title: Evidence for impaired subunit interaction in chemically deglycosylated human choriogonadotropin.
abstract: Using three different methods evidence was obtained that native and deglycosylated choriogonadotropin show differences in their conformations which might account for the antagonistic properties of deglycosylated choriogonadotropin: 1. In the deglycosylated hormone additional peptide bonds were susceptible to chymotrypsin. 2. In the far ultraviolet circular dichroism only small differences existed between native and deglycosylated choriogonadotropin. However, in 80% hexafluoropropanol the deglycosylated hormone adopted a higher degree of ordered structure. 3. At 37 degrees C the deglycosylated hormone showed a 13 fold increase of the dissociation rate into subunits at pH 3 in comparison to native choriogonadotropin. The results provide evidence that in chemically deglycosylated choriogonadotropin the subunit interactions are disturbed due to conformational changes.
authors.affiliation: Department of Biochemistry II, University of Heidelberg, F.R.G.
authors.forename: W E
authors.initials: WE
authors.lastname: Merz
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis / Q000502:physiology; D055598:Chemical Phenomena; D002621:Chemistry; D006063:Chorionic Gonadotropin / Q000032:analysis*; D002918:Chymotrypsin / Q000494:pharmacology; D002942:Circular Dichroism; D006801:Humans; D006868:Hydrolysis; D010446:Peptide Fragments / Q000032:analysis; D011487:Protein Conformation; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D006063:Chorionic Gonadotropin; D010446:Peptide Fragments; D002918:Chymotrypsin