Biochemical characteristics of a novel protease from the basidiomycete Amanita virgineoides

Abstract

The characterization of a novel protease from Amanita virgineoides is described. The A. virgineoides protease was purified to homogeneity using Q-Sepharose, carboxymethyl-cellulose, diethylaminoethyl-cellulose, and a gel filtration step on Superdex 75. The molecular mass of the purified protease was estimated to be 16.6 kDa. The protease was purified 32.1-fold, and its specific activity was 301.4 U/mg. The optimum pH was 4.0, and the optimum temperature was 50 °C. Kinetic constants (K , V ) were determined under the optimum reaction conditions, with K and V , being 3.74 mg/mL and 9.98 μg mL Min , respectively. The activity of the protease was curtailed by Cu , Pb , Fe , Cd , and Hg ions but enhanced by Mg , Ca , and K ions at low concentrations. The protease activity was adversely affected by ethylene diamine tetraacetic acid, suggesting that it is a metalloprotease. Four peptide sequences were obtained from liquid chromatography-tandem mass spectrometry, including KQALSGIR, TIAMDGTEGLVR, VALTGLTVAEYFR, and AGAGSATLSMAYAGAR, which showed 86%, 64%, 60%, and 75% identity with peptides of Hypsizygus marmoreus, Dacryopinax sp. DJM-731 SS1, Trametes versicolor FP-101664 SS1, and Paxillus involutus ATCC 200175, respectively. The newly isolated protease showed good hydrolytic activity and biochemical characteristics, which expanded the knowledge of biologically active proteins and provided further insight on this poisonous fungus.

Sarconesin II, a New Antimicrobial Peptide Isolated from Sarconesiopsis magellanica Excretions and Secretions

“…The sarconesin II primary sequence obtained by HPLC-ESI-Orbitrap-MS had the same identity as that for the ATP synthase beta subunit protein conserved domain. Sarconesin II was also detected in the organisms of other larval extracts, as the BLAST search showed, and has been previously identified in research into human breast cancer MCF-7 and MDA-MB-231 cell lines, and as proteases in basidiomycete Amanita virgineoides [88,89]. Sarconesin II is a derivative of the subunit beta ATP synthase reported in a broad range of organisms.…”

Purification and biochemical characterization of a novel thermostable protease from the oyster mushroom Pleurotus sajor-caju strain CTM10057 with industrial interest

“…However, the enzyme activity of protease produced by Aspergillus flavus strain AP2 was the highest with gelatin [55]. The protease from Pleurotus sajor-caju strain CTM10057 has a less K m value (0.275 mg/mL) as proteases isolated from Pleurotus citrinopileatus (3.44 mg/mL) [46], Amanita virgineoides (3.74 mg/mL) [56], and Helvella lacunose (3.81 mg/mL) [57], i.e. SPPS protease evinced a higher affinity towards casein than the above-mentioned proteases.…”