Comparative study on the effects of nystose and fructofuranosyl nystose in the glycation reaction on the antigenicity and conformation of β-lactoglobulin

Food Chem. 2015 Dec 1:188:658-63. doi: 10.1016/j.foodchem.2015.05.015. Epub 2015 May 6.

Abstract

Our previous work indicated that the antigenicity of bovine β-lactoglobulin (β-LG) decreased after conjugation with fructo-oligosaccharides (FOS) which was related to its conformational changes. In attempt to unravel further changes of β-LG antigenicity, nystose (GF3) and 1(F)-β-fructofuranosyl nystose (GF4) of FOS were used to investigate the relationship between conformation and antigenicity. The antigenicity of β-LG after conjugated with GF3 and GF4 decreased from 143.4 to 29.5 and 31.6 μg/mL, respectively. The results of mass spectrometry revealed that the molecular weight of β-LG increased from 18.4 to 19.8 and 19.1 kDa after conjugation with GF3 and GF4, respectively. It was shown that the conformational changes of β-LG after conjugation with GF3 were bigger than that with GF4, including quenching of fluorescence intensity, the red-shift of fluorescence spectra, and the increase in sulfhydryl content. However, there was no significant difference in the antigenicity between β-LG-GF3 and β-LG-GF4 conjugates (P>0.05).

Keywords: Antigenicity; Conformation; Conjugation; β-Lactoglobulin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Glycosylation
  • Lactoglobulins / chemistry*
  • Mass Spectrometry
  • Molecular Conformation
  • Oligosaccharides / chemistry*

Substances

  • Lactoglobulins
  • Oligosaccharides
  • fungitetraose