توصيف أنزيم اليورييز المنقى من نوى تمر الزهدي Phoenix dactylifera L.

الملخص EN

Characterization of urease extracted from Zahdi seeds showed that the molecular weight was 409,260 and 89,125 Daltons as determined by gel filtration and SDS- polyacrylamide gel electrophoresis, respectively.

This indicates that the enzyme is composed of five similar units bounded by disulfide bonds, the isoelectric point (pI) was 5.1.

The optimum pH for the enzyme activity and stability were 8 and 7.5-8.0 respectively.

The optimum temperature of the enzyme activity was 40 oC and that for stability was 35 oC for 15 minutes, using sodium phosphate buffer at pH 8.0 and the maximum activity of the enzyme was at ionic strength of 0.25M.

Kinetic studies showed that Km and Vmax values were 10.53 and 1110 mmole/ min, respectively, when urea was used as substrate.