A 31P nuclear magnetic resonance study of the pH gradient and the inorganic phosphate distribution across the membrane in intact rat liver mitochondria
1981; Elsevier BV; Volume: 210; Issue: 2 Linguagem: Inglês
10.1016/0003-9861(81)90241-1
ISSN1096-0384
AutoresSeiji Ogawa, Carmelita C. Boens, Tso-Ming Lee,
Tópico(s)Metabolism and Genetic Disorders
ResumoThe pH dependence of the chemical shift of the inorganic phosphate (Pi) inside mitochondria observable by 31P nmr has been examined and used for the measurement of the internal pH. The pH gradient and the Pi concentration gradient were in the simple relation expected for the neutral exchange process of H2PO4− and OH−. This Pi distribution across the mitochondrial membrane was not influenced by the cross-membrane electrical potential. Both the Pi, distribution and the pH titration curve of the internal Pi indicate that the activity of the internal Pi can be well represented by the concentration of Pi measured by 31P nmr peak intensity. The present results give a sound base for applying 31P nmr to study bioenergetics and cell metabolism.
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