Induced circular dichroism as a tool to monitor the displacement of ligands between albumins

Autor(es)

Bertozo, Luiza de Carvalho ; Kogut, Malgorzata ; Maszota-Zieleniak, Martyna ; Samsonov, Sergey A. ; Ximenes, Valdecir F.

• Tipo de documento: Artigo Científico
• Fonte: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY; v. 278, p. 13-pg., 2022-10-05.

Resumo

The induction of chirality in a ligand can be a powerful analytical tool for studying protein-ligand interactions. Here, we advanced by applying the technique to monitor the inversion of the induced circular dichroism (ICD) spectrum when ligands move between human and bovine serum albumin proteins (HSA and BSA). ICD experiments were performed using dimers of methyl vanillate (DVT) and vanillin (DVN). The sign and spectra shape were dependent on the albumin type. DVN presented a positive maximum in 312 nm when complexed with HSA and a negative one in BSA. It was possible to induce and follow the time-dependent displacement of the ligand from BSA (2.2 x 10(6) M-1) to HSA (6.6 x 10(5) M-1) via ICD inversion. The Molecular Mechanics Generalized Born Surface Area approach was used to calculate the binding free energy of the conformers, and a dissociation pathway for each system was proposed using Umbrella Sampling calculations. Four energy minima dihedral angle conformers were identified, and the corresponding CD spectra were calculated using the quantum chemistry approach. Then, weighted spectra for the conformationally accessible conformers were obtained based on each conformer's Boltzmann probability distribution. In conclusion, the methodology described in the manuscript might be helpful in monitoring the movement of ligands between proteins that they bind. (C) 2022 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 19/18445-5 - Síntese, estudos e aplicações de sondas fluorescentes e circular dicroicas para caracterização de interações com proteínas, DNA e determinação de atividade enzimática
• Beneficiário: Valdecir Farias Ximenes
• Modalidade de apoio: Auxílio à Pesquisa - Regular