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The gate of mitochondrial porin channel is controlled by a number of negative and positive charges
Author(s) -
Mirzabekov Tajib A.,
Ermishkin Lev N.
Publication year - 1989
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(89)80662-3
Subject(s) - porin , carbodiimide , conductance , chemistry , voltage dependent anion channel , gating , lipid bilayer , biophysics , membrane potential , membrane , biochemistry , bacterial outer membrane , biology , physics , escherichia coli , gene , condensed matter physics
Negatively charged carboxyl groups of mitochondrial porin have been converted into positively charged ones by means of reaction with water‐soluble carbodiimide in the presence of ethylenediamine. Properties of channels formed in a planar lipid bilayer by native and modified porins are compared. Amidation has only little influence on the porin channel‐forming activity as well as on the open‐state conductance of the channel. However, the modification results in a significant enhancement of the voltage dependence of the channel gating and in an increase of the anionic selectivity. It is suggested that the voltage sensor of the porin channel gate is composed of a number of negative (> 14) and positive (> 22) charges.