scholarly journals Efficient Synthesis of Single-Chain Globules Mimicking the Morphology and Polymerase Activity of Metalloenzymes

2015 ◽  
Vol 36 (17) ◽  
pp. 1592-1597 ◽  
Author(s):  
Ana Sanchez-Sanchez ◽  
Arantxa Arbe ◽  
Joachim Kohlbrecher ◽  
Juan Colmenero ◽  
José A. Pomposo
Keyword(s):  
Polymerase Activity ◽  
Efficient Synthesis ◽  
Single Chain

scholarly journals The Methyltransferase Region of Vesicular Stomatitis Virus L Polymerase Is a Target Site for Functional Intramolecular Insertion

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 989
Author(s):  
Emmanuel Heilmann ◽  
Janine Kimpel ◽  
Stephan Geley ◽  
Andreas Naschberger ◽  
Carles Urbiola ◽  
...  
Keyword(s):  
Vesicular Stomatitis Virus ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Insertion Site ◽  
Polymerase Activity ◽  
Temperature Sensitive ◽  
Single Chain ◽  
Intracellular Location ◽  
L Protein ◽  
Vesicular Stomatitis

The L-protein of vesicular stomatitis virus (VSV) is a single-chain multi-domain RNA-dependent RNA polymerase. Previously reported attempts of intramolecular insertions of fluorescent proteins into the L-protein resulted in temperature-sensitive and highly attenuated polymerase activity. Here, we describe a novel insertion site that was selected based on in silico prediction. Of five preselected locations, insertion of the fluorescent protein mCherry in the VSV polymerase between amino acids 1620 and 1621 preserved polymerase function even after extended passaging and showed only mild attenuation compared to wildtype VSV polymerase. High magnification fluorescence imaging revealed a corpuscular cytosolic pattern for the L-protein. To confirm that the insertion site tolerates inclusion of proteins others than mCherry, we cloned mWasabi into the same position in L, generating a VSV-LmWasabi, which was also functional. We also generated a functional dual-color-dual-insertion VSV construct with intramolecularly labeled P and L-proteins. Together, our data present an approach to tag VSV polymerase intramolecularly without perturbing enzymatic activity. This L fusion protein might enable future tracing studies to monitor intracellular location of the VSV transcription and replication machinery in real-time life-imaging studies.

scholarly journals Efficient Synthesis of Single-Chain Polymer NanoparticlesviaAmide Formation

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ana Sanchez-Sanchez ◽  
José A. Pomposo
Keyword(s):  
Polymer Chains ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Efficient Synthesis ◽  
Single Chain ◽  
Chain Polymer ◽  
H Nmr ◽  
Exclusion Chromatography ◽  
Methylene Groups

Single-chain technology (SCT) allows the transformation of individual polymer chains to folded/collapsed unimolecular soft nanoparticles. In this work we contribute to the enlargement of the SCT toolbox by demonstrating the efficient synthesis of single-chain polymer nanoparticles (SCNPs)viaintrachain amide formation. In particular, we exploit cross-linking between active methylene groups and isocyanate moieties as powerful “click” chemistry driving force for SCNP construction. By employing poly(methyl methacrylate)- (PMMA-) based copolymers bearingβ-ketoester units distributed randomly along the copolymer chains and bifunctional isocyanate cross-linkers, SCNPs were successfully synthesized at r.t. under appropriate reaction conditions. Characterization of the resulting SCNPs was carried out by means of a combination of techniques including size exclusion chromatography (SEC), infrared (IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, dynamic light scattering (DLS), and elemental analysis (EA).

Single-chain crosslinked polymers via the transesterification of folded polymers: from efficient synthesis to crystallinity control

2020 ◽  
Vol 11 (32) ◽  
pp. 5181-5190 ◽  
Author(s):  
Daiki Ito ◽  
Yoshihiko Kimura ◽  
Mikihito Takenaka ◽  
Makoto Ouchi ◽  
Takaya Terashima
Keyword(s):  
Crystallization Behavior ◽  
Random Copolymers ◽  
Organic Media ◽  
Efficient Synthesis ◽  
Single Chain ◽  
Crosslinked Polymers

Herein we report efficient synthetic systems of single-chain crosslinked polymers via the intramolecular transesterification of folded random copolymers in organic media and the unique crystallization behavior of their crosslinked polymers.

scholarly journals A bio-inspired approach to ligand design: folding single-chain peptoids to chelate a multimetallic cluster

2018 ◽  
Vol 9 (47) ◽  
pp. 8806-8813 ◽  
Author(s):  
Andy I. Nguyen ◽  
Ryan K. Spencer ◽  
Christopher L. Anderson ◽  
Ronald N. Zuckermann
Keyword(s):  
Ligand Design ◽  
Chelating Ligands ◽  
Efficient Synthesis ◽  
Single Chain ◽  
Design And Optimization ◽  
Highly Efficient ◽  
Rapid Design

Highly efficient synthesis of biomimetic peptoid sequences enables the rapid design and optimization of chelating ligands for multimetallic clusters.

Cryo-electron microscopy of two-dimensional crystals of reduced type B botulinum neurotoxin

1992 ◽  
Vol 50 (1) ◽  
pp. 530-531
Author(s):  
P. F. Flicker ◽  
V.S. Kulkarni ◽  
J. P. Robinson ◽  
G. Stubbs ◽  
B. R. DasGupta
Keyword(s):  
Disulfide Bonds ◽  
Clostridium Botulinum ◽  
Structural Changes ◽  
Two Dimensional ◽  
Type B ◽  
Single Chain ◽  
Muscle Paralysis ◽  
Cryo Electron Microscopy ◽  
Disulfide Linkages ◽  
Intracellular Action

Botulinum toxin is a potent neurotoxin produced by Clostridium botulinum. The toxin inhibits release of neurotransmitter, causing muscle paralysis. There are several serotypes, A to G, all of molecular weight about 150,000. The protein exists as a single chain or or as two chains, with two disulfide linkages. In a recent investigation on intracellular action of neurotoxins it was reported that type B neurotoxin can inhibit the release of Ca++-activated [3H] norepinephrine only if the disulfide bonds are reduced. In order to investigate possible structural changes in the toxin upon reduction of the disulfide bonds, we have prepared two-dimensional crystals of reduced type B neurotoxin. These two-dimensional crystals will be compared with those of the native (unreduced) type B toxin.

Fine structure and properties of defects in naturally occurring silicates and oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 460-461
Author(s):  
David R. Veblen
Keyword(s):  
Chemical Reactions ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Single Chain ◽  
Naturally Occurring ◽  
Resolution Electron ◽  
Fine Structures ◽  
Image Simulations ◽  
Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

Elemental mass loss in silicate minerals during x-ray analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 804-805
Author(s):  
P.E. Champness ◽  
R.W. Devenish
Keyword(s):  
Mass Loss ◽  
Current Density ◽  
Damage Mechanism ◽  
Beam Current ◽  
Single Chain ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Alkali Ions ◽  
Structural Order ◽  
Sheet Silicate

It has long been recognised that silicates can suffer extensive beam damage in electron-beam instruments. The predominant damage mechanism is radiolysis. For instance, damage in quartz, SiO2, results in loss of structural order without mass loss whereas feldspars (framework silicates containing Ca, Na, K) suffer loss of structural order with accompanying mass loss. In the latter case, the alkali ions, particularly Na, are found to migrate away from the area of the beam. The aim of the present study was to investigate the loss of various elements from the common silicate structures during electron irradiation at 100 kV over a range of current densities of 104 - 109 A m−2. (The current density is defined in terms of 50% of total current in the FWHM probe). The silicates so far ivestigated are:- olivine [(Mg, Fe)SiO4], a structure that has isolated Si-O tetrahedra, garnet [(Mg, Ca, Fe)3Al2Si3AO12 another silicate with isolated tetrahedra, pyroxene [-Ca(Mg, Fe)Si2O6 a single-chain silicate; mica [margarite, -Ca2Al4Si4Al4O2O(OH)4], a sheet silicate, and plagioclase feldspar [-NaCaAl3Si5O16]. Ion- thinned samples of each mineral were examined in a VG Microscopes UHV HB501 field- emission STEM. The beam current used was typically - 0.5 nA and the current density was varied by defocussing the electron probe. Energy-dispersive X-ray spectra were collected every 10 seconds for a total of 200 seconds using a Link Systems windowless detector. The thickness of the samples in the area of analysis was normally 50-150 nm.

Sign in / Sign up

Export Citation Format

Share Document