Cordysobin, a novel alkaline serine protease with HIV-1 reverse transcriptase inhibitory activity from the medicinal mushroom Cordyceps sobolifera.

Shou-Xian Wang, Yu Liu, Guo-Qing Zhang, Shuang Zhao, Feng Xu, Xiao-Li Geng, He-Xiang Wang

Index: J. Biosci. Bioeng. 113(1) , 42-7, (2011)

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Abstract

A novel serine protease, designated as cordysobin, 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 sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the protease resolved as a single band with an apparent molecular mass of 31 kDa. Its optimal pH was 10.0, and the optimal temperature was 65°C. The protease displayed a K(m) value of 0.41 μM and 13.44 μM·min⁻¹ using Suc-Leu-Leu-Val-Tyr-MCA as substrate at pH 10.0 and 37°C. Protease activity was enhanced by the Fe²⁺ ion at low concentration range of 1.25-10 mM and was strongly inhibited by Hg²⁺ up to 1.25 mM. The protease was strongly inhibited by chymostatin and phenylmethylsulfonyl fluoride (PMSF), suggesting that it is 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 is the highest anti-HIV-1 RT activity of reported mushroom proteins.Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.