Articolo in rivista, 1996, ENG, 10.1111/j.1432-1033.1996.0171t.x

The mechanism of proline/glutamate antiport in rat kidney mitochondria. Energy dependence and glutamate-carrier involvement

Atlante, Anna; Passarella, S.; Pierro, Pasqualina; Di Martino, Catello; Quagliariello, Ernesto

Ctro. Stud. Mitocondri M.; Universita degli Studi del Molise; Universita degli Studi di Bari; Consiglio Nazionale delle Ricerche

Energy dependence of the proline/glutamate antiporter in rat kidney mitochondria has been investigated by means of both spectroscopic measurements and isotopic techniques, using either normal or [C-14]glutamate-loaded mitochondria. The sensitivity of the proline/glutamate antiport to the ionophores valinomycin and nigericin, under conditions in which Delta Psi and Delta pH are selectively affected, shows that the exchange is energy dependent. Measurements of both membrane potential and proton movement across the mitochondrial membrane suggest that proline/glutamate antiport is driven by the electrochemical proton gradient via the Delta Psi dependent proline/glutamate translocator and Delta pH-dependent glutamate/ OH- carrier. Such a carrier provides for re-uptake of glutamate that has already passed out of the mitochondria in exchange with incoming proline, made possible by the existence of a separate pool of glutamate in the intermembrane space, directly shown by means of HPLC measurements.

European journal of biochemistry (Print) 241 (1), pp. 171–177

Keywords

Compartmentation, Glutamate, Mitochondria, Proline, Transport

CNR authors

Atlante Anna

CNR institutes

IBIOM – Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari