Subunit heterogeneity of buffalo thyroglobulin
Deshpande, V.
Indian Journal of Biochemistry and Biophysics 25(5): 455-457
1988
ISSN/ISBN: 0301-1208 PMID: 3243566 Document Number: 313196
Polyacrylamide disc-gel electrophoresis of DEAE-purified buffalo thyroglobulin either at alkaline or neutral pH indicated a major band with traces of impurities. Interestingly, electrophoresis at acidic pH (2.6) led to the separation of three distinct bands at the anode. However, the protein when examined either by SDS or urea gel-electrophoresis yielded two zones; one corresponding to a subunit of 220,000 Da and the other at origin to native thyroglobulin. Experiments only with mercaptoethanol either at neutral or acidic pH revealed no influence on subunit composition. Reduction of the protein with 2-mercaptoethanol in SDS followed by electrophoresis yielded a complex pattern with eight subunits of varying molecular weights (44,000-200,000 Da). The pattern in urea-mercaptoethanol was not as complex as in SDS-mercaptoethanol. Thus, it appears that the quaternary structure of buffalo thyroglobulin is comprised of eight non-identical subunits.