Physicochemical and structural properties of lunasin revealed by spectroscopic, chromatographic and molecular dynamics approaches.

Biochim Biophys Acta Proteins Proteom

Laboratório de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; Programa de Pós-Graduação em Nanobiossistemas (PPGIM-NANOBIOS), Universidade Federal do Rio de Janeiro, Duque de Caxias, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. Electronic address:

Published: August 2020

Lunasin is a 43-amino acid peptide from seeds and grains with bioavailability in humans and potent chemotherapeutic action against several cancer cell lines. Here, we investigate new information about the physicochemical and structural properties of lunasin using circular dichroism (CD), fluorescence spectroscopy, electrospray ionization-ion mobility spectrometry-mass spectrometry (ESI-IMS-MS), size exclusion chromatography (SEC), molecular dynamics (MD), and bioinformatics. CD analysis and disorder prediction obtained by PONDR indicate that lunasin has a mostly unordered structure. Double wavelength [θ] x [θ] plot data suggests that lunasin is an intrinsically disordered peptide (IDP) in a pre-molten globule-like (PMG-like) state, while CD spectrum deconvolution and MD simulation indicate small β-strand content. The presence of residual structure was supported by loss of CD signal at 222 nm after treatment with urea and by increasing fluorescence emission upon bis-ANS binding. Lunasin also demonstrated stability to heating up to the temperature of 100 °C, as verified by CD. MD and CD analyses in the presence of TFE and MoRFpred prediction indicated the helix propensity of lunasin. ESI-IMS-MS data revealed that lunasin shows a propensity to form disulfide bonds at the conditions used. MD data also indicated that disulfide bond formation affects the adopted structure, showing a possible role of aspartyl-end in structure stabilization and compaction. In conclusion, our data support a characterization of lunasin as a peptide with an intrinsic disorder in a PMG-like state and reveal new aspects about its structural stability and plasticity, as well as the effects of disulfide bond formation and electrostatic attractions.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbapap.2020.140440DOI Listing

Publication Analysis

Top Keywords

lunasin
9
physicochemical structural
8
structural properties
8
properties lunasin
8
molecular dynamics
8
pmg-like state
8
disulfide bond
8
bond formation
8
lunasin revealed
4
revealed spectroscopic
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!