Revisiting the specificity of Mamestra brassicae and Antheraea polyphemus pheromone-binding proteins with a fluorescence binding assay
Revisiting the specificity of Mamestra brassicae and Antheraea polyphemus pheromone-binding proteins with a fluorescence binding assay
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DOI：
10.1074/jbc.m100713200
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发表时间：
2001-06-08
影响因子：
4.8
通讯作者：
Tegoni, M
中科院分区：
文献类型：
--
作者：
Campanacci, V;Krieger, J;Tegoni, M
信息素结合蛋白（PBP）位于信息素反应性触角毛的感器淋巴中，被认为将疏水性信息素转运至嗅觉神经元的化学感应膜。目前尚不清楚 PBP 在识别和区分物种特异性信息素中可能发挥什么作用，我们研究了来自 Mamestra brasciae (MbraPBP1)、Antheraea polyphemus (ApolPBP1)、Bombyx mori (BmorPBP) 和 MbraPBP1 六突变体 (Mbra1-M6) 的 PBP 的结合特性和特异性，MbraPBP1 的六突变体在内腔残基处突变以模仿BmorPBP，使用荧光探针 1-氨基蒽 (AMA)，AMA 与 MbraPBP1 和 ApolPBP1 结合，但未观察到与 BmorPBP 或 Mbra1-M6 的结合。后一个结果表明，对 PBP 腔的相对有限的修饰实际上干扰了 AMA 结合，表明 ARIA 在内腔中结合。几种信息素能够从 MbraPBP1 和 ApolPBP1 结合位点取代 AMA，但是没有任何证据表明其生理相关信息素具有特异性。此外，一些脂肪酸还能够与 AMA 结合竞争。这些发现使人们对目前认为所有 PBP 都专门针对不同的信息素化合物进行调节的观点产生了怀疑。
Pheromone-binding proteins (PBPs), located in the sensillum lymph of pheromone-responsive antennal hairs, are thought to transport the hydrophobic pheromones to the chemosensory membranes of olfactory neurons. It is currently unclear what role PBPs may play in the recognition and discrimination of species-specific pheromones, We have investigated the binding properties and specificity of PBPs from Mamestra brassicae (MbraPBP1), Antheraea polyphemus (ApolPBP1), Bombyx mori (BmorPBP), and a hexa-mutant of MbraPBP1 (Mbra1-M6), mutated at residues of the internal cavity to mimic that of BmorPBP, using the fluorescence probe 1-aminoanthracene (AMA), AMA binds to MbraPBP1 and ApolPBP1, however, no binding was observed with either BmorPBP or Mbra1-M6. The latter result indicates that relatively limited modifications to the PBP cavity actually interfere with AMA binding, suggesting that ARIA binds in the internal cavity. Several pheromones are able to displace AMA from the MbraPBP1- and ApolPBP1-binding sites, without, however, any evidence of specificity for their physiologically relevant pheromones. Moreover, some fatty acids are also able to compete with AMA binding. These findings bring into doubt the currently held belief that all PBPs are specifically tuned to distinct pheromonal compounds.