Creative Enzymes is a well known enzymology research supplier serving the global enzyme industry. Our services cover a wide range of applications including pharmaceutical, chemical, and environmental sciences. With the unique advantage of excellence in enzymology and related experiment techniques, we have demonstrated reliability and accuracy of our assays that marks the first class in the field. Especially, we have brought the latest progresses in enzymology into activity tests of phosphorus transferases to satisfy the increasing demands from the customers.

Phosphotransferase, also known as phosphorus transferases and designated as EC 2.7, is a large enzyme category among all transferases. While EC 2.7 contains enzymes that specifically transfer phosphorus-containing groups, it also includes nucleotidyl transferases as well. These transferases are further classified into sub-categories based on the type of the acceptors, which include alcohols, carboxyl groups, nitrogenous groups, and phosphate groups. A majority of the EC 2.7 enzymes are kinases, including protein-tyrosine kinases and protein-serine/threonine kinases.

A protein kinase is an enzyme that modifies other proteins by phosphorylation, the chemical reaction that adds a phosphate group to the substrate. Phosphorylation usually changes the biological functions of the target protein, including changes in enzyme activity, cellular location, or interactions with other proteins. Thus, phosphorylation is a common and important regulatory mechanism of enzyme functions. Up to 30% of all human proteins may be modified by various kinases, in addition to other significant roles of kinases including signal transduction, transcription, mRNA processing, and the differentiation of nerve cell. As a keystone in cell cycle regulation, kinases are heavily studied during development of cancer treatment. While some kinase inhibitors just became available in the market as antitumor agents, such as imatinib and gefitinib, more kinase inhibitors are being investigated in the pipeline for the next generation of cancer therapy.

Besides the large number of kinases, other examples of typical EC 2.7 transferases are listed below:

• EC 2.7.1 Phosphotransferases with an alcohol group as acceptor
• EC 2.7.2 Phosphotransferases with a carboxyl group as acceptor
• EC 2.7.3 Phosphotransferases with a nitrogenous group as acceptor
• EC 2.7.4 Phosphotransferases with a phosphate group as acceptor

Most of these transferases bear other important functions other than phosphorylation of proteins. For example, many transferase enzymes participate in the phosphotransferase system (PTS). The PTS is a complex group translocation system present in many bacteria, which transports sugars, including glucose, mannose, and mannitol, into the cell. The transport starts with phosphorylation of the sugars and enables the downstream glycolysis pathway that generates essential energy for all cell activities by degrading the sugars to pyruvate.

The phosphotransferases accommodate a great variety of substrates, from small organic molecules to large proteins, which lead to complex assays when determining the enzyme activity. In addition, many kinases share high homology in amino acid sequences, which makes the activity assays further suffer from interferences among different types of kinases in a mixed enzyme system. At the same time, research interests have dramatically increased following the discovery of the critical roles of phosphotransferases in cell proliferation and signal transduction. Therefore, Creative Enzymes developed robust and customizable activity assays for phosphotransferases based on the expertise on enzymology.

Creative Enzymes puts customers’ satisfaction in the first place. We have worked closely with every client to deliver the precise results upon every request for all the industrial applications. Creative Enzymes has demonstrated high reliability in a wide range of enzyme applications and will continue to serve the customers in enzyme activity measurement of phosphotransferases.

Figure: The crystallographic structure of the complex of an inhibitors and receptor tyrosine-protein kinase erbB-2 (HER2), a kinase that is closely related to breast cancer.