Effect of zinc and calcium ions on the rat kidney membrane-bound form of dipeptidyl peptidase IV
Por:
Gómez H., Chappé M., Valiente P.A., Pons T., Chavez, MD, Charli, JL, Pascual I.
Publicada:
1 sep 2013
Resumen:
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 V-max of
0.86 +/- 0.01 mu mol min(-1)mL(-1) and K-M of 76 +/- 6 mu M. The enzyme
was inhibited by the DPP-IV family inhibitor L-threo-Ile-thiazolidide
(K-i=64.0 +/- 0.53 nM), competitively inhibited by bacitracin (K-i=0.16
+/- 0.01 mM) and bestatin (K-i=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 (K-i 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
beta-propeller domain of the rat and human enzymes, while Zn2+ ions to
the alpha-beta 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.
Filiaciones:
Gómez H.:
Centro de Estudios de Proteínas (CEP), Facultad de Biología, Universidad de la Habana, Calle 25 No. 455, Vedado, La Habana 10400, Cuba
Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
Chappé M.:
Centro de Estudios de Proteínas (CEP), Facultad de Biología, Universidad de la Habana, Calle 25 No. 455, Vedado, La Habana 10400, Cuba
Valiente P.A.:
Centro de Estudios de Proteínas (CEP), Facultad de Biología, Universidad de la Habana, Calle 25 No. 455, Vedado, La Habana 10400, Cuba
Pons T.:
Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), C/Melchor Fernández Almagro 3, Madrid E-28029, Spain
Charli, JL:
UNAM, Inst Biotecnol, Dept Genet Desarrollo & Fisiol Mol, Cuernavaca 62210, Morelos, Mexico
Pascual I.:
Centro de Estudios de Proteínas (CEP), Facultad de Biología, Universidad de la Habana, Calle 25 No. 455, Vedado, La Habana 10400, Cuba
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