RESUMO
Many bioinspired transition-metal catalysts have been developed over the recent years. In this review the progress in the design and application of ligand systems based on peptides and DNA and the development of artificial metalloenzymes are reviewed with a particular emphasis on the combination of phosphane ligands with powerful molecular recognition and shape selectivity of biomolecules. The various approaches for the assembly of these catalytic systems will be highlighted, and the possibilities that the use of the building blocks of Nature provide for catalyst optimisation strategies are discussed.
Assuntos
DNA Catalítico/química , Metaloproteínas/química , Peptídeos/química , Elementos de Transição/química , Catálise , Cristalografia por Raios X , Ligantes , Estrutura Molecular , EstereoisomerismoRESUMO
The preparation of hybrid transition metalloproteins by thiol-selective incorporation of organometallic rhodium- and ruthenium complexes is described. Phosphine ligands and two rhodium-diphosphine complexes bearing a carboxylic acid group were coupled to the cysteine of PYP R52G, yielding a metalloenzyme active in the rhodium catalyzed hydrogenation of dimethyl itaconate. The successful coupling was shown by (31)P NMR spectroscopy and ESI mass spectroscopy. In addition wild-type PYP (PYP WT), PYP R52G and ALBP were successfully modified with a (eta(6)-arene) ruthenium(II) phenanthroline complex via a maleimide linker.
Assuntos
Proteínas de Bactérias/química , Metaloproteínas/síntese química , Fenantrolinas/química , Fosfinas/química , Fotorreceptores Microbianos/química , Ródio/química , Rutênio/química , Compostos de Sulfidrila/química , Substituição de Aminoácidos , Proteínas de Bactérias/genética , Catálise , Complexos de Coordenação/química , Hidrogenação , Espectroscopia de Ressonância Magnética , Metaloproteínas/química , Mutação , Fotorreceptores Microbianos/genética , Succinatos/químicaAssuntos
Proteínas de Bactérias/química , Cisteína/química , Fosfinas/química , Fotorreceptores Microbianos/química , Substituição de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Catálise , Halorhodospira halophila/metabolismo , Paládio/química , Fotorreceptores Microbianos/genética , Fotorreceptores Microbianos/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
The first synthesis of the trisaccharide repeating unit of the acidic polysaccharide of the bacteriolytic complex of lysoamidase is presented. The construction is based on a linear glycosylation strategy that starts from the reducing end and employs thio- and selenoglycosides in a highly stereoselective manner by a single set of activation conditions. The thus-formed trisaccharide is selectively deprotected and oxidised, after which a final deprotection step furnishes the desired repeating unit.
Assuntos
Peptídeo Hidrolases/química , Polissacarídeos/síntese química , Xanthomonas/química , Configuração de Carboidratos , Sequência de Carboidratos , Dados de Sequência Molecular , Polissacarídeos/química , Xanthomonas/enzimologiaRESUMO
Diphenylsulfoxide in combination with triflic anhydride provides a very potent thiophilic glycosylation promotor system, capable of activating disarmed thioglycosides. The usefulness of this novel thiophilic activator is illustrated in a successful chemoselective glycosylation sequence in which the donor thioglycoside in the first condensation step may be either armed or disarmed. [reaction: see text]
