Purification and characterization of a bovine pregnancy-associated glycoprotein.
A 67000 Mr bovine pregnancy-associated glycoprotein (bPAG) has been isolated from fetal cotyledons and purified to homogeneity by HPLC. The purification was monitored by a double immunodiffusion test and by RIA in conjunction with an antiserum raised against a crude fraction of placenta-specific antigens. The molecular weight of bPAG was estimated to be 67000 by SDS-PAGE. The isoelectric points (pI) of the four isoforms, determined by high-resolution analytical electrofocusing in polyacrylamide gel, were 4.4, 4.6, 5.2, and 5.4. The carbohydrate content of the bPAG consisted of approximately 10.02 +/- 1.09% neutral sugar and variant amounts of sialic acid (from 0.29 +/- 0.06% in the most basic isoform to 2.1 +/- 0.31% in the most acidic isoform). A specific antiserum was raised against the purified bPAG. A specific RIA showed that the bPAG was antigenically unrelated to BSA, alphafetoprotein (AFP), and human schwangerschafts-spezifischen (pregnancy-specific) beta 1 glycoprotein (SP1). According to some characteristics (e.g. the molecular weight), the purified bPAG may correspond to a form of the pregnancy-specific protein B previously described by Sasser and colleagues (Biol Reprod 1986; 35:936-942).
Zoli
A P
AP
Département d'Endocrinologie et de Reproduction Animales (Unité de Recherche IRSIA) Faculté de Médecine Vétérinaire, Bruxelles, Belgique.
Beckers
J F
JF
Wouters-Ballman
P
P
Closset
J
J
Falmagne
P
P
Ectors
F
F
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007106:Immune Sera / Q000276:immunology; D015151:Immunoblotting; D005779:Immunodiffusion; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D008970:Molecular Weight; D019158:N-Acetylneuraminic Acid; D011247:Pregnancy; D011268:Pregnancy-Specific beta 1-Glycoproteins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D011863:Radioimmunoassay; D012794:Sialic Acids / Q000032:analysis
D000596:Amino Acids; D002241:Carbohydrates; D007106:Immune Sera; D011268:Pregnancy-Specific beta 1-Glycoproteins; D012794:Sialic Acids; D019158:N-Acetylneuraminic Acid