综述或非传感器论文 2011 非传感器论文

Isolation, Purification, and Characterization of Fungal Laccase from Pleurotus sp.

Enzyme research More SS, P S R, K P, M S, Malini S, S M V
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Isolation, Purification, and Characte... 传感器构成示意图

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传感器类型

综述或非传感器论文

检测对象

ABTS(2,2'-联嗪双(3-乙基苯并噻唑啉-6-磺酸))、2,6-DMP(2,6-二甲氧基苯酚)等酚类/芳香胺底物;样品基质:Pleurotus sp. 培养滤液/纯化酶液

检测原理

本文未构建传感器,其检测为漆酶酶活比色法。漆酶作为多铜氧化酶,催化ABTS或酚类底物发生单电子氧化,分子氧作为电子受体被还原为水;ABTS被氧化为较稳定的自由基阳离子,在420 nm处产生强蓝绿色吸收,吸光度随底物氧化程度和酶量增加而升高。对2,6-DMP等酚类底物,氧化后生成自由基并进一步发生水合、歧化或聚合等非酶促反应。实验通过测定A420变化计算酶活,并据此获得Km、Vmax等动力学参数。该过程没有电极换能、信号放大或传感界面,因此不属于生物传感器检测。

检测灵敏度

未报告LOD、线性范围、灵敏度斜率、相关系数。

效应效果

本文主要评价漆酶纯化与稳定性,而非传感器性能。纯化后漆酶为40±1 kDa单体,纯化倍数72.2倍,收率22.4%;最适pH 4.5、最适温度65°C,60°C稳定8 h,75°C处理90 min后保留38%活性;室温稳定20天,-4°C保存60天。金属离子影响不一:CuSO4、BaCl2、MgCl2相对活性为90%、72%、75%,MnCl2、FeCl2、HgCl2为40%、55%、25%;SDS(0.1%)完全失活,叠氮钠相对活性10%,EDTA 65%。未报告选择性、抗干扰、RSD、实际样品回收率或与ELISA/HPLC/qPCR对比。作者主张该漆酶可用于开发检测纸浆工业废水酚类化合物的生物传感器。

传感器的构成

  • 识别元件:漆酶(Laccase,EC 1.10.3.2),来源于Pleurotus sp.培养滤液,可催化ABTS/酚类底物氧化,但本文未将其固定为传感器识别层
  • 换能器/基底:未报道,本文未构建电极或传感基底
  • 信号标记物/读出:未报道传感器信号标记物;仅用ABTS氧化产物在420 nm吸光度比色测定酶活

中文摘要

漆酶是一类蓝铜氧化酶(EC 1.10.3.2,苯二酚:氧氧化还原酶),可催化酚类、芳香胺及其他富电子底物发生单电子氧化,同时使O2还原为H2O,因底物谱广而具有工业应用潜力。本研究从土壤等样品中筛选并分离到一株产漆酶真菌,经鉴定为不产孢子的担子菌平菇属(Pleurotus sp.)。以ABTS为底物测定漆酶活性,经离子交换层析和凝胶过滤层析纯化。SDS-PAGE显示纯化漆酶为单体,分子量约40±1 kDa,纯化倍数72倍,收率22%。最适pH和温度分别为4.5和65°C。对ABTS的Km和Vmax分别报告为250 mM和0.33 μmol/min。CuSO4、BaCl2、MgCl2、FeCl2、ZnCl2对纯化漆酶活性无明显影响,HgCl2和MnCl2使其活性中等下降;SDS和叠氮钠抑制酶活,尿素、PCMB、DTT和巯基乙醇无明显影响。作者认为该漆酶可用于开发检测纸浆工业废水中酚类化合物的生物传感器。

英文摘要

Laccases are blue copper oxidases (E.C. 1.10.3.2 benzenediol: oxygen oxidoreductase) that catalyze the one-electron oxidation of phenolics, aromatic amines, and other electron-rich substrates with the concomitant reduction of O(2) to H(2)O. They are currently seen as highly interesting industrial enzymes because of their broad substrate specificity. A positive strain was isolated and characterized as nonspore forming Basidiomycetes Pleurotus sp. Laccase activity was determined using ABTS as substrate. Laccase was purified by ionexchange and gel filtration chromatography. The purified laccase was a monomer showed a molecular mass of 40 ± 1 kDa as estimated by SDS-PAGE and a 72-fold purification with a 22% yield. The optimal pH and temperature were 4.5 and 65(°)C, respectively. The K(m) and V(max) values are 250 (mM) and 0.33 (μmol/min), respectively, for ABTS as substrate. Metal ions like CuSO(4), BaCl(2), MgCl(2), FeCl(2), ZnCl(2) have no effect on purified laccase whereas HgCl(2) and MnCl(2) moderately decrease enzyme activity. SDS and sodium azide inhibited enzyme activity, whereas Urea, PCMB, DTT, and mercaptoethanol have no effect on enzyme activity. The isolated laccase can be used in development of biosensor for detecting the phenolic compounds from the effluents of paper industries.