title: A novel endo-β-N-acetylglucosaminidase releases specific N-glycans depending on different reaction conditions.
abstract: Milk glycoproteins are involved in different functions and contribute to different cellular processes, including adhesion and signaling, and shape the development of the infant microbiome. Methods have been developed to study the complexities of milk protein glycosylation and understand the role of N-glycans in protein functionality. Endo-β-N-acetylglucosaminidase (EndoBI-1) isolated from Bifidobacterium longum subsp. infantis ATCC 15697 is a recently isolated heat-stable enzyme that cleaves the N-N'-diacetyl chitobiose moiety found in the N-glycan core. The effects of different processing conditions (pH, temperature, reaction time, and enzyme/protein ratio) were evaluated for their ability to change EndoBI-1 activity on bovine colostrum whey glycoproteins using advanced mass spectrometry. This study shows that EndoBI-1 is able to cleave a high diversity of N-glycan structures. Nano-LC-Chip-Q-TOF MS data also revealed that different reaction conditions resulted in different N-glycan compositions released, thus modifying the relative abundance of N-glycan types. In general, more sialylated N-glycans were released at lower temperatures and pH values. These results demonstrated that EndoBI-1 is able to release a wide variety of N-glycans, whose compositions can be selectively manipulated using different processing conditions.
authors.affiliation: Dept. of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616.
authors.forename: Annabelle Le
authors.initials: AL
authors.lastname: Parc
authors.affiliation: Dept. of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616.
authors.forename: Sercan
authors.initials: S
authors.lastname: Karav
authors.affiliation: Dept. of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616.
authors.forename: Juliana Maria Leite Nobrega
authors.initials: JMLN
authors.lastname: De Moura Bell
authors.affiliation: Dept. of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Frese
authors.affiliation: Dept. of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Dept. of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616.
authors.forename: David A
authors.initials: DA
authors.lastname: Mills
authors.affiliation: Dept. of Viticulture and Enology, University of California, Davis, CA 95616.
authors.forename: David E
authors.initials: DE
authors.lastname: Block
authors.affiliation: Dept. of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616.
authors.forename: Daniela
authors.initials: D
authors.lastname: Barile
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000201:enzymology; D002417:Cattle; D055598:Chemical Phenomena; D003126:Colostrum; D006023:Glycoproteins / Q000737:chemistry; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000378:metabolism*; D008894:Milk Proteins / Q000737:chemistry; D010865:Pilot Projects; D011134:Polysaccharides / Q000737:chemistry*; D013696:Temperature
chemical_list: D006023:Glycoproteins; D008894:Milk Proteins; D011134:Polysaccharides; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase
keywords: N-glycans; deglycosylation; whey