| Autor: |
Atlante, Anna, Passarella, Salvatore, Pierro, Pasqualina, Martino, Catello Di, Quagliariello, Ernesto |
| Předmět: |
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| Zdroj: |
European Journal of Biochemistry; 10/1/96, Vol. 241 Issue 1, p171-177, 7p |
| Abstrakt: |
Proline/glutamate antiport in rat kidney mitochondria has been studied in terms of two different features: energy dependence and glutamate-carrier contribution to accomplish proline movement across the mitochondrial membrane. 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 [14C]glutamate-loaded mitochondria. The sensitivity of the proline/glutamate antiport to the ionophores valinomycin and nigericin, under conditions in which ΔΨ and ΔpH 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 ΔΨ dependent proline/glutamate translocator and ΔpH-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. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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