RT Journal Article ID 31e9bb783820dd74 A1 Geng, Xueran A1 Te, Rigen A1 Tian, Guoting A1 Zhao, Yongchang A1 Zhao, Liyan A1 Wang, Hexiang A1 Ng, Tzi Bun T1 Purification and Characterization of a Novel Serine Protease from the Fruiting Bodies of a Rare Edible Medicinal Mushroom, Lyophyllum shimeji (Agaricomycetes) JF International Journal of Medicinal Mushrooms JO IJM YR 2016 FD 2016-09-01 VO 18 IS 6 SP 547 OP 554 K1 Lyophyllum shimeji K1 medicinal mushrooms K1 protease K1 purification AB In this study, a novel protease with a molecular mass of 30 kDa was purified from Lyophyllum shimeji using a purification procedure that involved anion exchange chromatography on a Q-Sepharose column, cation chromatography on an SP-Sepharose column, and gel filtration on a Superdex 75 column. The protease was purified 57-fold, and its specific activity was 6.67 U/mg. Its inner amino acid sequence, determined by liquid chromatography-tandem mass spectrometry, contains AASIIAVLVLSDK, which has 93% identity with the sequence of Hypsizygus marmoreus serine protease. The optimal reaction temperature and pH for L. shimeji protease were 50°C and 10.0, respectively. It is an alkaline protease and has higher activity when the pH lies between 6.8 and 10.0. The Km and Vmax at 50°C and pH 9.0 were 1.32 mg/mL and 454.55 μg/mL/min, respectively. The activity of L. shimeji protease was significantly suppressed by Cd2+, Hg2+, Cu2+, and Fe3+ ions, as well as by phenylmethylsufonyl fluoride; therefore, it is a serine protease. PB Begell House LK https://www.dl.begellhouse.com/journals/708ae68d64b17c52,1e217131685b463b,31e9bb783820dd74.html