Abstract: Ginger protease(GP-Ⅱ)could cleave peptides and proteins through proline at the P2 position.The unusual specificity of proline has made GP-Ⅱan attractive tool for protein sequencing and identification for stably folded domain in proteins.Ginger protease was found to have clotting activity.The traditional Chinese food,“Jiangzhuang juice",a ginger juice was used as clotting agent.The component,responsible for milk clotting by the juice,was verified as ginger protease.The milk clotting activity has made ginger protease an attractive subsitute for the calf rennet in cheesemaking.In this study,an effective separating and purifying plan has been worked out on the basis of former researchers’ performance,so the critical data of each step were determinated.Ginger rhizome was made into acetone powder,then the protease was extracted with a certain buffer.With the ammonium sulfate precipitate and chromatography on DEAE-cellulose the protease was purified.The sample obtained showed a single protein band on SDS-PAGE.During the experiment ginger protease was characterized as a typical acid protein.

Key words: ginger, protease, purification