Polyethylene glycol augments thyroid cAMP responses by fragments from protease-digested TSAb or TSBAb-IgG.
In the previous reports, we have demonstrated (1) that polyethylene glycol (PEG)(5%) augmented TSAb (thyroid stimulating antibody)-stimulated cAMP responses of porcine thyroid cells, and (2) that fragments from papain-digested TSBAb (thyroid stimulation blocking antibody) could stimulate thyroid cAMP synthesis. Thus, we studied the effect of 5% PEG on cAMP responses stimulated by the protease-digested TSAb- or TSBAb-fragments. Stimulatory effect of 5% PEG on cAMP production by Fab fragment (Mr 50 KDa) and the retarded fraction (Mr 20 KDa) from the gel-filtration on Sephadex G-100 using papain-digested TSAb-IgG unbound to Protein A-Sepharose was observed. Similar stimulatory effect of 5% PEG on the second fraction (Fc with trace amounts of Fab) in the gel-filtration on Sephadex G-100 using papain digested TSAb-IgG bound to Protein A-Sepharose was observed. Stimulatory effect of PEG on the second fraction was derived from Fab fragment. PEG (5%) also showed stimulatory effect on cAMP production by F(ab')2 fragment (Mr 100 KDa) from the gel-filtration on Sephadex G-100 using pepsin-digested TSAb-IgG unbound to Protein A-Sepharose. PEG (5%) augmented cAMP responses by both Fab and the retarded fractions from the gel-filtration using papain-digested TSBAb-IgG unbound to Protein A when these fractions could stimulate cAMP synthesis. In conclusion, PEG (5%) augments cAMP responses stimulated by F(ab')2, Fab and the smaller molecular components (Mr 20 KDa) separated from protease-digested TSAb-IgG. PEG also augments cAMP responses stimulated by Fab and the smaller molecular components with thyroid stimulating activity separated from papain-digested TSBAb-IgG.
Yamashiro
K
K
Second Dept of Internal Medicine, Univ of the Ryukyus, Okinawa, Japan.
Takasu
N
N
Inui
T
T
Kouki
T
T
Ochi
Y
Y
Kajita
Y
Y
Sato
Y
Y
Nagata
A
A
D001323:Autoantibodies / Q000276:immunology*; D000242:Cyclic AMP / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D010450:Endopeptidases / Q000494:pharmacology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D018828:Immunoglobulins, Thyroid-Stimulating / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology*; D011092:Polyethylene Glycols / Q000494:pharmacology*; D011989:Receptors, Thyrotropin / Q000276:immunology*; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism
D001323:Autoantibodies; D007074:Immunoglobulin G; D018828:Immunoglobulins, Thyroid-Stimulating; D010446:Peptide Fragments; D011989:Receptors, Thyrotropin; C094372:thyrotropin-binding inhibitory immunoglobulin; D011092:Polyethylene Glycols; D000242:Cyclic AMP; D010450:Endopeptidases