BACKGROUND Proteases are hydrolytic enzymes that catalyze peptide linkage cleavage reactions at the level of proteins and peptides with different degrees of specificity. This group draws the attention of industry. More than one protease in three is a serine protease. Classically, they are active at neutral to alkaline pH. The serine proteases are researched for industrial uses, especially detergents. They are the most commercially available enzyme group in the world market. Overall, fungi produced extracellular proteases, easily separated from mycelium by filtration. RESULTS A new basidiomycete fungus CTM10057, a hyperproducer of a novel protease (10,500 U/mL), was identified as Pleurotus sajor-caju (oyster mushroom). The enzyme, called SPPS, was purified to homogeneity by heat-treatment (80 °C for 20 min) followed by ammonium sulfate precipitation (35-55%)-dialysis, then UNO Q-6 FPLC ion-exchange chromatography and finally HPLC-ZORBAX PSM 300 HPSEC gel filtration chromatography, and submitted to biochemical characterization assays. The molecular mass was estimated to be 65 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Native-PAGE, casein-zymography, and size exclusion by HPLC. A high homology with mushroom proteases was displayed by the first 26 amino-acid residues of the NH2-terminal aminoacid sequence. Phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP) strongly inhibit SPPS, revealing that it is a member of the serine-proteases family. The pH and temperature optima were 9.5 and 70 °C, respectively. Interestingly, SPPS possesses the most elevated hydrolysis level and catalytic efficiency in comparison with SPTC, Flavourzyme® 500 L, and Thermolysin type X proteases. More remarkably, a high tolerance towards organic solvent tolerance was exhibited by SPPS, together with considerable detergent stability compared to the commercial proteases Thermolysin type X and Flavourzyme® 500 L, respectively. CONCLUSIONS This proves the excellent proprieties characterizing SPPS, making it a potential candidate for industrial applications especially detergent formulations.

中文翻译：

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牡蛎蘑菇侧耳假丝酵母菌株CTM10057的新型热稳定蛋白酶的纯化和生化特性具有工业价值。

背景技术蛋白酶是水解酶，其以不同程度的特异性催化蛋白质和肽水平上的肽键裂解反应。该小组引起了业界的关注。丝氨酸蛋白酶是三分之一以上的蛋白酶。通常，它们在中性至碱性pH值下均具有活性。丝氨酸蛋白酶已被研究用于工业用途，尤其是去污剂。它们是世界市场上最可商购的酶类。总体而言，真菌产生的细胞外蛋白酶很容易通过过滤与菌丝体分离。结果鉴定出一种新的担子菌真菌CTM10057，它是一种新型蛋白酶（10,500 U / mL）的高产者，被鉴定为平菇。这种叫做SPPS的酶 通过热处理（80°C，20分钟），硫酸铵沉淀（35-55％）-渗析，然后进行UNO Q-6 FPLC离子交换色谱，最后进行HPLC-ZORBAX PSM 300 HPSEC凝胶过滤，将其纯化至均质色谱，并进行生化特征分析。通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE），Native-PAGE，酪蛋白酶谱和通过HPLC的尺寸排阻，估计分子量为65kDa。NH2末端氨基酸序列的前26个氨基酸残基显示出与蘑菇蛋白酶的高度同源性。苯甲磺酰氟（PMSF）和二碘丙基氟磷酸盐（DFP）强烈抑制SPPS，表明它是丝氨酸蛋白酶家族的成员。最适pH和温度分别为9.5和70°C。有趣的是，与SPTC，Flavourzyme®500 L和X型嗜热菌蛋白酶相比，SPPS具有最高的水解水平和催化效率。更为显着的是，与商业蛋白酶X型和500 L嗜热菌蛋白酶相比，SPPS对有机溶剂具有很高的耐受性，并且洗涤剂具有显着的稳定性。结论这证明了SPPS具有出色的特性，使其成为工业应用特别是洗涤剂配方的潜在候选者。分别与商业蛋白酶X型和500 L嗜热菌蛋白酶相比，具有显着的洗涤剂稳定性。结论这证明了SPPS具有出色的特性，使其成为工业应用特别是洗涤剂配方的潜在候选者。分别与商业蛋白酶X型和500 L嗜热菌蛋白酶相比，具有显着的洗涤剂稳定性。结论这证明了SPPS具有出色的特性，使其成为工业应用特别是洗涤剂配方的潜在候选者。