Wang P, Granados R R
Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA.
Insect Biochem Mol Biol. 2000 Feb;30(2):135-43. doi: 10.1016/s0965-1748(99)00108-3.
The insect midgut is generally lined with a unique protective chitin/protein structure, the peritrophic membrane (PM). We demonstrated that in Trichoplusia ni larvae, the majority of PM proteins were assembled with chitin as a consequence of their chitin binding properties. These proteins could be dissociated from the PM in vitro by Calcofluor, a well-known chemical with chitin binding properties. The chitin binding characteristics of PM proteins were confirmed by their high affinity binding in vitro to regenerated chitin. In vivo assays demonstrated that Calcofluor could inhibit PM formation in five lepidopteran insects tested. The inhibition of T. ni PM formation by Calcofluor, was accompanied by increased larval susceptibility to baculovirus infection. Continuous inhibition of PM formation by Calcofluor resulted in retarded larval development and mortality. The destructive effect of Calcofluor on PM formation was demonstrated to be transient and reversible depending on the presence of Calcofluor within the midgut. In addition, degradation of the insect intestinal mucin was observed concurrently with the inhibition of PM formation by Calcofluor. Our studies revealed a potential novel approach to develop strategies for insect control by utilizing chitin binding molecules to specifically target PM formation in a broad range of insect pest species.
昆虫中肠通常内衬有独特的保护性几丁质/蛋白质结构，即围食膜（PM）。我们证明，在粉纹夜蛾幼虫中，由于其几丁质结合特性，大多数围食膜蛋白与几丁质组装在一起。这些蛋白质在体外可以被钙黄绿素从围食膜上解离下来，钙黄绿素是一种具有几丁质结合特性的知名化学物质。围食膜蛋白的几丁质结合特性通过其在体外与再生几丁质的高亲和力结合得到证实。体内试验表明，钙黄绿素可以抑制所测试的五种鳞翅目昆虫围食膜的形成。钙黄绿素对粉纹夜蛾围食膜形成的抑制作用伴随着幼虫对杆状病毒感染易感性的增加。钙黄绿素对围食膜形成的持续抑制导致幼虫发育迟缓并死亡。已证明钙黄绿素对围食膜形成的破坏作用是短暂且可逆的，这取决于中肠内是否存在钙黄绿素。此外，在钙黄绿素抑制围食膜形成的同时，观察到昆虫肠道粘蛋白的降解。我们的研究揭示了一种潜在的新方法，即利用几丁质结合分子特异性地靶向多种害虫物种的围食膜形成，来制定昆虫控制策略。
