Enzyme Activity Measurement of Carboxylate Reductase

Creative Enzymes is a pioneer in enzyme activity determination. Our extensive experiences in providing fast and effective testing methods guarantee the accurate assay results. Besides, we have the capability to provide measurement under strict anaerobic conditions for some unique enzymes, such as carboxylate reductase.

Carboxylate reductase belongs to the tungsten-containing aldehyde oxidoreductases (AOR) family. As a common structure of the AOR family, the tungsten ion resides in the enzymatic active site ligated by two pyranopterin cofactors and an oxo group. In addition to pyranopterin, molybdopterin, pterin, and FAD (flavin adenine dinucleotideare) are also found to be cofactors. This enzyme catalyzes the dehydrogenation of various aldehydes as well as the reduction of non-activated carboxylates to aldehydes. The catalysis reaction needs electron acceptors, such as benzyl viologen and methyl viologen which serve as artificial electron acceptors rather than NAD(P). This enzyme can act on several aldehydes such as acetaldehyde, butyraldehyde, and benzaldehyde to form the corresponding acids. In the reverse direction, non-activated acids are reduced by viologens to give aldehydes, but not the corresponding alcohols. In nature, carboxylate reductase has mainly been isolated from hyperthermophilic archaea such as Pyrococcus furiosus and Thermococcus litoralis, and from acetogenic bacteria such as Moorella thermoacetica and Clostridium formicoaceticum.

This enzyme participates in the most important chemical compound metabolism in microorganism, the pyruvate metabolism. Through the mutual transformation of acetate and acetaldehyde, this enzyme can balance the level of aldehyde and carboxylate. The applications of this enzyme have gradually aroused attentions. Many aldehydes serve as good substrates for this enzyme, and thus the enzyme activity is allowed to be modified to target only specific substrates, which becomes useful in synthetic biology. The activity measurement of this enzyme needs special cautions and handling. It has been reported that the enzyme activity sharply decreases in the presence of oxygen. For example, the enzyme from Clostridium formicaceticum is very sensitive to oxygen, especially in the reduced state, and the reduced enzyme loses 80% of the activity after 10 min. To avoid the influence of oxygen, Creative Enzymes performs completely anaerobic assays to guarantee the accuracy of the results.

Creative Enzymes is one of the few companies that provide enzyme activity testing services for carboxylate reductase. We have established a perfect quantification system for enzymes that could be deactivated by oxygen. With unique techniques such as anaerobic assays, Creative Enzyme will continue to be your top choice in enzyme activity determination in the future.

Figure: The carboxylate reductase cofactor pyranopterin.