Cervelli Manuela, Polticelli Fabio, Angelucci Emanuela, Di Muzio Elena, Stano Pasquale, Mariottini Paolo
Department of Sciences, University of Roma Tre, 00146, Rome, Italy,
Amino Acids. 2015 May;47(5):949-61. doi: 10.1007/s00726-015-1924-2. Epub 2015 Feb 6.
Polyamine oxidases catalyse the oxidation of polyamines and acetylpolyamines and are responsible for the polyamine interconversion metabolism in animal cells. Polyamine oxidases from yeast can oxidize spermine, N(1)-acetylspermine, and N(1)-acetylspermidine, while in vertebrates two different enzymes, namely spermine oxidase and acetylpolyamine oxidase, specifically catalyse the oxidation of spermine, and N(1)-acetylspermine/N(1)-acetylspermidine, respectively. In this work we proved that the specialized vertebrate spermine and acetylpolyamine oxidases have arisen from an ancestor invertebrate polyamine oxidase with lower specificity for polyamine substrates, as demonstrated by the enzymatic activity of the mollusc polyamine oxidase characterized here. This is the first report of an invertebrate polyamine oxidase, the Pacific oyster Crassostrea gigas (CgiPAO), overexpressed as a recombinant protein. This enzyme was biochemically characterized and demonstrated to be able to oxidase both N(1)-acetylspermine and spermine, albeit with different efficiency. Circular dichroism analysis gave an estimation of the secondary structure content and modelling of the three-dimensional structure of this protein and docking studies highlighted active site features. The availability of this pluripotent enzyme can have applications in crystallographic studies and pharmaceutical biotechnologies, including anticancer therapy as a source of hydrogen peroxide able to induce cancer cell death.
多胺氧化酶催化多胺和乙酰多胺的氧化反应，负责动物细胞中的多胺相互转化代谢。酵母中的多胺氧化酶可氧化精胺、N(1)-乙酰精胺和N(1)-乙酰亚精胺，而在脊椎动物中，两种不同的酶，即精胺氧化酶和乙酰多胺氧化酶，分别特异性催化精胺和N(1)-乙酰精胺/N(1)-乙酰亚精胺的氧化反应。在本研究中，我们证明了脊椎动物特有的精胺和乙酰多胺氧化酶起源于一种对多胺底物特异性较低的无脊椎动物多胺氧化酶祖先，本文所表征的软体动物多胺氧化酶的酶活性证明了这一点。这是关于无脊椎动物多胺氧化酶——太平洋牡蛎（Crassostrea gigas，CgiPAO）作为重组蛋白过表达的首次报道。对该酶进行了生化表征，结果表明它能够氧化N(1)-乙酰精胺和精胺，尽管效率不同。圆二色性分析估计了该蛋白的二级结构含量，并对其三维结构进行了建模，对接研究突出了活性位点特征。这种多功能酶的可用性可应用于晶体学研究和药物生物技术，包括作为能够诱导癌细胞死亡的过氧化氢来源用于抗癌治疗。
