Isolation of a protease-resistant and pH-stable α-galactosidase displaying hydrolytic efficacy toward raffinose family oligosaccharides from the button mushroom Agaricus bisporus

Yujing Hu; Mengjuan Zhu; Guoting Tian; Liyan Zhao; Hexiang Wang; Tzi Bun Ng

doi:10.1016/j.ijbiomac.2017.06.077

Isolation of a protease-resistant and pH-stable α-galactosidase displaying hydrolytic efficacy toward raffinose family oligosaccharides from the button mushroom Agaricus bisporus

Int J Biol Macromol. 2017 Nov;104(Pt A):576-583. doi: 10.1016/j.ijbiomac.2017.06.077. Epub 2017 Jun 19.

Authors

Yujing Hu¹, Mengjuan Zhu², Guoting Tian³, Liyan Zhao⁴, Hexiang Wang⁵, Tzi Bun Ng⁶

Affiliations

¹ Department of Plant Science and Techonology, Beijing University of Agriculture, Beijing 102206, China; State Key Laboratory for Agrobiotechnology and Department of Microbiology, China Agricultural University, Beijing 100193, China. Electronic address: huyujing1216@126.com.
² Department of Fungal Resource, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, China. Electronic address: mengfan7777@163.com.
³ Institute of Biotechnology and Germplasmic Resource, Yunnan Academy of Agricultural Science, Kunming 650223, China. Electronic address: tiangt@aliyun.com.
⁴ College of Food Science and Technology, Nanjing Agricultural University, Weigang, Nanjing 210095, China. Electronic address: zhlychen@njau.edu.cn.
⁵ State Key Laboratory for Agrobiotechnology and Department of Microbiology, China Agricultural University, Beijing 100193, China. Electronic address: hxwang@cau.edu.cn.
⁶ School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China. Electronic address: b021770@mailserv.cuhk.edu.hk.

PMID: 28634061
DOI: 10.1016/j.ijbiomac.2017.06.077

Abstract

A 45-kDa monomeric acidic α-galactosidase with a specific activity of 193.12 units/mg was isolated from the fruiting bodies of Agaricus bisporus. Blast search of internal peptide sequences suggested that it is a member of GH family 27 and it is most similar to hypothetical protein AGABI2DRAFT_70106. The enzyme displayed maximal activity at pH 4.0 and 60°C, respectively. The enzyme remained stable within the pH range 2.0-9.0 but its activity was markedly suppressed in the presence of Cu²⁺, Hg²⁺, Fe³⁺ and Ag⁺ ions. It displayed resistance to α-chymotrypsin and neutral protease. Moreover, it manifested degradative activity toward both oligosaccharides and polysaccharides. The enzyme manifested Km values of 0.30mM, 10.65mM and 19.21mM, toward pNPGal, stachyose and raffinose respectively. These results suggest that Agaricus bisporus α-galactosidase is a promising candidate for elimination of raffinose oligosaccharides (RFOs) in biotechnological applications.

Keywords: Agaricus bisporus; Protease-resistant; Raffinose family oligosaccharides; α-galactosidase.

MeSH terms

Agaricus / chemistry*
Biocatalysis
Enzyme Stability
Hydrogen-Ion Concentration
Hydrolysis
Kinetics
Molecular Weight
Peptide Hydrolases / metabolism*
Raffinose / metabolism*
Substrate Specificity
alpha-Galactosidase / chemistry
alpha-Galactosidase / metabolism*

Substances

alpha-Galactosidase
Peptide Hydrolases
Raffinose