TY - JOUR
T1 - Permeation of redox species through a cell membrane of a single, living algal protoplast studied by microamperometry
AU - Yasukawa, Tomoyuki
AU - Uchida, Isamu
AU - Matsue, Tomokazu
N1 - Funding Information:
This work was partly supported by Grants-in-Aid for Scientific Research A (08555198) and for Scientific Research on Priority Area of "Electrochemistry of Ordered Interfaces" (09237106) from the Ministry of Education, Science and Culture, Japan.
PY - 1998/2/2
Y1 - 1998/2/2
N2 - Permeation of several redox species through a cell membrane of a single algal protoplast (radius 100 μm) was investigated by amperometry with a Pt microdisk electrode (disk radius, 6.5 μm) located near the membrane. The redox current observed at the microelectrode decreased as the microelectrode approached the cell membrane since the membrane acted as a barrier for diffusion of redox species from bulk to the microelectrode. Permeability coefficient (P(n)) of the protoplast membrane was determined by the quantitative analysis of the variation of the redox current with micro electrode- membrane distance using digital simulation. The P(m) values for Fe(CN)64-, Fe(CN)63-, Co(phen)32+, ferrocenyl methanol(FMA) and p- hydroquinone(QH2) were ≤ 1.0 x 10-4, ≤ 1.0 x 10-4, 1.0 x 10-3, 5.0 x 10-3 and 2.0 x 10-2 cm/s, respectively. Using these Pm values, the concentration changes inside a model cell and chloroplast were theoretically calculated.
AB - Permeation of several redox species through a cell membrane of a single algal protoplast (radius 100 μm) was investigated by amperometry with a Pt microdisk electrode (disk radius, 6.5 μm) located near the membrane. The redox current observed at the microelectrode decreased as the microelectrode approached the cell membrane since the membrane acted as a barrier for diffusion of redox species from bulk to the microelectrode. Permeability coefficient (P(n)) of the protoplast membrane was determined by the quantitative analysis of the variation of the redox current with micro electrode- membrane distance using digital simulation. The P(m) values for Fe(CN)64-, Fe(CN)63-, Co(phen)32+, ferrocenyl methanol(FMA) and p- hydroquinone(QH2) were ≤ 1.0 x 10-4, ≤ 1.0 x 10-4, 1.0 x 10-3, 5.0 x 10-3 and 2.0 x 10-2 cm/s, respectively. Using these Pm values, the concentration changes inside a model cell and chloroplast were theoretically calculated.
KW - Algal protoplast
KW - Microamperometry
KW - Microelectrode
KW - Permeability coefficient
KW - Single cell
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U2 - 10.1016/S0005-2736(97)00220-4
DO - 10.1016/S0005-2736(97)00220-4
M3 - Article
C2 - 9528683
AN - SCOPUS:0032472882
SN - 0005-2736
VL - 1369
SP - 152
EP - 158
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
IS - 1
ER -