Intermediary Glucan Structures Formed during Starch Granule Biosynthesis Are Enriched in Short Side Chains, a Dynamic Pulse Labeling Approach

Based on the analysis of the chemical structure of polycarboxylate-type SPs grafted PEO side chains, as well as sulfonic and carboxylic acid groups, a kind of polycarboxylate-based SPs grafted varied PEO side chains were synthesized by using radical polymerisation techniques.The relative dispersing effectiveness of the SPs was evaluated in cement paste and concrete by measuring paste flow and concrete slumps. The test results indicat that the copolymers with shorter PEO side chains (with 9 and 14 EO units) give lower initial dispersing power but higher time retention,with the prolonging of PEO side chains the higher initial dispersing effect and the lower time retention can be received. The excellent dispersing property and time retention of synthesized SPs for cementious systems can be achieved by grafted long side chain(with 45 EO units) integrated with short side chain(9 or 14 EO) at the backbone of anionic polymer.

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The Mobility of Tryptophan and Dansyl Fluorophores in Labelled Poly(N-ethylacrylamide) and Poly(N-ethylmethacrylamide)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19932383 ◽

1993 ◽

Vol 58 (10) ◽

pp. 2383-2395 ◽

Cited By ~ 1

Author(s):

František Mikeš ◽

Drahomír Výprachtický ◽

Jan Pecka

Keyword(s):

Conformational Changes ◽

High Viscosity ◽

Side Chains ◽

Fluorescence Depolarization ◽

Polymer Backbone ◽

Short Side ◽

Low Viscosity ◽

Viscosity Range ◽

Methylene Groups ◽

Intramolecular Association

The mobility of tryptophan fluorophore in N-butyl-Nα-acetyltryptophanamide and in side chain of labelled poly(N-ethylacrylamide) and poly(N-ethylmethacrylamide) was investigated by the fluorescence depolarization method. The mobility of the fluorophore in the low-molecular-weight model is much higher than in side chains of the polymers. Different steric hindrance by the polymer backbone can explain the higher mobility of the fluorophore in poly(N-ethylacrylamide) and in poly(N-ethylmethacrylamide). The mobility of 5-dimethylamino-1-naphthalenesulfonamide (dansyl) fluorophore in side chains of labelled poly(N-ethylmethacrylamide) in the high-viscosity range increases with increasing number of methylene groups in side chains. The low-viscosity range, the rate s of conformational changes in short side chains (n = 2 - 7) are approximately constant and significantly decrease in long side chains (n = 10, 12). The drop in the rates is probably due to intramolecular association of the long hydrophobic chains in water.

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Electrophysiological evidence for acidic, basic, and neutral amino acid olfactory receptor sites in the catfish.

The Journal of General Physiology ◽

10.1085/jgp.84.3.403 ◽

1984 ◽

Vol 84 (3) ◽

pp. 403-422 ◽

Cited By ~ 98

Author(s):

J Caprio ◽

R P Byrd

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Ictalurus Punctatus ◽

Olfactory Receptor ◽

Olfactory Receptors ◽

Receptor Potential ◽

Side Chains ◽

Short Side ◽

Neutral Amino Acids ◽

Receptor Sites

Electrophysiological experiments indicate that olfactory receptors of the channel catfish, Ictalurus punctatus, contain different receptor sites for the acidic (A), basic (B), and neutral amino acids; further, at least two partially interacting neutral sites exist, one for the hydrophilic neutral amino acids containing short side chains (SCN), and the second for the hydrophobic amino acids containing long side chains (LCN). The extent of cross-adaptation was determined by comparing the electro-olfactogram (EOG) responses to 20 "test" amino acids during continuous bathing of the olfactory mucosa with water only (control) to those during each of the eight "adapting" amino acid regimes. Both the adapting and test amino acids were adjusted in concentrations to provide approximately equal response magnitudes in the unadapted state. Under all eight adapting regimes, the test EOG responses were reduced from those obtained in the unadapted state, but substantial quantitative differences resulted, depending upon the molecular structure of the adapting stimulus. Analyses of the patterns of EOG responses to the test stimuli identified and characterized the respective "transduction processes," a term used to describe membrane events initiated by a particular subset of amino acid stimuli that are intricately linked to the origin of the olfactory receptor potential. Only when the stimulus compounds interact with different transduction processes are the stimuli assumed to bind to different membrane "sites." Four relatively independent L-alpha-amino acid transduction processes (and thus at least four binding sites) identified in this report include: (a) the A process for aspartic and glutamic acids; (b) the B process for arginine and lysine; (c) the SCN process for glycine, alanine, serine, glutamine, and possibly cysteine; (d) the LCN process for methionine, ethionine, valine, norvaline, leucine, norleucine, glutamic acid-gamma-methyl ester, histidine, phenylalanine, and also possibly cysteine. The specificities of these olfactory transduction processes in the catfish are similar to those for the biochemically determined receptor sites for amino acids in other species of fishes and to amino acid transport specificities in tissues of a variety of organisms.

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The Unique Branching Patterns of Deinococcus Glycogen Branching Enzymes Are Determined by Their N-Terminal Domains

Applied and Environmental Microbiology ◽

10.1128/aem.02141-08 ◽

2009 ◽

Vol 75 (5) ◽

pp. 1355-1362 ◽

Cited By ~ 52

Author(s):

M. Palomo ◽

S. Kralj ◽

M. J. E. C. van der Maarel ◽

L. Dijkhuizen

Keyword(s):

Deinococcus Radiodurans ◽

Catalytic Domain ◽

Amino Acid Sequence Similarity ◽

Side Chains ◽

Branching Pattern ◽

Short Side ◽

High Amino Acid ◽

Branching Points ◽

Branching Patterns ◽

Branching Enzymes

ABSTRACT Glycogen branching enzymes (GBE) or 1,4-α-glucan branching enzymes (EC 2.4.1.18) introduce α-1,6 branching points in α-glucans, e.g., glycogen. To identify structural features in GBEs that determine their branching pattern specificity, the Deinococcus geothermalis and Deinococcus radiodurans GBE (GBEDg and GBEDr, respectively) were characterized. Compared to other GBEs described to date, these Deinococcus GBEs display unique branching patterns, both transferring relatively short side chains. In spite of their high amino acid sequence similarity (88%) the D. geothermalis enzyme had highest activity on amylose while the D. radiodurans enzyme preferred amylopectin. The side chain distributions of the products were clearly different: GBEDg transferred a larger number of smaller side chains; specifically, DP5 chains corresponded to 10% of the total amount of transferred chains, versus 6.5% for GBEDr. GH13-type GBEs are composed of a central (β/α) barrel catalytic domain and an N-terminal and a C-terminal domain. Characterization of hybrid Deinococcus GBEs revealed that the N2 modules of the N domains largely determined substrate specificity and the product branching pattern. The N2 module has recently been annotated as a carbohydrate binding module (CBM48). It appears likely that the distance between the sugar binding subsites in the active site and the CBM48 subdomain determines the average lengths of side chains transferred.

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New Photoreactive Polymers Containing Short Side Chains as Orientation Layer Materials: Effect of Side Chain Lengths on the Alignment of Liquid-Crystals

Molecular Crystals and Liquid Crystals Science and Technology Section A Molecular Crystals and Liquid Crystals ◽

10.1080/10587250108029981 ◽

2001 ◽

Vol 368 (1) ◽

pp. 503-508 ◽

Cited By ~ 2

Author(s):

M. Ree ◽

S. W. Lee ◽

J.-H. Kim

Keyword(s):

Liquid Crystals ◽

Side Chain ◽

Side Chains ◽

Short Side ◽

Chain Lengths

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Facile Approach to Perylenemonoimide with Short Side Chains for Nonfullerene Solar Cells

The Journal of Organic Chemistry ◽

10.1021/acs.joc.7b00272 ◽

2017 ◽

Vol 82 (11) ◽

pp. 5926-5931 ◽

Cited By ~ 14

Author(s):

Yu Hu ◽

Shixiao Chen ◽

Lifu Zhang ◽

Youdi Zhang ◽

Zhongyi Yuan ◽

...

Keyword(s):

Solar Cells ◽

Side Chains ◽

Short Side

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Incorporation of bisphosphonates into adenine nucleotides by amoebae of the cellular slime mould Dictyostelium discoideum

Biochemical Journal ◽

10.1042/bj3030303 ◽

1994 ◽

Vol 303 (1) ◽

pp. 303-311 ◽

Cited By ~ 74

Author(s):

M J Rogers ◽

X Ji ◽

R G G Russell ◽

G M Blackburn ◽

M P Williamson ◽

...

Keyword(s):

Bone Resorption ◽

Dictyostelium Discoideum ◽

Adenine Nucleotides ◽

Side Chains ◽

Short Side ◽

Slime Mould ◽

Trna Synthetases ◽

Aminoacyl Trna Synthetases ◽

Antiresorptive Agents

Bisphosphonates are a class of synthetic pyrophosphate analogues. Some are known to be potent inhibitors of osteoclast-mediated bone resorption in vivo, but their mechanisms of action are unclear. The order of potency of bisphosphonates as inhibitors of bone resorption closely matches the order of potency as inhibitors of growth of amoebae of the slime mould Dictyostelium discoideum, indicating that bisphosphonates may have a mechanism of action that is similar in both osteoclasts and Dictyostelium. Methylenebisphosphonate and several halogenated derivatives, which have low potency as antiresorptive agents and as growth inhibitors of Dictyostelium, are metabolized intracellularly by Dictyostelium amoebae into methylene-containing adenine nucleotides. We have used a combination of n.m.r. and f.p.l.c. analysis to determine whether incorporation into nucleotides is a feature of other bisphosphonates, especially those that are potent antiresorptive agents. Only bisphosphonates with short side chains or of low potency are incorporated into adenine nucleotides, whereas those with long side chains or of high potency are not metabolized. Bisphosphonate metabolism in cell-free extracts of Dictyostelium was accompanied by inhibition of aminoacylation of tRNA by several aminoacyl-tRNA synthetases. These enzymes were barely affected by the bisphosphonates that were not metabolized. The results indicate that some bisphosphonates are not metabolically inert analogues of pyrophosphate and appear to be metabolized by aminoacyl-tRNA synthetases. The cellular effects of some bisphosphonates may be the result of their incorporation into adenine nucleotides or inhibition of aminoacyl-tRNA synthetases, although the potent bisphosphonates appear to act by a different mechanism.

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Effect of perfluorosulfonic acid side chains on oxygen permeation in hydrated ionomers of PEMFCs: Molecular dynamics simulation approach

10.21203/rs.3.rs-127966/v1 ◽

2020 ◽

Author(s):

Sung Hyun Kwon ◽

Haisu Kang ◽

Young-Jun Sohn ◽

Jinhee Lee ◽

Sunbo Shim ◽

...

Keyword(s):

Molecular Dynamics ◽

Water Content ◽

Polymer Electrolyte Membrane ◽

Md Simulations ◽

Dynamics Simulation ◽

Side Chain ◽

Side Chains ◽

Perfluorosulfonic Acid ◽

Short Side ◽

Water Contents

Abstract We prepared two types of perfluorosulfonic acid (PFSA) ionomers with Aquivion (short side chain) and Nafion (long side chain) on a Pt surface and varied their water contents (2.92 ≤ λ ≤ 13.83) to calculate the solubility and permeability of O2 in hydrated PFSA ionomers on a Pt surface using full atomistic molecular dynamics (MD) simulations. The solubility and permeability of O2 molecules in hydrated Nafion ionomers were greater than those of O2 molecules in hydrated Aquivion ionomers at the same water content, indicating that the permeation of O2 molecules in the ionomers is affected not only by the diffusion coefficient of O2 but also by the solubility of O2. Notably, O2 molecules are more densely distributed in regions where water and hydronium ions have a lower density in hydrated Pt/PFSA ionomers. Radial distribution function (RDF) analysis was performed to investigate where O2 molecules preferentially dissolve in PFSA ionomers on a Pt surface. The results showed that O2 molecules preferentially dissolved between hydrophilic and hydrophobic regions in a hydrated ionomer. The RDF analysis was performed to provide details of the O2 location in hydrated PFSA ionomers on a Pt surface to evaluate the influence of O2 solubility in ionomers with side chains of different lengths. The coordination number of C(center)–O(O2) and O(side chain)–O(O2) pairs in hydrated Nafion ionomers was higher than that of the same pairs in hydrated Aquivion ionomers with the same water content. Our investigation provides detailed information about the properties of O2 molecules in different PFSA ionomers on a Pt surface and with various water contents, potentially enabling the design of better-performing PFSA ionomers for use in polymer electrolyte membrane fuel cells.

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Fabrication of a polymer electrolyte membrane with uneven side chains for enhancing proton conductivity

RSC Advances ◽

10.1039/c6ra17477a ◽

2016 ◽

Vol 6 (83) ◽

pp. 79593-79601 ◽

Cited By ~ 16

Author(s):

Yunfeng Zhang ◽

Cuicui Li ◽

Xupo Liu ◽

Zehui Yang ◽

Jiaming Dong ◽

...

Keyword(s):

Polymer Electrolyte ◽

Proton Conductivity ◽

Polymer Electrolytes ◽

Polymer Electrolyte Membrane ◽

Polymer Electrolyte Membranes ◽

Side Chains ◽

Short Side ◽

Electrolyte Membrane ◽

Electrolyte Membranes ◽

Transfer Channels

Enhancement of proton conductivity of polymer electrolyte membranes was achieved by broadening the proton transfer channels via attaching acid groups to both long and short side chains of polymer electrolytes simultaneously.

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