ZP1 has recently been delivered to the mitochondria by a
Zn2+-depended ester cleavage reaction and tryphenylphosphonium
(TPP) targeting.68 Addition of a TPP group is a widely
used method of targeting a molecule to the mitochondria, but
this strategy is dependent on mitochondrial membrane
potential, and therefore the respiratory state of the cells can
affect probe localization.67b,c Conjugation of a TPP motif to the
6-position of the benzoic acid group of diacetylated ZP1 (DAZP1-
TPP) allowed for successful delivery of the probe to
mitochondria