Enzyme Activity Measurement for Isomerases

Creative Enzymes has been known for a prominent provider of enzyme services. We perform the most reliable activity assays for all classes of enzymes, especially for isomerases. The high quality of the test results have been rewarded with predominant market shares. Fully equipped with brilliant scientists and advanced instruments, we assure the testing results of isomerase assays in a professional and timely manner.

Isomerases, designated as EC 5, are a major class of enzymes that catalyze reactions involving a structural rearrangement of a molecule. Isomerases can either facilitate intramolecular rearrangements in which bonds are broken and formed or catalyze conformational changes. Isomerases are present in the metabolism and genome of most living organisms, catalyzing up to 4% of the biochemical reactions present in central metabolism, in particular, carbohydrate metabolism. Isomerases also play a critical role in the terpenoid/polyketide metabolic pathways, and both terpenoids and polyketides are important in generating secondary metabolites, especially in plants (Figure 1).

Figure 1: Biological importance of isomerases. Core metabolic pathways (the isomerase reactions are emboldened in black). Carbohydrate and terpenoid/polyketide metabolic pathways are highlighted in blue and green squares.
Reference: Cuesta S M, Furnham N, Rahman S A, et al. Current opinion in structural biology, 2014, 26: 121-130.

Isomerases are grouped according to the chemistry of the reactions that they catalyze, including 6 subclasses, 17 sub-subclasses, and 231 serial numbers, which are correlated with almost 300 biochemical reactions (Figure 2).

Figure 2: EC classification of isomerases.
Reference: Cuesta S M, Furnham N, Rahman S A, et al. Current opinion in structural biology, 2014, 26: 121-130.

• EC 5.1: Racemases and epimerases. This category inverts stereochemistry at the target chiral carbon. Racemases act upon molecules with one chiral carbon for inversion of stereochemistry, whereas epimerases target molecules with multiple chiral carbons and act upon one of them. These enzymes are subdivided according to their substrates: amino acids (EC 5.1.1), hydroxy acids (EC 5.1.2), carbohydrates and derivatives (EC 5.1.3), or other compounds (EC 5.1.99).
• EC 5.2: Cis-trans-isomerases. These enzymes rearrange the geometry at double bonds.
• EC 5.3: Intramolecular oxidoreductases. These enzymes catalyze the oxidation of one part of a molecule with a corresponding reduction of another part. They include sugar isomerases (EC 5.3.1), tautomerases (EC 5.3.2), enzymes shifting a C=C bond from one position to another (EC 5.3.3), enzymes transposing S-S bonds (EC 5.3.4), and other isomerases (EC 5.3.99).
• EC 5.4: Intramolecular transferases catalyze transfer of functional groups from one part of a molecule to another, including acyl (EC 5.4.1), phospho (EC 5.4.2), amino (EC 5.4.3), hydroxy (EC 5.4.4) or other groups (EC 5.4.99) from one position to another.
• EC 5.5: Intramolecular lyases. These enzymes catalyze reactions in which a group can be regarded as eliminated from one part of a molecule, leaving a double bond, while remaining attached to the molecule covalently.
• EC 5.99: A subclass of miscellaneous enzymes.

Isomerases can be used in many applications. For instance, in metabolic engineering, xylose isomerase (EC 5.3.1.5) has been traditionally used to convert glucose to fructose in the syrup industry and has recently been engineered to increase the yield of alcohol-based biofuels in S. cerevisiae. In organic synthesis, several racemases and epimerases (EC 5.1) have been exploited in resolving racemic mixtures in mild conditions and for the production of stereochemically pure amino acids. Efforts in enzyme design have also managed to successfully convert racemases and epimerases acting on amino acids and derivatives (EC 5.1.1) into enzymes with lyase activity (EC 4). Note that, some racemases and epimerases acting on amino acids are also targets for the development of antimicrobial drugs and the treatment of neuropathological disorders. Therefore, to investigate the functional significance of these isomerases, the essential first step is to monitor the activity of isomerases accurately and efficiently.

Creative Enzymes has been diligent in development and optimization of accurate activity assays for isomerases. Through years of testing and exploring, we have accumulated extensive research experience and are able to test isomerases either as a routine sample or from unique sources. Our state-of-the-are facility and quality management system are the strong support to the promise of 100% customer satisfaction. Overall, Creative Enzymes will always be your best partner in achieving business success.