Studies on Xyloglucanase during the Germination of Seeds of Tamarindus Indica

摘要

Germinating seeds of Tamarindus indicacontain endo-β-1, 4-xyloglucanases which degrade tamarind xyloglucan, but notcarboxymethylcellulose (CMC). The xyloglucanases are isolated from thegerminating tamarind seeds using 50 mM acetate buffer, pH 5.5 containing 0.5 MNaCl. The Km value is 0.667 g/liter and the enzyme is optimally active at pH5.5 and stable between pH 4 - 6.5. The optimum temperature is 45C and is quitestable upto 50C. The activity declined by 50% at 60C and is completelyinactivated at 70C. Highest xyloglucanase activity and specific activity areobserved on the 23rd day of germination. The polyacrylamide gel electrophoresis(PAGE) indicated the presence of five isozymes of xyloglucanases which arevisualized by activity staining separately with congo red and grams iodine.Isozyme 2 is the major xyloglucanase present throughout the germination period.