Abstract: Cyclic AMP-binding protein was purified 30 fold from the mycelia of Ganoderma lucidum by the methods of ammonium sulfate precipitation, DEAE-cellulose, phospho-cellulose ion exchange chromatography and Sephacryl S-100 gel filtration.The molecular mass of the purified protein is 34.5 kDa and 17 kDa by Sephacryl S-100 gel filtration and SDS-ployacrylamide gel electrophoresis, respectively.From these results it is suggested that the protein has a homometric dimmer structure.The pI of the purified protein is pH 8.2 by native isoelectric focusing gel.The half-life of the protein activity in 10% glycerol at 4 ℃ is 7 d in crude extract, but its half-life is only 3 d under purifying conditions.The optimal conditions of the protein activity are at 1 ℃ and pH 7.5.Its activity is increased 6 times by 1 mmol/L Zn²⁺ and is slightly inhibited by cGMP,Cu²⁺ and Mn²⁺.

Key words: cAMP-binding protein, Purification, Characterization, Ganoderma lucidum