Lobasso Simona, Saponetti Matilde Sublimi, Polidoro Francesco, Lopalco Patrizia, Urbanija Jasna, Kralj-Iglic Veronika, Corcelli Angela
Department of Medical Biochemistry, Medical Biology and Medical Physics, University of Bari, P.zza G. Cesare, I-70124 Bari, Italy.
Chem Phys Lipids. 2009 Jan;157(1):12-20. doi: 10.1016/j.chemphyslip.2008.09.002. Epub 2008 Sep 30.
The dye 10-N-nonyl acridine orange (NAO) is used to label cardiolipin domains in mitochondria and bacteria. The present work represents the first study on the binding of NAO with archaebacterial lipid membranes. By combining absorption and fluorescence spectroscopy with fluorescence microscopy studies, we investigated the interaction of the dye with (a) authentic standards of archaebacterial cardiolipins, phospholipids and sulfoglycolipids; (b) isolated membranes; (c) living cells of a square-shaped extremely halophilic archaeon. Absorption and fluorescence spectroscopy data indicate that the interaction of NAO with archaebacterial cardiolipin analogues is similar to that occurring with diacidic phospholipids and sulfoglycolipids, suggesting as molecular determinants for NAO binding to archaebacterial lipids the presence of two acidic residues or a combination of acidic and carbohydrate residues. In agreement with absorption spectroscopy data, fluorescence data indicate that NAO fluorescence in archaeal membranes cannot be exclusively attributed to bisphosphatidylglycerol and, therefore, different from mitochondria and bacteria, the dye cannot be used as a cardiolipin specific probe in archaeal microorganisms.
染料10-N-壬基吖啶橙（NAO）用于标记线粒体和细菌中的心磷脂结构域。目前的工作是关于NAO与古细菌脂质膜结合的首次研究。通过将吸收光谱和荧光光谱与荧光显微镜研究相结合，我们研究了该染料与（a）古细菌心磷脂、磷脂和磺基糖脂的真实标准品；（b）分离的膜；（c）方形嗜盐古菌活细胞之间的相互作用。吸收光谱和荧光光谱数据表明，NAO与古细菌心磷脂类似物的相互作用类似于与二酸磷脂和磺基糖脂的相互作用，这表明NAO与古细菌脂质结合的分子决定因素是存在两个酸性残基或酸性和碳水化合物残基的组合。与吸收光谱数据一致，荧光数据表明古菌膜中的NAO荧光不能完全归因于双磷脂酰甘油，因此，与线粒体和细菌不同，该染料不能用作古菌微生物中的心磷脂特异性探针。
