Laurent lebt in verschiedenen Welten. Seine Freunde sagen er habe Ähnlichkeiten mit einer blauen Ameise. Aber blaue Ameisen gibt es nicht - oder doch? Laurent kennt sich in der Welt der chemischen Bindungen aus wie kein Zweiter. Es macht klick und ein Peptid wächst, es macht krack und ein Nukleotid ist aus einer DNA-Kette herausgetrennt. Wo andere mit dem Säbel schlagen, da fechtet Laurent mit dem Florett. Good to know its made by Laurent Fourmi.
The peptides in question are called cell-penetrating peptides (CPP) and were developed by for example Jonathan McMurray and his research team at Kennesaw State University. McMurray took a viral protein fragment (from HIV) or another special tailored synthetic peptide and attached it to Calmodulin, a human protein. What they made was a peptide that carries and delivers other drugs into cells. Yes, into. Not like the other carriers that never drop their deliveries. This peptide couples with the cells does its delivery and then leaves again. Which means none of the drugs go to waste, and you milk every mg of peptide you can from your dose.
a) The higher extracellular pH deprotonates fatty acids attracting arginine rich peptides.
b) The positively charged guanidinium groups bind strongly to the deprotonated carboxyl groups of fatty acids.
c) The positive charge of the peptides is now screened by the fatty acids. This allows the peptides to get efficiently inserted in the core of the plasma membrane. This insertion destabilizes the plasma membrane nucleating a transient toroidal pore.
d) The peptide diffuses on the surface of this pore towards the interior of the cell while the lower pH in the cytosol protonates the fatty acids releasing the peptide.
e) The peptide gets released and the transient pore becomes unstable and closes.
f) The protonated (and neutral) fatty acids rapidly flip-flop across the plasma membrane eventually becoming in contact with the extracellular media at higher pH where they become negatively charged and the process can start again.