PURIFICATION AND PROPERTIES OF A HIGH-MOLECULAR-WEIGHT HEMAGGLUTININ FROM THE RED ALGA, GRACILARIA-VERRUCOSA

A high molecular weight hemagglutinin was purified from a phosphate bu ffer extract of the red alga, Gracilaria verrucosa, by ammonium sulfat e precipitation, followed by ion exchange and gel filtration chromatog raphies. Its molecular weight was estimated by gel filtration to be ap proximately M-r 480 000. It contained large amounts of hexose and sulf ate along with a small amount of protein. Because the acidic polysacch aride demonstrated by sodium dodecyl sulfate polyacrylamide gel electr ophoresis (SDS-PAGE) had hemagglutinating activity, the agglutinin was assumed to be sulfated polysaccharide with low protein content. Its e rythrocyte specificity is different from those of other G. verrucosa h emagglutinins as it agglutinated rabbit and guinea pig erythrocytes, b ut was inactive against horse: erythrocytes. Similar to many other mar ine algal hemagglutinins, it agglutinated a sheep erythrocyte suspensi on treated with pronase (SETP), but had no affinity for monosaccharide s, and had no divalent cation requirement for hemagglutination. Howeve r, it was different from other algal hemagglutinins with regards to he at-durability and periodate-sensitivity. These results suggest that th e hemagglutinin is a new component found in the buffer extract of G. v errucosa.