A method has been developed to demonstrate the alpha-acylamido carboxyl groups of protein, taking advantage of the fact that acylamido carboxyl groups are converted to ketonic carbonyls by the action of acetic anhydride and absolute pyridine. The method utilizes deparaffinized sections of tissues fixed in a variety of fixatives. Following the conversion of carboxyls to the methyl ketones, the l...

It has been found that ultrasonic treatment of diamond nanopowders contributes to surface cleaning due the removal non-diamond carbon and impurities from boundary nanodiamond grains (from 0.4 0.32 % for ASUD-99 0.67 0.55 ASUD 75, respectively). does not affect total sorption volume values specific studied samples do change, but it changes composition groups on nanoparticles, which its hydrophil...

In the structure of the title compound, NH(4) (+)·C(8)H(11)O(4) (-), the carboxyl and carboxyl-ate groups of the cation adopt C-C-C-O torsion angles of 174.9 (2) and -145.4 (2)°, respectively, with the alicyclic ring. The ammonium H atoms of the cations give a total of five hydrogen-bonding associations with carboxyl-ate O-atom acceptors of the anion which, together with a carboxyl O-H⋯O(carbox...

A novel technique to estimate the distribution state of carboxyl groups within submicron-sized, carboxylated polymer particles was proposed. For the purpose, carboxyl groups in two kinds of butyl methacrylate-methacrylic acid copolymer emulsion, which were prepared by emulsion copolymerizations with different monomer addition methods, were titrated by isothermal titration calorimetry with an ex...

Herein, direct production of hydrogen peroxide (H2O2) through hydroxylamine (NH2OH) oxidation by molecular oxygen was greatly enhanced over modified activated carbon fiber (ACF) catalysts. We revealed that the higher content pyrrolic/pyridone nitrogen (N5) and carboxyl-anhydride could effectively promote selectivity yield H2O2. By changing volume ratio concentrated H2SO4 HNO3, N5 surface contai...

To explore electrostatic interactions in ubiquitin, pK(a) values have been determined by NMR for all 12 carboxyl groups in wild-type ubiquitin and in variants where single lysines have been replaced by neutral residues. Aspartate pK(a) values in ubiquitin range from 3.1 to 3.8 and are generally less than model compound values. Most aspartate pK(a) values are within 0.2 pH unit of those predicte...

Native insulin causes fusion of negatively charged liposomes in the pH range from 3.0 to 5.5. In marked contrast, insulin with all three amino groups succinylated did not show fusion ability at any pH. On the other hand, insulin amidated with glycine methyl ester with all six carboxyl groups blocked shifted its activity to higher pH, showing a pH range of activity from 3.0 to 7.4. When the carb...

Chemical modification and electron spin resonance techniques were used to study the topography of carboxyl residues in purple membranes. The results showed that buried carboxyl groups are )ocated in hydrophobic protein domains at least 16 A from the membrane surface, and that the carboxyl-terminal tail is partially immobilized. Carboxyl groups on bacteriorhodopsin in purple membranes...