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Table 2 Ureolytic activity of purified pecan xylem sap RNase A compared to that of jack bean urease and bovine pancreatic RNase A

From: Nickel affects xylem Sap RNase a and converts RNase A to a urease

Sample Activity (Unit/ml)a Specific activity (Unit/mg protein)a
Purified bovine pancreatic RNase A (13.4 kDa) 179.9 ± 15.7 179.9 ± 15.7
Purified jack bean urease (590 kDa)b 589.0 ± 64.1 589.0 ± 64.1
Crude xylem sap proteins 24.93 ± 2.04 80.41 ± 6.56
Purified xylem sap 14 kDa protein 371.25 ± 17.33 222.75 ± 10.44
Buffer control 0 0
  1. aActivity and Specific Activity is mean values (± SD) of three replicate assays; urease catalyzes the hydrolysis of urea to ammonia and carbon dioxide.
  2. bThe molecular mass for native jack bean urease is from 480 kDa to 590 kDa13 and calculated size is about 540 kDa for the hexamer.