Creative Enzymes is a leading company of high-quality bioanalytical services and customized contract research specialized in enzyme activity analysis. We satisfy the needs of countless clients from pharmaceutical, biotechnological, and diagnostic industries. Fully equipped with the most advanced spectrophotometric instruments, Creative Enzymes assures the performance of its tests in a professional and timely manner. Herein, we provide the rapid and precise activity assay for guanylate kinase.

Guanylate kinase (EC 2.7.4.8; ATP:(d) GMP phosphotransferase) catalyzes the reversible phosphorylation of GMP and dGMP to GDP and dGDP, respectively. Guanylate kinase is essential for converting GMP to GDP and thus for synthesis of GTP. This enzyme also functions in the recycling of cGMP, and this activity is considered to regulate the supply of guanosine nucleotides to signal transduction pathway components, such as cGMP, GMP, GDP, GTP, and cGMP. As a critical enzyme involved in nucleotide metabolism, guanylate kinase is a target for antineoplastic agents. Besides, this enzyme is also inhibited by the potent antitumor drug 6-thioguanine. Furthermore, guanylate kinase is correlated with the potential antiviral activity in virus-infected cells. For instance, activation of guanosine analogs acyclovir and ganciclovir after a first phosphorylation step by the herpes viral thymidine kinase is conducted by guanylate kinase.

Owning to the central role that guanylate kinase plays in antiviral and antineoplastic drug activation, it is considerably important to be able to monitor the activity of this enzyme. Activity measurement could be challenging but will shed light on the design of new drugs as therapeutic solutions. Fortunately, Creative Enzymes is fully prepared to provide the most accurate enzyme activity assay for guanylate kinase. Creative Enzymes owns the latest technology, the professional knowledge, and the most up-to-date equipment, which can support your research in a remarkable way. For details, the activity of guanylate kinase is determined by using a lactate dehydrogenase-pyruvate kinase coupled method. It measures the product by coupling their formation to the oxidation of NADH in the presence of non-limiting concentrations of phosphoenolpyruvate, pyruvate kinase, lactate dehydrogenase, and NADH. The decrease in absorbance at 340 nm is monitored spectrophotometrically.

With years of discovery in enzymology, Creative Enzymes has emerged as a worldwide leader in the supply of enzyme assays. We are able to work together with our customers through the process to solve sophisticated problems or optimize the operations. Working closely with the customers is important to method development because of the technical nature of enzymes. So far, the strategy has brought thousands of loyal to Creative Enzymes, and we expect to work with you soon in the future.

Figure: The crystal structure of oligomeric E.coli guanylate kinase in complex with GMP.
PDB: 2ANB