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Table 1 Summary of effects on PsOep23 channel activity by the added compounds

From: Oep23 forms an ion channel in the chloroplast outer envelope

    Change of
Compound Charge at pH 7 Conc. [mM] Channel conductance P open
+100 mV −100 mV  
Malic acid −2 20 - - -
Oxaloacetic acid −2 2.5 - - -
Adenine 0 3-5 - - -
Thymine +1 3-5 - - -
Ornithine +1 2-10 - - -
Caderverine +2 5-10 - - -
Spermidine +3 5 −25% −12% -
   10 −36% −21% -
Spermine +4 5 −28% - Yes
   10 −51% −22% Yes
  1. Only spermidine and spermine at 5-10 mM induced a substantial reduction of single channel conductance while spermine alone also reduced the open probability. The bulk conductivity and pH were changed by max. 3% or 0.2 units, respectively (exception: thymine and adenine at 5 mM +0.7 pH units).
  2. - : less than 10% charge.
  3. Popen: open probability.