是一类广泛存在于各类生物中的具有分子伴侣功能的蛋白质。近年来研究发现HSP与机体许多功能如免疫、凋亡、衰老等密切相关。柞蚕（Antheraea pernyi）小热休克蛋白20.1（Aphsp20.1）基因的开放读码框长度为534 bp，编码178个氨基酸。序列比对结果表明，柞蚕小热休克蛋白20.1属于HSP20家族。组织定量显示这Aphsp20.1在中肠和脂肪体分布较高。此外用大肠杆菌Escherichia coli及Micrococcus luteus病原微生物注射入5龄3天柞蚕幼虫后，发现Aphsp20.1的基因表达菌明显上调。另外体外抑菌试验结果发现纯化后的蛋白也具有一定的抑菌作用。该研究表明ApHSP20.1在柞蚕的免疫功能中具有重要作用，该研究不仅为我们进一步了解更加复杂的高等生物天然免疫反应提供一些相关的研究线索；而且对柞蚕天然免疫的研究有利于更好地理解昆虫自身的免疫系统，为保护益虫防治害虫提供重要依据。

In our previous study, we found that small heat shock proteins (HSPs) in Antheraea pernyi  have an important role in response to biotic stress. In order to investigate more function and mechanism of HSP in insect immunity, we report the cloning of Hsp20.1 from the Chinese oak silkworm A.pernyi (Aphsp20.1). The open reading frame of ApHSP20.1 encodes 187 amino acid protein, sharing 75% amino acid sequence identity with the other ApHSP. And phylogenetic analysis reveals that ApHSP20.1 is closely related to other known lipidopteran HSP20 genes. A quantitative realtime PCR (RTqPCR) analysis indicated that Aphsp20.1was expressed in all tested tissues and was induced by exposure to the microbes Escherichia coli and Micrococcus luteus.Notably, the recombinant ApHSP20.1 protein exhibited significant antimicrobial activity.Taken together, these results suggest that ApHSP20.1  might play an important role in the response to biotic stresses and in immune reactions.