Structure of the Variant Glycoproteins and Surface Coat of Trypanosoma Brucei

摘要: The pathogenic African trypanosomes have a unique mechanism for antigenic variation. Each cell is covered by surface coat consisting of about seven million essentially identical glycoprotein molecules drawn from large repertoire variants, each encoded an individual gene. Amino acid sequence variation extends throughout the molecule but reduces amino terminus to carboxy terminus, where certain features, especially grouping cysteine residues, are quite conserved. range diversity within thousand or so variant genes that exist in large. New variants may arise instantaneously segmental gene conversion. Variant glycoproteins synthesized with terminal signal sequences and hydrophobic tails. tails extraordinarily After synthesis, they replaced complex glycolipid structure which myristic (dodecanoic) serves anchor polypeptide membrane. Enzymic cleavage releases coat.