INFLUENCE OF BOVINE SERUM-ALBUMIN ON THE PROTON CONDUCTANCE OF POTATO MITOCHONDRIA MEMBRANES

Pulsed acid base titrations, according to the procedure of Mitchell and Moyle, have been carried out on potato mitochondria in the presence and absence of Bovine Serum Albumine (BSA). The rate of the pH decay is slower when BSA is present. The buffering capacities of the outer and inner phases, the t1/2 of the pH decay after an acid pulse and the proton conductance of the inner membrane have been measured. The results show that plant mitochondria are relatively impermeable to H+ and OH-, but leakier than animal mitochondria. This may be related to the lower respiratory control ratios generally found with plant mitochondria. © 1979 Springer-Verlag.