Evidence for a preferential iodination site within the thyroglobulin molecule.
Mouse 330 kDa thyroglobulin labeled in vivo was analyzed using a tryptic peptide mapping technique and high performance liquid chromatography (HPLC). 30 min after Na125I injection, one peptide spot (spot 7) on a silica gel plate was the only prominent labeled peptide, followed by other labeled peptide spots after 1 h. HPLC showed that spot 7 was rich in monoiodotyrosine. The ratios between the iodoamino acids were strictly maintained from 1 to 6 h after Na125I injection. Spot 7 was again the first spot that appeared from the samples of iodine-deficient mice. These data indicate that there is some preferential iodination site(s) within the thyroglobulin molecule and also that their iodoamino acid composition is predetermined.
Haraguchi
K
K
Third Department of Internal Medicine, University of Yamanashi Medical School, Japan.
Endo
T
T
Onaya
T
T
Sho
K
K
Ohmiya
Y
Y
Kondo
Y
Y
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D007455:Iodine / Q000032:analysis / Q000378:metabolism*; D051379:Mice; D007470:Monoiodotyrosine / Q000032:analysis; D010449:Peptide Mapping; D013954:Thyroglobulin / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*
D000596:Amino Acids; D013954:Thyroglobulin; D007455:Iodine; D007470:Monoiodotyrosine