Premium
Inhibition of adenine nucleotide transport through the mitochondrial porin by a synthetic polyanion
Author(s) -
Benz Roland,
Wojtczak Lech,
Bosch Waltraud,
Brdiczka Dieter
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)80706-3
Subject(s) - porin , nucleotide , chemistry , biochemistry , adenine nucleotide , biophysics , biology , gene , escherichia coli , bacterial outer membrane
The effect of a synthetic polyanion of M r 10 000 (a copolymer of methacrylate, maleate and styrene in a 1:2:3 proportion) was studied on isolated rat liver mitochondria and on mitochondrial porin reconstituted into lipid bilayer membranes. Increasing concentrations of the polyanion inhibited the adenyl kinase located between both mitochrondrial membranes in a dose‐dependent fashion. Upon addition of the detergent digitonin in increasing concentrations the adenyl kinase activity was fully reversible. In reconstitution experiments with mitochondrial porin the polyanion increased the voltage dependence of the pore in such a way that the pore is switched into the closed state at much smaller voltages than in the absence of the polyanion. The asymmetric addition of the polyanion resulted in an asymmetric shift of the voltage‐dependence of the pore. If the voltage is negative at the cis ‐side (the side of the addition of the polyanion) the pore closed rapidly whereas it was always open for potentials of opposite polarity. The results are discussed on the basis of a modification of the gate properties of the mitochondrial porin by the polyanion and by the assumption that the closed state of the pore is not permeable for nucleotides.