Effect of zinc and calcium ions on the rat kidney membrane-bound form of dipeptidyl peptidase IV

Journal of biosciences

Marí­a de Los Angeles Chávez³  Pedroa Valiente³  Mae Chappé³  Tirso Pons¹  Isel Pascual1³  Jean-Louis Charli²  Hansel Gómez³ 

[1] Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), C/Melchor Fernández Almagro 3, Madrid E-28029, Spain$$;Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, México$$;Centro de Estudios de Proteínas (CEP), Facultad de Biología, Universidad de la Habana, Calle 25 No. 455, Vedado, La Habana( 10400, Cuba$$

关键词: Binding site prediction;    cancer;    diabetes;    dipeptidyl peptidase IV;    divalent cations;    inhibition;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

Dipeptidyl peptidase IV (DPP-IV) is an ectopeptidase with many roles, and a target of therapies for different pathologies. Zinc and calcium produce mixed inhibition of porcine DPP-IV activity. To investigate whether these results may be generalized to mammalian DPP-IV orthologues, we purified the intact membrane-bound form from rat kidney. Rat DPP-IV hydrolysed Gly-Pro-𝑝-nitroanilide with an average Vmax of 0.86±0.01 𝜇mol min–1mL–1 and KM of 76±6 𝜇M. The enzyme was inhibited by the DPP-IV family inhibitor L-threo-Ile-thiazolidide (Ki=64.0±0.53 nM), competitively inhibited by bacitracin (Ki=0.16±0.01 mM) and bestatin (Ki=0.23±0.02 mM), and irreversibly inhibited by TLCK (IC50 value of 1.20±0.11 mM). The enzyme was also inhibited by divalent ions like Zn2+ and Ca2+, for which a mixed inhibition mechanism was observed (Ki values of the competitive component: 0.15±0.01 mM and 50.0±1.05 mM, respectively). According to bioinformatic tools, Ca2+ ions preferentially bound to the 𝛽-propeller domain of the rat and human enzymes, while Zn2+ ions to the 𝛼-𝛽 hydrolase domain; the binding sites were essentially the same that were previously reported for the porcine DPP-IV. These data suggest that the cationic susceptibility of mammalian DPP-IV orthologues involves conserved mechanisms.

【 授权许可】

Unknown