Plasma membrane associated antigens of trophozoites of axenic Giardia lamblia.

Plasma membrane isolated from axenically grown Giardia lamblia (Portland 1 strain) by treatment with a membrane stabilizing agent followed by osmotic stress and manual sheer showed a significant enrichment of the membrane bound marker enzymes CA++ATPase/Mg++ATPase. Crossed immunoelectrophoresis (CIE) was used to identify membrane antigens. 11 major peaks were detected in CIE profiles of the whole trophozoites. 6 major peaks were detected in CIE profiles of the membrane preparation. 2 surface membrane peaks with relative mobilities of 0.10 (peak 2) and 0.70 (peak 6) were identified by absorption studies. Peak 2 had a molecular mass of 82 kDa whereas peak 6 had a molecular mass of 56 kDa. The monospecific antiserum raised against the surface antigens of strain Portland 1 with molecular masses of 82 kDa and 56 kDa revealed the existence of identical antigens on 2 other isolates (Isr & WB) of G. lamblia.