New generation of cell‐penetrating peptides: Functionality and potential clinical application

Cell‐penetrating peptides (CPPs) can transport various cargoes through membranes of live cells. Since the first generations of CPPs suffered from insufficient cell and tissue selectivity, stability against proteases, and escape from endosomes, a new generation of peptides, with optimized properties, was developed. These are either derived from natural sources or created through the combination of multivalent structures. The second method allows achieving high internalization efficiency, high cell and tissue selectivity, and release from endosomes via hybrid structures, combining sequences for endosomal release, homing sequences, and sequences for activation at the target tissue and for local delivery of cargoes. CPPs with innate tumor selectivity include azurin, crotamine, maurocalcine, lycosin‐I, buffalo cathelicidin, and peptide CB5005. Some of them can penetrate the membranes of live cells and influence intracellular signaling pathways, thereby exerting cytotoxic effects against tumor cells. To obtain multilayer penetration and stabilization against proteolytic degradation, as well as for better handling, CPPs are often conjugated to nanoparticles. A special problem for tumor treatment is the efficiency of drug transport through three‐dimensional cell cultures. Therefore, the capability of CPPs to deliver the drug even to the innermost tissues is of crucial importance. Notably, the ability of certain CPPs to penetrate barriers such as skin, the blood‐brain barrier (BBB), and cornea or conjunctiva of eyes enabled the replacement of dangerous and painful injections with soothing sprays, creams, and drops. However, it is difficult to rank the efficacy of CPPs because transport efficiency and tissue selectivity depend not only on the CPP itself but also on the target tissue or organ, as well as on the cargo and method of CPP‐cargo coupling. Therefore, the present review describes some examples of new‐generation CPPs and aims to provide advice on how to find or create the right CPP for a given task

Электроприводы механизмов заградительной сетки водозабора

Целью выпускной квалификационной работы является проектирование электропривода промыва водоочистной сетки водозабора.The purpose of final qualifying work is the design of the electric grid flushing water treatment intake

Structure and Alignment of the Membrane-Associated Peptaibols Ampullosporin A and Alamethicin by Oriented 15N and 31P Solid-State NMR Spectroscopy

Ampullosporin A and alamethicin are two members of the peptaibol family of antimicrobial peptides. These compounds are produced by fungi and are characterized by a high content of hydrophobic amino acids, and in particular the α-tetrasubstituted amino acid residue α-aminoisobutyric acid. Here ampullosporin A and alamethicin were uniformly labeled with 15N, purified and reconstituted into oriented phophatidylcholine lipid bilayers and investigated by proton-decoupled 15N and 31P solid-state NMR spectroscopy. Whereas alamethicin (20 amino acid residues) adopts transmembrane alignments in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membranes the much shorter ampullosporin A (15 residues) exhibits comparable configurations only in thin membranes. In contrast the latter compound is oriented parallel to the membrane surface in 1,2-dimyristoleoyl-sn-glycero-3-phosphocholine and POPC bilayers indicating that hydrophobic mismatch has a decisive effect on the membrane topology of these peptides. Two-dimensional 15N chemical shift – 1H-15N dipolar coupling solid-state NMR correlation spectroscopy suggests that in their transmembrane configuration both peptides adopt mixed α-/310-helical structures which can be explained by the restraints imposed by the membranes and the bulky α-aminoisobutyric acid residues. The 15N solid-state NMR spectra also provide detailed information on the helical tilt angles. The results are discussed with regard to the antimicrobial activities of the peptides

Relationships between Cargo, Cell Penetrating Peptides and Cell Type for Uptake of Non-Covalent Complexes into Live Cells

Modulating signaling pathways for research and therapy requires either suppression or expression of selected genes or internalization of proteins such as enzymes, antibodies, nucleotide binding proteins or substrates including nucleoside phosphates and enzyme inhibitors. Peptides, proteins and nucleotides are transported by fusing or conjugating them to cell penetrating peptides or by formation of non-covalent complexes. The latter is often preferred because of easy handling, uptake efficiency and auto-release of cargo into the live cell. In our studies complexes are formed with labeled or readily detectable cargoes for qualitative and quantitative estimation of their internalization. Properties and behavior of adhesion and suspension vertebrate cells as well as the protozoa Leishmania tarentolae are investigated with respect to proteolytic activity, uptake efficiency, intracellular localization and cytotoxicity. Our results show that peptide stability to membrane-bound, secreted or intracellular proteases varies between different CPPs and that the suitability of individual CPPs for a particular cargo in complex formation by non-covalent interactions requires detailed studies. Cells vary in their sensitivity to increasing concentrations of CPPs. Thus, most cells can be efficiently transduced with peptides, proteins and nucleotides with intracellular concentrations in the low micromole range. For each cargo, cell type and CPP the optimal conditions must be determined separately