The interaction between lipoprotein(a) and recombinant dihydrolipoamide dehydrogenase derived from Pseudomonas aeruginosa

Abstract:

[Objective] To investigate the interaction between plasminogen (Plg), lipoprotein(a) [Lp(a)] and dihydrolipoamide dehydrogenase (Lpd) on the surface of P. aeruginosa. [Methods] Recombinant Lpd and its mutants (rLpdK476A, rLpdK477A, rLpdΔKKR) were used to explore the interaction with enzyme-linked immunosorbent assay (ELISA) and affinity chromatography-binding assay followed by Western blot analysis. [Results] The recombinant rLpd and its mutants were expressed and purified from Escherichia coli. The results indicated that rLpd could specifically bind to Lp(a) but not to LDL. The binding capacity of rLpdΔKKR to Lp(a) is significantly lower than that of rLpd. The binding of rLpd to Lp(a) could be significantly inhibited by 1 mmol/L of EACA. 1 000 μg/L of Lp(a) could inhibit the interaction between rLpd and Plg. [Conclusion] Lpd could bind to Lp(a) and the 476th and 477th lysine residues of Lpd were main binding sites. Lp(a) could significantly inhibit the binding of Plg to Lpd.

Key words:Pseudomonas aeruginosa, Dihydrolipoamide dehydrogenase, Lipoprotein(a), Plasminogen