Identification and analysis of an alpha galactosidase(EmGalase) acting on species-differentiated epitopes
GUO Yameng1, HOU Linlin1, SHEN Danfeng1, ZOU Lin1, WANG Lei1, LI Tiansheng1, SUN Guiqin2, CHEN Li1
1. Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China; 2. College of Medical Technology, Zhejiang Chinese Medical University, Hangzhou, 310053
Abstract：Through a functional genomic analysis for glycosidase, we identified a candidate alpha galactosidase in the genome of Elizabethkingia meningoseptica. The gene was cloned and expressed in Escherichia coli (E.coli). The purified protein was subjected to assays with synthetic p-nitrophenol (pNP) substrates for its enzymatic properties. The results indicated that it had alpha-linked galactose (α-Gal) substrate specificity. The optimum pH was between 3.0 and 8.0, and the optimum temperature was between 4 and 45 ℃. Further assays with oligosaccharide substrates and Mass Spectrometry analysis found that this enzyme could digest the terminal α-1，3/1，4/1，6Gal, respectively. In addition, we also demonstrated that the enzyme can efficiently remove the terminal Galα1-3Gal antigen presented on porcine erythrocytes to alleviate hyperacute immune rejection in heterologous blood transfusion. As terminal alpha galactose modification plays an important biological role in immunity and infection, the reported alpha galactosidase may serve as a new tool for research in this field.
郭雅萌1，侯琳琳1，沈旦枫1，邹琳1，王蕾1，李天胜1，孙桂芹2，陈力1. 作用于种属差异性表位的细菌α-半乳糖苷酶(EmGalase)的鉴定和研究[J]. 微生物与感染, 2019, 14(3): 153-162.
GUO Yameng1, HOU Linlin1, SHEN Danfeng1, ZOU Lin1, WANG Lei1, LI Tiansheng1, SUN Guiqin2, CHEN Li1. Identification and analysis of an alpha galactosidase(EmGalase) acting on species-differentiated epitopes. JOURNAL OF MICROBES AND INFECTIONS, 2019, 14(3): 153-162.
2019, Vol. 14 
