[show abstract][hide abstract] ABSTRACT: A laccase, with HIV-1 reverse transcriptase inhibitory activity (IC(50)=12.7 μM) and antiproliferative activity against HepG2 cells (IC(50)=5.6 μM) and MCF7 cells (IC(50)=6.5 μM), was purified from fresh fruiting bodies of the edible white common Agrocybe cylindracea mushroom. The laccase, which had a novel N-terminal sequence, displayed a molecular mass of 58 kDa within the range reported for most other mushroom laccases. The purification protocol entailed ion exchange chromatography on DEAE-cellulose, SP-Sepharose, and Q-Sepharose and gel filtration on Superdex 75. The laccase was adsorbed on DEAE-cellulose and Q-Sepharose, but unadsorbed on SP-Sepharose. Its optimum pH was pH 3-4 and its optimum temperature was 50°C. The activity of the isolated laccase differed from one substrate to another. The ranking was ABTS>N,N-dimethyl-1,4-phenylenediamine>hydroquinone>catechol>2-methylcatechol>pyrogallol.
Phytomedicine: international journal of phytotherapy and phytopharmacology 03/2011; 18(5):374-9. · 2.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: A 14.5-kDa ribonuclease, with an optimum pH of 6 and a temperature optimum at 70 degrees C, was isolated from fresh fruiting bodies of the edible mushroom Lyophyllum shimeiji. It was purified by ion exchange chromatography on DEAE cellulose, Q Sepharose, and SP Sepharose, followed by FPLC gel filtration on Superdex 75, and was adsorbed on all three ion exchangers. It showed the highest ribonucleolytic potency toward poly (U), 25% as much activity toward poly (C), and undetectable activity toward poly (A) and poly (G). Its ribonucleolytic activity at 100 degrees C was similar to that at 20 degrees C. It suppressed proliferation of hepatoma HepG2 cells and breast cancer MCF7 cells with an IC(50) of 10 and 6.2 microM, respectively. It inhibited the activity of HIV-1 reverse transcriptase with an IC(50) of 7.2 microM.