2 research outputs found
Peptides Derived from the Transmembrane Domain of Bcl‑2 Proteins as Potential Mitochondrial Priming Tools
The
Bcl-2 family of proteins is crucial for apoptosis regulation.
Members of this family insert through a specific C-terminal anchoring
transmembrane domain (TMD) in the mitochondrial outer membrane where
they hierarchically interact to determine cell fate. While the mitochondrial
membrane has been proposed to actively participate in these protein–protein
interactions, the influence of the TMD in the membrane-mediated interaction
is poorly understood. Synthetic peptides (TMD-pepts) corresponding
to the putative TMD of antiapoptotic (Bcl-2, Bcl-xL, Bcl-w, and Mcl-1)
and pro-apoptotic (Bax, Bak) members were synthesized and characterized.
TMD-pepts bound more efficiently to mitochondria-like bilayers than
to plasma membrane-like bilayers, and higher binding correlated with
greater membrane perturbation. The Bcl-2 TMD peptides promoted mitochondrial
outer membrane permeabilization (MOMP) and cytochrome c release from
isolated mitochondria and different cell lines. TMD-pepts exhibited
nonapoptotic pro-death activity when apoptosis stimuli were absent.
In addition, the peptides enhanced the apoptotic pathway induced by
chemotherapeutic agents in cotreatment. Overall, the membrane perturbation
effects of the TMD-pepts observed in the present study open the way
for their use as new chemical tools to sensitize tumor cells to chemotherapeutic
agents, in accordance with the concept of mitochondria priming
Identification of New Snake Venom Metalloproteinase Inhibitors Using Compound Screening and Rational Peptide Design
The majority of snakebite envenomations in Central America
are
caused by the viperid species <i>Bothrops asper</i>, whose
venom contains a high proportion of zinc-dependent metalloproteinases
that play a relevant role in the pathogenesis of hemorrhage characteristic
of these envenomations. Broad metalloproteinase inhibitors, such as
the peptidomimetic hydroxamate Batimastat, have been shown to inhibit
snake venom metalloproteinases (SVMP). However, the difficulty in
having open public access to Batimastat and similar molecules highlights
the need to design new inhibitors of SVMPs that could be applied in
the treatment of snakebite envenomations. We have chosen the SVMP
BaP1 as a model to search for new inhibitors using different strategies,
that is, screening of the Prestwick Chemical Library and rational
peptide design. Results from these approaches provide clues on the
structural requirements for efficient BaP1 inhibition and pave the
way for the design of new inhibitors of SVMP