A novel aspartic protease with HIV-1 reverse transcriptase inhibitory activity from fresh fruiting bodies of the wild mushroom Xylaria hypoxylon.
A novel aspartic protease with HIV-1 RT inhibitory activity was isolated and characterized from fruiting bodies of the wild mushroom Xylaria hypoxylon. The purification protocol comprised distilled water homogenization and extraction step, three ion exchange chromatographic steps (on DEAE-cellulose, Q-Sepharose, and CM-cellulose in succession), and final purification was by FPLC on Superdex 75. The protease was adsorbed on all the three ion exchangers. It was a monomeric protein with a molecular mass of 43 kDa as estimated by SDS-PAGE and FPLC. Its N-terminal amino acid sequence was HYTELLSQVV, which exhibited no sequence homology to other proteases reported. The activity of the protease was adversely affected by Pepstatin A, indicating that it is an aspartic protease. The protease activity was maximal or nearly so in the pH range 6-8 and in the temperature range 35-60°C. The purified enzyme exhibited HIV-1 RT inhibitory activity with an IC₅₀ value of 8.3 μM, but was devoid of antifungal, ribonuclease, and hemagglutinating activities.
State Key Laboratory for Agrobiotechnology and Department of Microbiology, China Agricultural University, Beijing 100193, China.
Qing-Xiu
QX
Hu
Guo-Qing
GQ
Zhang
Rui-Ying
RY
Zhang
Dan-Dan
DD
Hu
He-Xiang
HX
Wang
Tzi Bun
TB
Ng
D057055:Aspartic Acid Proteases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D002364:Caseins / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D048690:Fruiting Bodies, Fungal / Q000737:chemistry / Q000201:enzymology*; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors*; D006863:Hydrogen-Ion Concentration; D020539:Sequence Analysis, Protein; D013696:Temperature; D013098:Xylariales / Q000737:chemistry / Q000201:enzymology*
D002364:Caseins; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase; D057055:Aspartic Acid Proteases