Variant surface glycoproteins of Trypanosoma congolense bloodstream and metacyclic forms are anchored by a glycolipid tail.

The variant surface glycoproteins (VSGs) of both metacyclic and bloodstream forms of Trypanosoma congolense are shown to be anchored to the plasma membrane through a glycolipid similar to that found in Trypanosoma brucei. Release of soluble VSG from both metacyclic and bloodstream forms is associated with the exposure of an antigenic determinant homologous to the cross-reacting determinant of T. brucei VSGs. Release of soluble VSG of T. congolense can be achieved by lysates of both bloodstream and metacyclic forms of T. congolense, by lysates of T. brucei bloodstream forms, but not by lysates of procyclic forms.