Conjugation of chitopentaose with β-lactoglobulin using Maillard reaction, and its effect on the allergic desensitization in vivo

Abstract

The conjugation of chitopentaose (CHP) on β-lactoglobulin (βLg) via Maillard reaction was used to desensitize βLg. The stable βLg-CHP conjugate (βC-4) was formed at 4 h incubation, which contains 5 CHP attached molecules and a conjugated degree of 42 %. The conjugation promoted the thermal stability and emulsifying properties of βLg, and inhibited the immunoglobulin E (IgE) combining capacity by decreasing the content of β-sheet in βLg. Moreover, βLg-CHP conjugates were imparted with anti-oxidant properties and anti-inflammatory activities. Further, the combined action of inhibited IgE combining capacity and anti-inflammatory activities improved the allergy desensitization in βLg sensitized mice. The results showed that overexpressed IgE and inflammatory factors, unbalanced Th1-/Th2- immune cytokines were significantly attenuated after βLg was conjugated with CHP, avoiding the inflammatory lesions in spleen and colon. Additionally, the adverse changes in gut microbiota were alleviated in βC-4 group with a decrease of Bacteroidetes and increase of Firmicutes at phylum level and the probiotic bacteria of Lactobacillaceae was significantly improved at the family level. Thus, the conjugation of CHP can desensitize allergic reaction caused by βLg.

Keywords: Chitopentaose (CHP); Desensitization; Gut microbiota; Maillard reaction; β-Lactoglobulin (βLg).