Fávaro, Regiane Degan [UNESP]Borecký, JiriColombi, Débora [UNESP]Maia, Ivan de Godoy [UNESP]2014-05-272014-05-272006-05-26Biochemical and Biophysical Research Communications, v. 344, n. 1, p. 194-199, 2006.0006-291X1090-2104http://hdl.handle.net/11449/68890Uncoupling proteins (UCPs) are specialized mitochondrial transporter proteins that uncouple respiration from ATP synthesis. In this study, cDNA encoding maize uncoupling protein (ZmPUMP) was expressed in Escherichia coli and recombinant ZmPUMP reconstituted in liposomes. ZmPUMP activity was associated with a linoleic acid (LA)-mediated H+ efflux with Km of 56.36 ± 0.27 μM and Vmax of 66.9 μmol H+ min-1 (mg prot)-1. LA-mediated H+ fluxes were sensitive to ATP inhibition with Ki of 2.61 ± 0.36 mM (at pH 7.2), a value similar to those for dicot UCPs. ZmPUMP was also used to investigate the importance of a histidine pair present in the second matrix loop of mammalian UCP1 and absent in plant UCPs. ZmPUMP with introduced His pair (Lys155His and Ala157His) displayed a 1.55-fold increase in LA-affinity while its activity remained unchanged. Our data indicate conserved properties of plant UCPs and suggest an enhancing but not essential role of the histidine pair in proton transport mechanism. © 2006 Elsevier Inc. All rights reserved.194-199engFunctional reconstitutionMaizeMitochondrial carriersPlant mitochondriaProton transportUCPUncoupling mitochondrial proteinadenosine triphosphatealaninecomplementary DNAfatty acidhistidinelinoleic acidliposomelysinemitochondrial proteincontrolled studyEscherichia colimammalnonhumanpHplantpriority journalprotein expressionprotein functionproton transportAdenosine TriphosphateAmino Acid SubstitutionCarrier ProteinsDNA, ComplementaryFatty AcidsHistidineIon ChannelsKineticsLinoleic AcidLiposomesMembrane ProteinsMitochondrial ProteinsMutationPlant ProteinsProtonsRecombinant ProteinsZea maysMammaliaArtigo10.1016/j.bbrc.2006.03.132WOS:000237408000030Acesso restrito2-s2.0-336460563978649222099176162