Haptoglobin glycoforms in a case of carbohydrate-deficient glycoprotein syndrome.
Alterations in haptoglobin (Hp) glycosylation were examined in the plasma of the first patient with carbohydrate-deficient glycoprotein syndrome (CDGS) who was described in Poland. Hp concentration in the CDGS patient plasma was low (240 mg/l) and the Hp phenotype was shown to be 2-2. Three glycoforms of the Hp beta subunit were observed in SDS-PAGE in CDGS. The densitometric analysis and molecular weight determinations suggested that 50% of glycoforms were fully glycosylated; 30% contained three out of four and 20% only two out of four glycan units compared to those that are present in Hp derived from healthy people. Results with lectins (concanavalin A and Sambucus nigra, Maackia amurensis and Alleuria aurantia agglutinins) indicate that all three glycoforms of beta subunit of CDGS-Hp contained biantennary complex glycans terminated with alpha2,6 bound sialic acid, but without fucose or alpha2,3 linked sialic acid. Hp glycosylation abnormalities described in this work suggest that this case was a type I carbohydrate-deficient glycoprotein syndrome.
Ferens-Sieczkowska
M
M
Department of Chemistry and Immunochemistry, Wrocław Medical University, Poland.
Midro
A
A
Mierzejewska-Iwanowska
B
B
Zwierz
K
K
Katnik-Prastowska
I
I
D000293:Adolescent; D000581:Amidohydrolases / Q000378:metabolism; D015153:Blotting, Western; D002648:Child; D018981:Congenital Disorders of Glycosylation / Q000097:blood* / Q000145:classification / Q000503:physiopathology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005643:Fucose / Q000032:analysis; D006031:Glycosylation; D006242:Haptoglobins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007223:Infant; D037102:Lectins / Q000378:metabolism; D008970:Molecular Weight; D019158:N-Acetylneuraminic Acid / Q000032:analysis; D009439:Neuraminidase / Q000378:metabolism; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D011044:Poland; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D020033:Protein Isoforms / Q000097:blood / Q000737:chemistry / Q000378:metabolism
D006242:Haptoglobins; D037102:Lectins; D011134:Polysaccharides; D020033:Protein Isoforms; D005643:Fucose; D009439:Neuraminidase; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D019158:N-Acetylneuraminic Acid