Enzyme Activity Measurement for 1,4-Alpha-Glucan Branching Enzyme Using Spectrophotometric Assays

Creative Enzymes is a leading company providing high-quality bioanalytical services and customized contract research specialized in enzyme activity analysis. We serve the needs of numerous clients from the pharmaceutical, biotechnological and chemical industry. Fully equipped with the most advanced spectrophotometric instruments, we are proud to offer the reliable activity assay for 1,4-alpha-glucan branching enzyme in a professional and timely manner.

1,4-Alpha-glucan branching enzyme belongs to the α-amylase family 13 containing three domains: an amino-terminal domain, involved in determining the length of the chain transfer, a carboxyl-terminal domain, involved in substrate preference and catalytic capacity, and a central (α/β) barrel catalytic domain. 1,4-Alpha-glucan branching enzyme (EC 2.4.1.18, 1,4-alpha-D-glucan:1,4-alpha-D-glucan 6-alpha-D-(1,4-alpha-D-glucano)-transferase) has an important role in the determination of the structure of starch in plants and of glycogen in animals and bacteria as it transfers α-1,4-linked glucose units from the outer non-reducing end of a glycogen chain into a α-1,6 position of the same or neighboring chain, thereby creating glycogen branches. Starch and glycogen are megadalton-sized glucose polymers and serve as the major reservoir of readily available energy and carbon compounds in most living organisms, ranging from archaea, bacteria and yeasts, up to higher eukaryotes including plants and animals. The growth in the glycogen chain relies on branching enzymes such as 1,4-alpha-glucan branching enzyme. The branching reaction increases the number of non-reducing ends and makes glycogen more reactive to synthesis and digestion. It is also essential for assuring solubility of glycogen in the cell. Glycogen supplies in the liver are essential for maintaining blood glucose homeostasis, while cardiac and skeletal muscle glycogen are used to fuel muscle contraction. Accumulation of insoluble glycogen in the cell is known as glycogen storage disease type IV (GSD IV) and is caused by mutations of 1,4-alpha-glucan branching enzyme. GSD IV in its different forms affects the liver, muscular tissue, or the central and peripheral nervous system. Therefore, it can be concluded that 1,4-alpha-glucan branching enzyme has a central role in treating the disease. This enzyme can be also used in the production of food ingredients and dietary nutrition.

Creative Enzymes is fully competent to supply the accurate activity assay for 1,4-alpha-glucan branching enzyme. The activity of this enzyme can be determined by spectrophotometrically measuring the decrease in absorbance of the visible light at 520nm, although other technical difficulties, such as solubility of the substrate and incubation conditions, may still trouble the activity assay. Nonetheless, Creative Enzymes is engaged in providing the best technical support and personalized customer service for all industries.

Figure: The crystal structure of human glycogen branching enzyme (GBE1).
PDB: 4BZY