Structural characteristics of the N-glycans of two isoforms of prostate-specific antigens purified from human seminal fluid.
Prostate-specific antigen (PSA) is a glycosylated chymotrypsin-like serine protease and is found mainly in prostatic tissue and seminal fluid. We purified two forms of PSA (PSA-A and PSA-B) from human seminal fluid with pI values of approx. 7.2 and approx. 6.9, respectively. To characterize the N-glycans of the two isoforms, the sugar chains were liberated by hydrazinolysis followed by N-acetylation, and derivatized with 2-aminobenzamide. Both PSA-A and PSA-B contained mono- and disialylated sugar chains, although PSA-B had a much higher content of the latter. After removal of sialic acid residues by sialidase digestion, mono- and biantennary N-glycans and three outer chain moieties (Galbeta1-4GlcNAcbeta1-, GlcNAcbeta1-, GalNAcbeta1-4GlcNAcbeta1-) were found in both samples. However, the ratios of each N-glycan were different. These results indicate that PSA-A and PSA-B differ not only in their sialic acid contents, but also in their outer chain features.
Okada
T
T
Department of Glycobiology, Tokyo Metropolitain Institute of Gerontology, Japan.
Sato
Y
Y
Kobayashi
N
N
Sumida
K
K
Satomura
S
S
Matsuura
S
S
Takasaki
M
M
Endo
T
T
D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D017430:Prostate-Specific Antigen / Q000737:chemistry* / Q000276:immunology* / Q000302:isolation & purification; D020033:Protein Isoforms / Q000737:chemistry / Q000302:isolation & purification; D012661:Semen / Q000737:chemistry* / Q000276:immunology*
D009844:Oligosaccharides; D011134:Polysaccharides; D020033:Protein Isoforms; D017430:Prostate-Specific Antigen