Your browser doesn't support javascript.
loading
Purification and cDNA cloning of UDP-GlcNAc:GlcNAcbeta1-3Galbeta1-4Glc(NAc)-R [GlcNAc to Gal]beta1,6N-acetylglucosaminyltransferase from rat small intestine: a major carrier of dIGnT activity in rat small intestine.
Korekane, Hiroaki; Taguchi, Tomohiko; Sakamoto, Yoshihiro; Honke, Koichi; Dohmae, Naoshi; Salminen, Heidi; Toivonen, Suvi; Helin, Jari; Takio, Koji; Renkonen, Ossi; Taniguchi, Naoyuki.
Afiliación
  • Korekane H; Department of Biochemistry, Osaka University Medical School/graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Glycobiology ; 13(5): 387-400, 2003 May.
Article en En | MEDLINE | ID: mdl-12626393
ABSTRACT
A rat intestinal beta1,6N-acetylglucosaminyltransferase (beta1-6GnT) responsible for the formation of the beta1,6-branched poly-N-acetyllactosamine structure has been purified to apparent homogeneity by successive column chromatographic procedures using an assay wherein pyridylaminated lacto- N-triose II (GlcNAcbeta1-3Galbeta1-4Glc-PA) was used as an acceptor substrate and the reaction product was GlcNAcbeta1-3(GlcNAcbeta1-6)Galbeta1-4Glc-PA. The purified enzyme catalyzed the conversion of the polylactosamine acceptor GlcNAcbeta1-3'LacNAc into GlcNAcbeta1-3'(GlcNAcbeta1-6') LacNAc (dIGnT activity), but it could not transfer GlcNAc to LacNAcbeta1-3'LacNAc (cIGnT activity). This enzyme could also convert mucin core 1 and core 3 analogs, Galbeta1-3GalNAcalpha1-O-paranitrophenyl (pNP) and GlcNAcbeta1-3GalNAcalpha1-O-pNP, into Galbeta1-3(GlcNAcbeta1-6) GalNAcalpha1-O-pNP (C2GnT activity) and GlcNAcbeta1-3(GlcNAcbeta1-6)GalNAcalpha1-O-pNP (C4GnT activity), respectively. Based on the partial amino acid sequences of the purified protein, the cDNA encoding this enzyme was cloned. The COS-1 cells transiently transfected with this cDNA had high dI/C2/C4GnT activities in a ratio of 0.341.000.90, compared with non- or mock-transfected cells. The primary structure shows a significant homology with human and viral mucin-type core 2 beta1-6GnTs (C2GnT-Ms), indicating that this enzyme is the rat ortholog of human and viral C2GnT-Ms. This is the first identification and purification of this enzyme as a major carrier of dIGnT activity in the small intestine. This rat ortholog should mostly be responsible for making distal I-branch structures on poly-N-acetyllactosamine sequences in this tissue, as well as making mucin core 2 and core 4 structures, given that it also has high C2/C4GnT activities.
Asunto(s)
Buscar en Google
Colección: 01-internacional Base de datos: MEDLINE Asunto principal: N-Acetilglucosaminiltransferasas / ADN Complementario / Intestino Delgado Límite: Animals Idioma: En Revista: Glycobiology Asunto de la revista: BIOQUIMICA Año: 2003 Tipo del documento: Article País de afiliación: Japón
Buscar en Google
Colección: 01-internacional Base de datos: MEDLINE Asunto principal: N-Acetilglucosaminiltransferasas / ADN Complementario / Intestino Delgado Límite: Animals Idioma: En Revista: Glycobiology Asunto de la revista: BIOQUIMICA Año: 2003 Tipo del documento: Article País de afiliación: Japón