Purification and Characterization of Ficin
|Course||Biochemistry and Molecular Biology|
|Keywords||Fig tree gum Protease Separation and purification Characterization|
Ficin (EC 22.214.171.124) is a proteolytic enzyme is mainly present in the fig tree gum . Figs belong to the Moraceae Ficus plants . Ficin is a general term for a series of complex enzyme , these enzymes are single-chain thiol protease molecular weight of about 25,000 , and its enzymatic properties similar to papain . The ficin used the meat tenderizer agent, the wine industry in the food industry clarifying agents and stabilizers , surface point improver; production of protein hydrolyzate ; soft wool epidermis leather and textile industries ; medicine repellents ; enzymatic synthesis of peptides , ficin omnipotent catalyst . Fig tree gum compared to the high content of fruit protease and easy storage and transport , and therefore for the further development of the application of ficin , Shandong fig tree gum (Brunswike, country of origin , France Ficus carica) as raw material , the use of cation exchange and gel filtration chromatography separation and purification to obtain a ficin . Determined by SDS-PAGE and cathodic electrodeposition which is a single-chain protein , molecular weight of about 25kDa , vitality staining results determine protease . Enzyme most suitable for a catalyst temperature of 65 ℃, catalytic casein has two optimum pH , 7.0 and 9.0 , respectively . Heavy metal ions Cu 2 sup > Zn 2 sup > , Hg 2 sup > completely inhibited the vitality , DTT, β -ME , L-Cysteine ??vitality activation . Enzyme at 65 ℃ half - life of greater than 1 hour , 75 ° C half-life of less than 20 minutes . 37 ° C under pH7.0 the enzyme casein hydrolyzate Km the value 1.56mg/mL . L-cysteine- activated enzyme the most suitable concentration for the 10- 20mmol / L . Contains two molecules of free sulfhydryl groups per molecule of enzyme . Enzyme a maximum absorption wavelength at 280nm . L-cysteine ??and the enzyme , fluorescence spectroscopy and circular dichroism change the native conformation of the enzyme .