oxygen species that are known to induce the peroxidation of polyunsaturated lipids in cell membranes and to cause degradation of structural proteins, enzymes and ribonucleic acids. These reactive intermediates of oxygen metabolism are converted mainly into molecular oxygen and water by antioxidant enzymes and normally are kept to a minimum in blood and organ tissues (Fridovich, 1978; Fridovich ...

Abstract The sucrose isomerase SmuA from Serratia plymuthica catalyses the production of isomaltulose, an artificial sweetener used in food industry. To suppress formation hygroscopic by-product trehalulose we applied a semirational protein engineering strategy inspired by “battleship” board game. After seven cycles introducing amino acid exchanges around active site and investigating their inf...

Escherichia coli caseinolytic protease (Clp)B is a hexameric AAA+ [expanded superfamily of AAA (ATPase associated with various cellular activities)] enzyme that has the unique ability to catalyse protein disaggregation. Such enzymes are essential for proteome maintenance. Based on structural comparisons to homologous enzymes involved in ATP-dependent proteolysis and clever protein engineering s...

Ketohexokinase (KHK; E.C. 2.7.1.3) catalyses the (reversible) phosphorylation of fructose to fructose-1-phosphate. KHK is the first enzyme in a specialized catabolic pathway metabolizing dietary fructose to the glycolytic intermediate glyceraldehyde-3-phosphate. Mutations inactivating KHK underlie the metabolic disorder essential fructosuria. The primary structure of KHK shows no significant ho...

A cell-free supernatant of lysates of Lactobacillus plantarum catalyses the synthesis of lipids from [2-(14)C]mevalonate. Of the added mevalonate, 7.5% is incorporated into lipids, which were fractionated into five components. About 4% of the radioactivity in these lipids co-chromatographs with compounds shown by mass spectrometry, n.m.r. and i.r. spectroscopy to be C(55) polyprenols, and about...

Carbonic anhydrase (CA) is the zinc metalloenzyme that catalyses the reversible reactions of CO(2) with water. CA plays a crucial role in systemic acid-base regulation in fish by providing acid-base equivalents for exchange with the environment. Unlike air-breathing vertebrates, which frequently utilize alterations of breathing (respiratory compensation) to regulate acid-base status, acid-base ...

The most common bacterial mechanism for resistance to mercuric-ion species involves intracellular reduction of Hg(II) to Hg(0). Key proteins of the pathway typically include: MerR, which regulates pathway expression; MerP, which protects the external environment; MerT or MerC, which transport Hg(II) species across the inner membrane; MerA, which catalyses reduction of Hg(II); and sometimes MerB...

The subcellular localization of enzymes involved in indole alkaloid biosynthesis in leaves of Catharanthus roseus has been investigated. Tryptophan decarboxylase and strictosidine synthase which together produce strictosidine, the first indole alkaloid of this pathway, are both cytoplasmic enzymes. S-Adenosyl-l-methionine: 16-methoxy-2,3-dihydro-3-hydroxytabersonine-N-methyltransferase which ca...

Abstract We present a five-dimensional twice anisotropic holographic model supported by Einstein-dilaton-three-Maxwell action describing light quarks. The first of the Maxwell fields provides finite chemical potential. second field serves for anisotropy, characterizing spatial anisotropy QGP produced in heavy-ion collisions (HIC). third is related to magnetic that appears HIC. dependence 5-dim ...