Synthesis of NTA3-DTDA — A Chelator-Lipid that Promotes Stable Binding of His-Tagged Proteins to Membranes

Abstract

A six-step reaction sequence is described for the preparation of compound 1 (NTA3-DTDA), a membrane-penetrating and potent chelator that can be incorporated into liposomes and plasma membrane vesicles containing antigens and thus allowing targeted delivery of such assemblies to a variety of cells for the purposes of eliciting anti-tumour responses. Full spectroscopic characterization of this dendritic-type compound as well as certain of its precursors is reported.

Antigen-Containing Liposomes Engrafted with Flagellin-Related Peptides Are Effective Vaccines That Can Induce Potent Antitumor Immunity and Immunotherapeutic Effect

“…NTA 3 -DTDA was produced in the Research School of Chemistry (Australian National University [ANU]), as described previously (27,29). Disteroylphosphatidylethanolamine (polyethylene glycol)-750 was obtained from Avanti Polar Lipids (Alabaster, AL).…”

“…In this study, we explored the potential of using relatively short flagellin-related peptides (pFlgs) to manipulate immunity by targeting Ag-containing liposomes and membrane vesicles to TLR5 on APCs. Using the chelator lipid 3 (nitrilotriacetic acid)-ditetradecylamine (NTA 3 -DTDA) (27,28), we engrafted Ag-containing liposomes and tumor cell-derived plasma membrane vesicles (PMVs) with synthetic His-tagged peptides that contain a sequence derived from flagellin and explored the ability of these to enhance immunity when used as vaccines. The results show that peptides having a sequence related to conserved regions in bacterial flagellin can be used to elicit dramatic Agspecific and antitumor responses in mouse tumor models.…”

Targeted Liposomal Delivery of TLR9 Ligands Activates Spontaneous Antitumor Immunity in an Autochthonous Cancer Model

“…The chelator lipid 3(nitrilotriacetic acid)ditetradecylamine (NTA 3 -DTDA) was produced in the Research School of Chemistry (Australian National University) as described previously (18,19). 1,2-Disteroyl-sn-glycero-3-phophoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-mPEG 2000 ) and 1,2-dioleoyl-3-dimethylammonium propane (DODAP) were obtained from Avanti Polar Lipids.…”

Antibody Response to Polyhistidine-Tagged Peptide and Protein Antigens Attached to Liposomes via Lipid-Linked Nitrilotriacetic Acid in Mice

“…To address this issue, we and others have developed facile synthetic routes to multivalent nitrilotriacetic acid adaptors with nanomolar affinities for polyhistidine-tagged proteins (K D [equilibrium dissociation constant], ϳ10 M and ϳ1 nM for monovalent and trivalent NTA [tris-NTA], respectively) ( Fig. 1) (3,21,22,27). This approach has shown promise for in vivo delivery; most notably, plasma membrane vesicles to which polyhistidinylated dendritic cell-targeting moieties and costimulatory molecules were engrafted via trivalent NTA elicited functional antitumor immunity upon administration to mice (44).…”