| Description | Pyruvate phosphate dikinase (PPDK, EC 2.7.9.1) is a rate-limiting enzyme in the C4 pathway and Crassulacean acid metabolism (CAM) pathway. It catalyzes the three-step conversion of ATP, pyruvate, and Pi to phosphoenolpyruvate. This enzyme is primarily located in the chloroplast stroma of C4 plants Pyruvate phosphate dikinase (PPDK, EC 2.7.9.1) is a rate-limiting enzyme in the C4 pathway and Crassulacean acid metabolism (CAM) pathway. It catalyzes the three-step conversion of ATP, pyruvate, and Pi to phosphoenolpyruvate. This enzyme is primarily located in the chloroplast stroma of C4 plants and plays a crucial regulatory role in photosynthetic function.Assay Principle The reverse reaction catalyzed by PPDK converts phosphoenolpyruvate, AMP, and PPi into pyruvate, ATP, and Pi. Lactate dehydrogenase then further catalyzes the reaction of pyruvate and NADH to produce lactate and NAD+. The decrease in NADH is measured at 340 nm, and the rate of this decrease is used to calculate PPDK activity.Component50TStorageExtraction Buffer60 mL2-8℃Reagent 160 mL2-8℃Reagent 22 EA-20℃Reagent 360 µL2-8℃Note for Reagent 3: The volume is small. If the liquid is on the tube wall, briefly centrifuge before use.User-Prepared Instruments & MaterialsUV spectrophotometer, benchtop centrifuge, adjustable pipettes, 1 ml quartz cuvette, mortar, ice, and distilled water.Sample PreparationHomogenize the tissue sample in ice-cold Extraction Buffer using a mortar and pestle, using a ratio of 1:5 to 1:10 (tissue weight (g) : Extraction Buffer volume (mL)). (It is recommended to weigh about 0.1 g of tissue and add 1 mL of Extraction Buffer). Centrifuge the homogenate at 8000 g, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.Assay Procedure1. Spectrophotometer Setup: Preheat the spectrophotometer for at least 30 minutes. Set the wavelength to 340 nm. Zero the instrument with distilled water.2. Sample Measurement:2.1 Working Solution Preparation: Just before use, add one vial of Reagent 2 to 25 mL of Reagent 1 and add 12.5 µL of Reagent 3. Mix thoroughly and incubate at 37°C for 5 minutes. Any unused solution should be aliquoted and stored at -20°C. Avoid repeated freeze-thaw cycles.2.2 Reaction Setup: Add 50 µL of the sample supernatant and 950 µL of the Working Solution into a 1 mL quartz cuvette. Mix immediately and record the initial absorbance value at 340 nm (A1). After incubating at 37°C for exactly 5 minutes, record the absorbance value again (A2). Calculate ΔA = A1 - A2. PPDK Activity Calculation 1. Based on Sample Protein Concentration: Unit Definition: One unit of enzyme activity is defined as the amount that consumes 1 nmol of NADH per minute per mg of protein. Formula: PPDK Activity (nmol/min/mg prot) = [ΔA × V total_reaction ÷ (ε × d) × 10⁹] ÷ (V sample × Cpr) ÷ T = 643 × ΔA ÷ Cpr 2. Based on Sample Fresh Weight: Unit Definition: One unit of enzyme activity is defined as the amount that consumes 1 nmol of NADH per minute per gram of fresh tissue. Formula: PPDK Activity (nmol/min/g fresh weight) = [ΔA × V total_reaction ÷ (ε × d) × 10⁹] ÷ (W × V sample ÷ V total_extract ) ÷ T = 643 × ΔA ÷ WParameters Explanation: V total reaction : Total reaction volume, 1 × 10⁻³ L ε: Molar extinction coefficient of NADH, 6.22 × 10³ L/mol/cm d: Light path of the cuvette, 1 cm V sample : Volume of sample supernatant added, 0.05 mL V total extract : Total volume of extraction buffer added, 1 mL T: Reaction time, 5 min Cpr: Sample protein concentration, mg/mL W: Sample mass, g Notes It is essential to perform a preliminary assay using 2-3 samples expected to have significant activity differences before formal testing... Read More | Products Content:F666101Component500 U5000 UStorageF666101AFastStar Probe Buffer (for bisDNA)2×1.2 mL2×12 mL-20℃. Avoid freeze/thaw cycle. Protect from light.F666101BSuperFastStar DNA Polymerase (5U/µL)100 µL1 mL-20℃. Avoid freeze/thaw cycle. Protect from light.Products Content:F666101Component500 U5000 UStorageF666101AFastStar Probe Buffer (for bisDNA)2×1.2 mL2×12 mL-20℃. Avoid freeze/thaw cycle. Protect from light.F666101BSuperFastStar DNA Polymerase (5U/µL)100 µL1 mL-20℃. Avoid freeze/thaw cycle. Protect from light.Products IntroductionThis product is mainly used for PCR using bisulfite-treated DNA as template, in which SuperFastStar DNA Polymerase is a new high-efficiency hot-start enzyme modified by bis-monoclonal antibody, which is completely blocked at room temperature, thus effectively avoiding non-specific amplification caused by the non-specific binding of the primer to the template or the primer dimerization under the condition of room temperature. The optimized FastStar Probe Buffer (for bisDNA) contains PCR Buffer, dNTPs and Mg2+, etc., which is easy to use as customers only need to add templates, primers and probes.caveat1 Before use, please mix the product gently by turning it up and down after it has been completely melted and centrifuged briefly.2. Avoid repeated freezing and thawing of the product, which may degrade its performance. This product can be stored at -20℃ for a long period of time, protected from light. If frequent use is required within a short period of time, it can be stored at 2-8℃.Usage The following examples are conventional PCR reaction systems and conditions, which should be improved and optimized according to the template, primer structure and target fragment size.1.PCR reaction system Note: 1) Usually, better results can be obtained with a primer concentration of 0.2 µM, and 0.1-1.0 µM can be used as a reference for setting the range.2）The concentration of the probe used is related to the fluorescence quantitative PCR instrument used, the type of probe, and the type of fluorescent labeling substance, so please refer to the instrument manual or the specific requirements for the use of each fluorescent probe to adjust the concentration.3）Usually the amount of DNA template is 10-100 ng of genomic DNA or 1-10 ng of cDNA as a reference. Since the templates of different species contain different copy numbers of the target gene, the templates can be diluted in gradients to determine the optimal amount of template to use.2.PCR reaction conditionsNote: 1) The initial denaturation of this product at 95°C for 30s is sufficient for enzyme activation; complex templates can be extended to 3min denaturation.(2) It is recommended to use two-step PCR reaction program, if you can't get good experimental results due to the use of primers with lower Tm value, etc., you can try three-step PCR amplification, and the annealing temperature should be set in the range of 56℃-64℃ as a reference... Read More | Inquire | Inquire | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export |