Aix Marseille Univ, Centrale Marseille, CNRS, iSm2.
Aix Marseille Univ, CNRS, ICR, 13013, Marseille, France.
Chembiochem. 2021 Mar 16;22(6):992-995. doi: 10.1002/cbic.202000650. Epub 2020 Nov 24.
Plant dirigent proteins (DIRs) control the stereoselectivity of the monolignol coniferyl alcohol radical coupling. The main mechanistic hypothesis on this chemo- and stereoselective reaction invokes a binding of coniferyl alcohol radical substrates in the dirigent protein active site so that only one enantiomeric form can be produced. We have studied the influence of the Arabidopsis thaliana AtDIR6 protein on the transient coniferyl alcohol radical by EPR. Herein, we show that AtDIR6 stabilizes coniferyl alcohol radicals prior to directing their coupling towards the formation of (-)-pinoresinol.
植物定向蛋白 (DIRs) 控制着木质素单体松柏醇自由基偶联的立体选择性。关于这种化学和立体选择性反应的主要机制假说涉及松柏醇自由基底物在定向蛋白活性位点的结合，使得只能产生一种对映体形式。我们通过 EPR 研究了拟南芥 AtDIR6 蛋白对瞬态松柏醇自由基的影响。在此，我们表明 AtDIR6 在定向其偶联形成 (-)-松脂醇之前稳定松柏醇自由基。
