STUDY ON THE INTERACTION BETWEEN MAGNETIC NANOPARTICLES AND PEPTIDES BY CAPILLLARY ELECTROPHORESIS

CROS, BD; LAVARI, D; LEZCANO, GV; ARELLANO, A; SOTO, S; CARBALLO R; VIZIOLI, NM

Mendoza

Simposio; 24th Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology- LACE 2018; 2018

In this work, the interaction of functionalized magnetic nanoparticles (MNP) with peptides was studied to evaluate MNP as a potential pseudo-stationary phase in capillary electrophoresis (CE) techniques. The MNP were synthesized by co-precipitation of iron salts in alkaline medium and inert atmosphere1. Particles were subsequently coated with the corresponding metal-porphyrin in organic medium2. Different systems were studied: bare MNP and MNP modified with metal-porphyrin Co(II) (CoPP@MNP) and Ni(II) (NiPP@MNP). Bare and modified MNP were characterized by means of vibrating sample magnetometery, microscopy, UV-visible spectroscopy, and zeta potential. In order to assess the interaction of MNP with the synthetic bioactive peptides angiotensin I and oxytocin, an exactly measured amount of MNP was kept in contact with peptide solutions. The adsorption assays were performed at pH 5.0 and pH 7.0. Aliquots of supernatant were taken at different times and analyzed by CE in a P/ACE MDQ system, using a 50 mM sodium phosphate solution, pH 7.0, as background electrolyte. Quantification of peptides demonstrated that both the CoPP@MNP and NiPP@MNP had a stronger interaction with angiotesin I than with oxytocin. The adsorption of angiotensin I to bare MNP could mainly attributed to electrostatic interaction and to the presence of an aspartic residue to link with Fe(III). Interaction of oxytocin with CoPP@MNP was a little more appreciable than with the NiPP@MNP, which could be explained through the low-spin Co(II) ions in non planar Co(II)-porphyrin complexes activated by core contraction of porphyrin macrocycles. Such complexes can be further activated by axial ligation of imidazole providing greater affinity for angiotensin I.The MNP under study have demonstrated to be selective for the two assayed model peptides. Physicochemical characteristics and their behavior as peptide adsorbents were reproducible, which would indicate that their use as a pseudo-stationary phase is potentially successful.