title: Purification of the membrane-form variant surface glycoprotein of Trypanosoma brucei.
abstract: The membrane-form variant surface glycoprotein (mfVSG) is anchored in the plasma membrane of African trypanosomes by a diacylglycerol residue. On cell rupture the anchor is rapidly cleaved by an endogenous phospholipase C. A purification procedure is described which results in native mfVSG devoid of lipase activity. A total membrane fraction is prepared in the presence of the SH-inhibitor p-chloromercuribenzenesulphonic acid (pCMBS). Membrane proteins are solubilized in the presence of pCMBS and the detergent Zwittergent 3-12, conditions which inhibit the activity of the phospholipase. mfVSG is then purified by successive chromatography on rabbit anti-VSG affinity and cation-exchange columns (25% yield). The isolated protein is electrophoretically pure and partitions into the detergent phase on Triton X-114 phase separation, proving that it retains the diacylglycerol anchor.
authors.affiliation: Max-Planck-Institut für Biologie, Tübingen, F.R.G.
authors.forename: D
authors.initials: D
authors.lastname: Schell
authors.forename: P
authors.initials: P
authors.lastname: Overath
mesh_terms: D002731:4-Chloromercuribenzenesulfonate; D000818:Animals; D002462:Cell Membrane / Q000737:chemistry; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D000644:Quaternary Ammonium Compounds; D014346:Trypanosoma brucei brucei / Q000032:analysis*; D010738:Type C Phospholipases / Q000302:isolation & purification; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000302:isolation & purification*
chemical_list: D000644:Quaternary Ammonium Compounds; D014643:Variant Surface Glycoproteins, Trypanosoma; C034730:zwittergent 3-12; D002731:4-Chloromercuribenzenesulfonate; D010738:Type C Phospholipases