TY - JOUR
T1 - The facilitated diffusion of ions across cellulose membranes loaded with cytochrome c
AU - Margalit, Rimona
AU - Schejter, Abel
N1 - Funding Information:
This work was partly supported by a grant from the BATH-SHEVA de ROTHSCHILD fund for the advancement of Science and Technology awarded to one of the authors (RX.)
PY - 1976
Y1 - 1976
N2 - Ferricytochrome c bound to a cellulose membrane facilitates the diffusion of Cl- ions across the membrane, along the electrochemical gradient. Ferrocytochrome c facilitates in a similar fashion the diffusion of Co2+ ions. The observed dependence of the facilitated fluxes on the electrochemical gradient is compatible with cytochrome c acting as a carrier, utilising the specific, reversible, ion binding reaction previously observed in solution. The diffusion coefficients observed for ferri and ferrocytochrome in the membrane media are, respectively, 1.9×10-7 cm2 s-1 and 0.8×10-7 cm2 s-1. A cellulose membrane was the system used for these diffusion studies. Cytochrome c, in both oxidation states, binds to the cellulose membrane with a high affinity. The dissociation constant determined is 4×10-5 M. The association rate is 5×103 M-1 hour-1, and the dissociation rate is 5×10-2 per hour. The membrane-bound protein retains its redox and ion-binding properties. The spectrum of the membrane-bound protein is identical qualitatively and quantitatively to the one of the aqueous soluble protein in the range of 400-600 nm.
AB - Ferricytochrome c bound to a cellulose membrane facilitates the diffusion of Cl- ions across the membrane, along the electrochemical gradient. Ferrocytochrome c facilitates in a similar fashion the diffusion of Co2+ ions. The observed dependence of the facilitated fluxes on the electrochemical gradient is compatible with cytochrome c acting as a carrier, utilising the specific, reversible, ion binding reaction previously observed in solution. The diffusion coefficients observed for ferri and ferrocytochrome in the membrane media are, respectively, 1.9×10-7 cm2 s-1 and 0.8×10-7 cm2 s-1. A cellulose membrane was the system used for these diffusion studies. Cytochrome c, in both oxidation states, binds to the cellulose membrane with a high affinity. The dissociation constant determined is 4×10-5 M. The association rate is 5×103 M-1 hour-1, and the dissociation rate is 5×10-2 per hour. The membrane-bound protein retains its redox and ion-binding properties. The spectrum of the membrane-bound protein is identical qualitatively and quantitatively to the one of the aqueous soluble protein in the range of 400-600 nm.
UR - http://www.scopus.com/inward/record.url?scp=49549131911&partnerID=8YFLogxK
U2 - 10.1016/0302-4598(76)80001-3
DO - 10.1016/0302-4598(76)80001-3
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AN - SCOPUS:49549131911
SN - 0302-4598
VL - 3
SP - 189
EP - 202
JO - Bioelectrochemistry and Bioenergetics
JF - Bioelectrochemistry and Bioenergetics
IS - 2
ER -