The first evidence for a cofactor necessary in acetate metabolism was provided by Nachmansohn and Machado (13) who discovered a soluble enzyme system in extracts of brain tissue which catalyzed the acetylation of choline in the presence of adenosine triphosphate (ATP). Lipmann (8) and Kaplan and Lipmann (5) described an enzyme system in extracts of pigeon liver which catalyzed the ATP and coenz...

Conjugated Linoleic Acid (CLA), Glycerol (G) and sunflower oil blends with varying concentration were subjected to enzymatic esterification using a 1, 3- specific immobilized lipase. CLA was used as acyl due to its purported health benefits. The transesterified lipids were evaluated for free fatty acids (FFA) and composition of fatty acids by gas chromatography. Lipozyme RM IM is preferred for ...

By William A. Eaton and James Hofrichter T HE FUNDAMENTAL cause ofsickle cell disease is the decreased deformability of the sickled red cell produced by gelation of hemoglobin S. Partial inhibition of gelation should therefore reduce clinical severity, while complete inhibition should result in a “cure.” These basic ideas have stimulated an enormous effort to understand the gelation process in ...

Inosinic acid dehydrogenase was prepared from a derepressed mutant of Escherichia coli. Although the reaction catalyzed formally resembles those catalyzed by chicken liver xanthine dehydrogenase and related enzymes, this enzyme is devoid of any flavin, iron complex, or molybdenum component, and the kinetics indicate necessity for concomitant binding of substrate and DPN. The enzyme is absolutel...

The pH dependence of the steady state kinetic parameters K,(app) and $,t of the a-, acetylated 6-, and ar-chymotrypsincatalyzed hydrolysis of the specific amide substrate N-acetylr.-tryptophanamide, has been investigated in the neutral and alkaline pH regions. A completely automatic technique for measuring the hydrolysis of amides was used. New results and important aspects of the chymotrypsin-...

Limited treatment of Escherichia coli DNA ligase with trypsin results in rapid loss of DNA joining activity. However, the ability to react with DPN to form the covalent enzyme-AMP intermediate is unaffected. The cleaved enzyme is also unable to catalyze the formation of DNA-adenylate, the second covalent intermediate in the ligase-catalyzed reaction. These findings demonstrate that portions of ...

The rationale fo the development of prodrugs relies upon delivery of higher concentrations of a drug to target cells compared to administration of the drug itself. In the last decades, numerous prodrugs that are enzymatically activated into anti-cancer agents have been developed. This review describes the most important enzymes involved in prodrug activation notably with respect to tissue distr...

N/O-methylation of DNA can be cytotoxic and mutagenic; therefore, enzymes that reverse DNA methylation are essential for organism survival. Several 2-oxoglutarate-dependent oxygenases and methyltransferases that remove a methyl group from a methylated DNA base have been identified. Studies of their kinetics and search for their inhibitors have been retarded by the lack of an approach to directl...