Electrostatic interactions play an essential role in the binding of oleic acid with α-lactalbumin in the HAMLET-like complex: A study using charge-specific chemical modifications

2012 ◽  
Vol 81 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Yongjing Xie ◽  
Soyoung Min ◽  
Níal P. Harte ◽  
Hannah Kirk ◽  
John E. O'Brien ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Electrostatic Interactions ◽  
Essential Role ◽  
Chemical Modifications ◽  
Specific Chemical ◽  
The Hamlet

Chemical Modifications of Escherichia coli Ribosomal Proteins S4, S7, and S8 in Regard to Their Capacity for Binding 16 S RNA

1974 ◽  
Vol 52 (11) ◽  
pp. 1038-1043 ◽  
Author(s):  
Gérald Lemieux
Keyword(s):  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Binding Capacity ◽  
Cysteine Residue ◽  
Amino Groups ◽  
Chemical Modifications ◽  
Specific Chemical ◽  
Rna Interaction ◽  
Rna Complex ◽  
Rna Complexes

Mild specific chemical modifications were used to test the possible role of cysteines, tyrosines, and amino groups of ribosomal proteins S4, S7, and S8 for binding to 16 S RNA (Escherichia coli). The single cysteine residue present in proteins S4 and S8 is not directly involved in the binding process with RNA. The protein S7 does not contain cysteine. Total nitration of tyrosines in S4, S7, and S8 abolishes the binding capacity of these proteins. However, when the modification is done with the preformed protein–RNA complexes, some protection occurs. Two amino groups could be reacted in free S8 as well as in an S8–RNA complex. This modification does not influence protein–RNA interaction. Proteins S4, S7, and S8 in Regard to Their Capacity for Binding 16 S RNA. Can. J. Biochem. 52, modified. A new method for the stoichiometric determination of single protein–RNA complexes is presented.

The evolution of self-assemblies in the mixed system of oleic acid–diethylenetriamine based on the transformation of electrostatic interactions and hydrogen bonds

Soft Matter ◽  
2014 ◽  
Vol 10 (40) ◽  
pp. 8023-8030 ◽  
Author(s):  
Chengcheng Zhou ◽  
Xinhao Cheng ◽  
Oudi Zhao ◽  
Shuai Liu ◽  
Chenjiang Liu ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Hydrogen Bonds ◽  
Electrostatic Interactions ◽  
Mixed System

Novel Colloidal Assembly Methods for the Preparation of Core-Shell Composite Materials

2000 ◽  
Vol 636 ◽  
Author(s):  
Michael S. Fleming ◽  
Tarun K. Mandal ◽  
David R. Walt
Keyword(s):  
Electron Microscopy ◽  
Electrostatic Interactions ◽  
Physical Adsorption ◽  
Polymer Nanoparticles ◽  
Biological Interactions ◽  
Specific Chemical ◽  
Capillary Action ◽  
Colloidal Assembly ◽  
Transmission Electron ◽  
Shell Composite

AbstractColloidal assembly is a process by which particles ranging in size from nanometers to micrometers are organized into structures by mixing two or more particle types. Assembly is controlled by either specific or non-specific interactions between particles. Examples include chemical bonding, biological interactions, electrostatic interactions, capillary action and physical adsorption. The assembly process is performed such that smaller particles assemble around larger ones. In this paper, we report on colloidal assembly of polymer nanoparticles (50-200 nm diameter) onto silica particles (3-5 μm diameter) using specific chemical interactions (i.e. aminealdehyde). Annealing the assembled composites at temperatures above the glass transition (Tg) of the polymer nanospheres allows polymer to flow and uniformly coat the microsphere surfaces. Polystyrene and poly(methyl methacrylate) nanospheres were used to produce such materials. Shell composites were created by mixing both nanosphere types prior to assembly/annealing. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the materials presented herein.

scholarly journals A localized molecular automaton for in situ visualization of proteins with specific chemical modifications

2020 ◽  
Vol 11 (6) ◽  
pp. 1665-1671
Author(s):  
Lu Liu ◽  
Siqiao Li ◽  
Anwen Mao ◽  
Guyu Wang ◽  
Yiran Liu ◽  
...  
Keyword(s):  
Cell Surface ◽  
Specific Protein ◽  
Chemical Modifications ◽  
Specific Chemical ◽  
Propagation Algorithm ◽  
In Situ Visualization

A localized DNA automaton is reported for in situ visualization of a specific protein subtype with dual chemical modifications on the cell surface, which executes protein-confined computation according to an anticoding–coding propagation algorithm.

scholarly journals Researches Concerning Chemical Modifications of Hair Keratin

2019 ◽  
Vol 70 (6) ◽  
pp. 2091-2095
Author(s):  
Vasile Ciprian Macarel ◽  
Cezar Doru Radu ◽  
Liliana Verestiuc ◽  
Florina Daniela Ivan ◽  
Eugen Ulea ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Electrostatic Interactions ◽  
Control Sample ◽  
Cellulose Film ◽  
Chemical Modifications ◽  
Alcoholic Medium ◽  
Swelling Degree ◽  
Hair Keratin ◽  
Morphological Organization

The work presents chemical procedures used to obtain a film or a hydrogel after hydrolyze treatment of hair at the temperature of 150oC and the pressure of 4.9 atm. In order to obtain the hydrogel, this treatment is followed by a stage of oxidation with hydrogen peroxide, and a stage of reduction with Na2S2O4 or, in another variant, a stage of oxidation with hydrogen peroxide and a treatment with NaOH in alcoholic medium, to form natrium cationic groups. The protein chains with sulphonic groups and natrium cations determine opposite electrostatic interactions, with the formation of a polymer loop that incorporate water. The evaluation of formed hydrogel was carried out by determining the swelling degree. We have used optical and SEM photomicrographs to determine morphological organization, and EDAX micropictures for chemical modifications. A cellulose film realized by growing Gluconoacetobacter xylinus bacteria was used as control sample.

scholarly journals Effect of Surface Modifications of SBA-15 with Aminosilanes and 12-Tungstophosphoric Acid on Catalytic Properties in Environmentally Friendly Esterification of Glycerol with Oleic Acid to Produce Monoolein

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 360 ◽  
Author(s):  
Kullatida Ratchadapiban ◽  
Piyasan Praserthdam ◽  
Duangamol Tungasmita ◽  
Chutima Tangku ◽  
Wipark Anutrasakda
Keyword(s):  
Oleic Acid ◽  
Electrostatic Interactions ◽  
Heterogeneous Catalysts ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Hexagonal Structure ◽  
Tungstophosphoric Acid ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
X Ray

A series of protonated amino-functionalized SBA-15 materials was synthesized and tested as heterogeneous catalysts for the esterification of glycerol with oleic acid to produce monoolein. Mesoporous SBA-15 (S) was functionalized with three different aminosilanes: 3-aminopropyltriethoxysilane (N1); [3-(2-amino-ethylamino)propyltrimethoxysilane] (N2); and (3-trimethoxysilylpropyl) diethylenetriamine (N3), before being impregnated with 40 wt % 12-tungstophosphoric acid (HPW). The resulting nanocatalysts (S-Nx-HPW) were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption-desorption, SEM equipped with energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM), and elemental analysis techniques. The presence of components of the nanocatalysts and the preservation of the hexagonal structure of SBA-15 were confirmed. Using different functionalizing agents considerably affected the textural properties and acidity of the synthesized nanocatalysts, which helped to improve the catalytic performance. In particular, S-N2-HPW was more active and selective than other catalysts in this study, as well as than a number of other commercial acid catalysts, with 95.0% oleic acid conversion and 60.9% monoolein selectivity being obtained after five h of reaction at 160 °C using 2.5 wt % of catalyst loading and glycerol/oleic acid molar ratio of 4:1. Aminosilane functionalization also helped to increase the reusability of the catalysts to at least six cycles without considerable loss of activity through strong electrostatic interactions between HPW anions and the protonated amino-functionalized SBA-15 materials.

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