recruited for ribosomal protein synthesis. The nonenzymatic assembly of ribozymes from short RNA oligomers under realistic conditions remains a key challenge in demonstrating a plausible pathway from prebiotic chemistry to the RNA World. Here, we show that aminoacylated RNAs can undergo template-directed assembly into chimeric amino acid-RNA polymers that are active ribozymes. We demonstrate that such chimeric polymers can retain the enzymatic function of their all-RNA counterparts by generating chimeric hammerhead, RNA ligase, and aminoacyl transferase ribozymes. Amino acids with diverse side chains form linkages that are well tolerated within the RNA backbone, potentially bringing novel functionalities to ribozyme catalysis. Our work suggests that aminoacylation chemistry may have played a role in primordial ribozyme assembly. Increasing the efficiency of this process provides an evolutionary rationale for the emergence of sequence and amino acid specific aminoacyl-RNA synthetase ribozymes, which could then have generated the substrates for ribosomal protein synthesis.

Directed assembly of metal nanoparticles in polymer bilayers

2018 ◽  
Vol 3 (2) ◽  
pp. 390-396 ◽  
Author(s):  
Su-Wen Hsu ◽  
Yuhan Long ◽  
Aatheya G. Subramanian ◽  
Andrea R. Tao
Keyword(s):  
Metal Nanoparticles ◽  
Self Assembly ◽  
Directed Assembly ◽  
Nanocomposite Materials ◽  
Layer By Layer ◽  
Polymer Bilayers

The integration of layer-by-layer (LbL) and self-assembly methods has the potential to achieve precision assembly of nanocomposite materials.

Electrochemical Detection of Alginate Penetration in Immobilized Layer-by-Layer Films by Unnatural Amino Acid Containing Antimicrobial Peptides

2015 ◽  
Vol 186 ◽  
pp. 245-252 ◽  
Author(s):  
Sergey M. Vinogradov ◽  
Jennifer E. Satterwhite-Warden ◽  
Rickey P. Hicks ◽  
Eric Anderson ◽  
Eli G. Hvastkovs
Keyword(s):  
Amino Acid ◽  
Antimicrobial Peptides ◽  
Electrochemical Detection ◽  
Unnatural Amino Acid ◽  
Layer By Layer

Silk Macromolecules with Amino Acid–Poly(Ethylene Glycol) Grafts for Controlling Layer-by-Layer Encapsulation and Aggregation of Recombinant Bacterial Cells

ACS Nano ◽  
2015 ◽  
Vol 9 (2) ◽  
pp. 1219-1235 ◽  
Author(s):  
Irina Drachuk ◽  
Rossella Calabrese ◽  
Svetlana Harbaugh ◽  
Nancy Kelley-Loughnane ◽  
David L. Kaplan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Ethylene Glycol ◽  
Layer By Layer ◽  
Bacterial Cells ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

In Aqua Manufacturing of a Three-Dimensional Nanostructure Using a Peptide Aptamer

MRS Bulletin ◽  
2008 ◽  
Vol 33 (5) ◽  
pp. 524-529 ◽  
Author(s):  
Ken-Ichi Sano ◽  
Kiyotaka Shiba
Keyword(s):  
Amino Acid ◽  
Mutational Analysis ◽  
Three Dimensional ◽  
Multilayer Structures ◽  
Layer By Layer ◽  
Top Down ◽  
Peptide Aptamers ◽  
Amino Acid Peptide ◽  
Cargo Protein ◽  
Peptide Aptamer

AbstractTBP-1 is a 12-amino-acid peptide aptamer that has been isolated as a Ti binder using a peptide-phage system. Subsequent analyses have shown that TBP1 also binds Si and Ag, and has the ability to enhance the formation of titania and silica as well as nanoparticles of Ag. TBP-1 is thus a bifunctional peptide: a binder that also acts as a mediator of mineralization. These two functions can be grafted onto heterologous molecules. For instance, mutational analysis of the TBP-1 revealed that its N -terminal hexapeptide, RKLPDA (minTBP-1), is sufficient for Ti binding. When the surface of ferritin, a nano-sized spherical cargo protein, was ornamented with minTBP-1 either genetically or chemically, the resultant modified ferritin acquired the ability to bind Ti and mediate mineralization. By alternately applying the binding and mineralization activities of the minTBP-1-modified nanocage, we were able to construct, in stepwise fashion, multilayer structures composed of titania (or silica) and nanocages. We named this process the biomimetic layer-by-layer (BioLBL) method. By coupling BioLBL with a conventional top-down lithographic method, in aqua structuralization of a three-dimensional (3D) configuration of nanomolecules was realized. As shown in this article, binding and mineralization activities of peptide aptamers, when they are combined with nanostructured materials, play active roles in manufacturing nanostrucutre in aqua.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

The staining pattern of the tropomyosin sequence is displayed in a new paracrystal

1986 ◽  
Vol 44 ◽  
pp. 150-151
Author(s):  
M.K. Lamvik ◽  
L.L. Klatt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Staining Pattern ◽  
Banding Patterns ◽  
Mass Thickness ◽  
New Form

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

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