“…Discrepancies are also seen between the activities of Amuc_0010 GH29 and Amuc_1120 GH95 against HMOs, with the latter releasing more fucose and, therefore, these particular HMOs have predominantly lacto-N-tetraose structures (Supplementary Figure 7). These two observations correspond to the understanding of type II structures being present on red blood cells and type I structures being associated with glycan decorations on secretions 16 . Notably, Amuc_0010 GH29 clusters on a phylogenetic tree with 'Mfuc5' from a soil metagenome and has comparable activities 22 .…”
Section: α-Fucosidasessupporting
confidence: 84%
“…These displayed activity towards blood group B (BGB) Types I and II and Galα1,3-Gal/GalNAc (Figure 1; Supplementary Figures 13-16). BGB is slightly less prevalent than BGA in the human population, ranging between 0-30 %, depending on geographical location 16 . In addition, Amuc_1463 GH110 was also able to hydrolyse the α1,4-linked galactose on globotriose fully and P1 antigen partially under the conditions tested.…”
Section: Resultsmentioning
confidence: 99%
“…In this work, we explored whether these enzymes act upon ganglioside structures, which have structural similarities to O-glycans (Supplementary Figure 1). Gangliosides are important components of eukaryotic plasma membranes and are linked to several genetic diseases and pathogen interactions 16 . Gangliosides (GM3 and GD3; Supplementary Figure 4) are also found in the membranes of milk fat globules in breast milk, so it is likely that gut microbes in the infant gut would encounter these 17 .…”
Akkermansia muciniphila is a human microbial symbiont residing in the mucosal layer of the large intestine. Its main carbon source is the highly heterogeneous mucin glycoprotein that constitutes the majority of the mucus dry weight. A. muciniphila uses an array of Carbohydrate-Active enZymes (CAZymes) and sulfatases to access this complex energy source. Here we describe the biochemical characterisation of fifty-four glycoside hydrolases (from twenty-four families), twelve sulfatases, and one polysaccharide lyase to provide a holistic understanding of the O-glycan degrading activities A. muciniphila carries out in the colon. The results provide an extensive insight into the sequence of O-glycan degradation and the localisation of the different activities. One of the most outstanding elements of this work was the demonstration that these enzymes can act synergistically to degrade the O-glycans on the mucin polypeptide to completion, down to the core GalNAc.
“…Discrepancies are also seen between the activities of Amuc_0010 GH29 and Amuc_1120 GH95 against HMOs, with the latter releasing more fucose and, therefore, these particular HMOs have predominantly lacto-N-tetraose structures (Supplementary Figure 7). These two observations correspond to the understanding of type II structures being present on red blood cells and type I structures being associated with glycan decorations on secretions 16 . Notably, Amuc_0010 GH29 clusters on a phylogenetic tree with 'Mfuc5' from a soil metagenome and has comparable activities 22 .…”
Section: α-Fucosidasessupporting
confidence: 84%
“…These displayed activity towards blood group B (BGB) Types I and II and Galα1,3-Gal/GalNAc (Figure 1; Supplementary Figures 13-16). BGB is slightly less prevalent than BGA in the human population, ranging between 0-30 %, depending on geographical location 16 . In addition, Amuc_1463 GH110 was also able to hydrolyse the α1,4-linked galactose on globotriose fully and P1 antigen partially under the conditions tested.…”
Section: Resultsmentioning
confidence: 99%
“…In this work, we explored whether these enzymes act upon ganglioside structures, which have structural similarities to O-glycans (Supplementary Figure 1). Gangliosides are important components of eukaryotic plasma membranes and are linked to several genetic diseases and pathogen interactions 16 . Gangliosides (GM3 and GD3; Supplementary Figure 4) are also found in the membranes of milk fat globules in breast milk, so it is likely that gut microbes in the infant gut would encounter these 17 .…”
Akkermansia muciniphila is a human microbial symbiont residing in the mucosal layer of the large intestine. Its main carbon source is the highly heterogeneous mucin glycoprotein that constitutes the majority of the mucus dry weight. A. muciniphila uses an array of Carbohydrate-Active enZymes (CAZymes) and sulfatases to access this complex energy source. Here we describe the biochemical characterisation of fifty-four glycoside hydrolases (from twenty-four families), twelve sulfatases, and one polysaccharide lyase to provide a holistic understanding of the O-glycan degrading activities A. muciniphila carries out in the colon. The results provide an extensive insight into the sequence of O-glycan degradation and the localisation of the different activities. One of the most outstanding elements of this work was the demonstration that these enzymes can act synergistically to degrade the O-glycans on the mucin polypeptide to completion, down to the core GalNAc.
“…As adaptive immunity is predicted to be limited in this scenario, innate immune factors, which are not subject to the same tolerance programs, may have evolved to protect individuals from microbes that utilize molecular mimicry to evade humoral immunity 13 . Prior examples of innate immunity against molecular mimicry primarily focused on ABO(H) blood group antigens 15 , 26 , 36 , 51 . This was in part due to differences in anti-A and anti-B antibody production based on polymorphic ABO(H) blood group status that had been recognized for over a century 52 .…”
Microbial glycan microarrays (MGMs) populated with purified microbial glycans have been used to define the specificity of host immune factors toward microbes in a high throughput manner. However, a limitation of such arrays is that glycan presentation may not fully recapitulate the natural presentation that exists on microbes. This raises the possibility that interactions observed on the array, while often helpful in predicting actual interactions with intact microbes, may not always accurately ascertain the overall affinity of a host immune factor for a given microbe. Using galectin-8 (Gal-8) as a probe, we compared the specificity and overall affinity observed using a MGM populated with glycans harvested from various strains of Streptococcus pneumoniae to an intact microbe microarray (MMA). Our results demonstrate that while similarities in binding specificity between the MGM and MMA are apparent, Gal-8 binding toward the MMA more accurately predicted interactions with strains of S. pneumoniae, including the overall specificity of Gal-8 antimicrobial activity. Taken together, these results not only demonstrate that Gal-8 possesses antimicrobial activity against distinct strains of S. pneumoniae that utilize molecular mimicry, but that microarray platforms populated with intact microbes present an advantageous strategy when exploring host interactions with microbes.
“…In contrast to red blood cell (RBC)-induced alloantibody formation ( 13 , 14 , 15 , 16 , 17 , 18 , 19 ), antibodies against ABO(H) antigens are naturally occurring and form within the first few months of life ( 20 ). While conflicting data exist regarding the development of naturally occurring anti-ABO(H) antibodies ( 21 , 22 , 23 , 24 , 25 ), several studies suggest that microbes that express ABO(H)-like antigens may stimulate anti-ABO(H) antibody formation relevant to transfusion and transplantation ( 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ). However, as tolerance mechanisms prevent the formation of anti-ABO(H) antibodies in ABO(H) blood group–positive individuals, how these individuals protect themselves against blood group–decorated microbes is incompletely understood.…”
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