Carlsson Anette, Nyström Thomas, de Cock Hans, Bennich Hans
Department of Medical Biochemistry & Microbiology, Uppsala UniversityBox 582, S-75123 UppsalaSweden.
Department of Microbiology, Lund UniversitySölveg. 12, S-22362 LundSweden.
Microbiology (Reading). 1998 Aug;144 ( Pt 8):2179-2188. doi: 10.1099/00221287-144-8-2179.
Attacin is a 20 kDa antibacterial protein, originally isolated from the immune haemolymph of Hyalophora cecropia. It has been demonstrated previously that attacin causes increased permeability of the outer membrane of Escherichia coli and inhibition of outer-membrane protein synthesis at the transcriptional level. This is accompanied by inhibition of growth. Here, LPS is shown to serve as the receptor for attacin and evidence is presented that attacin does not need to enter the cell to exert its activity. The increase in outer-membrane permeability precedes any increase in inner-membrane permeability by at least one generation time (approximately 45 min), and the inhibiting effect of attacin on synthesis of outer-membrane proteins is detectable after only 10 min. It is also shown that attacin causes induction of several stress proteins and increased synthesis of LPS within, respectively, 25 and 60 min of treatment. Based on the results presented, it is proposed that attacin has the unique ability to specifically interfere with synthesis of outer-membrane proteins without entering the inner membrane or cytoplasm.
杀菌肽是一种20千道尔顿的抗菌蛋白，最初从大透翅蛾的免疫血淋巴中分离出来。先前已经证明，杀菌肽会导致大肠杆菌外膜通透性增加，并在转录水平上抑制外膜蛋白合成。这伴随着生长抑制。在这里，脂多糖被证明是杀菌肽的受体，并且有证据表明杀菌肽不需要进入细胞就能发挥其活性。外膜通透性的增加比内膜通透性的任何增加至少提前一个世代时间（约45分钟），并且杀菌肽对外膜蛋白合成的抑制作用在仅10分钟后就可检测到。还表明，杀菌肽分别在处理25分钟和60分钟内导致几种应激蛋白的诱导和脂多糖合成的增加。基于所呈现的结果，有人提出杀菌肽具有独特的能力，能够在不进入内膜或细胞质的情况下特异性干扰外膜蛋白的合成。
