d-Maurocalcine, a Pharmacologically Inert Efficient Cell-penetrating Peptide Analogue

Abstract

Maurocalcine has been the first demonstrated animal toxin acting as a cell-penetrating peptide. Although it possesses competitive advantages, its use as a cell-penetrating peptide (CPP) requires that analogues be developed that lack its characteristic pharmacological activity on ryanodine-sensitive calcium channels without affecting its cell-penetrating and vector efficiencies. Here, we present the synthesis, three-dimensional 1 H NMR structure, and activity of D-maurocalcine. We demonstrate that it possesses all of the desired features for an excellent CPP: preserved structure, lack of pharmacological action, conserved vector properties, and absence of cell toxicity. This is the first report of a folded/oxidized animal toxin in its D-diastereomer conformation for use as a CPP. The protease resistance of this new peptide analogue, combined with its efficient cell penetration at concentrations devoid of cell toxicity, suggests that D-maurocalcine should be an excellent vector for in vivo applications.

Small Efficient Cell-penetrating Peptides Derived from Scorpion Toxin Maurocalcine

“…The second strategy, which has yield success, is based on the chemical synthesis of D-MCa, an analogue entirely based on the use of D-amino acids. This peptide is a mirror image of the natural L-MCa but, like other D-CPPs, preserves its cell penetration properties while losing entirely its ability to interact with RyR1 (19). This method has several advantages.…”

“…Solid Phase Peptide Syntheses-Chemical syntheses of MCa analogues were performed as described previously (19). Briefly, analogues of MCa were chemically synthesized by the solid phase method (20) using an automated peptide synthesizer (CEM© Liberty).…”

“…It no longer is sensitive to proteases that may be an additional advantage for in vivo experiments where the half-life of the circulating peptide matters. It is also possible to improve this analog by introducing point mutations shown previously to improve cell penetration (19). In these two strategies, although being effective, one may argue that (i) the peptides are still among the longest CPP known to date, implying increased costs of production, and (ii) the yield of production of these peptides is hampered by the folding process.…”

Selective mono-radioiodination and characterization of a Cell-Penetrating Peptide: L-Tyr-Maurocalcine

“…Cell-penetrating peptides (CPPs) are peptides which enter into cells and allow the intracellular delivery of a number of bioactive molecules such as proteins, peptides, oligonucleotides, and nanoparticles [1][2][3]. Originally isolated from the venom of the scorpion Scorpio maurus palmatus [4], Lmaurocalcine (L-MCa) is an animal toxin acting as a highly efficient CPP [5][6][7][8]. It presents a low toxicity profile, penetrates at lower concentrations, and efficiently accumulates into the cytoplasm which is a highly desirable quality for many applications involving CPPs.…”

What Does Maurocalcine Tell Us About the Process of Excitation-Contraction Coupling?

“…These observations have prompted us to investigate the cell penetration properties of maurocalcine. A series of studies have demonstrated since 2005 that maurocalcine belongs to the cell penetrating peptide family with vector properties that can be derived for various diagnostic, imaging and therapeutic applications (Aroui et al, 2009;Boisseau et al, 2006;Esteve et al, 2005;Jayagopal et al, 2009;Mabrouk et al, 2007;Poillot et al, 2010). A more detailed investigation of the mode of action of maurocalcine in developing skeletal muscle cells and adult fibers reveals that the peptide acts preferentially on type 1 ryanodine receptors that are uncoupled from the L-type calcium channels (Szappanos et al, 2005).…”