Nature of 54Mn binding protein in rat brain, liver and serum

Studies were undertaken to investigate the 54Mn binding protein in rat serum, liver and brain. Equilibrium dialysis pattern in three biological media with 54Mn against distilled water showed a rectangular hyperbola after 24 hr dialysis. 54Mn in the bag was in the non-dialysable form, presumably bound to protein. Gel filtration studies with 54Mn bound protein showed that 54Mn had a specific carrier protein, which was identical for all the three biological media tested. The electrophorogram of concentrated 54Mn protein with Comassie blue stain for protein and PAS stain for glycoprotein showed a single band with an equal RF value clearly indicating the glycoprotein nature of 54Mn binding protein. Sulphydryl groups were absent and it had molecular weight of 6.3 X 10(4) dalton.