The greigite Fe3S4{111} surface catalyses the CO2 conversion into acetic acid (CH3–COOH) via a glyoxylic (CHO–COOH) intermediate.

A protease, ;trypsinogenase', secreted in small amounts by the sea-urchin blastula, is assayed in two steps as an example of enzyme-amplifying kinetics. In reaction 1 the trypsinogenase catalyses the activation of trypsinogen to trypsin. In reaction 2 the trypsin catalyses the hydrolysis of N-alpha-toluene-p-sulphonylarginine methyl ester, at a rate that is linear with trypsinogenase concentrat...

The glyoxalase system catalyses the conversion of methylglyoxal to D-lactic acid via the intermediate S-D-lactoylglutathione (Fig. 1). It comprises two enzymes, glyoxalase I and glyoxalase II, and a catalytic amount of reduced glutathione (Carrington & Douglas, 1986; Thornalley, 1989). Glyoxalase I (EC 4.4.1.5, lactoylglutathione lyase) catalyses the formation of S-D-lactoylglutathione from the...

In Xer site-specific recombination, two related recombinases, XerC and XerD, mediate the formation of recombinant products using Holliday junction-containing DNA molecules as reaction intermediates. Each recombinase catalyses the exchange of one pair of specific strands. By using synthetic Holliday junction-containing recombination substrates in which two of the four arms are tethered in an ant...

Horseradish peroxidase catalyses the oxidation of NAD dimers, (NAD)2, to NAD+ in accordance with a reaction that is pH-dependent and requires 1 mol of O2 per 2 mol of (NAD)2. Horseradish peroxidase also catalyses the peroxidation of (NAD)2 to NAD+. In contrast, bacterial NADH peroxidase does not catalyse the peroxidation or the oxidation of (NAD)2. A free-radical mechanism is proposed for both ...

Rhodococcus sp. strain IGTS8 (ATCC 53968) is able to utilize dibenzothiophene (DBT) as a sole source of sulphur. The carbon skeleton of DBT is not metabolized and is conserved as 2-hydroxybiphenyl (HBP), which accumulates in the medium. This phenotype is due to the expression of the plasmid-encoded DBT-desulphurization (dsz) operon, which encodes three proteins, DszA, B and C. In this paper it ...

Co-oxidation of xenobiotics has been shown t o occur during prostaglandin synthase (PGS)-catalysed synthesis of prostaglandins (Marnett. 198 I ; EIing et al.. 1983; Marnett & Eling. 1983). PGS catalyses the oxygenation of polyunsaturated fatty acids to hydroxy endoperoxides (e.g. PGH2). The most important substrate in vivo is arachidonic acid (AA) . PGS contains two activities: the fatty acid c...