Subject(s)
Gonadotropins, Pituitary/metabolism , Gonadotropins/metabolism , Guanidine/chemistry , Animals , Antigens/chemistry , Arginine/chemistry , Arginine/metabolism , Dimerization , Fishes , Free Radicals , Glycoproteins/chemistry , Hormones/metabolism , Lysine/chemistry , Oocytes/metabolism , Protein Structure, Tertiary , Signal TransductionABSTRACT
The specific stimulatory effect of sturgeon Acipenser güldenstädti Br. gonadotropic hormone (GTH) on frog Rana temporaria L. oocyte maturation in vitro was investigated in relation to humic acid (HA) concentrations from 12.5 to 50 mg/l. HA was observed to bind to both the follicular membrane of the oocytes and the GTH molecule, reducing the oocytes' hormone sensitivity and maturation ability. It was also shown that HA inactivated GTH, lowering its specific ability to stimulate oocyte maturation.
Subject(s)
Gonadotropins/antagonists & inhibitors , Humic Substances/toxicity , Oocytes/drug effects , Rana temporaria/metabolism , Reproduction/drug effects , Animals , Dose-Response Relationship, Drug , Fishes/metabolism , Fresh Water , Gonadotropins/metabolism , Oocytes/cytology , Oocytes/metabolismSubject(s)
Chromatography, Affinity/methods , Fishes , Gonadotropins, Pituitary/analysis , Pituitary Gland/chemistry , Sepharose/analogs & derivatives , Animals , Electrophoresis, Polyacrylamide Gel/methods , Gonadotropins, Pituitary/immunology , Gonadotropins, Pituitary/metabolism , Immunoassay/methods , In Vitro Techniques , Molecular Structure , Sepharose/metabolismABSTRACT
Chemical deglycosylation (dg) of sturgeon Acipenser gueldenstaedti Br. (alphaGTH) resulted in the loss of 83% of its initial carbohydrate content. It altered also recombinant dg alphaGTH + betaGTH dimer molecule, reducing its immunoreactivity by 30%, and fully blocking the hormonal function. CD spectroscopy showed that deglycosylation led to changes in the secondary structure of dg alphaGTH and in the alpha-beta recombinant. The sugar moiety of sturgeon alphaGTH is suggested to play an important role in maintaining the biological function of the hormone dimer molecule.
