Institut für Lebensmittelchemie, Gottfried Wilhelm Leibniz Universität Hannover, Callinstraße 5, 30167 Hannover, Germany.
Molecules. 2020 Mar 27;25(7):1536. doi: 10.3390/molecules25071536.
Alkene cleavage is a possibility to generate aldehydes with olfactory properties for the fragrance and flavor industry. A dye-decolorizing peroxidase (DyP) of the basidiomycete (PsaPOX) cleaved the aryl alkene -anethole. The PsaPOX was semi-purified from the mycelium via FPLC, and the corresponding gene was identified. The amino acid sequence as well as the predicted tertiary structure showed typical characteristics of DyPs as well as a non-canonical Mn-oxidation site on its surface. The gene was expressed in GS115 yielding activities up to 142 U/L using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) as substrate. PsaPOX exhibited optima at pH 3.5 and 40 °C and showed highest peroxidase activity in the presence of 100 µM HO and 25 mM Mn. PsaPOX lacked the typical activity of DyPs towards anthraquinone dyes, but oxidized Mn to Mn. In addition, bleaching of -carotene and annatto was observed. Biotransformation experiments verified the alkene cleavage activity towards the aryl alkenes ()-methyl isoeugenol, -methylstyrene, and -anethole, which was increased almost twofold in the presence of Mn. The resultant aldehydes are olfactants used in the fragrance and flavor industry. PsaPOX is the first described DyP with alkene cleavage activity towards aryl alkenes and showed potential as biocatalyst for flavor production.
烯键断裂是一种为香精和香料行业生成具有气味特性的醛类的可能性。担子菌的一种染料脱色过氧化物酶（DyP）（PsaPOX）可裂解芳基烯烃-茴香脑。通过 FPLC 从菌丝体中半纯化 PsaPOX，并鉴定了相应的基因。氨基酸序列和预测的三级结构显示了 DyP 的典型特征，以及其表面上的非典型 Mn 氧化位。该基因在 GS115 中表达，使用 2,2'-偶氮双（3-乙基苯并噻唑啉-6-磺酸）作为底物时，酶活可达 142 U/L。PsaPOX 的最适 pH 为 3.5，最适温度为 40°C，在 100 µM HO 和 25 mM Mn 存在下表现出最高的过氧化物酶活性。PsaPOX 缺乏 DyP 对蒽醌染料的典型活性，但可将 Mn 氧化为 Mn。此外，还观察到 -胡萝卜素和胭脂树橙的漂白。生物转化实验验证了 PsaPOX 对芳基烯烃（）-甲基异丁香酚、-甲基苯乙烯和茴香脑的烯键断裂活性，在 Mn 存在下，该活性增加了近两倍。生成的醛类是香精和香料行业中使用的气味物质。PsaPOX 是第一种描述的具有芳基烯烃烯键断裂活性的 DyP，并且具有作为风味生产生物催化剂的潜力。
