RESUMO
Glutathione is a nearly ubiquitous, low-molecular-mass thiol and antioxidant, but it is conspicuously absent from most Gram-positive bacteria. We identify here the structure of bacillithiol, a newly described and abundant thiol produced by Bacillus species, Staphylococcus aureus and Deinococcus radiodurans. Bacillithiol is the alpha-anomeric glycoside of L-cysteinyl-D-glucosamine with L-malic acid and most probably functions as an antioxidant. Bacillithiol, like the structurally similar mycothiol, may serve as a substitute for glutathione.
Assuntos
Antioxidantes/isolamento & purificação , Cisteína/análogos & derivados , Deinococcus/metabolismo , Glucosamina/análogos & derivados , Staphylococcus aureus/metabolismo , Compostos de Sulfidrila/isolamento & purificação , Antioxidantes/química , Antioxidantes/farmacologia , Cisteína/química , Cisteína/isolamento & purificação , Cisteína/farmacologia , Glucosamina/química , Glucosamina/isolamento & purificação , Glucosamina/farmacologia , Glutationa/química , Glutationa/farmacologia , Modelos Moleculares , Estrutura Molecular , Compostos de Sulfidrila/química , Compostos de Sulfidrila/farmacologiaRESUMO
Actinomycetes produce mycothiol as their major low molecular weight thiol, which parallels the functions of glutathione found in prokaryotes and most Gram-negative bacteria. This review covers progress that has so far been made in terms of its distribution, biosynthesis and metabolic functions, as well as chemical syntheses of mycothiol and alternative substrates and inhibitors of mycothiol biosynthesis and mycothiol-dependent enzymes. 152 references are cited.
Assuntos
Actinobacteria/química , Cisteína/biossíntese , Glicopeptídeos/biossíntese , Inositol/biossíntese , Compostos de Sulfidrila/química , Actinobacteria/enzimologia , Actinobacteria/metabolismo , Cisteína/metabolismo , Glicopeptídeos/metabolismo , Inositol/metabolismo , Estrutura Molecular , Peso Molecular , Compostos de Sulfidrila/metabolismoRESUMO
A solid phase synthesis of des-myo-inositol mycothiol disulfide and its alpha-configured methyl- and benzyl-glycoside derivatives has been developed. Kinetic characterisation of these compounds has demonstrated their viability as alternative substrates for use in mycothiol disulfide reductase enzyme assays.