Abstract:
The mechanism by which filarial parasites derive fatty acids bound to the host’s carrier protein is poorly
understood. The capacity of a secretory protein of Onchocerca 6ol6ulus (OvS1:Ov20) to compete with serum albumin
for arachidonic and other fatty acids was investigated in this study. Binding affinities of the two proteins for the
long-chain fatty acids were determined using displacement assays. The fluorescent probes used included 11-((5-
dimethylaminonaphthalene-1-sulfonyl)amino) undecanoic acid (DAUDA) and cis-parinaric acid. OvS1 protein bound
arachidonic acid with an affinity five-fold greater than the affinity exhibited by serum albumin. Oleic acid was bound
by the parasite protein with an affinity two-fold greater than the affinity shown by serum albumin. Furthermore, the
affinities exhibited by OvS1 protein in binding arachidonic and linoleic acid were about two times higher than the
affinity for oleic acid. The results suggest that the OvS1 protein has the capacity to compete with the main host’s fatty
acid carrier protein for the long-chain fatty acids, in particular arachidonic acid, the precursor for eicosanoids
