Electrophoretic analysis of thyroid iodoproteins in highly cross-linked polyacrylamide gels.
The electrophoretic behavior of thyroglobulin and larger thyroglobulin-like iodoproteins prepared from the hog thyroid was studied in polyacrylamide gels over a wide range of cross-linking degrees (C%). When examined at a constant total acrylamide monomer concentration (T%) of 5%, the mobility of 19S thyroglobulin decreased with increase in C below C = 5%, whereas above C = 5%, it increased markedly with increase in C, giving a minimum mobility at C = 5%. Similar biphasic mobility curves were obtained with 27S and 37S thyroid iodoproteins. Furthermore, in a region above C = 15%, at least two additional larger components which escaped detection in the gels with lower degrees of cross-linking appeared as separate bands. Ferguson plots constructed for thyroid iodoproteins at a higher constant C of 20% gave straight lines intersecting at a common point at T = 0%. From the calculated slopes of the Ferguson plots, it has been established that the thyroid contains a series of multimers of 19S thyroglobulin as constituent iodoproteins. Structural parameters of highly cross-linked gels were estimated under the assumption that the gels would be predominantly composed of a random meshwork of gel beads.
D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D007467:Iodoproteins / Q000032:analysis*; D008970:Molecular Weight; D013552:Swine; D013954:Thyroglobulin / Q000032:analysis*; D013961:Thyroid Gland / Q000032:analysis*
D007467:Iodoproteins; D013954:Thyroglobulin