Conversion of milled pine wood by manganese peroxidase from Phlebia radiata
Conversion of milled pine wood by manganese peroxidase from Phlebia radiata
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DOI：
10.1128/aem.67.10.4588-4593.2001
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发表时间：
2001-10-01
影响因子：
4.4
通讯作者：
Hatakka, A
中科院分区：
文献类型：
--
作者：
Hofrichter, M;Lundell, T;Hatakka, A
从白腐担子菌Plebia Radiata中分离纯化的锰过氧化物酶(MNP)，在含有Tw-en20、Mn2+、键合有机酸(丙二酸)和过氧化氢产生体系(葡萄糖-葡萄糖氧化酶)的水溶液中，对磨细松材(MPW)进行了体外转化。高效尺寸排阻色谱(HPSEC)表明，酶的攻击导致低分子质量的可溶木材组分聚合，并导致松材不溶部分解聚。含有不饱和脂肪酸残基的表面活性剂吐温80促进了块状MPW的崩解。HPSEC分析表明，解聚产物主要是木质纤维素碎片，其主要相对分子质量约为0.5 kDa。辐射假单胞菌的MNP(MnP3)是一种稳定的酶，即使在37℃下剧烈搅拌也能保持2天的活性，在吐温20和吐温80反应混合物中分别保持了65%和35%的活性。在反应过程中，锰络合剂丙二酸酯的大部分被分解(85%~87%)，导致pH从4.4增加到>；6.5。一种芳香族非酚类木质素结构(β-O-4二聚体)在松木粉存在下可被氧化，这种结构通常不受MNP的攻击。这一发现表明，某些木材成分可能会促进MNP的降解活性，其方式与吐温80、不饱和脂肪酸或硫醇促进的方式相似。
Purified manganese peroxidase (MnP) from the white-rot basidiomycete Phlebia radiata was found to convert in vitro milled pine wood (MPW) suspended in an aqueous reaction solution containing Tw-een 20, Mn2+, bon-chelating organic acid (malonate), and a hydrogen peroxide-generating system (glucose-glucose oxidase). The enzymatic attack resulted in the polymerization of lower-molecular-mass, soluble wood components and in the partial depolymerization of the insoluble bulk of pine wood, as demonstrated by high-performance size exclusion chromatography (HPSEC). The surfactant Tween 80 containing unsaturated fatty acid redsidues promoted the disintegration of bulk MPW. HPSEC showed that the depolymerization yielded preferentially lignocellulose fragments with a predominant molecular mass of ca. 0.5 kDa. MnP from P. radiata (MnP3) turned out to be a stable enzyme remaining active for 2 days even at 37 degreesC with vigorous stirring, and 65 and 35% of the activity applied was retained in Tween 20 and Tween 80 reaction mixtures, respectively. In the course of reactions, major part of the Mn-chelator malonate was decomposed (85 to 87%), resulting in an increase of pH from 4.4 to > 6.5. An aromatic nonphenolic lignin structure (beta -O-4 dimer), which is normally not attacked by MnP, was oxidizible in the presence of pine wood meal. This finding indicates that certain wood components may promote the degradative activities of MnP in a way similar to that promoted by Tween 80, unsaturated fatty acids, or thiols.