Activity and preliminary characterisation of a hemagglutinin from the hemichordate Saccoglossus ruber.

Examination of whole body homogenates of the hemichordate, Saccoglossus ruber, has revealed the presence of a hemagglutinin with specificity for carbohydrates containing a D-galactose configuration. An analysis of the chemical and physical properties of the agglutinin showed it to be a non-dialysable, heat-labile protein, susceptible to the action of pronase E, but resistant to trypsin. Oxidation by periodate had no effect on agglutination and activity was not dependent upon the divalent cations, Ca2+ or Mg2+. The agglutinin was associated with the proboscis, collar and trunk regions, and was also detected in mucus covering the body surface. A possible role for the agglutinin in the defence system of the animal is discussed.