Rapid high-yield N-acylation of aminothiols: N-acetylglutathione and N-acetylhomocysteine and their thiol pK(a) values.
J Pept Sci
; 19(5): 263-7, 2013 May.
Article
em En
| MEDLINE
| ID: mdl-23532793
ABSTRACT
Methodology for the rapid N-acylation of aminothiols in aqueous solution using procedures commonly employed in biochemical studies is described here. Glutathione disulfide (GSSG) and homocystine were diN-acetylated in ~100% yield in 0.1 M aqueous NaHCO3 (pH 8.5) at room temperature by 2.5 equiv of the activated ester, N-hydroxysulfosuccinimidyl acetate, an efficient water-soluble acetylating reagent. Following acetone precipitation, diN-acetylGSSG was further purified and desalted on a strong anion-exchange (SAX) cartridge. DiN-acetylhomocystine was simultaneously purified and desalted on a C18 cartridge. The N-acetylated aminothiols were generated using gel-immobilized tris(2-carboxyethyl)phosphine as a reductant, which obviated the need for further purification. Alternatively, disulfide exchange with dissolved dithiothreitol yielded N-acetylglutathione, which was purified on the SAX cartridge. pH titrations of N-acetylglutathione (8.99) and N-acetylhomocysteine (9.66) as well as those of commercially available N-acetylcysteine (9.53) and N-acetylpenicillamine (10.21) yielded pK(a) (SH) values of importance for biological studies.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos de Sulfidrila
/
Acilação
/
Glutationa
/
Homocisteína
Idioma:
En
Revista:
J Pept Sci
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Canadá