Enzymatic dephosphorylation of ovalbumin and plakalbumin.

Abstract

THE work presented here was designed primarily to test the suggestion of Linderstrom-Lang and Ottesen1 that the failure of the phosphorus content of ovalbumin to correspond to an integral number of atoms of this element per mole could be correlated with the electrophoretic complexity2 of this protein. Thus a typical preparation of ovalbumin consisted of 82 per cent of the A1 component, 18 per cent of A2 and contained l.81. atoms of phosphorus per mole of 44,000. If it is assumed that A1 contains two -atoms of phosphorus per mole and A2 one atom per mole, the computed phosphorus content of this preparation is 2 × 0.82 + 1 × 0.18 = l.82, in good agreement with the observed value of l.81. Additional evidence for this assumption and further insight into the nature of the phosphate groups in ovalbumin have also been obtained from the enzymatic dephosphorylation described below.