Sialic acid in thyroglobulin. II. Influence of sialic acid on ionization of tyrosine residues.
During electrophoresis in polyacrylamide gel at pH 9-5, it was noticed that sialic acid-poor thyroglobulin contains fewer low molecular weight fragments than sialic acid-rich thyroglobulin. Splitting off of sialic acid diminishes thenumber of phenolic groups of tyrosine, MIT, DIT and T4, which dissociate below pH 12-5. This phenomenon was interpreted as a result of lowered hydrophilia of these regions of the thyroglobulin molecule which contains tyrosine and its iodinated derivatives.
D000818:Animals; D001001:Anura; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D012794:Sialic Acids / Q000032:analysis*; D013954:Thyroglobulin / Q000032:analysis*; D014443:Tyrosine / Q000032:analysis*
D012794:Sialic Acids; D014443:Tyrosine; D013954:Thyroglobulin