Location and characterization of the three carbohydrate prosthetic groups of human protein HC

FEBS Letters

Grubb, A.³  Hjerpe, A.¹  Lopex-Otin, C.²  Mendez, E.²  Escribano, J.² 

[1] Department of Pathology II, Karolinska Institute, Sweden;Servicio de Endocrinologia, Hospital Ramon y Cajal, 28034 Madrid, Spain;Department of Clinical Chemistry, University Hospital, S-22185 Lund, Sweden

关键词: Protein HC;    α1-Microglobulin;    Glycoprotein;    Carbohydrate;    Glc;    glucose;    Gal;    galactose;    Man;    mannose;    Fuc;    fucose;    NANA;    N-acetylneuraminic acid;    GlcNac;    N-acetylglucosamine;    GalNAc;    N-acetylgalactosamine;    RP-HPLC;    reversed-phase high-performance liquid chromatography;   

DOI  :  10.1016/0014-5793(90)81531-R

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Three different carbohydrate prosthetic groups associated to three chymotryptic peptides, Ql, Q2 and Q3, were isolated from the reduced and carboxymethylated human protein HC. The first oligosaccharide forms an O-glycosidic linkage with a threonine residue at position 5 in the polypeptide chain of protein HC. The second and third carbohydrate prosthetic groups form N-linkages with asparagine residues at positions 17 and 96. Oligosaccharides present in Q1 contain 1 residue of NANA, 2 of Ga1NAc and 1 of Gal corresponding to the following structure: -O-Ga1NAc-Ga1NAc-Gal-NANA. Q2 contains 3 NANA, 9 GlcNAc, 2 Gal and 3 Man, and Q3 contains 2 NANA, 5 GlcNAc, 1 Gal and 2 Man. The sugar compositions of Q2 and Q3 oligosaccharides are compatible with that of the complex kind. The amount of oligosaccharides present in Q1, Q2 and Q3 corresponded respectively to 3.0%, 12.2% and 7.3% of the weight of protein HC. No difference was found between the carbohydrate composition of urinary and plasma protein HC.

【 授权许可】

Unknown