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

摘要

The objective of this study was to prepare and purify alpha-galactosidase (alpha-Gal) from germinating coffee beans. The molecular weight of purified alpha-Gal from germinating coffee beans was determined to be 38.8 kDa by SDS-PAGE. Then the purified alpha-Gal was applied to synthesize galactosyl beta-cyclodextrin using melibiose as donor and beta-cyclodextrin as acceptor. Galactosyl beta-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 C-13 nuclear magnetic resonance. Our results strongly demonstrate that the synthesized product is a mono-6-O-alpha-d-galactopyranosyl-beta-cyclodextrin and the purified alpha-galactosidase could transfer one galactosyl residue directly to the beta-cyclodextrin ring and synthesize the mono-6-O-alpha-d-galactosyl beta-cyclodextrin.