(klaklak)2 peptide

(KLAKLAK)2 (referred to as KLAK from here) is an antimicrobial peptide known to induce apoptosis via mitochondrial membrane disruption. KLAK exerts low cytotoxicity to mammalian cells owing to its low internalization capacity and thus requires an internalizing peptide for effective anticancer activity. KLAK has been conjugated to several peptides such as RGD-4C and NGR, NRP-1 binding peptide (CGFYWLRSC), and bladder tumor homing nonapeptide (Bld-1; CSNRDARRC). Conjugation strategy that utilizes the coupling of pro-apoptotic KLAK peptide either to the C- or the N-terminus of the targeting peptide have been used. Most of the peptides identified using the T7 phage display system use the N-terminus for conjugation. However, it is important not to interfere with the binding site of the targeting peptide while considering the conjugation strategy. The iron oxide nanoworms were functionalized by conjugation of the D(KLAKLAK)2 to the N-terminus of the p32 targeting tumor penetrating peptide (LinTT1; AKRGARSTA through a polyethylene glycol (PEG) linker (NW-PEG-Cys-D(KLAKLAK)2-X-LinTT1). The conjugate showed significantly improved anticancer activity in several p32-expressing peritoneal tumor models. Modification of the N-terminus of glioma homing peptide (CooP; CGLSGLGVA) by introduction of alanine and TAMRA fluorophore (TAMRA-ACooP) did not affect CooP homing in vivo using glioblastoma model.