近日，德国汉诺威莱布尼茨大学Jesko Koehnke团队报道了植物与细菌中胍异戊烯基转移酶介导的天然产物生物合成。相关论文于2026年10月22日发表于《科学》杂志上。

胍几乎完全以共振稳定的阳离子形式存在，这使其直接酶促官能化具有挑战性。

研究组鉴定出蓝细菌酶NosH，它催化异戊烯基直接转移至游离胍。结构和机理分析揭示，胍由双天冬氨酸钳激活，并通过一种独特的催化架构与异戊烯基供体结合相偶联。受这些特征指导，研究组在细菌和植物中鉴定出一个庞大的胍异戊烯基转移酶家族。植物酶在体外产生山羊豆碱等胍类生物碱，而在本氏烟草中异源表达一个植物直系同源基因可在植物体内产生山羊豆碱，从而为植物特化代谢提供了直接的酶学联系。

附：英文原文

Title: Natural product biosynthesis by guanidine prenyltransferases in plants and bacteria

Author: Dominik Kolling, Katharina Konzok, Daghan Taser, Tom Jentsch, Svenja Schwoerer, Henry Struwe, Arne Bültemeier, Jonas Freiberg, Claus-Peter Witte, Jakob Franke, Andriy Luzhetskyy, Andreas Kirschning, Sophia Rudorf, Jesko Koehnke

Issue&Volume: 2026-10-22

Abstract: Guanidine exists almost exclusively as a resonance-stabilized cation, making its direct enzymatic functionalization challenging. We identified the cyanobacterial enzyme NosH, which catalyzes direct prenyl transfer to free guanidine. Structural and mechanistic analyses revealed guanidine activation by a two-aspartate clamp coupled to prenyl-donor binding through a distinct catalytic architecture. Guided by these features, we identified a large family of guanidine prenyltransferases across bacteria and plants. Plant enzymes produced guanidine alkaloids such as galegine in vitro and heterologous expression of a plant ortholog in Nicotiana benthamiana produced galegine in planta, providing a direct enzymatic link to plant-specialized metabolism.

DOI: 10.1126/science.aeg1821

Source:https://www.science.org/doi/10.1126/science.aeg1821