Purification and preliminary characterization of L-asparaginase from Erwinia aroideae NRRL B-138.
Indian J Biochem Biophys
;
1996 Oct; 33(5): 371-6
Article
in English
| IMSEAR
| ID: sea-27548
ABSTRACT
L-Asparaginase (L-asparagine amidohydrolase EC 3.5.1.1) from Erwinia aroideae NRRL B-138 has been purified to apparent homogeneity by ammonium sulphate precipitation, chromatography on sulfopropyl-sephadex C-50 and sephadex G-200 with 22% recovery and 567-fold purification. The enzyme obtained from sulfopropyl-sephadex C-50 was unstable and lost activity within a few hours. Addition of glycerol helped in restoring the activity of the enzyme. The enzyme has an apparent molecular mass of approximately 155 kDa and has four subunits of identical molecular mass of approximately 38 kDa. The K(m) for L-asparagine is 2.8 x 10(-3) M. Enzyme shows optimal activity at 45 degrees C and pH 8.2. Energy of activation as determined from Arrhenius plot was 9.1 kcal/mol. Substrate L-asparagine and analogue L-glutamine, D-asparagine and 6 diazo-5-oxo-L-norleucine provide full protection to the enzyme against thermal denaturation.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Protein Conformation
/
Asparaginase
/
Thermodynamics
/
Enzyme Stability
/
Kinetics
/
Erwinia
/
Hydrogen-Ion Concentration
/
Molecular Weight
Language:
English
Journal:
Indian J Biochem Biophys
Year:
1996
Type:
Article
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