Shi Yi-Jun, Wang Ren-Tsung, Chu Yu-Hui, Chen Ying-Jung, Tang Ching-Chia, Fu Yaw-Syan, Lee Yuan-Chin, Wang Liang-Jun, Huang Chia-Hui, Chang Long-Sen
Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
Laboratory Medicine Division, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung 813, Taiwan.
Arch Biochem Biophys. 2018 Feb 1;639:1-8. doi: 10.1016/j.abb.2017.12.006. Epub 2017 Dec 19.
Mannosylated ovalbumin (Man-OVA) prepared by modification of carboxyl groups with p-aminophenyl α-d-mannopyranoside shows an increase of net positive charge, which may enhance its binding to bacterial membrane. Thus, we aimed to investigate whether Man-OVA exerts antibacterial activity on Escherichia coli and Staphylococcus aureus via membrane-perturbing effect. Man-OVA inhibited the growth of E. coli and S. aureus, whereas ovalbumin (OVA) did not show any antibacterial activity. Moreover, Man-OVA induced an increase in the membrane permeability of E. coli and S. aureus, which was positively correlated to its bactericidal action. Morphological examination using scanning electron microscopy revealed that Man-OVA disrupted the bacterial membrane integrity. Destabilization of the lipopolysaccharide (LPS) layer and inhibition of lipoteichoic acid (LTA) biosynthesis in the cell wall increased the bactericidal effect of Man-OVA. In contrast to OVA, Man-OVA also induced leakage of bacterial membrane-mimicking liposomes. Color transformation of phospholipid/polydiacetylene membrane assay revealed that the membrane-interaction mode of Man-OVA was distinct from that of OVA. LPS and LTA suppressed the membrane-damaging activity of Man-OVA, whereas an increase in the Man-OVA concentration attenuated the inhibitory action of LPS and LTA. Taken together, our data indicate that the bactericidal activity of Man-OVA depends strongly on its ability to induce membrane permeability.
用对氨基苯基α - D - 甘露吡喃糖苷修饰羧基制备的甘露糖基化卵清蛋白（Man - OVA）显示出净正电荷增加，这可能增强其与细菌膜的结合。因此，我们旨在研究Man - OVA是否通过膜扰动作用对大肠杆菌和金黄色葡萄球菌发挥抗菌活性。Man - OVA抑制了大肠杆菌和金黄色葡萄球菌的生长，而卵清蛋白（OVA）未显示出任何抗菌活性。此外，Man - OVA诱导大肠杆菌和金黄色葡萄球菌的膜通透性增加，这与其杀菌作用呈正相关。使用扫描电子显微镜进行的形态学检查显示，Man - OVA破坏了细菌膜的完整性。脂多糖（LPS）层的不稳定和细胞壁中脂磷壁酸（LTA）生物合成的抑制增加了Man - OVA的杀菌效果。与OVA不同，Man - OVA还诱导了模拟细菌膜的脂质体泄漏。磷脂/聚二乙炔膜测定的颜色转变表明，Man - OVA的膜相互作用模式与OVA不同。LPS和LTA抑制了Man - OVA的膜损伤活性，而Man - OVA浓度的增加减弱了LPS和LTA的抑制作用。综上所述，我们的数据表明，Man - OVA的杀菌活性强烈依赖于其诱导膜通透性的能力。
