Nontoxic membrane translocation peptide from protamine, low molecular weight protamine (LMWP), for enhanced intracellular protein delivery: in vitro and in vivo study

Abstract

Naturally derived, nontoxic peptides from protamine by the authors, termed low molecular weight protamines (LMWPs), possess high arginine content and carry significant sequence similarity to that of TAT, by far the most potent protein transduction domain peptide. Therefore, it was hypothesized that these LMWPs would also inherit the similar translocation activity across the cell membrane, which enables any impermeable species to be transduced into the cells. LMWPs were prepared by enzymatic digestion of protamine, examined their capability of transducing an impermeable protein toxin into the tumor cells by chemical conjugation, and determined cytotoxicity of transduced protein toxin (e.g., gelonin) against cancer cell lines and a tumor-bearing mouse. In vitro results showed that LMWPs could indeed translocate themselves into several mammalian cell lines as efficiently as TAT, thereby transducing impermeable gelonin into the cells by chemical conjugation. In vivo studies further confirmed that LMWP could carry an impermeable gelonin across the tumor mass and subsequently inhibit the tumor growth. In conclusion, the presence of equivalent cell translocation potency, absence of toxicity of peptide itself, and the suitability for low-cost production by simple enzymatic digestion could expand the range of clinical applications of LMWPs, including medical imaging and gene/protein therapies.

Surface coating of PLGA microparticles with protamine enhances their immunological performance through facilitated phagocytosis

“…However, in 2005, two independent groups reported that protamine can act as an efficient membrane-translocating peptide both in vitro [44] and in vivo [44] and [45]. Park et al showed that a protein toxin conjugated to protamine was able to translocate into cells in vitro, resulting in the inhibition of tumour growth in vivo.…”

Cell-penetrating and cell-targeting peptides in drug delivery

“…At concentrations 1000 times the IC50 values, the Antennapedia peptide showed no toxicity, whereas Tat caused some mild eyelid swelling [84]. Park et al described the equivalent cell translocation potency of a short protamine derivative rich in arginine residues which was equivalent to that of the Tat peptide combined with the absence of toxicity [85]. Cardozo et al showed that concentrations of up to 100 M of Tat (48)(49)(50)(51)(52)(53)(54)(55)(56)(57) were essentially harmless in all cells tested, whereas Antp(43-58) was significantly more toxic [86].…”

Cell-penetrating superoxide dismutase attenuates oxidative stress-induced senescence by regulating the p53-p21Cip1 pathway and restores osteoblastic differentiation in human dental pulp stem cells

“…Previous studies have demonstrated that LMWP itself has no effect on cells. 34,35,37,38 Next, we determined the transduction kinetics for the LMWP-SOD1 conjugate. The SOD1 and LMWP-SOD1 conjugate was added to the culture medium of DPSCs at a concentration of 2 µM for various time periods.…”

“…We demonstrated that LMWP achieved protein transduction in various cell types with activity equivalent to that of unconjugated TAT for molecular imaging and therapeutic purposes. 34,35 In this study, we investigated transduction of LMWP-SOD1 conjugates into DPSCs and the effect of LMWP-SOD1 conjugates on H 2 O 2 -induced senescence by testing changes in cellular morphology, senescenceassociated beta-galactosidase (SA-β-gal) activity, mRNA levels of related genes, cell cycle distribution, and levels of p53 and p21…”