Analysis of Amyloid Fibrillation of Two Family 1 Glycoside Hydrolases.

The formation and analysis of amyloid fibers by two β-glucosidases, BglA and BglB, belonging to the GH1 enzyme family, are reported. Both proteins have the (β/α) TIM-barrel fold, which is characteristic of this family and is also the most common protein structure. BglA is an octamer, whereas BglB is a monomer.

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

The gastrointestinal microbiota members produce α-l-fucosidases that play key roles in mucosal, human milk, and dietary oligosaccharide assimilation. Here, 36 open reading frames (ORFs) coding for putative α-l-fucosidases belonging to glycosyl hydrolase family 29 (GH29) were identified through metagenome analysis of breast-fed infant fecal microbiome. Twenty-two of those ORFs showed a complete coding sequence with deduced amino acid sequences displaying the highest degree of identity with α-l-fucosidases from Bacteroides thetaiotaomicron, Bacteroides caccae, Phocaeicola vulgatus, Phocaeicola dorei, Ruminococcus gnavus, and Streptococcus parasanguinis.

Factors Affecting Spontaneous Endocytosis and Survival of Probiotic Lactobacilli in Human Intestinal Epithelial Cells.

Mutualistic bacteria have different forms of interaction with the host. In contrast to the invasion of pathogenic bacteria, naturally occurring internalization of commensal bacteria has not been studied in depth. Three in vitro methods, gentamicin protection, flow cytometry and confocal laser scanning microscopy, have been implemented to accurately assess the internalization of two lactobacillus strains- BL23 and GG-in Caco-2 and T84 intestinal epithelial cells (IECs) under a variety of physiological conditions and with specific inhibitors.

Lactobacillus casei extracellular vesicles stimulate EGFR pathway likely due to the presence of proteins P40 and P75 bound to their surface.

In the complex interplay of beneficial bacteria with the host, there are few examples of bacterial metabolites and effector molecules that have been consistently identified. Protective effects on the intestinal epithelium have been ascribed to P40 and P75, two well characterized cell wall muramidases, present in the culture supernatant of strains belonging to the taxon Lactobacillus casei/paracasei/rhamnosus. This work reports that Lactobacillus casei BL23 extracellular vesicles (BL23 EVs) have a small size (17-20 nm or 24-32 nm, depending on the method used) and contain lipoteichoic acid (LTA).

Differences in the expression of cell envelope proteinases (CEP) in two Lactobacillus paracasei probiotic strains.

Proteinase PrtP (EC:3.4.21.