By hydrolysis of the attached glycolipid, releases soluble variant surface glycoprotein containing phosphoinositol from the cell wall of T.brucei after cell lysis. It also cleaves similar membrane anchors on some mammalian proteins. VSG lipase may play a role in processes such as parasite differentiation or antigenic variation (By similarity). an alpha-D-GlcN-(1->6)-(1,2-diacyl-sn-glycero-3-phospho)-1D-myo-inositol = 6-(alpha-D-glucosaminyl)-1D-myo-inositol 1,2-cyclic phosphate + a 1,2-diacyl-sn-glycerol Monomer.