Silveira Célia M, Moe Elin, Fraaije Marco, Martins Lígia O, Todorovic Smilja
Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa Av. da República 2780-157 Oeiras Portugal
Molecular Enzymology, University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands.
RSC Adv. 2020 Mar 17;10(19):11095-11104. doi: 10.1039/d0ra00950d. eCollection 2020 Mar 16.
Dye decolorizing peroxidases (DyPs) are novel haem-containing peroxidases, which are structurally unrelated to classical peroxidases. They lack the highly conserved distal histidine that acts as an acid-base catalyst in the catalytic reaction of classical peroxidases, which implies distinct mechanistic properties. Despite the remarkable catalytic properties and recognized potential for biotechnology applications, the knowledge of DyP's structural features in solution, which govern the reactivity and catalysis, is lagging behind. Resonance Raman (RR) spectroscopy can reveal fine details of the active site structure in hemoproteins, reporting on the oxidation and spin state and coordination of the haem cofactor. We provide an overview of the haem binding pocket architecture of the enzymes from A, B and C DyP subfamilies, in the light of those established for classical peroxidases and search for subfamily specific features among DyPs. RR demonstrates that multiple spin populations typically co-exist in DyPs, like in the case of classical peroxidases. The haem spin/coordination state is strongly pH dependent and correlates well with the respective catalytic properties of DyPs. Unlike in the case of classical peroxidases, a surprisingly high abundance of catalytically incompetent low spin population is observed in several DyPs, and tentatively related to the alternative physiological function of these enzymes. The molecular details of active sites of DyPs, elucidated by RR spectroscopy, can furthermore guide approaches for biotechnological exploitation of these promising biocatalysts.
染料脱色过氧化物酶（DyPs）是一类新型的含血红素过氧化物酶，其结构与经典过氧化物酶无关。它们缺乏在经典过氧化物酶催化反应中作为酸碱催化剂的高度保守的远端组氨酸，这意味着其具有独特的作用机制特性。尽管DyPs具有显著的催化特性并在生物技术应用方面具有公认的潜力，但关于其溶液中结构特征（这些特征决定了反应活性和催化作用）的了解却滞后了。共振拉曼（RR）光谱能够揭示血红蛋白中活性位点结构的精细细节，报告血红素辅因子的氧化、自旋状态及配位情况。鉴于已确定的经典过氧化物酶的情况，我们概述了A、B和C类DyP亚家族酶的血红素结合口袋结构，并在DyPs中寻找亚家族特异性特征。RR表明，与经典过氧化物酶一样，DyPs中通常同时存在多种自旋态。血红素的自旋/配位状态强烈依赖于pH值，并且与DyPs各自的催化特性密切相关。与经典过氧化物酶不同的是，在几种DyPs中观察到催化无活性的低自旋态的丰度出奇地高，这初步与这些酶的替代生理功能有关。通过RR光谱阐明的DyPs活性位点的分子细节，还可以指导对这些有前景的生物催化剂进行生物技术开发的方法。
