Characterisation of Dyp-type peroxidases from Pseudomonas fluorescens Pf-5: Oxidation of Mn(II) and polymeric lignin by Dyp1B
Characterisation of Dyp-type peroxidases from Pseudomonas fluorescens Pf-5: Oxidation of Mn(II) and polymeric lignin by Dyp1B
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DOI：
10.1016/j.abb.2014.12.022
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发表时间：
2015-05-15
影响因子：
3.9
通讯作者：
Bugg, Timothy D. H.
中科院分区：
文献类型：
--
作者：
Rahmanpour, Rahman;Bugg, Timothy D. H.
革兰氏阳性菌中过氧化物酶的DyP家族的成员最近已被证明氧化Mn（II）和木质素模型化合物。革兰氏阴性假单胞菌，也表现出活性的木质素氧化，也含有dyp-type过氧化物酶基因。荧光假单胞菌Pf-5含有三种dyp-type过氧化物酶（35，40和55 kDa），其中每一种都已在大肠杆菌中过表达，纯化，并进行了表征。三种酶中的每一种都显示出氧化酚底物的活性，但35 kDa Dyp 1B酶也显示出氧化Mn（II）和硫酸盐木质素的活性。在Mn（II）和过氧化氢的存在下用Dyp 1B处理粉末状木质纤维素导致释放低分子量木质素片段，其已通过质谱法鉴定为含有一个G单元和一个H单元的β-芳基醚木质素二聚体，其带有苄基酮。提出了从木质素氧化中释放该片段的机制。(C)2015 Elsevier Inc. All rights reserved.
Members of the DyP family of peroxidases in Gram-positive bacteria have recently been shown to oxidise Mn(II) and lignin model compounds. Gram-negative pseudomonads, which also show activity for lignin oxidation, also contain dyp-type peroxidase genes. Pseudomonas fluorescens Pf-5 contains three dyp-type peroxidases (35, 40 and 55 kDa), each of which has been overexpressed in Escherichia coli, purified, and characterised. Each of the three enzymes shows activity for oxidation of phenol substrates, but the 35 kDa Dyp1B enzyme also shows activity for oxidation of Mn(II) and Kraft lignin. Treatment of powdered lignocellulose with Dyp1B in the presence of Mn(II) and hydrogen peroxide leads to the release of a low molecular weight lignin fragment, which has been identified by mass spectrometry as a beta-aryl ether lignin dimer containing one G unit and one H unit bearing a benzylic ketone. A mechanism for release of this fragment from lignin oxidation is proposed. (C) 2015 Elsevier Inc. All rights reserved.