Abstract
Three different hemagglutinins, of which the molecular weight was about 300-400K, 100K and 45K respectively, were found in the extract from a red alga Gracilaria verracosa by means of molecular sieve gel chromatography.
300-400K and 100K hemagglutinins showed the isoelectric point of pI 4.2, and agglutinated horse erythrocytes but not those of goose. On the other hand, 45K hemagglutinin had the iso-electric point of pI 4.7 and agglutinated both horse and goose erythrocytes.
Hemagglutinating activities in the algal extract were found during the period of November to next June, and not in July and August. Hemagglutinins with higher molecular weight (300-400K and 100K) and lower isoelectric point (pI 4.2) were detectable in December, February and March but little or nothing in November, while 45K hemagglutinin was detected in all test periods (No-vember to next March).
