Identification of an aldehyde oxidase involved in indole-3-acetic acid synthesis in Bombyx mori silk gland
Identification of an aldehyde oxidase involved in indole-3-acetic acid synthesis in Bombyx mori silk gland
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DOI：
10.1080/09168451.2018.1525275
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发表时间：
2019-01-01
影响因子：
1.6
通讯作者：
Suzuki, Yoshihito
中科院分区：
文献类型：
--
作者：
Takei, Mami;Kogure, Syota;Suzuki, Yoshihito
生长素被认为是叮咬昆虫引起虫胆的一个重要因素。我们以前已经证明，叮咬昆虫和非叮咬昆虫都是由色氨酸(Trp)通过两个中间体--吲哚-3-乙醛(IAOx)和吲哚-3-乙醛(IAAd)合成吲哚-3-乙酸(IAA)。在本研究中，我们从家蚕丝腺提取物中分离出一种催化最后一步“IAAd->；IAA”的酶。该酶命名为“BmIAO1”，含有两个2Fe-2S铁硫簇结合域、一个FAD结合域和一个钼紫蝶呤结合域，它们在乙醛氧化酶中是保守的。BmIAO1引起色氨酸的非酶转化和IAOx的酶促转化，提示BmIAO1单独参与了家蚕体内IAA的合成。然而，对纯BmIAO1和丝腺粗提物的详细比较表明，参与从Trp产生IAA的其他酶的存在。
Auxin is thought to be an important factor in the induction of galls by galling insects. We have previously shown that both galling and nongalling insects synthesize indole-3-acetic acid (IAA) from tryptophan (Trp) via two intermediates, indole-3-acetaldoxime (IAOx) and indole-3-acetaldehyde (IAAld). In this study, we isolated an enzyme that catalyzes the last step "IAAld -> IAA" from a silk-gland extract of Bombyx mori. The enzyme, designated "BmIAO1", contains two 2Fe-2S iron-sulfur-cluster-binding domains, an FAD-binding domain, and a molybdopterin-binding domain, which are conserved in aldehyde oxidases. BmIAO1 causes the nonenzymatic conversion of Trp to IAAld and the enzymatic conversion of IAOx to IAA, suggesting that BmIAO1 alone is responsible for IAA production in B. mori. However, a detailed comparison of pure BmIAO1 and the crude silk-gland extract suggested the presence of other enzymes involved in IAA production from Trp.