Sucrose synthetase (SS) is the key enzyme in the sugar metabolism of plants. It is responsible for the
reversible reaction of sucrose decomposition and synthesis. Its decomposition activity can catalyze the
hydrolysis of sucrose to UDPG and fructose. It is also involved in the synthesis of starch, cellulose and
hemicellulose.
SS-I can catalyze the production of fructose and UDPG from sucrose and UDP. Fructose reacts with 3,5-
Dinitrosalicylic acid to form brownish red substance with characteristic absorption peak at 540 nm. The
activity of SS-I can be calculated by measuring the change of absorption value at 540 nm.
Required but Not Provided:
Spectrophotometer/microplate reader, desk centrifuge, water-bath, transferpettor, micro glass cuvette/96
well flat-bottom plate, mortar/homogenizer, EP tube, ice and distilled water.
Protocol
I. Preparation:
Tissue: according to the ratio of mass (g): extraction volume (mL): 1:5-10 to add the extract solution. It is
suggested that add 1 mL of extract solution to 0.1 g of tissue. Homogenize on ice. Centrifuge at 8000 g 4℃
for 10 min. Take the supernatant on ice for test.
II. Determination
