Purification and application of α-galactosidase from germinating coffee beans (Coffea arabica)

摘要

The objective of this study was to prepare and purify α-galactosidase (α-Gal) from germinating coffee beans. The molecular weight of purified α-Gal from germinating coffee beans was determined to be 38.8 kDa by SDS-PAGE. Then the purified α-Gal was applied to synthesize galactosyl β-cyclodextrin using melibiose as donor and β-cyclodextrin as acceptor. Galactosyl β-cyclodextrin was isolated by preparative high-performance liquid chromatography (HPLC) and its structure was analyzed and elucidated by HPLC, fourier transform infrared spectrometer, electro spraying ionization-mass spectrometry, and 13C nuclear magnetic resonance. Our results strongly demonstrate that the synthesized product is a mono-6-O-α-d-galactopyranosyl-β-cyclodextrin and the purified α-galactosidase could transfer one galactosyl residue directly to the β-cyclodextrin ring and synthesize the mono-6-O-α-d-galactosyl β-cyclodextrin.