Functional Assays

The BLM helicase, also known as Bloom syndrome protein, is a key enzyme involved in DNA replication and repair (DDR). The BLM helicase is a member of the RecQ family of helicases, which are evolutionarily conserved and found in many organisms, including bacteria, yeast, and humans. It catalyzes the unwinding of duplex DNA with 3' to 5' directionality, driven by the energy generated from ATP hydrolysis. BLM plays a crucial role in maintaining genomic stability by unwinding DNA structures during processes such as DNA replication, recombination, and repair. Mutations in the BLM gene can lead to Bloom syndrome, a rare genetic disorder characterized by growth deficiency, sun-sensitive skin lesions, and an increased risk of cancer. High expression of BLM is found in glioblastoma, and it was found that inhibition of its activity leads to increased susceptibility to treatment with drugs targeting other proteins involved in DDR, such as PARP1 (poly-ADP ribosylation protein 1). The use of BLM in

β-glucuronidase (β-GD), a matrix degradation enzyme involved in tumor invasion and metastasis, is widely found in animal tissues. It has physiological functions such as hydrolyzing sterol glucuronic acid and acidic mucopolysaccharide. The content of this enzyme is high in hepatocytes. In addition, it is rich in gastric cancer, so the determination of β-GD activity in gastric juice is of great significance for the study of gastric cancer. CheKine™ Micro β-glucuronidase (β-GD) Activity Assay Kit can detect animal tissues. In this kit, β-GD catalyzed phenol β-D-glucuronic acid to produce free phenolphthalein, and the enzyme activity was determined by determining the content of phenol.

Asparagine synthetase (AS) is a widely distributed enzyme in living organisms belonging to the class of amino transferases. It catalyzes the transfer of an amine group from glutamine to aspartic acid. When a plant is subjected to ammonia toxicity, the formation of asparagine serves as a detoxification mechanism. CheKine™ Micro Asparagine Synthetase (AS) Activity Assay Kit is designed to quantify asparagine synthetase activity in animal and plant tissues, bacterial and cellular samples, as well as in serum (plasma). The assay principle relies on the AS enzyme's ability to catalyze the hydrolysis of L-asparagine into L-aspartic acid and ammonia. By employing Nessler's reagent to detect the rate of ammonia accumulation, the enzymatic activity of AS can be determined.

Nitrate reductase (NR, EC1.7.1.3) exists widely in plants. It is not only the key enzyme for the conversion of nitrate nitrogen to ammonia nitrogen, but also an inducing enzyme, which has an effect on the yield and quality of crops. CheKine™ Micro Nitrate Reductase (NR) Activity Assay Kit allows for the detection of nitrate reductase activity in plant tissues, bacterial, or cellular samples. The principle behind this assay involves NR catalyzing the reduction of nitrate to nitrite, following the reaction:NO3ˉ+NADH+H＋ →NO2ˉ+NAD＋ +H2O. The resulting nitrite, under acidic conditions, then reacts quantitatively with p-amino benzenesulfonic acid and α-naphthylamine to produce a red azo compound. This red azo compound exhibits a maximum absorption peak at 540 nm, which can be measured by spectrophotometry, thereby enabling the quantification of nitrate reductase activity in the sample.

Nitrite reductase (NiR) is a crucial enzyme in the reduction process of nitrite nitrogen and plays a vital role in the nitrogen cycle of nature. It is widely distributed in microorganisms and plants, capable of catalyzing the reduction of nitrite, thereby decreasing the accumulation of nitrite nitrogen in the environment and alleviating its toxic effects on the growth and development of organisms. CheKine™ Micro Nitrite Reductase (NiR) Activity Assay Kit is designed to quantify nitrite reductase activity in plant tissues, bacterial, and fungal samples. It operates on the principle that nitrite reductase catalyzes the reduction of NO2- to NO, thereby reducing the amount of NO2- available in the sample to participate in diazotization reactions that form a purple-colored compound. The change in absorbance at 540 nm reflects the activity of NiR in the sample.