β-galactosidase

β-Galactosidase, a glycoside hydrolase, breaks down β-glycosidic bonds in galactose and its derivatives. In E. coli, it is encoded by the lacZ gene, playing a crucial role in the lac operon induction system. This enzyme not only converts lactose into glucose and galactose for glycolysis but also facilitates the transgalactosylation of lactose into allolactose, which subsequently breaks down into monosaccharides [1].

α-Galactosidase (EC 3.2.1.22), a glycoside hydrolase enzyme, is prevalent across animals, plants, and microorganisms, and is often utilized in biochemical research. It facilitates the hydrolysis of α-1,6-linked terminal galactose residues in substrates such as galactooligosaccharides, galactomannans, and galactolipids. This includes catalyzing key catabolic processes involved in the cleavage of glycoproteins, glycolipids, and polysaccharides [1].

Tryptophan, N-indol-3-ylacetyl- (6CI) (Indole-3-acetyl-L-tryptophan) is involved in regulatory mechanisms for the control of auxin activity during physiological and pathophysiological responses. It may also be used in the synthesis of β-D-galactosidase and β-D-glucosidase inhibitors.

Cetyldimethylethylammonium Bromide can be used to induce extracellular secretion of beta-galactosidase.

SSK1 is a compound that selectively kills senescent cells and is a precursor for β-galactosidase, which can reduce the inflammatory response of the body. SSK1 can activate the phosphorylation of p38 MAPK and MKK3/MKK6 in senescent cells, and promote mitochondrial DNA damage in senescent cells.

Pyrindolol is a bacterial metabolite that has been found inS. alboverticillatus.1It inhibits neutral β-galactosidase by 50% under acidic, but not neutral, conditions when used at a concentration of 2 μg/ml. It is selective for β-galactosidase isolated from bovine liver over β-galactosidases isolated from human, bovine, pig, and rat tissues and sialidases isolated fromC. perfringens,Streptomyces, and the H3N2 strain of influenza virus (IC50s = >250 μg/ml for all).1,2 1.Aoyagi, T., Kumagai, M., Hazato, T., et al.Pyridindolol, a new β-galactosidase inhibitor produced by actinomycetesJ. Antibiot. (Tokyo)28(7)555-557(1975) 2.Kumagai, M., Aoyagi, T., and Umezawa, H.Inhibitory activity of pyridindolol on β-galactosidaseJ. Antibiot. (Tokyo)29(7)696-703(1976)

Australine is a pyrrolizidine alkaloid originally isolated fromC. australethat has enzyme inhibitory activities.1,2,3It is an inhibitor of glucoamylase (IC50= 5.8 μM) that also inhibits glucosidase I, sucrase, maltase, andA. nigerα-glucosidase (IC50s = 20, 28, 35, and 28 μM, respectively).2,3Australine is selective for these enzymes over glucosidase II, α- and β-mannosidase, and α- and β-galactosidase up to 500 μM, β-glucosidase, with only 5% inhibition at 66 μM, as well as isomaltase and trehalase (IC50= 97 and 160 μM, respectively). Australine (500 μg/ml) inhibits glycoprotein processing of viral glycoproteins in influenza virus-infected MDCK cells and induces the accumulation of glycoproteins.2 1.Molyneux, R.J., Benson, M., Wong, R.Y., et al.Australine, a novel pyrrolizidine alkaloid glucosidase inhibitor from Castanospermum australJ. Nat. Prod.51(6)1198-1206(1988) 2.Tropea, J.E., Molyneux, R.J., Kaushal, G.P., et al.Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processingBiochemistry28(5)2027-2034(1989) 3.Kato, A., Kano, E., Adachi, I., et al.Australine and related alkaloids: easy structural confirmation by 13C NMR spectral data and biological activitiesTetrahedron Asymmetry14(3)325-331(2003)

resorufin galactopyranoside is a fluorescent substrate for β-galactosidase.After cleavage by β-galactosidase, the fluorescent portion of resorufin is released and its fluorescence can be used to quantify β-galactosidase activity. It has an excitation light of 570 and an emission light of 580 nm.

Cyclic di-IMP (sodium salt) (c-di-IMP) is a synthetic second messenger structurally related to the bacterial second messengers cyclic di-GMP and cyclic di-AMP . C-di-IMP has adjuvant properties when co-administered with antigens in vitro and by mucosal routes in vivo. C-di-IMP enriches the population of MHC class I and II, CD80, CD86, CD40, and CD54 positive dendritic cells derived from murine bone marrow. It also stimulates macrophages at 500 ng/ml. Mice immunized with β-galactosidase (β-gal) plus c-di-IMP through the intranasal route show a humoral immune response, evidenced by an increase in IgG titers up to 2-fold compared to mice immunized with β-gal alone. Mice immunized with β-gal plus c-di-IMP also exhibit a Th1/Th2 response, indicating that the adjuvant activity of c-di-IMP leads to a cellular immune response as well.

(2R)-Glycerol-O-β-D-galactopyranoside is a substrate for β-galactosidase, the lactose repressor, the galactose-binding protein, and the β-methylgalactoside transport system. It also serves as a substrate for the third lac operon encoded enzyme, thiogalactoside transacetylase.

5-Fluorouridine 5'-O-β-D-galactopyranoside, also known as 5'-O-β-D-galactosyl-5-fluorouridine, is a prodrug of 5-Fluorouridine. 5-Fluorouridine 5'-O-β-D-galactopyranoside can be enzymatically converted by β-D-galactosidase into 5-Fluorouridine, which is a highly effective antineoplastic agent.

ONPG (2-Nitrophenyl β-D-galactopyranoside) is a colorimetric and spectrophotometric substrate used to detect β-galactosidase activity.

Ganglioside GM1is a monosialylated ganglioside and the prototypic ganglioside for those containing one sialic acid residue.1,2It is found in a large variety of cells, including immune cells and neurons, and is enriched in lipid rafts in the cell membrane.3It associates with growth factor receptors, including TrkA, TrkB, and the GDNF receptor complex containing Ret and GFRα, and is required for TrkA expression on the cell surface. Ganglioside GM1interacts with other proteins to increase calcium influx, affecting various calcium-dependent processes, including inducing neuronal outgrowth during differentiation. Ganglioside GM1acts as a receptor for cholera toxin, which binds to its oligosaccharide group, facilitating toxin cell entry into epithelial cells of the jejunum.4,5Similarly, it is bound by the heat-labile enterotoxin fromE. coliin the pathogenesis of traveler's diarrhea.6Ganglioside GM1gangliosidosis, characterized by a deficiency in GM1-β-galactosidase, the enzyme that degrades ganglioside GM1, leads to accumulation of the gangliosides GM1and GA1in neurons and can be fatal in infants.1Levels of ganglioside GM1are decreased in the substantia nigra pars compacta in postmortem brain from patients with Parkinson's disease.3Ganglioside GM1mixture contains a mixture of ovine ganglioside GM1molecular species with primarily C18:0 fatty acyl chain lengths, among various others. [Matreya, LLC. Catalog No. 1544] 1.Kolter, T.Ganglioside biochemistryISRN Biochem.506160(2012) 2.Mocchetti, I.Exogenous gangliosides, neuronal plasticity and repair, and the neurotrophinsCell Mol. Life Sci.62(19-20)2283-2294(2005) 3.Ledeen, R.W., and Wu, G.The multi-tasked life of GM1 ganglioside, a true factotum of natureTrends Biochem. Sci.40(7)407-418(2015) 4.Turnbull, W.B., Precious, B.L., and Homans, S.W.Dissecting the cholera toxin-ganglioside GM1 interaction by isothermal titration calorimetryJ. Am. Chem. Soc.126(4)1047-1054(2004) 5.Blank, N., Schiller, M., Krienke, S., et al.Cholera toxin binds to lipid rafts but has a limited specificity for ganglioside GM1Immunol. Cell Biol.85(5)378-382(2007) 6.Minke, W.E., Roach, C., Hol, W.G., et al.Structure-based exploration of the ganglioside GM1 binding sites of Escherichia coli heat-labile enterotoxin and cholera toxin for the discovery of receptor antagonistsBiochemistry38(18)5684-5692(1999)

D-Ribonolactone is sugar lactone and an inhibitor of β-galactosidase of Escherichia coli (Ki : 26 Mm).

Beta-gal-nonoate, a β-galactosidase dependent nitric oxide (NO) donor, releases NO upon activation by β-galactosidase. It exhibits bactericidal activity, thus serving as an effective bactericide [1].

Maltotriose is an inducer of E. coli maltose regulator, the second most abundant sugar in brewing. It induces beta-galactosidase synthesis.