Identification of differentially glycosylated forms of the soluble p75 tumor necrosis factor (TNF) receptor in human urine.
Human urine is known to contain a 30 kDa soluble form of the p75-TNF receptor (sTNF-R2). In this work we have purified sTNF-R2 from the urine of normal subjects and further characterized its structure and activity. sTNF-R2 was resolved by reducing SDS-PAGE in a major band of 30 kDa, similar in size to the previously described urinary sTNFR2, and in a minor band of 45 kDa. "Western" blotting analysis with anti-TNF-R1 and anti-TNF-R2 antibodies showed that both bands were immunologically related to the membrane TNF-R2. Glycosylation studies indicated that the 30 kDa is N-glycosylated while the 45 kDa form is N- and O-glycosylated, and suggested that both forms contain terminally linked sialic acid that is differentially recognized by lectins. These results indicate that human urine contains, besides the 30 kDa form, a new form of 45 kDa characterized by different glycosylation type and degree.
Corti
A
A
DIBIT, San Raffaele H Scientific Institute, Milan, Italy.
D'Ambrosio
F
F
Marino
M
M
Merli
S
S
Cassani
G
G
D000581:Amidohydrolases; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D006596:Hexosaminidases; D006801:Humans; D008233:Lymphotoxin-alpha / Q000378:metabolism; D015394:Molecular Structure; D008970:Molecular Weight; D009439:Neuraminidase; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D018124:Receptors, Tumor Necrosis Factor / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification*; D011994:Recombinant Proteins / Q000737:chemistry; D012794:Sialic Acids / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D008233:Lymphotoxin-alpha; D018124:Receptors, Tumor Necrosis Factor; D011994:Recombinant Proteins; D012794:Sialic Acids; D014409:Tumor Necrosis Factor-alpha; D006596:Hexosaminidases; D009439:Neuraminidase; C060638:glycopeptide alpha-N-acetylgalactosaminidase; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase