Portal de Periódicos da CAPES

Filarial surface antigens: the major 29 kilodalton glycoprotein and a novel 17–200 kilodalton complex from adult Brugia malayi parasites

1989; Elsevier BV; Volume: 32; Issue: 2-3 Linguagem: Inglês

10.1016/0166-6851(89)90072-8

1872-9428

Rick M. Maizels, William F. Gregory, G E Kwan-Lim, Murray E. Selkirk,

Trypanosoma species research and implications

Adult Brugia malayi nematode parasites possess a range of cuticular and epicuticular molecules which may be defined by various surface-labelling techniques. We present here evidence that at least two distinct antigens are associated with the surface, a glycoprotein of 29 kDa, and a complex of twelve components forming a regular series or ‘ladder’ between 17 and 200 kDa (17200kDa) which have not previously been described. Each of these products is antigenic in infected hosts, although responses in infected humans to the 17200kDa are relatively weak. Digestion of the 29 kDa antigen with proteases and endoglycosidases indicates that it is closely conserved between B. malayi and B. pahangi, and that it carries at least two N-linked oligosaccharide chains each of 1.5–2 kDa. By contrast, a smaller surface-labelled antigen of 15 kDa shows no glycosylation by either lectin adherence or endoglycosidase digestion assays. Trypsin treatment of intact, labelled parasites results in cleavage of 29 kDa molecules to 27 kDa, indicating that only one susceptible site in the 29 kDa molecule is exposed on the epicuticular surface. Exposure of isolated 17200kDa ‘ladder’ to trypsin abolishes all bands except the 17 kDa base unit. Both the 29 kDa and 17200kDa antigens can be recovered as water-soluble molecules by homogenisation of the parasite in the absence of detergent, or by disruption of the cuticle with reducing agents such as 2-mercaptoethanol. In the presence of such agents, both the 17200kDa series and the 29 kDa glycoprotein are shed rapidly from intact parasites. Finally, two-dimensional electrophoretic analysis shows that while the 29 kDa glycoprotein is strongly basic and the 15 kDa acidic, the 17200kDa antigens form a related series of neutral pI.