A novel protease was purified from dried fruiting bodies of the mushroom Cordyceps sobolifera. The isolation procedure utilized ion exchange chromatography on DEAE-cellulose and SP-sepharose followed by gel filtration on Superdex 75. The protease did not adsorb on DEAE-cellulose but bound to SP-Sepharose. In sodium dodecyl sulfatepolyacrylamide gel electrophoresis ( SDS-PAGE) , the protease resolved as a single band with an apparent molecular mass of 31 kDa. It exhibited optimal activity at a temperature of 60 ℃, a pH of 12.4 with a Km of 1. 98 mg/mL and a Vmax of 23. 56 μg/mL/min against its substrate casein. Protease activity was enhanced by the Fe2+ ion at low concentrations in 1. 25 - 10 mM and was strongly inhibited by Hg2+ up to 1. 25 mM. The protease was strongly inhibited by phenylmethylsulfonyl fluoride (PMSF), suggesting that it was a serine protease. It manifested significant inhibitory activity toward HIV-1 reverse transcriptase (RT) with an IC50 value of 8. 2 × 10-3 μM, which was the highest anti-HIV-1 RT activity of reported mushroom proteins.
Shou-Xian Wang Guo-Qing Zhang Shuang Zhao Feng Xu Lan-Qing Wang Xiao-Li Geng Li-Li Meng Yu Liu He-Xiang Wang
Institute of Plant Protection and Environment Protection, Beijing Academy of Agriculture and Forestr Key Laboratory of Urban Agriculture (North) of Ministry of Agriculture, Beijing University of Agricu Institute of Plant Protection and Environment Protection, Beijing Academy of Agriculture and Forestr State Key Laboratory for Agrobiotechnology and Department of Microbiology, China Agricultural Univer