Enzyme Substrates

5-Bromo-4-chloro-3-indolyl b-D-galactofuranoside is a chromogenic substrate used to detect the specific enzymatic activity of beta-D-galactofuranosidase. After cleavage, 5-bromo-4-chloro-indoxyl is released, resulting in a blue to blue-green color change in bacterial colonies or media. 5-Bromo-4-chloro-3-indolyl b-D-galactofuranoside is used in assays for detecting bacterial pathogens (e.g., Mycobacterium tuberculosis).

Ostazin Brilliant Red H-3B is a water soluble, non-toxic, and non-hazardous substrate for enzymes that catalyze reactions involving the cleavage of β-D-glucosides. It is used as a chromogenic or fluorogenic substrate in diagnostic tests. Ostazin Brilliant Red H-3B can also be used in bioluminescence reaction with luciferase to measure ATP levels in living cells.

L-Lysyl-L-alanine 7-amido-4-methylcoumarin dihydrochloride is a fluorogenic peptide substrate for aminopeptidase. This AMC peptide substrate is normally used to rapidly profile the N-terminal specificity of proteases.

4-Nitrophenyl b-D-cellotetraoside is a chromogenic substrate utilized for the detection and quantification of cellulase enzyme activity. Cellulase enzymes hydrolyze the beta-1,4-glycosidic bonds of cellulose, a major component of plant cell walls. Upon cleavage by cellulase, it releases 4-nitrophenol, a compound that exhibits a yellow color and absorbs strongly at 405 nm, allowing for easy spectrophotometric measurements of cellulase activity levels in various sample types, including bacterial and fungal cultures, environmental samples, and industrial applications.

4-Methylumbelliferyl 2-deoxy-2-sulfamino-a-D-glucopyranoside sodium salt (M3A or MU-GlcNS) is a fluorogenic substrate of heparin sulfamidase, used in the diagnosis of Mucopolysaccharidosis III type A (MPS III A). MPS III A, also known as Sanfilippo syndrome type A, is caused by the deficiency of heparan N-sulfatase. Heparin sulfamidase in the assay desulfates MU-GlcNS to 4-methylumbelliferyl 2-amino-2-deoxy-α-D-glucopyranoside (MU-GlcNH2). To release fluorometrically measurable 4-methylumbelliferone (MU) and by-product glucosamine, MU-GlcNH2 is further hydrolysed by an enzyme such as yeast α-glucosidase during a second incubation.

Aldol® 458 phosphate is a chromogenic and fluorogenic enzyme substrate used for detection of phosphatase activity. The colorless enzyme substrate is cleaved by phosphatases secreted by bacteria grown in liquid media, yielding yellow color and green fluorescence. Aldol® 458 phosphate can also be used in assays involving phosphatase-coupled antibodies in immunoassay applications (ELISA). Aldol® 458 phosphate can be used under aerobic and anaerobic conditions.

Chromogenic substrate for fucosyltransferases

4-Methylumbelliferyl alpha-D-glucosaminide is a fluorogenic substrate for alpha-N-acetylglucosaminidase. After enzymatic cleaveage, free 4-methylumbelliferone (also known as hymecromone) is released, exhibiting blue fluorescence upon excitation with UV light. The strongest fluorescence of 4-methylumbelliferone requires deprotonation of the hydroxyl group (thus requires alkaline pH), with a maximal fluorescence intensity obtained with excitation at 350 to 370 nm and emission at 440 to 470 nm. The use of 4-methylumbelliferyl alpha-D-glucosaminideas a substrate for measuring the alpha-N-acetylglucosaminidase activity is used for Sanfilippo syndrome B and Mucopolysaccharidosis IIIB (MPS IIIB) diagnosis.

5-Bromo-4-chloro-3-indoxyl oleate is a chromogenic substrate used to detect the specific enzymatic activity of lipase. After cleavage, 5-bromo-4-chloro-indoxyl is released, resulting in a blue to blue-green color change in bacterial colonies or media. 5-Bromo-4-chloro-3-indoxyl oleate is used in lipid metabolism disorder screening.

6'-(Diethylamino)spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3'-yl b-D-glucopyranoside is a fluorogenic substrate that is used in diagnostic applications. It has been shown to be a useful ligand for the determination of enzyme activity, and it can also be used to detect bacterial culture media contaminants. 6'-(Diethylamino)spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3'-yl b-D-glucopyranoside is used as an enzyme substrate in chemiluminescent assays, and with other reagents, it can be used for the detection of environmental contaminants. This product has a CAS number of 55426-02-8 and can be found on the website www.sigmaaldrich.com/catalog/product

5-Bromo-6-chloro-3-indolyl a-D-galactopyranoside is a chromogenic substrate that yields a magenta-colored product after cleavage. The chromophore 5-bromo-6-chloro-indoxyl is released, generating the observable color. It is used in glycolipid metabolism studies.

Resorufin b-D-xylobioside is a fluorogenic substrate for xylanases useful for xylanase activity assays.

Fluorogenic substrate for esterase yielding a blue fluorescent solution upon cleavage.

5-Bromo-4-chloro-3-indolyl a-D-mannopyranoside is a chromogenic substrate used to detect the specific enzymatic activity of alpha-mannosidase. After cleavage, 5-bromo-4-chloro-indoxyl is released, resulting in a blue to blue-green color change in bacterial colonies or media. 5-Bromo-4-chloro-3-indolyl a-D-mannopyranoside is used in alpha-mannosidosis diagnosis and other lysosomal storage disorder.

DMNPE-caged form of luciferin

A fluorogenic substrate for detection of enzymatic activity of the SARS-CoV-2 Mpro protease. The fluorophore 7-Amino-4-methylcoumarin (AMC) is linked to the tetrapeptide via a peptide bond at the C-terminal of the glutamine residue. Following the hydrolytic activity of the Mpro protease, the fluorogenic AMC group get released from the substrate, generating a fluorescent signal (Ex 380 nm / Em 455 nm).