Peiren Nico, de Graaf Dirk C, Vanrobaeys Frank, Danneels Ellen L, Devreese Bart, Van Beeumen Jozef, Jacobs Frans J
Laboratory of Zoophysiology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium.
Toxicon. 2008 Jul;52(1):72-83. doi: 10.1016/j.toxicon.2008.05.003. Epub 2008 May 29.
Honey bee workers use venom for the defence of the colony and themselves when they are exposed to dangers and predators. It is produced by a long thin, convoluted, and bifurcated gland, and consists of several toxic proteins and peptides. The present study was undertaken in order to identify the mechanisms that protect the venom gland secretory cells against these harmful components. Samples of whole venom glands, including the interconnected reservoirs, were separated by two-dimensional gel electrophoresis and the most abundant protein spots were subjected to mass spectrometric identification using MALDI TOF/TOF-MS and LC MS/MS. This proteomic study revealed four antioxidant enzymes: CuZn superoxide dismutase (SOD1), glutathione-S-transferase sigma 1 isoform A (GSTS1), peroxiredoxin 2540 (PXR2540) and thioredoxin peroxidase 1 isoform A (TPX1). Although glutathione-S-transferase (GST) has also been associated with xenobiotic detoxification, the protein we found belongs to the GST Sigma class which is known to protect against oxidative stress only. Moreover, we could demonstrate that the GST and SOD activity of the venom gland was low and moderate, respectively, when compared to other tissues from the adult honey bee. Several proteins involved in other forms of stress were likewise found but it remains uncertain what their function is in the venom gland. In addition to major royal jelly protein 9 (MRJP9), already found in a previous proteomic study, we identified MRJP8 as second member of the MRJP protein family to be associated with the venom gland. Transcripts of both MRJPs were amplified and sequenced. Two endocuticular structural proteins were abundantly present in the 2D-gel and most probably represent a structural component of the epicuticular lining that protects the secretory cells from the toxins they produce.
蜜蜂工蜂在面临危险和天敌时会用毒液来保卫蜂群和自身。毒液由一个细长、盘绕且分叉的腺体产生，由几种有毒蛋白质和肽组成。本研究旨在确定保护毒腺分泌细胞免受这些有害成分影响的机制。包括相连储液器在内的整个毒腺样本通过二维凝胶电泳进行分离，对最丰富的蛋白质斑点使用基质辅助激光解吸电离飞行时间串联质谱（MALDI TOF/TOF-MS）和液相色谱-质谱联用（LC MS/MS）进行质谱鉴定。这项蛋白质组学研究揭示了四种抗氧化酶：铜锌超氧化物歧化酶（SOD1）、谷胱甘肽-S-转移酶西格玛1同工型A（GSTS1）、过氧化物酶2540（PXR2540）和硫氧还蛋白过氧化物酶1同工型A（TPX1）。尽管谷胱甘肽-S-转移酶（GST）也与外源性物质解毒有关，但我们发现的这种蛋白质属于GST西格玛类，已知仅能抵御氧化应激。此外，我们能够证明，与成年蜜蜂的其他组织相比，毒腺的GST和SOD活性分别较低和中等。同样发现了几种参与其他形式应激的蛋白质，但其在毒腺中的功能仍不确定。除了先前蛋白质组学研究中已发现的主要蜂王浆蛋白9（MRJP9）外，我们还鉴定出MRJP8是与毒腺相关的MRJP蛋白家族的第二个成员。对这两种MRJP的转录本进行了扩增和测序。两种内表皮结构蛋白大量存在于二维凝胶中，很可能代表表皮内衬的一种结构成分，可保护分泌细胞免受它们所产生毒素的侵害。
