Interaction of synthetic peptides corresponding to hepatitis G virus (HGV/GBV-C) E2 structural protein with phospholipid vesicles.

The interaction with phospholipid bilayers of two synthetic peptides with sequences corresponding to a segment next to the native N-terminus and an internal region of the E2 structural hepatitis G virus (HGV/GBV-C) protein [E2(7-26) and E2(279-298), respectively] has been characterized. Both peptides are water soluble but associate spontaneously with bilayers, showing higher affinity for anionic than zwitterionic membranes. However, whereas the E2(7-26) peptide is hardly transferred at all from water to the membrane interface, the E2(279-298) peptide is able to penetrate into negatively charged bilayers remaining close to the lipid/water interface.

Enhancement of polymethacrylate-mediated gene delivery by Penetratin.

Polymethacrylates are vinyl-based polymers that are used for DNA transfection. Cationic polymethacrylates efficiently condense DNA by forming inter-polyelectrolyte complexes. Their use for DNA transfection is, however, limited due to their low ability to interact with membranes.

Expression and activity of the nucleotide-binding domains of the human ABCA1 transporter.

The aim of this study was the expression and production in Escherichia coli of the nucleotide-binding domains (NBDs) of the human ABCA1 transporter, in a soluble, non-denatured form. To increase the protein solubility, and avoid expression in E. coli inclusion bodies, we extended the length of the expressed NBD domains, to include proximal domains.

Membrane interaction and cellular internalization of penetratin peptides.

Penetratin is a 16-residue peptide [RQIKIWFQNRRMKWKK(43-58)] derived from the Antennapedia homeodomain, which is used as a vector for cellular internalization of hydrophilic molecules. In order to unravel the membrane translocation mechanism, we synthesized new penetratin variants. The contribution of the positively charged residues was studied by double substitutions of Lys and/or Arg residues to Ala, while the specific contribution of Trp48 and Trp56 was studied by individual substitution of these residues to Phe.

Buffering properties of cationic polymethacrylates are not the only key to successful gene delivery.

Recently, we have shown that polymethacrylates containing imidazole side groups (HYMIMMA) or acid functions (MA), which have similar buffering properties as polyethyleneimine, were not able to transfect Cos-1 cells, whereas polymers containing only tertiary amines (DMAEMA) do transfect Cos-1 cells (Dubruel, P. et al. Eur.

Poly-l-glutamic acid derivatives as multifunctional vectors for gene delivery. Part B. Biological evaluation.

Cationic polymers, such as poly-l-lysine (pLL) and polyethyleneimine (pEI), are receiving growing attention as vectors for gene therapy. They form polyelectrolyte complexes with DNA, resulting in a reduced size of the DNA and an enhanced stability toward nucleases. The major disadvantages of using both polymers for in vivo purposes are their cytotoxicity and, in the case of pEI, the fact that it's not biodegradable.

Physicochemical and biological evaluation of cationic polymethacrylates as vectors for gene delivery.

We report here the physicochemical and biological evaluation of a series of polymethacrylates with side groups of different pK(a) values, such as tertiary amines, pyridine groups, acid functions and imidazole groups as synthetic vectors for gene delivery. The ability of the different polymers to condense DNA was studied by ethidium bromide exclusion tests and agarose gel electrophoresis. The results show that all polymers are able to condense DNA.

Tryptophan fluorescence study of the interaction of penetratin peptides with model membranes.

Penetratin is a 16-amino-acid peptide, derived from the homeodomain of antennapedia, a Drosophila transcription factor, which can be used as a vector for the intracellular delivery of peptides or oligonucleotides. To study the relative importance of the Trp residues in the wild-type penetratin peptide (RQIKIWFQNRRMKWKK) two analogues, the W48F (RQIKIFFQNRRMKWKK) and the W56F (RQI KIWFQNRRMKFKK) variant peptides were synthesized. Binding of the three peptide variants to different lipid vesicles was investigated by fluorescence.