Figure 4. CyP-D modulates PTP opening triggered by detachment of HK II from mitochondria.

CRC experiments were performed on mitochondria isolated from muscle of either wild-type (A) or CyP-D knock-out mice (B), or from liver of wild-type animals (C). Assays were started by the addition of mitochondria followed by pulses of the indicated concentrations of Ca²⁺; where indicated, the reported concentrations of the HK peptide lacking the TAT sequence and/or Debio 025 (DB, 8 µM) were added to mitochondria 5 minutes before recordings. Calcium Green-5N fluorescence is reported as arbitrary units on the y axis. Total Ca²⁺ loading required to open the pore is reported for each condition, and all reported results are representative of at least four experiments. Treatment of mitochondria with the control peptide (40 µM) or with a HK peptide harbouring the TAT sequence did not change the number of Ca²⁺ pulses (not shown). All reported measures in the Figure are representative of at least four experiments.