1 research outputs found
Apoptosis Inducing, Conformationally Constrained, Dimeric Peptide Analogs of KLA with Submicromolar Cell Penetrating Abilities
The apoptosis inducing KLA peptide,
(KLAKLAK)<sub>2</sub>, possesses
an ability to disrupt mitochondrial membranes. However, this peptide
has a poor eukaryotic cell penetrating potential and, as a result,
it requires the assistance of other cell penetrating peptides for
effective translocation in micromolar concentrations. In an effort
to improve the cell penetrating potential of KLA, we have created
a library in which pairs of residues on its hydrophobic face are replaced
by Cys. The double Cys mutants were then transformed to bundle dimers
by oxidatively generating two intermolecular disulfide bonds. We envisioned
that once transported into cells, the disulfide bonds would undergo
reductive cleavage to generate the monomeric peptides. The results
of these studies showed that one of the mutant peptides, dimer B,
has a high cell penetrating ability that corresponds to 100% of fluorescence
positive cells at 250 nM. Even though dimer B induces disruption of
the mitochondrial potential and cytochrome c release followed by caspase
activation at submicromolar concentrations, it displays an LD<sub>50</sub> of 1.6 μM under serum conditions using HeLa cells.
Taken together, the results demonstrate that the strategy involving
formation of bundle dimeric peptides is viable for the design of apoptosis
inducing KLA peptide that translocate into cells at submicromolar
concentrations