title: Characterization of serum immunoglobulins in a chondrostean fish, Acipenser baeri.
abstract: The euglobulin fraction of sturgeon (Acipenser baeri) serum was analyzed using electrophoretic and immunoblotting techniques. The major protein of this fraction is an IgM-like molecule composed of equimolar 70-kDa glycosylated H chains and 26-30 kDa L chains. In the absence of a reducing agent, the L and H polypeptides may form (mu 2L2)n high molecular weight polymers, mu 2L2 170-kDa units or L2 dimers. These different bonding patterns suggest some structural heterogeneity in the distribution of cysteine residues along the sturgeon Ig chains. The H chain N-terminal sequence indicates significant homologies with the conserved VHIII subgroup. Heavy chains antigenically different from the 70-kDa H chain were not detected, suggesting that IgM is the only Ig class synthesized by this sturgeon species.
authors.affiliation: Université Pierre et Marie Curie and CNRS (URA 1135), Groupe d'Immunologie Comparée, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Partula
authors.forename: J
authors.initials: J
authors.lastname: Charlemagne
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005399:Fishes / Q000276:immunology*; D015151:Immunoblotting / Q000662:veterinary; D007122:Immunoelectrophoresis / Q000662:veterinary; D007136:Immunoglobulins / Q000097:blood*; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid
chemical_list: D007136:Immunoglobulins; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase