Further Characterization of the Alkali-Stable Material from the Scales of Pleurochrysis scherffelii: A Cellulosic Glycoprotein

Crude and alkali-purified fractions of scales isolated from the haptophycean alga Pleurochrysis scherffelii Pringsheim were analyzed. The predominantly cellulosic nature of the fibrillar, alkali-resistent polysaccharide component has been confirmed by gas chromatography of the hydrolysate, by X-ray diffraction and by viscosimetric studies using the nitrified product. Peptide material is covalently linked to this cellulosic structural polysaccharide and remains associated with it through the harsh purification treatments. The amino acid composition of this peptide moiety is given. The relationship of this cellulosic "glycoprotein" to other cell wall glycoproteins is discussed and possible functions during the formation and secretion of wall materials are hypothesized.