Hydrogen Peroxide in Biocatalysis. A Dangerous Liaison

Hydrogen peroxide is a substrate or side-product in many enzyme-catalyzed reactions. For example, it is a side-product of oxidases, resulting from the re-oxidation of FAD with molecular oxygen, and it is a substrate for peroxidases and other enzymes. However, hydrogen peroxide is able to chemically modify the peptide core of the enzymes it interacts with, and also to produce the oxidation of some cofactors and prostetic groups (e.g., the hemo group). Thus, the development of strategies that may permit to increase the stability of enzymes in the presence of this deleterious reagent is an interesting target. This enhancement in enzyme stability has been attempted following almost all available strategies: site-directed mutagenesis (eliminating the most reactive moieties), medium engineering (using stabilizers), immobilization and chemical modification (trying to generate hydrophobic environments surrounding the enzyme, to confer higher rigidity to the protein or to generate oxidation-resistant groups), or the use of systems capable of decomposing hydrogen peroxide under very mild conditions. If hydrogen peroxide is just a side-product, its immediate removal has been reported to be the best solution. In some cases, when hydrogen peroxide is the substrate and its decomposition is not a sensible solution, researchers coupled one enzyme generating hydrogen peroxide “in situ” to the target enzyme resulting in a continuous supply of this reagent at low concentrations thus preventing enzyme inactivation. This review will focus on the general role of hydrogen peroxide in biocatalysis, the main mechanisms of enzyme inactivation produced by this reactive and the different strategies used to prevent enzyme inactivation caused by this “dangerous liaison”.

Avaliação de resposta a Vinorelbina-Estramustina em segunda linha terapêutica, em doentes com carcinoma da próstata hormono-refratário previamente tratados com Docetaxel

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Will Familial Hypercholesterolaemia Cohorts Hide Many More Lisosomal Acid Lipase Deficiency Patients?

Aims: Lisosomal Acid Lipase Deficiency (LALD), historical known as Cholesterol Ester Storage Disease (CESD), is an autosomal lisosomal storage recessive disorder and an unrecognized cause of dyslipidaemia. Mutations in LIPA gene are the underlying cause of LALD, being a mutation in the splice site of exon 8 the most common cause of the disease. Patients with LALD present dyslipidaemia and altered liver function. The aim of this work was to analyze LIPA gene in patients with unexplained dyslipidaemia.

The infant school grammar, consisting of elementary lessons in the analytical method; illustrated by sensible objects and actions. Originally composed for Infant School No. 1 of New York.

Mode of access: Internet.

El Viajador sensible /

Tít. en epígrafe: El viajador sensible, ó, Mi paseo a Iverdun.

Recreaciones del hombre sensible ó Colección de sucesos verdaderos y ejemplos sublimes de virtud, conformes a las máximas de la sana moral /

Mode of access: Internet.

Carta consolatoria a la ciudad de Guanajuato en la sensible muerte de su zeloso apostol el padre rector Ignacio Raphael Coromina .../

Mode of access: Internet.

Recreaciones y desahogos del hombre sensible : sucesos verdaderos, exemplos sublimes, heróycos y virtuosos, conformes á las máximas de la ... religion /

Mode of access: Internet.

Recreaciones y desahogos del hombre sensible : sucesos verdaderos, exemplos sublimes, heróycos y virtuosos, conformes á las máximas de la ... religion /

Mode of access: Internet.

Recreaciones y desahogos del hombre sensible : sucesos verdaderos, exemplos sublimes, heróycos y virtuosos, conformes á las máximas de la ... religion /

Mode of access: Internet.

Memoires sur la nature sensible et irritable des parties du corps animal /

Mode of access: Internet.

L'Homme, le monde sensible et le péché dans la philosophie de Jean Scot Erigène /

"Les quatre textes qui composent ce volume ont d'abord étt́ publiés en articles dans la Revue Thomiste (1983-1984)."--P. [4]

Dictionnaire d'archéologie sacrée : contenant, par ordre alphabétique, des notions ... sur les antiquités et les arts ecclésiastiques ... suivi d'un Résumé des caractères architectoniques ... et d'un Tableau méthodique ... Le tout rendu sensible par des gravures nombreuses ... /

"Essai sur divers arts, en trois livres, par Théophile, prêtre et moine, formant une encyclopédie de l'art chrétien au XIIe siècle. Éd. nouv. et très-complète , avec traduction et notes, par M. l'abbé J.-J. Bourassé ...": v.2, col.[729]-1014.

Dictionnaire d'archéologie sacrée : contenant par ordre alphabétique, des notions sªures et complètes sur les antiquités et les arts ecclésiastiques ... ; suivi d'un Résumé des caractères architectoniques ... et d'un Tableau méthodique ... le tout rendu sensible par des gravures nombreuses et bien exécutées.

Mode of access: Internet.

Dictionnaire d'archéologie sacrée : contenant par ordre alphabétique, des notions sªures et complètes sur les antiquités et les arts ecclésiastiques ... ; suivi d'un Résumé des caractères architectoniques ... et d'un Tableau méthodique ... le tout rendu sensible par des gravures nombreuses et bien exécutées.

Mode of access: Internet.