The nematode polyprotein allergen homologues
NPA are polyproteins cleaved at tetrabasic, subtilisin-like cleavage sites to yield ~15 kDa subunits. Each subunit can form a four helix bundle with a hydrophobic core which can bind fatty acids and other lipids (such as retinol). The parasitic nematode NPA can be immunogenic and allergenic in infection.
Ce
Caenorhabditis elegans
11 repeats from cosmids F27B10 and
VC5
Dv
Dictyocaulus viviparus
12 repeats from GenBank U02568
As
Ascaris suum
9 repeats (5' truncated sequence) from
GenBank AF051702 and L03211
2 Phylogenetic analyses of the aligned NPA homologues
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