The biosynthetic pathway from linoleic acid to 1-octen-3-ol in Agaricus bisporus has long been established, in which linoleic acid is converted to 10-hydroperoxide (10-HPOD) by deoxygenation, and 10-HPOD is subsequently cleaved to yield 1-octene-3-ol and 10-oxodecanoic acid. However, the corresponding enzymes have not been identified and cloned. In the present study, four putative genes involved in oxylipid biosynthesis, including one lipoxygenase gene named AbLOX, two linoleate diol synthase genes named AbLDS1 and AbLDS2, and one hydroperoxide lyase gene named AbHPL were retrieved from the A. bisporus genome by a homology search and cloned and expressed prokaryotically. AbLOX, AbLDS1, and AbLDS2 all exhibited fatty acid dioxygenase activity, catalyzing the conversion of linoleic acid to generate hydroperoxide, and AbHPL showed a cleaving hydroperoxide activity, as was determined by the KI-starch method. AbLOX and AbHPL catalyzed linoleic acid to 1-octen-3-ol with an optimum temperature of 35 °C and an optimum pH of 7.2, whereas AbLDS1, AbLDS2, and AbHPL catalyzed linoleic acid without 1-octen-3-ol. Reduced AbLOX expression in antisense AbLOX transformants was correlated with a decrease in the yield of 1-octen-3-ol. AbLOX and AbHPL were highly homologous to the sesquiterpene synthase Cop4 of Coprinus cinerea and the yeast sterol C-22 desaturase, respectively. These results reveal that the enzymes for the oxidative cleavage of linoleic acid to synthesize 1-octen-3-ol in A. bisporus are the multifunctional fatty acid dioxygenase AbLOX and hydroperoxide lyase AbHPL.

中文翻译：

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双孢蘑菇多功能脂肪酸双加氧酶和过氧化氢裂解酶生物合成1-辛烯-3-醇

双孢蘑菇中亚油酸到 1-octen-3-ol 的生物合成途径早已建立，其中亚油酸通过脱氧转化为 10-氢过氧化物 (10-HPOD)，随后 10-HPOD 被裂解生成 1 -辛烯-3-醇和10-氧代癸酸。然而，相应的酶尚未被鉴定和克隆。在本研究中，通过同源性从双孢菌基因组中检索到4 个与氧脂生物合成有关的推定基因，包括一个名为 AbLOX 的脂氧合酶基因、两个名为AbLDS 1 和AbLDS 2 的亚油酸二醇合酶基因和一个名为AbHPL的氢过氧化物裂解酶基因。搜索和克隆和原核表达。Ab LOX、Ab LDS1 和Ab LDS2 均表现出脂肪酸双加氧酶活性，催化亚油酸转化为过氧化氢，而Ab HPL 表现出裂解过氧化氢活性，如通过 KI-淀粉法测定的那样。Ab LOX 和Ab HPL 催化亚油酸生成 1-octen-3-ol，最适温度为 35 °C，最适 pH 为 7.2，而Ab LDS1、Ab LDS2 和Ab HPL 在没有 1-octen-3 的情况下催化亚油酸-ol。反义AbLOX转化体中AbLOX表达降低与 1-octen-3-ol 产量降低相关。抗体LOX 和Ab HPL 分别与Coprinus cinerea的倍半萜合酶 Cop4和酵母甾醇 C-22 去饱和酶高度同源。这些结果表明，双孢菌中亚油酸氧化裂解合成1-辛烯-3-醇的酶是多功能脂肪酸双加氧酶Ab LOX和氢过氧化物裂解酶Ab HPL。