The biochemical basis for L-canavanine tolerance by the tobacco budworm Heliothis virescens (Noctuidae).
The biochemical basis for L-canavanine tolerance by the tobacco budworm Heliothis virescens (Noctuidae).
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烟草芽虫 Heliothis virescens（Noctuidae）对 L-刀豆氨酸耐受的生化基础。
DOI：
10.1073/pnas.94.6.2255
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发表时间：
1997
影响因子：
11.1
通讯作者：
Douglas L. Dalman
中科院分区：
文献类型：
--
作者：
Coromoto Melangeli;G. Rosenthal;Douglas L. Dalman
烟芽夜蛾Heliothis virescens（夜蛾科）是一种毁灭性的害虫，对L-刀豆氨酸（L-2-氨基-4-（胍基氧基）丁酸）具有显著的抗性，L-刀豆氨酸是一种精氨酸抗代谢物，是对不适应物种的有效杀虫剂。H. virescens利用幼虫肠道的组成酶（通常称为刀豆氨酸水解酶（CH））催化L-刀豆氨酸不可逆地水解为L-高丝氨酸和羟基胍。因此，它代表一种新型水解酶，作用于氧-氮键（EC 3.13.1.1）。这种酶已从H.它对L-刀豆氨酸的表观Km值为1.1 mM，周转数为21.1 μ mol × min（-1）× μ mol（-1）。该酶的分子量为285 kDa，由两个分子量为50 kDa或47.5 kDa的亚基组成。CH对L-刀豆氨酸具有高度特异性，因为它不能与L-2-氨基-5-（胍基氧基）戊酸或L-2-氨基-3-（胍基氧基）丙酸（分别是L-刀豆氨酸的较高或较低同系物）有效地起作用。L-刀豆氨酸衍生物如甲基-L-刀豆氨酸或L-刀豆氨酸和O-脲基-L-高丝氨酸不会被CH显著代谢。
The tobacco budworm, Heliothis virescens (Noctuidae), a destructive insect pest, is remarkably resistant to L-canavanine, L-2-amino-4-(guanidinooxy)butyric acid, an arginine antimetabolite that is a potent insecticide for nonadapted species. H. virescens employs a constitutive enzyme of the larval gut, known trivially as canavanine hydrolase (CH), to catalyze an irreversible hydrolysis of L-canavanine to L-homoserine and hydroxyguanidine. As such, it represents a new type of hydrolase, one acting on oxygen-nitrogen bonds (EC 3.13.1.1). This enzyme has been isolated from the excised gut of H. virescens and purified to homogeneity; it exhibits an apparent Km value for L-canavanine of 1.1 mM and a turnover number of 21.1 micromol x min(-1)x micromol(-1). This enzyme has a mass of 285 kDa and is composed of two subunits with a mass of 50 kDa or 47.5 kDa. CH has a high degree of specificity for L-canavanine as it cannot function effectively with either L-2-amino-5-(guanidinooxy)pentanoate or L-2-amino-3-(guanidinooxy)propionate, the higher or lower homolog of L-canavanine, respectively. L-Canavanine derivatives such as methyl-L-canavanine, or L-canaline and O-ureido-L-homoserine, are not metabolized significantly by CH.
用于确定 L-刀豆氨酸或 L-精氨酸掺入蛋白质的放射测定法。
影响因子：
2.9
作者：
Rosenthal,GA;Thomas,DA
通讯作者：
Thomas,DA