A simple purification of procyclic acidic repetitive protein and demonstration of a sialylated glycosyl-phosphatidylinositol membrane anchor.
The procyclic acidic repetitive protein is the major cell-surface glycoprotein of the insect-dwelling procyclic forms of the Trypanosoma brucei species of African trypanosomes. The glycoprotein contains an acidic Glu-Pro repeat domain, a glycosyl-phosphatidylinositol membrane anchor and a putative asparagine glycosylation site. In this paper we describe a rapid purification scheme for this glycoprotein, using solvent extraction and hydrophobic interaction chromatography, and a partial characterization of the glycosylphosphatidylinositol membrane anchor. The carbohydrate composition of the anchor is extremely unusual; it contains on average nine GlcNAc, nine Gal, and five sialic acid residues. This is the first description of such a heavily substituted and negatively charged anchor. A comparison between the trypanosome procyclic surface and the Leishmania promastigote surface is also presented.
Ferguson
M A
MA
Department of Biochemistry, University of Dundee, Scotland, U.K.
Murray
P
P
Rutherford
H
H
McConville
M J
MJ
D000117:Acetylglucosamine / Q000032:analysis; D000595:Amino Acid Sequence; D000818:Animals; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004150:Dipeptidases / Q000378:metabolism; D005690:Galactose / Q000032:analysis; D006028:Glycosphingolipids / Q000737:chemistry; D006031:Glycosylation; D017261:Glycosylphosphatidylinositols / Q000032:analysis* / Q000737:chemistry; D007891:Leishmania / Q000737:chemistry; D008562:Membrane Glycoproteins; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D015800:Protozoan Proteins; D012091:Repetitive Sequences, Nucleic Acid; D012794:Sialic Acids / Q000032:analysis / Q000378:metabolism; D014346:Trypanosoma brucei brucei / Q000737:chemistry*; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000032:analysis* / Q000737:chemistry
D002241:Carbohydrates; D006028:Glycosphingolipids; D017261:Glycosylphosphatidylinositols; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D015800:Protozoan Proteins; D012794:Sialic Acids; D014643:Variant Surface Glycoproteins, Trypanosoma; C008290:lipophosphonoglycan; C053277:procyclic acidic repetitive protein, Trypanosoma; D004150:Dipeptidases; C022449:proline dipeptidase; D019158:N-Acetylneuraminic Acid; D000117:Acetylglucosamine; D005690:Galactose