Identification of the active domain of insect antibacterial proteins and production of new antibacterial peptides.

抗菌肽KLKLLLLKLK-NH_2(L5)对感染MRSA的小鼠具有明显的体内化疗活性。对L5的抗菌机理进行了研究。L5具有利用细菌膜释放质子梯度的活性。L5的活性介于CCCP和DNP之间，L5对信号肽酶的活性也有抑制作用。因此，L5的这些作用似乎是其抗菌活性的主要原因。最近我们发现L5激活了人的中性粒细胞，导致超氧化物的产生。KLKLLLLKLK-NH_2(L4)和KLKLLLKLK-NH_2(L3)都没有这种活性，说明Leu的数量对激活中性粒细胞是重要的。

An antibacterial peptide, KLKLLLLLKLK-NH_2 (L5) showed significant chemotherapeutic activity in MRSA-infected mice in vivo. The antibacterial mechanisms of L5 were investigated. L5 was shown to have the activity to release the proton gradient using the bacterial membrane. The strength of the activity of L5 was between CCCP and DNP.And L5 was also shown to inhibit the activity of signal peptidase. Thus these effects of L5 seem to be the main reason of the antibacterial activity. Recently we found that L5 activated the human neutrophil, resulting the production of superoxide. Neither KLKLLLLKLK-NH_2 (L4), nor KLKLLLKLK-NH_2 (L3) has the activity at all, indicating that the number of Leu is important for activating neutrophil.