帮我润色尽量使用高级写作词汇。The enzyme specific activity was defined and determined as previously described 1 An appropriate amount of pure enzyme was added to 14 mL of a 10 wv DL-PL substrate prepared in 1 M Tris

The specific activity of the enzyme was ascertained and determined in accordance with established protocols [1]. A precise amount of pure enzyme was introduced into a 14 mL solution containing 10% (w/v) DL-PL substrate, which had been prepared in 1 M Tris-HCl buffer with a pH of 7.5. The reaction was terminated by heating at 100°C for 3 minutes, followed by filtration and measurement using HPLC. A single unit of D-Lacs activity was defined as the quantity of enzyme required to liberate 1 μmol of D-PA per minute. Samples were analyzed using a Waters HPLC system outfitted with a Chiralcel IG-3 column (4.6 mm × 250 mm, 3 µm, Diacel, Tokyo, Japan). The eluent used was formic acid/methanol (0.1%, 70:30, v/v), which was maintained at a flow rate of 0.3 mL/min at 35°C and measured at a wavelength of 210 nm