Béven L, Wróblewski H
Groupe Membranes et Osmorégulation, UPRES-A CNRS Q6026, Université de Rennes 1, Rennes, France.
Res Microbiol. 1997 Feb;148(2):163-75. doi: 10.1016/S0923-2508(97)87647-4.
The antibiotic activity of ten amphipathic peptides was investigated in six species of mollicutes belonging to the genera Acholeplasma, Mycoplasma and Spiroplasma. A. laidlawii was the most sensitive and M. mycoides subsp. mycoides SC the most resistant. Animal defence peptides (cecropins A and P1, and magainin 2) proved to be less potent than bee-venom mellitin and most of the peptides produced by bacteria (globomycin, gramicidin S, surfactin and valinomycin) or fungi (alamethicin). Gramicidin S was by far the most active peptide, with minimal inhibitory concentrations ranging from 2 to 50 nM. Alamethicin, gramicidin S, mellitin and surfactin had a cidal effect, whilst cecropins, globomycin, magainin 2, polymyxin B and valinomycin proved to be static. The peptides altered the membrane potential of spiroplasma cells with a potency independent of their linear or cyclic structure. However, globomycin depolarized the plasma membrane only weakly, whilst polymyxin B, in order to be active, required prior hyperpolarization of the membrane. The peptides also induced the loss of cell motility and helicity in spiroplasmas, suggesting that motility and cell shape in these bacteria are coupled to the transmembrane electrochemical gradient. Globomycin, an inhibitor of signal-peptidase II, prevented the growth of spiroplasmas, M. gallisepticum, and M. genitalium, but not that of A. laidlawii and M. mycoides subsp. mycoides SC, although the latter also synthesized membrane lipoproteins. Inhibition of spiralin processing by globomycin was demonstrated in S. citri and S. melliferum, with a more pronounced effect in the second species.
研究了10种两亲性肽对属于无胆甾原体属、支原体属和螺原体属的6种柔膜菌的抗菌活性。莱氏无胆甾原体最敏感，而蕈状支原体丝状亚种SC最耐药。动物防御肽（天蚕素A和P1以及蛙皮素2）的效力低于蜂毒溶血素以及大多数细菌（短杆菌肽S、短杆菌肽、表面活性素和缬氨霉素）或真菌（阿拉霉素）产生的肽。短杆菌肽S是迄今为止活性最高的肽，最低抑菌浓度范围为2至50 nM。阿拉霉素、短杆菌肽S、溶血素和表面活性素具有杀菌作用，而天蚕素、球霉素、蛙皮素2、多粘菌素B和缬氨霉素则具有抑菌作用。这些肽改变了螺原体细胞的膜电位，其效力与其线性或环状结构无关。然而，球霉素仅微弱地使质膜去极化，而多粘菌素B要发挥活性则需要膜先进行超极化。这些肽还导致螺原体失去细胞运动性和螺旋性，这表明这些细菌中的运动性和细胞形状与跨膜电化学梯度相关。信号肽酶II抑制剂球霉素可阻止螺原体、鸡毒支原体和生殖支原体的生长，但不能阻止莱氏无胆甾原体和蕈状支原体丝状亚种SC的生长，尽管后者也合成膜脂蛋白。在柑橘螺原体和蜜蜂螺原体中证实了球霉素对螺旋蛋白加工的抑制作用，在后者中作用更为明显。
