Characterization of fructose-1, 6-bisphosphate aldolase in Dermacentor silvarum

Fructose-1, 6-bisphosphate aldolase (FBA) catalyses the conversion of fructose-1, 6-diphosphatein to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate. It is an important enzyme for both glycolysis and gluconeogenesis in parasites. In this study, we cloned the open reading frame of the FBA gene from Dermacentor silvarum, which was 1095 bp and encoded a protein of 364 amino acids. The deduced amino acid sequence of D. silvarum FBA had high similarity with FBA homologues from other ticks. Phylogenetic analysis of FBA showed that D. silvarum and Amblyomma variegatum belonged to the same clade. The recombinant FBA of D. silvarum (rDsFBA) was expressed in Escherichia coli and the molecular weight was about 62 kDa, which was abundantly expressed in the supernatant of E. coli following induction by 0.5 mM IPTG for 8 h at 25°C. The activity of rDsFBA was characterized using a coupled enzymatic assay. The rDsFBA had a Km of 21.22 μM and a Vmax of 1.57 U/mg. Western blot analysis demonstrated that rDsFBA could be recognized by rabbit anti-D. silvarum polyclonal antibodies, suggesting it probably owned immunogenicity. The data reported here contribute to future research into the role of FBA in D. silvarum, and provides a new candidate antigen for controlling tick.