Functional Assays

The MLL1 (KMT2A): WDR5 Binding Chemiluminescent Assay Kit is an ELISA-based assay designed to measure the binding between MLL1 (mixed lineage leukemia protein-1, also known as KMT2A) and WDR5 (WD40 repeat-containing protein 5) for screening and profiling applications. The MLL1 (KMT2A): WDR5 Binding Chemiluminescent Assay Kit comes with enough purified MLL1 (amino acids 3745-end) and WDR5 proteins, primary and secondary antibody, assay buffer, and detection reagent for 100 enzyme reactions. A 96-well plate is coated with MLL1 protein. After coating and blocking, WDR5 is added in an optimized assay buffer. Unbound WDR5 is washed away, and the plate is incubated with a primary antibody followed by a secondary HRP-conjugated antibody. Finally, ELISA ECL substrate is added to produce chemiluminescence that can be measured using a chemiluminescence reader. The chemiluminescence signal is proportional to the efficacy of WDR5 binding to MLL1 (KMT2A).

The MLL4 (KMT2B): WDR5 Binding Chemiluminescent Assay Kit is an ELISA-based assay designed to measure the binding between MLL4 (mixed lineage leukemia protein-4, also known as KMT2B) and WDR5 (WD40 repeat-containing protein 5) for screening and profiling applications. The MLL4 (KMT2B): WDR5 Binding Chemiluminescent Assay comes with enough purified MLL4 (amino acids 2490-2715) and WDR5 proteins, primary and secondary antibody, assay buffer, and detection reagent for 100 enzyme reactions. A 96-well plate is coated with MLL4 protein. After coating and blocking, WDR5 is added in an optimized assay buffer. Next, unbound WDR5 is washed away, and the plate is incubated with a primary antibody followed by a secondary HRP-conjugated antibody. Finally, ELISA ECL substrate is added to produce chemiluminescence that can be measured using a chemiluminescence reader. The chemiluminescence signal is proportional to the efficacy of WDR5 binding to MLL4 (KMT2B).

The Chemi-Verse™ EGFR Kinase Assay Kit is designed to measure EGFR (epidermal growth factor receptor) kinase activity for screening and profiling applications using ADP-Glo™ as a detection reagent. The assay kit comes in a convenient 96-well format, with enough recombinant purified EGFR (amino acids 668-1210), kinase substrate, ATP, and kinase assay buffer for 100 enzyme reactions.

The TSLPR:TSLP [Biotinylated] Inhibitor Screening Chemiluminescence Assay Kit is designed for screening and profiling molecules that block the binding between TSLPR (thymic stromal lymphopoietin receptor) and TSLP. This kit comes in a convenient 96-well format, with enough recombinant human biotin-labeled TSLP (amino acids 29-159), human TSLP-R (amino acids 25-231), streptavidin-HRP, and assay buffer for 100 reactions. A 96-well plate  is coated with TSLPR protein. After blocking, the plate is pre-incubated with an inhibitor or neutralizing antibody. After incubation with Biotin-TSLP, the plate is washed and Streptavidin-HRP is added. The ELISA ECL substrate is added  and the resulting signal can be measured using a chemiluminescence microplate reader. The chemiluminescence signal is proportional to the binding of TSLPR to TSLP.

The BLM Helicase Activity Assay Kit is a fluorogenic assay designed for screening and profiling of BLM (Bloom syndrome protein) antagonists/inhibitors by monitoring their inhibitory effects on BLM-catalyzed DNA unwinding. The BLM Helicase Activity Assay Kit comes in a convenient 96-well format, with enough purified recombinant BLM (amino acids 630-1300), ATP, DNA substrate, assay buffer, and additives for 100 reactions. The DNA substrate is conjugated on one strand with the TAMRA (tetramethylrhodamine) fluorophore, and on the other strand with BHQ (Black Hole Quencher) which effectively quenches TAMRA fluorescence due to their proximity within the DNA double strand. BLM unwinding of the DNA probe separates the two strands, releasing TAMRA fluorescence. BLM activity, therefore, results in a proportional increase in fluorescence.

Cytoplasmic isocitrate dehydrogenase (ICDHc, EC 1.1.1.42) is widely distributed in animals, plants, microorganisms, and cultured cells. It catalyzes the decarboxylation and dehydrogenation of isocitrate to produce α-ketoglutarate, while simultaneously reducing NADP+ to NADPH. ICDHc serves as another significant source of NADPH in the cytoplasm, apart from the pentose phosphate pathway, and its activity often undergoes notable changes under stress conditions. CheKine™ Micro Isocitrate Dehydrogenase Cytoplasmic (ICDHc) Activity Assay Kit is capable of detecting cytosolic isocitrate dehydrogenase (ICDHc) activity in animal and plant tissues, cells, or bacteria, as well as in serum (plasma). The principle behind this involves utilizing ICDHc's catalytic action in reducing NADP+ to NADPH, with the subsequent increase in NADPH concentration being measured at a wavelength of 340 nm.

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.