Studies on Xyloglucanase during the Germination of Seeds of Tamarindus indica

Germinating seeds of Tamarindus indica contain endo-β-1, 4-xyloglucanases which degrade tamarind xyloglucan, but not carboxymethylcellulose (CMC). The xyloglucanases are isolated from the germinating tamarind seeds using 50 mM acetate buffer, pH 5.5 containing 0.5 M NaCl. The Km value is 0.667 g/liter and the enzyme is optimally active at pH 5.5 and stable between pH 4 6.5. The optimum temperature is 45 ̊C and is quite stable upto 50 ̊C. The activity declined by 50% at 60 ̊C and is completely inactivated at 70 ̊C. Highest xyloglucanase activity and specific activity are observed on the 23rd day of germination. The polyacrylamide gel electrophoresis (PAGE) indicated the presence of five isozymes of xyloglucanases which are visualized by activity staining separately with congo red and grams iodine. Isozyme 2 is the major xyloglucanase present throughout the germination period.