Functional Assays

ADP-glucose pyrophosphorylase (AGP, EC2.7.7.21) mainly exists in plants, glucose-1-phosphoric acid catalytic reaction with ATP generation of starch synthesis precursor ADPG directly, is the main limiting step of plant starch biosynthesis. CheKine™ Micro ADP-Glucose Pyrophosphorylase (AGP) Activity Assay Kit can detect plant tissues. In this kit, the reverse reaction catalyzed by AGP generates G1P, and the hexose phosphate mutase and glucose 6-phosphate dehydrogenase added to the reaction system catalyze 6-phosphogluconic acid and NADPH in turn. The AGP activity can be calculated by measuring the increase rate of NADPH at 340 nm.

Soluble starch synthase (SSS, EC2.4.1.21) exists in the starch body in a free state, catalyze the starch chain elongation reaction, and is mainly responsible for the synthesis of amylopectin. CheKine™ Micro Soluble Starch Synthase (SSS) Activity Assay Kit can detect plant tissues. In this kit, SSS catalyzes the reaction between ADPG and starch primers (glucan), transfers glucose molecules to starch primers, and generates ADP at the same time. Furthermore, the addition of pyruvate kinase, hexokinase and glucose 6-phosphate dehydrogenase in the reaction system catalyzed the reduction of NADP+to NADPH in turn, where the amount of NADPH generated was proportional to the amount of ADP generated in the previous reaction. SSS activity could be calculated by measuring the increase of NADPH at 340 nm.

Granule-bound starch synthase (GBSS, EC2.4.1.21) exists in the starch body in a bound state, catalyze the starch chain elongation reaction, and is mainly responsible for the synthesis of amylopectin. CheKine™ Micro Granule-Bound Starch Synthase (GBSS) Activity Assay Kit can detect plant tissues. In this kit, GBSS catalyzes the reaction between ADPG and starch primers (glucan), transfers glucose molecules to starch primers, and generates ADP at the same time. Furthermore, the addition of pyruvate kinase, hexokinase and glucose 6-phosphate dehydrogenase in the reaction system catalyzed the reduction of NADP+to NADPH in turn, where the amount of NADPH generated was proportional to the amount of ADP generated in the previous reaction. GBSS activity could be calculated by measuring the increase of NADPH at 340 nm.

Cellulose (CLL) is a large polysaccharide molecule composed of glucose units, typically associated with hemicelluloses, pectins, and lignin, serving as the primary structural component of plant cell walls. It is a significant dietary fiber and the most abundant and widely distributed polysaccharide in nature. CheKine™ Mirco Cellulose (CLL) Concent Assay Kit offers a simple, convenient, and rapid approach for assessing CLL activity, which is suitable for plant tissue samples. The principle involves cellulose, a polymer of β-glucose residues, decomposing into β-glucose under acidic conditions upon heating. Under strong acid conditions, β-glucose can dehydrate to form β-furfural compounds. These β-furfural compounds then undergo dehydration condensation with anthrone to generate furfural derivatives. The depth of the resulting color can be indirectly quantified to determine the cellulose content.

Lipase (LPS), also known as glycerol ester hydrolase, catalyzes the hydrolysis of triglycerides to produce free fatty acids and glycerol (or di- and mono-glycerides). LPS is widely distributed in various organisms. Elevated levels of LPS in the serum are commonly observed in pancreatitis and pancreatic cancer. CheKine™ Micro Acid Phosphatase (ACP) Activity Assay Kit provides a simple, convenient, and rapid method for detecting LPS activity, applicable to samples such as animal and plant tissues, cells, serum, and plasma. It works by having LPS catalyze the hydrolysis of oil esters into fatty acids, and by measuring the rate of fatty acid production using the copper soap method, the LPS activity can be calculated.

Invertase (Ivr) catalyzes the irreversible decomposition of sucrose into fructose and glucose, and is one of the key enzymes in sucrose metabolism in higher plants. According to the optimal pH, higher plant Ivr can be divided into acidic invertase (AI) and Neutralinvertase (NI) types. CheKine™ Micro Neutral Invertase (NI) Activity Assay Kit can detect plant tissues samples. In this kit, NI catalyzes sucrose decomposition to produce reducing sugar, which further reacts with 3,5-dinitrosalicylic acid to produce brown-red amino compounds, which have characteristic light absorption at 540 nm, and the light absorption value at 540 nm is proportional to the amount of reducing sugar generation in a certain range. NI activity was calculated by increasing rate of light absorption.

ACP (Acid Phosphatase) catalyzes the hydrolysis of phosphomonoesters into inorganic phosphate under acidic conditions, commonly found within lysosomes of macrophages. ACP is frequently employed as an auxiliary diagnostic tool for prostate cancer. CheKine™ Micro Acid Phosphatase (ACP) Activity Assay Kit provides a simple, convenient, and rapid method for determining ACP activity, applicable to a variety of samples including plant and animal tissues, serum, and plasma. Its principle relies on the ACP-catalyzed hydrolysis of sodium phenyl phosphate to produce phenol in an acidic milieu; subsequently, phenol reacts with 4-aminoantipyrene and potassium ferricyanide to form a red quinone derivative which exhibits characteristic light absorption at 510 nm. By measuring the rate of increase in absorbance at 510 nm, the ACP activity can be calculated.

Chalcone isomerase (CHI) is the first recognized enzyme related to flavonoid synthesis and one of the key enzymes in flavonoid metabolism. Chalcone isomerase and chalcone synthase together constitute rate-limiting enzymes for flavonoid biosynthesis. CheKine™ Micro Chalcone Isomerase (CHI) Activity Assay Kit can detect plant tissues samples. In this kit, CHI catalyzed the cyclization of chalcone to form 4,5,7-trihydroxyflavanones, and the activity of CHI was indicated by measuring the absorbance change at 381 nm.

Malic enzyme (ME) is widely present in the cytoplasm of microorganisms, cultured cells, animals, and plants, especially with high activity in plant tissues. ME catalyzes the reversible oxidation decarboxylation of malic acid, producing pyruvate and CO2, as well as the reduction reaction accompanied by NAD(P)+, which is a key enzyme in malic acid metabolism. ME activity is closely related to biosynthesis and antioxidant activity. Based on the specificity of coenzyme and substrate, ME can be divided into NAD-ME (EC1.1.1.38) and NADP-ME (EC1.1.1.40). NAD-ME can catalyze the reduction of NAD+ to NADH, and the rate of NADH increase at 340 nm can reflect its activity.