Synthesis and examination of antigenicity of four hormonogenic sites and two non-hormonogenic sites of human thyroglobulin.
Four peptides (HTg-1, 1-10; HTg-2, 2547-2558; HTg-4, 2592-2603; HTg-6, 2737-2748) which contain hormonogenic acceptor tyrosine (Tyr) residues and two control peptides (HTg-3, 2582-2591; HTg-5, 2687-2694) of human thyroglobulin (Tg) were synthesized, radioiodinated and their binding with serial anti-human Tg antisera which had been raised in two rabbits (TG-1, TG-2) tested. Although increased binding of each of the six peptides was observed, HTg-4 and HTg-2 had higher binding whereas HTg-1 and HTg-6 showed lower binding with the immune gamma globulin from both rabbits. Each of the six peptides was iodinated with inorganic iodine (127I) using the chloramine-T method and the inhibitory activity of each peptide on the interaction between 125I-T4 and anti-Tg antibodies was tested. At the same time, Tg obtained from a normal thyroid tissue (NTg, iodine content 0.38%) and from a Hürthle cell adenoma (CTg, iodine content 0.000%) were also tested for inhibition of 125I-T4 binding. 125I-T4 binding with rabbit anti-Tg antisera was displaced not only by NTg and CTg but also by three out of four hormonogenic peptides. Among the three peptides, HTg-2 had the highest inhibitory activity, inhibiting 125I-T4 binding to the extent of 21.5% (TG-1) and 16.0% (TG-2). Two control peptides (HTg-3, HTg-5) did not inhibit 125I-T4 binding with anti-Tg antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)
Sakata
S
S
Third Department of Internal Medicine, Gifu University School of Medicine, Japan.
Ogawa
T
T
Kimata
Y
Y
Takuno
H
H
Maekawa
H
H
Matsuda
M
M
Tarutani
O
O
Okuda
K
K
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D000936:Antigen-Antibody Complex; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis* / Q000276:immunology; D011817:Rabbits / Q000276:immunology; D013954:Thyroglobulin / Q000138:chemical synthesis* / Q000276:immunology; D014443:Tyrosine
D000906:Antibodies; D000936:Antigen-Antibody Complex; D010455:Peptides; D014443:Tyrosine; D013954:Thyroglobulin