COVALENTLY MODIFIED THIOREDOXIN PROTEIN (TRX-APAO-FITC) AFFECTING BIOPHYSICAL PARAMETERS AND CYTOTOXICITY OF LIPID-COTRANSPORTERS

A. LIS FEMIA; C. FACUNDO TEMPRANA; S. SOTO ESPINOZA; M. GRASSELLI; ALONSO, S. DEL V.

Pekín

Congreso; 17th IUPAB International Biophysics Congress (17th IBC); 2011

International Union for Pure and Applied Biophysics (IUPAB) and Biophysical Society of China

Arsenic compounds are useful against different kinds of cancer, like promyelocitic acute leukemia. The bioconjugate between Trx and arsenic-fluorescent compound synthetized APAO-FITC (Femia et al, 2012) is as an alternative arsenic therapeutic agent. This present study shows the special features generated when Trx/APAO-FITC is encapsulated/associated with different lipid formulations. Properties like size, interaction with MC540 probe, Z potential and encapsulation efficiency are shown within a lipid concentration range of 1-10 mM. Results showed that Trx/APAO-FITC influenced the molecular probe MC540 apparent equilibrium dimerization constant (Kadd (dim)/(mon)e2). Data obtained for Kadd were in the range 10e(7) - 10e(6), presenting lower Kadd values as a function of Trx/APAO-FITC concentration. Encapsulation efficiency determinations percentage of drug incorporated into liposomes was between 10-70%. Hydrophobicity factor (HF) and MC540 partitioning results showed that the probe partitioned between aqueous phase and hydrophobic lipid side chains depending on Trx-APAO-FITC presence. The effect of Trx-APAO-FITC on different cell lines: HL60, HeLa and PBMC are able to produce apoptosis on leukemia cells more significantly than on PBMC. Protein As-shuttle association with lipid formulations resulted in greater cell apoptosis depending on cell line. Some lipid formulations led to cell proliferation, like SPC and DPPC:Chol