Development of a Sortase A-mediated Peptide-labeled Liposome Applicable to Drug-delivery Systems.

Background/aim: In order to develop an efficient drug-delivery system (DDS), a lipopeptide-loaded liposome that functions as a platform for the transpeptidase reaction mediated by sortase A (SrtA) was constructed and its stability, as well as cell-specific targeting were evaluated in the present study.

Materials And Methods: Several lipopeptides possessing an acceptor peptide sequence (oligoglycine ≥ three residues) or donor peptide sequence (LPETG) for the SrtA-mediated reaction were chemically synthesized and then inserted into the liposome membrane composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol (DPPC-Chol-lipo) to obtain the lipopeptide-loaded liposomes. The transpeptidase reaction mediated by recombinant SrtA (His-ΔN59SrtA) was employed to modify the peptide moiety on the liposomal surface using a fluorescently-labeled substrate peptide corresponding to the species of each loaded lipopeptide.

Investigation on the reaction conditions of Staphylococcus aureus sortase A for creating surface-modified liposomes as a drug-delivery system tool.

Background/aim: This study aimed to determine the preferred conditions for the transpeptidase reaction of sortase A from Staphylococcus aureus, for the purpose of creating functional liposomes useful for a drug-delivery system (DDS).

Materials And Methods: His-tagged recombinant sortase A with 59 amino acids deleted from the N-terminus (His-ΔN59SrtA) was prepared using an Escherichia coli expression system. The pH dependency and sorting signal sequence dependency of the transpeptidase reaction of His-ΔN59SrtA were analyzed by monitoring the transfer of model donor-substrates (i.

The diversity of receptor recognition in cholesterol-dependent cytolysins.

Cholesterol-dependent cytolysins (CDCs) are bacterial pore-forming toxins secreted mainly by pathogenic Gram-positive bacteria. CDCs generally recognize and bind to membrane cholesterol to create pores and lyse target cells. However, in contrast to typical CDCs such as streptolysin O, several atypical CDCs have been reported.

Construction of an improved drug delivery system tool with enhanced versatility in cell-targeting.

Background/aim: The aim of this study was to develop an improved drug delivery system (DDS) tool with enhanced versatility in the cell-targeting step using as Z-domain, a modified IgG binding domain of protein A from Staphylococcus aureus, as an IgG adapter domain.

Materials And Methods: The chimera protein expression system composed of the Z-domain and chimeric cholesterol-dependent cytolysin mutant named His-Z-CDC(ss)(IS) was constructed in Escherichia coli. His-Z-CDC(ss)(IS) was purified by Ni-affinity chromatography, and its abilities for controlled pore formation, membrane binding, IgG binding, and target cell-specific delivery of liposomes carrying medicine were investigated.

Investigation of a bacterial pore-forming chimera toxin for application as a novel drug-delivery system tool.

Background/aim: Cholesterol-dependent cytolysins (CDCs) are pore-forming toxins from Gram-positive bacteria. The aim of this study was to investigate the potential of a CDC, intermedilysin, as a drug-delivery system (DDS) for clinical application.

Materials And Methods: Intermedilysin was modified by the addition of a disulfide bridge to regulate pore formation, by swapping domain 4 to provide cholesterol-binding capacity, and by the introduction of a targeting domain.