[Characteristics of carbohydrate chains of two forms of salmon gonadotropic hormone binding and not binding concanavalin A]. / Kharakteristika uglevodnykh tsepei sviazyvaiushcheisia i ne sviazyvaiushcheisia s konkanavalinom A form gonadotropnogo gormona gorbushi.

A comparative analysis of carbohydrate chains of two forms of hunchback salmon gonadotropin that bind or not with ConA-Sepharose was carried out. It was found that unbound, "protein", ConA(-)-form contains three times less carbohydrates and has slightly different amino acid composition as compared to the bound, normally glycosylated ConA(+)-form. HPLC fractionation showed the oligosaccharides released from both hormone forms to be mainly sialylated. The major oligosaccharides identified in ConA(+)-form are biantennary, fucosylated (approximately 20%) or nonfucosylated; minor bissected chains are also present. In ConA(-)-form the same oligosaccharides and also oligosaccharides with a higher degree of branching (tri- and tetraantennary) were detected. These two hormone forms isolated from pituitary glands of male or female fish differed neither in the type of oligosaccharides nor in their ratio. Essential structural differences in carbohydrate chains of hunchback salmon and sturgeon gonadotropins were distinctly demonstrated.

[Structure of carbohydrate chains of dimeric molecules and individual subunits of gonadotropin from the Russian sturgeon]. / Struktura uglevodnykh tsepei dimernoi molekuly i otdel'nykh sub''edinits gonadotropina russkogo osetra.

Carbohydrate chains of gonadotropin from the Russian sturgeon hypophysis, as well as of alpha- and beta-subunits of the hormone, were split off and fractionated by gel-chromatography and HPLC. More than ten oligosaccharides released from the male and female hormones gave almost identical patterns, whereas differences between alpha- and beta-subunits were more noticeable. Basing on the chromatographic properties and monosaccharide compositions of the oligosaccharides isolated and the known structures of N-linked carbohydrates of mammalian hormones, the common carbohydrate chain of sturgeon gonadotropin is as follows: [formula: see text] Some oligomannosidic and/or hybrid chains and small oligosaccharides of the pentasaccharide core type were also found. Carbohydrate chains of fish gonadotropin have fewer sialic acid residues and significantly fewer (if any) sulphate groups than the mammalian hormones.