Àá½Ã¸¸ ±â´Ù·Á ÁÖ¼¼¿ä. ·ÎµùÁßÀÔ´Ï´Ù.
KMID : 1094720090140010032
Biotechnology and Bioprocess Engineering
2009 Volume.14 No. 1 p.32 ~ p.37
Purification and Characterization of a Novel Plant-type Carbonic Anhydrase from Bacillus subtilis
Rishiram Ramanan

Krishnamurthi Kannan
Nadimuthu Vinayagamoorthy
Kunga Mohan Ramkumar
Saravana Devi Sivanesan
Tapan Chakrabarti
Abstract
Carbonic anhydrase enzyme, one of the fastest known enzymes, remains largely unexplored in prokaryotes when compared to its mammalian counterparts despite its ubiquity. In this study, the enzyme has been purified from Bacillus subtilis SA3 using sequential Sephadex G-75 chromatography, DEAE cellulose chromatography, and sepharose-4B-L-tyrosine-sulphanilamide affinity chromatography and characterized to provide additional insights into its properties. The apparent molecular mass of carbonic anhydrase obtained by SDS-PAGE was found to be approximately 37 kDa. Isoelectric focusing of the purified enzyme revealed an isoelectric point (pI) of around 6.1 when compared with marker. The presence of metal ions such as Zn2+, Co2+, Cu2+, Fe3+, Mg2+, and anion SO4- increased enzyme activity while strong inhibition was observed in the presence of Hg2+, Cl-, HCO3-, and metal chelator EDTA. The optimum pH and temperature for the enzyme were found to be 8.3 and 37¡É, respectively. Enzyme kinetics with p-nitrophenyl acetate as substrate at pH 8.3 and 37¡É determined the Vmax and Km values of the enzyme to be 714.28 ¥ìmol/mg protein/min and 9.09 mM, respectively. The Ki value for acetazolamide was 0.22 mM, compared to 0.099 mM for sulphanilamide. The results from N-terminal amino acid sequencing imply the purified protein is a putative beta-carbonic anhydrase with close similarities to CAs from plants, microorganisms.
KEYWORD
carbonic anhydrase, Bacillus subtilis, purification, N-terminal amino acids, enzyme characterization
FullTexts / Linksout information
Listed journal information
SCI(E) ÇмúÁøÈïÀç´Ü(KCI)