Purification, Characterization, and Solvent-Induced Thermal Stabilization of Ficin from Ficus carica

Devaraj, K. B. and Ramesh Kumar, P. and Prakash, V. (2009) Purification, Characterization, and Solvent-Induced Thermal Stabilization of Ficin from Ficus carica. Journal of Agricultural and Food Chemistry, 56. pp. 11417-11423.

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Abstract

Ficin (EC 3.4.22.3), a cysteine proteinase isolated from the latex of a Ficus tree, is known to occur in multiple forms. Although crude ficin is of considerable commercial importance, ficin as such has not been fully characterized. A major ficin from the commercial crude proteinase mixture preparation of Ficus carica was purified and characterized. The purified enzyme was homogeneous in both sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel-filtration chromatography and is a single polypeptide chain protein with a molecular mass of 23 100 ( 300 Da as determined by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF). The enzyme was active in the pH range of 6.5-8.5, and maximum activity was observed at pH 7.0. The N-terminal core sequence of ficin has homology with N-terminal sequences of plant cysteine proteinases. The enzyme contains three disulfide bonds and a single free cysteine residue at the active site. The effect of co-solvents, such as sorbitol, trehalose, sucrose, and xylitol, on the thermal stability of ficin was determined by activity measurements, fluorescence, and thermal denaturation studies. The apparent thermal denaturation temperature (Tm) of ficin was significantly increased from the control value of 72 ( 1 °C in the presence of all co-solvents. However, the maximum stabilization effect was observed in terms of thermal stabilization by the co-solvent trehalose.

Item Type:	Article
Uncontrolled Keywords:	Ficus; fig; cysteine protease; ficin; co-solvents; stabilization; sorbitol; trehalose; thermal denaturation temperature
Subjects:	500 Natural Sciences and Mathematics > 10 Plants > 06 Trees And Shrubs 600 Technology > 08 Food technology > 16 Nutritive value > 03 Proteins
Divisions:	Protein Chemistry and Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	05 Jan 2009 10:00
Last Modified:	15 Dec 2017 04:32
URI:	http://ir.cftri.res.in/id/eprint/8874

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