A new and rapid colorimetric determination of acetylcholinesterase activity.

Esters of Methanesulfonic Acid as Irreversible Inhibitors of Acetylcholinesterase

Publisher Summary This chapter discusses the chemistry, metabolism, and biological functions of sialic acids. Interest in the sialic acids has rapidly increased in recent years, especially because of the reorganization of their involvement in the regulation of a great variety of biological phenomena. The occurrence of sialic acids in plants has never unequivocally been established, although some positive reports exist. The acylneuraminic acids can be released from their glycosidic linkages either by dilute (aqueous or methanolic) acids or sialidases. The unequivocal determination of sialic acids occurring in low concentrations in many biological materials is rather difficult, and this explains the many errors that have been made in this field. The biosynthesis of N-acetylneuraminic acid (Neu5Ac) is briefly reported in this chapter and more attention is given to the enzyme reactions modifying this compound. Little information is available about the role of the modifications of sialic acid resulting in a species- and tissue-specific distribution of different N,O-acylated and O-methylated sialic acids.

Chemistry, Metabolism, and Biological Functions of Sialic Acids

The formation of 2-keto-3-deoxyheptonic acid in extracts of Escherichia coli B. I. Identification.

Publisher Summary This chapter discusses the analysis of the chemical composition and primary structure of the murein. Murein (peptidoglycan, mucopeptide) is the main cell wall polymer of eubacteria and is common to both Gram-negative and Gram-positive bacteria. There are only a few prokaryotic organisms, such as mycoplasmas and archaebacteria, which lack murein. The glycan moiety is rather uniform and shows only a few variations such as O-acetylation or O-phosphorylation or the exceptional absence of peptide substituents. The peptide moiety of the murein shows, in contrast to the glycan part, a considerable variation. Extensive investigation of the chemical structure of murein has demonstrated the existence of almost 100 different variations of the peptide moiety. Depending on the mode of cross-linking two main groups of murein, named A and B, have been distinguished. The different structure of cell walls of Gram-positive and Gram-negative bacteria necessitates discrete methods for preparing cell walls. The cell walls of Gram-positive bacteria reveal in profile one thick and more or less homogeneous layer, whereas Gram-negative bacteria have thinner, but distinctly layered cell walls with an outer membrane resembling the cytoplasmic membrane in profile.

5 Analysis of the Chemical Composition and Primary Structure of Murein

The reaction of acetylcholine and other carboxylic acid derivatives with hydroxylamine, and its analytical application.

Acylation reactions mediated by purified acetylcholine esterase II

Acylation reactions mediated by purified acetylcholine esterase.

http://www.jbc.org/content/180/2/875.full.pdf

Shlomo. Hestrin

Papers

The reaction of acetylcholine and other carboxylic acid derivatives with hydroxylamine, and its analytical application.

Acylation reactions mediated by purified acetylcholine esterase II

Acylation reactions mediated by purified acetylcholine esterase.

Enzymatic synthesis of a compound with acetylcholine-like biological activity.