Incorporation of Labelled Sulfate into Porphyra tenera and the Distribution of Sulfur in the Chromopeptides Isolated from Phycoerythrin

Abstract

During investigations on the chemical structure of the chromoproteins in Porphyra tenera, it was demonstrated that, one of them, phycoerythrin, yielded several chromopeptides on proteolytic degradation. These chromopeptides possessed unidentified sulfur containing moieties besides carbohydrate and peptide fragments close to the chromophore group which could not be attributed to the sulfurcontaining amino acids in the peptides.' '-5) To investigate these unidentified sulfur moieties close to the chromophore group, the incorporation of labelled sulfate into phycoerythrin was studied. Although most algae, like other microorganisms and higher plants, can utilize sulfate as their sole source of sulfur, the mechanism of reduction of sulfate in marine algae seems not yet be clarified in detail.