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Hunter disease/mucopolysaccharidosis type II/iduronate sulfatase deficiency
Published in William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop, Atlas of Inherited Metabolic Diseases, 2020
β-Galactosidase activity is diminished in the skin and other tissues of patients with the disease [60]. This abnormality, which also occurs in Hurler disease, is secondary to the primary defect, but it could relate to the accumulation of ganglioside and other lipids found in the brain of patients.
Macromolecular Absorption From The Digestive Tract In Young Vertebrates
Published in Károly Baintner, Intestinal Absorption of Macromolecules and Immune Transmission from Mother to Young, 2019
Di- and trisaccharides of the milk have to be split by enzymes to monosaccharides, for only the latter can be absorbed by carrier proteins of the brush border. An enzyme that splits lactose resides on the outer surface of the brush-border membrane in the form of small knobs, and has lactase, β-galactosidase, β-glucosidase, and cellobiase activities. It is found primarily on the proximal part of the intestine, where the pH does not much differ from its optimum at pH 5.0 to 5.5. It is called lactase or “neutral” β-galactosidase because its pH optimum is less acidic than that of the lysosomal type “acid” β-galactosidase (pH 3.0 to 4.0). The latter enzyme is found primarily in the vacuolated part of the intestine, probably dissolved in the vacuoles. It splits hetero^-galactosides more rapidly than lactose. A third β-galactosidase is found dissolved in the cytoplasm of enterocytes; it is the “hetero-β-galactosidase” with neutral pH-optimum, without any activity towards lactose. During closure, activity of acid β-galactosidase dramatically declines, while the decrease of lactase activity needs much more time.736
Beneficial Lactic Acid Bacteria
Published in K. Balamurugan, U. Prithika, Pocket Guide to Bacterial Infections, 2019
LAB are producers of many ferments that can be used in various fields. Enzymes degrade caseins yielding key flavor components, which contribute to the sensory perception of dairy products (Smit et al. 2005). These bacteria also possess a broad array of enzymatic activities influencing wine composition and quality of wine (Matthews et al. 2004). Some representatives of genera Lactobacillus, Lactococcus, and Streptococcus demonstrated amylolytic activity. It provides opportunity to produce lactic acid directly from starch as a carbon source (Petrova et al. 2013). β-galactosidase, or lactase, is extensively used in food and pharmaceutical industries due to its capability to hydrolyze lactose to monosaccharide and eliminate lactose intolerance problem (de Vrese et al. 2001).
Coordinated interaction between Lon protease and catalase-peroxidase regulates virulence and oxidative stress management during Salmonellosis
Published in Gut Microbes, 2022
Perumalraja Kirthika, Vijayakumar Jawalagatti, Amal Senevirathne, John Hwa Lee
The Lon proteolytic domain (Lon PD) contains a conserved lysine (Lys722), located 43 residues beyond the catalytic serine (Ser679) to carry out catalytic activities.26 To understand how Lon protease is involved in the degradation of KatG, we investigated whether KatG physically interacts with the proteolytic active site of Lon protease. We used a bacterial two-hybrid assay to assess the interaction between KatG and the PD of Lon protease by expressing the katG gene with a C-terminal fusion of the cyaA-T18 fragment and lon PD genes with N-terminal fusions of the cyaA-T25 fragment in an E. coli strain lacking CyaA adenylate cyclase. We then spotted cells on a MacConkey agar plate containing maltose and measured β-galactosidase production from a cAMP-dependent promoter produced when T18 and T25 fragments of the cyaA gene are functionally complemented by a physical interaction between fused KatG and the PD of Lon protease. The strain expressing KatG-T18 and the T25-Lon proteolytic domain showed a strong red color on the MacConkey-maltose plate, indicating that KatG interacts with Lon PD (Figure 3a). By contrast, no interaction was observed in KatG-T18 co-expressing the empty T25 fragment. The interaction was confirmed by measuring the β-galactosidase activity. The KatG-Lon PD interaction was further analyzed by in vitro cross-linking of purified proteins. We observed an additional band corresponding to roughly 99 kDa (79 + 20) on polyacrylamide gel when KatG and the Lon proteolytic domain were incubated with a cross-linker (Figure 3a).
Adaptation of adherent-invasive E. coli to gut environment: Impact on flagellum expression and bacterial colonization ability
Published in Gut Microbes, 2020
Gwladys Sevrin, Sébastien Massier, Benoit Chassaing, Allison Agus, Julien Delmas, Jérémy Denizot, Elisabeth Billard, Nicolas Barnich
In germ-free mice, commensal E. coli strain HS, which is highly motile in soft agar plates, expressed flagella at a low level in the gut environment and did not reach the epithelium surface (unlike LF82 bacteria). To investigate the regulation of flagellum expression in these strains, we measured fliC promoter activity in AIEC and commensal genetic backgrounds by using a β-galactosidase assay. The fliC promoter was cloned upstream of a lacZ reporter gene in a pRS550 plasmid, and the final construct was transformed into the LF82 strain and the commensal E. coli strain HS. We measured β-galactosidase activity under various conditions that mimic the gut environment. The presence of bile acids is a host signal that enteric bacteria encounter as they travel through the gastrointestinal tract, and enteric pathogens, including E. coli, respond to bile acids by increasing their expression of virulence factors.19,29-31 In a medium supplemented with 1% bile acids (compared to the medium without supplementation), the fliC promoter is activated in AIEC LF82 strain by 2.6-fold (3 h) and 3.4-fold (6 h). In contrast, no significant activation was observed in the commensal E. coli strain HS (Fig. 3A).
Enzyme-assisted modification of flavonoids from Matricaria chamomilla: antioxidant activity and inhibitory effect on digestive enzymes
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Elida Paula Dini de Franco, Fabiano Jares Contesini, Bianca Lima da Silva, Anna Maria Alves de Piloto Fernandes, Camila Wielewski Leme, João Pedro Gonçalves Cirino, Paula Renata Bueno Campos, Patrícia de Oliveira Carvalho
The bioconversion reaction was carried out in screw-capped glass tubes with shaking (130 rpm) at controlled temperature (40 °C) for 8 h using 10 ml of aqueous infusion of Matricaria chamomilla. To initiate the hydrolysis of the flavonoid glycosides, 1 ml of enzyme mixture solution prepared in 0.1 M acetate buffer pH 4.0 was added to the reaction mixture. The enzyme mixture used had equal parts of each up (hesperidinase and β-galactosidase) to a final concentration of 0.02 mg/mL. Optimisation of hydrolysis conditions and incubation time using the enzyme combination was previously performed21. The reactions were stopped by boiling for 20 min and the samples were stored in a refrigerator to await analysis. The assays were performed in triplicate. According to the manufacturer’s information, hesperidinase expresses both α-l-rhamnosidase (EC 3.2.1.40) and β-d-glucosidase (3.2.1.21) activities. One unit will liberate 1.0 µmole of reducing sugar (as glucose) from hesperidin per min at pH 3.8, at 40 °C. For β-galactosidase activity, one unit will hydrolyse 1.0 µmole of lactose per minute at pH 4.5, at 30 °C.