Enzymatic Dephosphorylation of Ovalbumin and Plakalbumin

Abstract

THE work presented here was designed primarily to test the suggestion of Linderstrøm-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.