In vitro and in vivo iodination of human thyroglobulin in relation to hormone release.
Reduced and S-alkylated thyroglobulin (Tgb) from different species were shown by SDS-PAGE to contain small peptides (from 45-9 kDa) rich in thyroxine. Several hypotheses were proposed to explain their origin. The polypeptide composition of iodine-poor (Tgb A) and normally iodinated (Tgb B) human Tgb prepared by two different procedures (one minimizing and the other favoring post-mortem proteolysis) was compared in the native state and after in vitro iodination. Results show that one of the hormonogenic sites of human Tgb is part of a domain of the molecule most susceptible to proteolysis, especially when it is very iodinated.
D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007455:Iodine / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D010447:Peptide Hydrolases / Q000378:metabolism; D011487:Protein Conformation; D013954:Thyroglobulin / Q000032:analysis / Q000378:metabolism*; D013963:Thyroid Hormones / Q000378:metabolism*; D013974:Thyroxine / Q000032:analysis; D014443:Tyrosine / Q000378:metabolism
D010446:Peptide Fragments; D013963:Thyroid Hormones; D014443:Tyrosine; D013954:Thyroglobulin; D007455:Iodine; D010447:Peptide Hydrolases; D013974:Thyroxine