Nakamura H, Shinya T
J Gen Microbiol. 1985 Jul;131(7):1639-47. doi: 10.1099/00221287-131-7-1639.
The acrA mutation in Escherichia coli led to a substantial increase of the acriflavine-binding capacity of the cell, whereas the related mutations acrB (gyrB) and arcC did not. Metal ions such as Na+, K+, Mg2+, Ca2+ and Al3+ effectively released the bound acriflavine, in proportion to their ionic strengths. The presence of cations, in fact, increased the survival fraction of the cells in the acriflavine-containing medium. Polymyxin B, an antibiotic which binds to membrane phospholipid, competed with acriflavine for binding sites. Cell wall digestion by treatment with lysozyme and EDTA slightly decreased the acriflavine-binding capacity. Almost no difference was observed in acriflavine-binding capacity between intact cells and cells from which lipopolysaccharide has been extracted (46.9% removed from the acrA cells and 47.4% from the acrA+ cells). Acriflavine bound to the cells was most effectively extracted by ethanol containing 1% HCl or by 2% (w/v) SDS. The difference in the acriflavine-binding capacity between the acrA and acrA+ cells was also observed in the spheroplasts. These facts indicate a relationship between the acrA gene product and the acriflavine-binding capacity of the cells.
大肠杆菌中的acrA突变导致细胞的吖啶黄素结合能力大幅增加，而相关突变acrB（gyrB）和arcC则没有这种情况。Na+、K+、Mg2+、Ca2+和Al3+等金属离子能根据其离子强度有效地释放结合的吖啶黄素。事实上，阳离子的存在增加了细胞在含吖啶黄素培养基中的存活比例。多粘菌素B是一种与膜磷脂结合的抗生素，它与吖啶黄素竞争结合位点。用溶菌酶和EDTA处理进行细胞壁消化会使吖啶黄素结合能力略有下降。完整细胞与已提取脂多糖的细胞（acrA细胞中去除46.9%，acrA+细胞中去除47.4%）之间的吖啶黄素结合能力几乎没有差异。结合到细胞上的吖啶黄素最有效地被含1%HCl的乙醇或2%（w/v）SDS提取。在原生质球中也观察到了acrA和acrA+细胞之间吖啶黄素结合能力的差异。这些事实表明acrA基因产物与细胞的吖啶黄素结合能力之间存在关联。
