SUBCELLULAR IMMUNO-LOCALIZATION, AMINO-ACID-COMPOSITION AND PARTIAL AMINO-ACID-SEQUENCES OF ALPHA-1,4-GLUCAN PHOSPHORYLASE OF GRACILARIA SPP (RHODOPHYTA)

Antibodies have been raised against an alpha-1,4-glucan phosphorylase (EC 2.4.1.1) purified from the red alga Gracilaria chilensis. Localiza tion of alpha-1,4-glucan phosphorylase in thin sections of G. chilensi s and G. tenuistipitata was performed using immuno-gold labelling and transmission electron microscopy. The enzyme was localized in the cyto sol and around the cytosolic starch granules of the algal cells. The l abelling was not associated with the chloroplast or the cell wall. Ami no acid composition of the red algal phosphorylase was quite similar t o that of potato tuber and rabbit muscle phosphorylases. Partial amino acid sequences showed 48, 54 and 65% homology with the rabbit, potato and Escherichia coli enzymes, respectively.