近日，发表于国际杂志Nature Chemical Biology上的一篇研究论文中，来自卡尔加里大学的研究人员对一种新型基因进行了特征性地描述，该基因在吗啡形成的过程中可以编码一种特殊的通道酶类，本文研究或可阐明罂粟如何合成抑制疼痛的酶类，相关研究为开发新型止痛药或可提供一定线索。
研究者Farrow教授表示，我们分离得到的基因实际上包括两个远古基因之间的天然融合片段，其在吗啡形成过程中可以编码特殊的通道酶，实际上我们对于融合基因在代谢途径中的作用非常感兴趣，而本文研究也为我们提供了一种新思路来寻找新型机制。
对该基因的分离是微生物机体中吗啡途径重新装配的一项关键步骤，比如酵母等；而相关研究也为开发新型可选择的生产系统来开发止痛药，比如吗啡、可待因及羟可酮提供了新的希望。研究者形象地将这项研究发现比喻为缺少指令的一盒乐高积木，而这些积木就是不同途径上的基因。
下一步研究者将基于当前的研究信息来书写操作指令，从而让不同基因发挥作用，这对于多种有机体中特殊途径的重建将非常关键；最后研究者说道，本文研究中我们揭示了罂粟如何来合成吗啡，同时也详细描述了吗啡合成过程中缺少的关键一步，这对于后期开发新型止痛药或提供了新的思路和研究数据。
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Stereochemical inversion of (S)-reticuline by a cytochrome P450 fusion in opium poppy
Scott C Farrow, Jillian M Hagel, Guillaume A W Beaudoin, Darcy C Burns & Peter J Facchini
The gateway to morphine biosynthesis in opium poppy (Papaver somniferum) is the stereochemical inversion of (S)-reticuline since the enzyme yielding the first committed intermediate salutaridine is specific for (R)-reticuline. A fusion between a cytochrome P450 (CYP) and an aldo-keto reductase (AKR) catalyzes the S-to-R epimerization of reticuline via 1,2-dehydroreticuline. The reticuline epimerase (REPI) fusion was detected in opium poppy and in Papaver bracteatum, which accumulates thebaine. In contrast, orthologs encoding independent CYP and AKR enzymes catalyzing the respective synthesis and reduction of 1,2-dehydroreticuline were isolated from Papaver rhoeas, which does not accumulate morphinan alkaloids. An ancestral relationship between these enzymes is supported by a conservation of introns in the gene fusions and independent orthologs. Suppression of REPI transcripts using virus-induced gene silencing in opium poppy reduced levels of (R)-reticuline and morphinan alkaloids and increased the overall abundance of (S)-reticuline and its O-methylated derivatives. Discovery of REPI completes the isolation of genes responsible for known steps of morphine biosynthesis.