Effects of Low-pH Treatment on the Allergenicity Reduction of Black Turtle Bean (Phaseolus vulgaris L.) Lectin and Its Mechanism.

Affiliation

He S(1), Zhao J(2), Zhang Y(3), Zhu Y(4), Li X(1), Cao X(1), Ye Y(1), Li J(5), Sun H(1).
Author information:
(1)Engineering Research Center of Bio-process of Ministry of Education, School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, Anhui, PR China.
(2)College of Food Science and Engineering, Ocean University of China, Qingdao 255003, Shandong, PR China.
(3)Department of Food Science and Agricultural Chemistry, Macdonald Campus, McGill University, Ste-Anne-de-Bellevue, Québec H9X 3 V9, Canada.
(4)College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China.
(5)Department of Biological and Environmental Engineering, Hefei University, Hefei 230009, Anhui PR China.

Abstract

A high content of potentially allergenic lectin in Phaseolus vulgaris L. beans is of increasing health concerns; however, understanding of the protein allergenicity mechanism on the molecular basis is scarce. In the present study, low-pH treatments were applied to modify black turtle bean lectin allergen, and a sensitization procedure was performed using the BALB/c mice for the allergenicity evaluation, while the conformational changes were monitored by the spectral analyses and the details were explored by the molecular dynamics simulation. Much milder anaphylactic responses were observed in BALB/c mice experiments. At the molecular level, the protein was unfolded in low acidic environments because of protonation, and α-helix was reduced with the exposure of trypsin cleavage sites, especially the improvement of protease accessibility for Lys121, 134, and 157 in the B cell epitope structural alterations. These results indicate that a low-pH treatment might be an efficient method to improve the safety of legume protein consumption.