Pascual Alonso I, Rivera Méndez L, Almeida García F, Valdés-Tresanco ME, Alonso Bosch R, Perera WH, Arrebola Sánchez Y, Bergado G, Sánchez Ramírez B, Charli JL. Bufadienolides preferentially inhibit aminopeptidase N among mammalian metallo-aminopeptidases; relationship with effects on human melanoma MeWo cells.
Int J Biol Macromol 2023;
229:825-837. [PMID:
36592847 DOI:
10.1016/j.ijbiomac.2022.12.280]
[Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/07/2022] [Accepted: 12/25/2022] [Indexed: 12/31/2022]
Abstract
Bufadienolides are steroids that inhibit Na+/K+-ATPase; recent evidence shows that bufalin inhibits the activity of porcine aminopeptidase N (pAPN). We evaluated the selectivity of some bufadienolides on metallo-aminopeptidases. Among the enzymes of the M1 and M17 families, pAPN and porcine aminopeptidase A (pAPA) were the only targets of some bufadienolides. ѱ-bufarenogin, telocinobufagin, marinobufagin, bufalin, cinobufagin, and bufogenin inhibited the activity of pAPN in a dose-dependent manner in the range of 10-7-10-6 M. The inhibition mechanism was classical reversible noncompetitive for telocinobufagin, bufalin and cinobufagin. Bufogenin had the lowest Ki value and a non-competitive behavior. pAPA activity was inhibited by ѱ-bufarenogin, cinobufagin, and bufogenin, with a classical competitive type of inhibition. The models of enzyme-inhibitor complexes agreed with the non-competitive type of inhibition of pAPN by telocinobufagin, bufalin, cinobufagin, and bufogenin. Since APN is a target in cancer therapy, we tested the effect of bufadienolides on the MeWo APN+ human melanoma cell line; they induced cell death, but we obtained scant evidence that inhibition of APN contributed to their effect. Thus, APN is a selective target of some bufadienolides, and we suggest that inhibition of APN activity by bufadienolides is not a major contributor to their antiproliferative properties in MeWo cells.
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