The 800-MHz 1H NMR spectra of oxidized plastocyanin from spinach are here reported. All hyperfine-shifted signals have been assigned through saturation transfer with the reduced diamagnetic species. To detect the copper(II)-bound cysteine β-CH2 signals, a technique has been applied which is based on irradiation of regions where such signals are expected but not detected, and the corresponding saturation transfer on the reduced species is observed. At the end, a full spectrum is reconstructed which permits, for the first time, the complete 1H NMR signal assignment of an oxidized blue copper protein. These data are discussed in terms of the factors affecting the line width as related to the electronic and geometric structure of the metal center. A Karplus-type relationship is proposed between the contact shift of the Cys-84 β-CH2 protons and the Cu−S−C−Hβ dihedral angle.

Liposome insertion of a newly synthesized octa-carboranylhexylthio-porphyrazine (H2HECASPz) with potentiality in anticancer multiple therapy was described at molecular and supramolecular level. Host−guest interactions between H2HECASPz and the liposome constituents were established and were confirmed by DFT calculations. An approach for the design of new porphyrin-like molecules to be carried by liposome is presented

Non-viral vectors represent an important alternative in gene delivery. Among these vectors, cationic liposomes are widely studied, because of their ability to form stable complexes with DNA fragments (lipoplexes). In the present work, we report on the characterization by electron spin resonance (ESR) spectroscopy and zeta potential measurements of cationic liposomes and of their complexes with oligonucleotides. Liposomes were made with a zwitterionic lipid, DOPE, and a cationic lipid, either DOTAP or DC-Chol. Oligonucleotides were the 20-base single strand polyA, the 20-base single strand polyT, and the corresponding double strand dsAT. The zeta potential as a function of the oligonucleotide/lipid+ ratio gave an S-shaped titration curve. Well-defined surface potential changes took place upon charge compensation between the cationic lipid heads and the phosphate groups on the oligonucleotides. The inversion point depended on the specific system under study. The bilayer properties and the changes that occurred with the incorporation of DNA fragments were also monitored by ESR spectroscopy of appropriately tailored spin probes. For all the systems investigated, the ESR spectra showed that no major alteration took place after lipoplex formation and molecular packing remained substantially unchanged. Both zeta potential and ESR measurements were in favor of an external mode of packing of the lipoplexes.