Carbohydrate and hydrophobic-carbohydrate recognition sites (CARS and HY-CARS) in solubilized glycosyltransferases.
Indian J Biochem Biophys
;
1990 Dec; 27(6): 386-95
Artigo
em Inglês
| IMSEAR
| ID: sea-26820
ABSTRACT
Six different glycosyltransferases that are active with glycosphingolipid substrates have been purified from Golgi-membranes after solubilization with detergents. It appears that GalT-4(UDP-GalGlcNAc-R1 beta 1-4GalT), GalNAcT-2(UDP-GalGal alpha-R2 beta 1-3GalNAcT) and FucT-2(GDP-FucGal beta GlcNAc-R3 alpha 1-2FucT) are specific for oligosaccharides bound to ceramide or to a protein moiety. These are called CARS (carbohydrate recognition sites) glycosyltransferases (GLTs). On the other hand, GalT-3(UDP-GalGM2 beta 1-3GalT), GalNAcT-1(UDP-GalNAcGM3 beta 1-4GalNAcT) and FucT-3 (GDP-FucLM1 alpha 1-3FucT) recognize both hydrophobic moieties (fatty acid of ceramide) as well as the oligosaccharide chains of the substrates. These GLTs are called HY-CARS (hydrophobic and carbohydrate recognition sites). D-Erythro-sphingosine (100-500 microM) modulates the in vitro activities of these GLTs. Modulation depends on the binding of D-sphingosine to a protein backbone, perhaps on more than one site and beyond transmembrane hydrophobic domains. Control of GLTs by free D-sphingosine was suggested with the concomitant discovery of ceramide glycanase in rabbit mammary tissues. The role of free sphingosine as an in vivo homotropic modulator of glycosyltransferases is becoming apparent.
Texto completo:
DisponíveL
Índice:
IMSEAR (Sudeste Asiático)
Assunto principal:
Coelhos
/
Solubilidade
/
Esfingosina
/
Sítios de Ligação
/
Humanos
/
Bovinos
/
Carboidratos
/
Dados de Sequência Molecular
/
Cinética
/
Ceramidas
Idioma:
Inglês
Revista:
Indian J Biochem Biophys
Ano de publicação:
1990
Tipo de documento:
Artigo
Similares
MEDLINE
...
LILACS
LIS