Table 2. PFO and its derivatives used herein.

Toxin or its derivative	Description
PFO	Recombinant native PFO that contains a alanine substitution for the native cysteine (Cys-459) in the undecapeptide [27]
PFOR468A	PFO substituted at Arg-468 with alanine
PFOβ4β5	PFO with an engineered disulfide between β-strands 4 and 5 at cysteine substituted Thr-319 in β4 and Val-334 in β5
PFOR468A•β4β5)	The analogous mutation to PFOβ4β5
PFOV322C	PFO with an engineered cysteine for Val-322. Val-322 is located in β4 and is buried under the α1β5 loop. It undergoes a nonpolar to polar transition as the α1β5 loop rotates away from β4 [25]
PFOR468A•V322C	The analogous mutation toPFOV322C
PFON197C	Cysteine-substituted Asn-197. Asn-197 undergoes a nonpolar to polar transition upon disruption of the D2–D3 interface [27]
PFOR468A•N197C	The analogous mutation toPFON197
PFOA215C	Cysteine-substituted Ala-215 in TMH1. Ala-215 faces the membrane in the β-barrel pore [27]
PFOR468A•A215C	The analogous mutation to PFOA215C
ILY	Recombinant native ILY
ILYDM	Cholesterol binding site knockout by glycine substitution for the Thr-Leu pair of the CRM in ILY
ILYH242C	The analogous mutation in ILY to PFOA215C
ILYV349C	The analogous mutation in ILY to PFOV322C

A summary of the CDCs and their derivatives used in the present study is shown.