A recent paper from researchers at Kyoto University, Japan, published in the journal Nature Chemistry, has demonstrated that a peptide (M-lycotoxin), found in spider venom, can be used to deliver biomacromolecules directly into cells.
Spider
According to the study authors, a major problem when trying to deliver biomacromolecules is the difficulty of accessing the interior of cells. “Efficient labelling of intracellular proteins with antibodies allows us to dramatically improve our understanding of their behaviour and significance,” said one of the study authors Misao Akishiba. “Cells can take in antibodies through membrane-bound vessels called ‘endosomes’. But normally once inside these endosomes, the antibodies have trouble escaping.”
In the study, redesigning the peptide, M-lycotoxin, was found to enable the release of biomacromolecules (such as antibodies) efficiently. “We took M-lycotoxin and replaced a leucine residue with glutamic acid, which we then called ‘L17E’,” Akishiba explained. “When L17E enters the cell, it specifically interacts with endosome membranes, breaking them down and releasing the antibodies.”
Additionally, the team demonstrated that using this strategy they could also deliver functional antibodies. Team leader Shiroh Futaki added: “This will benefit not only basic science, but also the development of new treatments and drugs. Moreover, this tool could potentially be used to transport other bioactive macromolecules — and even nanoparticles — into cells.”