1. It has been experimentally shown that breaking of the pyrrolidine ring of proline by nitrous acid is not a factor of sufficient magnitude to account for the amino nitrogen which is usually found in proline preparations. 2. A method for the preparation of racemic proline is described. The product was found to be free from amino nitrogen. 3. The dissociation constants of racemic proline and of...

We used actin filament bundles isolated from intestinal brush-border microvilli to nucleate the polymerization of pure muscle actin monomers into filaments. Growth rates were determined by electron microscopy by measuring the change in the length of the filaments as a function of time. The linear dependence of the growth rates on the actin monomer concentration provided the rate constants for m...

Cations of the alkali earth group have strong tendencies to form partially dissociated complexes in solution with the anions of carboxylic acids and other weak acids. The affinity of this association tends to increase with the number of carboxylic acid groups of the acid anion. In a considerable number of cases the effect has been studied quantitatively and expressed in terms of well defined di...

A novel polyzwitterion possessing weak ionic groups could be efficiently synthesized from cellulose phenyl carbonate. Polyanion, polycation, and polyzwitterion are accessible by orthogonal removal of protecting groups. The molecular structure was proofed by FTIR- and NMR spectroscopy. Characteristic properties of the cellulose derivatives, e.g., acid dissociation constants, isoelectric point an...

Humic acids extracted from different soils. The stability constants of metal humates and acid dissociation constant humic acids were calculated. Forms of metals in natural waters was determined with use account their chemical composition and content and properties of organic matter. We assessed metals speciation in water objects with account for competitive reactions resulting in formation of h...

Partially deuterated protonated water dimers, H2O·H(+)·D2O, H2O·D(+)·HDO, and HDO·H(+)·HDO, as important intermediates of isotopic labeled reaction of H3O(+) + D2O, undergo direct dissociation and indirect dissociation, i.e., isomerization before the dissociation. With Rice-Ramsperger-Kassel-Marcus theory and ab initio calculations, we have computed their dissociation and isomerization rate con...