Comparative study on the effects of nystose and fructofuranosyl nystose in the glycation reaction on the antigenicity and conformation of β-lactoglobulin. (1st December 2015) - Zhong, Junzhen
Highlights: β-LG were conjugated with GF3 and GF4, respectively. There was no significant different antigenicity between the two conjugations. Conformation of β-LG after conjugated with GF3 and GF4 changed differently. Different conformation changes may be also resulted in similar antigenicity. 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).