Infant Gut Microbial Metagenome Mining of α- l -Fucosidases with Activity on Fucosylated Human Milk Oligosaccharides and Glycoconjugates

Abstract

α- l -Fucosyl residues are frequently present in many relevant glycans, such as human milk oligosaccharides (HMOs), histo-blood group antigens (HBGAs), and epitopes on cell surface glycoconjugate receptors. These fucosylated glycans are involved in a number of mammalian physiological processes, including adhesion of pathogens and immune responses.

Exploring the sequence-function space of microbial fucosidases

“…Of the 63 clusters analysed, clusters 1-11, 13, 16, 18, 20, 21, 23, 26, 34, 41, 45 and 47 included sequences corresponding to functionally characterised enzymes. Among them, clusters 1, 13, and 45 contained GH29-B enzymes while the remaining clusters belonged to GH29-A apart from cluster 11, in which Fuc30 isolated from breast-fed infant faecal microbiome was found unrelated to GH29-A or GH29-B subfamilies 14 . Clusters 1 and 13 contained α1,3/4 fucosidases active towards α1,3/4 fucosylated GlcNAc found in Lewis antigens (Supplementary Table S1).…”

“…Cluster 5 contained fucosidases that speci cally act on α1,3 fucosyl linkages with cFase I from Elizabethkingia meningoseptica FMS-007 cleaving α1,3 Fuc from the core GlcNAc position from intact glycoproteins 35 . Clusters 6 contained two characterised fucosidases, BF0810 fromBacteroides fragilis NCTC 9343 active on pNP-Fuc but not on natural substrates with α1,2/3/4/6 linkages 36 ; and Fuc5372 isolated from breast-fed infant faecal microbiome, with preference for α1,2 fucosyl linkages found in HMOs and blood group antigens 14 . Clusters 7, 8 and 10 contained fucosidases with relatively high catalytic e ciency towards aryl-Fuc and marginal activity against α1,2/3/4 fucosyl linkages 7,13,[36][37][38] .…”

“…In addition, GH29 fucosidases are increasingly being considered as glyco-tools for their capacity to synthesise oligosaccharides by transglycosylation, as reported for AlfB and AlfC from Lactobacillus casei BL23 11,12 . Given the wide enzymatic diversity within the GH29 family, there is great interest in mining this family for applications 13,14 and several bioinformatics-based approaches are being tested to better predict substrate speci city and transglycosylation ability of these enzymes 15,16 .…”

Structure and function of microbial α-l-fucosidases: a mini review

“…This analysis revealed a remarkably high number of GH29 α- l -fucosidases present in the infant intestinal environment with high sequences identity (above 98% identity) with α- l- fucosidases from B. thetaiotaomicro n, Bacteroides caccae , Phocaeicola vulgatus , Phocaeicola dorei , R. gnavus , and Streptococcus parasanguinis (Supplementary Table S1). These enzymes showed different substrate specificities toward HMOs, blood group antigens, and glycoproteins [ 51 ]. GH95 fucosidases were also identified in the infant faecal microbiome from B. longum subsp.…”

“…No bacterial α- l -fucosidase has been described with the capability to remove the core Fuc from intact glycosylated IgG. However, recent work characterised four fucosidases showing high capacity to hydrolyse α-1,6-linked Fuc from the disaccharide 6FN [ 51 ]. These α- l -fucosidases might have applications in the development of therapeutic proteins with modified core fucosylation, although their capacity to act on core fucosylation in glycosylated antibodies needs further analysis.…”