Kishore A R, Erdei J, Naidu S S, Falsen E, Forsgren A, Naidu A S
Department of Medical Microbiology, Malmö General Hospital, University of Lund, Sweden.
FEMS Microbiol Lett. 1991 Sep 15;67(1):115-9. doi: 10.1016/0378-1097(91)90454-i.
The interaction of lactoferrin (Lf) with Aeromonas hydrophila (n = 28) was tested in a 125I-labeled protein-binding assay. The mean per cent binding values for human Lf (HLf) and bovine Lf (BLf) were 13.4 +/- 2.0 (SEM), and 17.5 +/- 2.7 (SEM), respectively. The Lf binding was characterized in type strain A. hydrophila subsp. hydrophila CCUG 14551. The HLf and BLf binding reached a complete saturation within 2 h. Unlabeled HLf and BLf displaced 125I-HLf binding in a dose-dependent manner, and more effectively by the heterologous (1 microgram for 50% inhibition) than the homologous (10 micrograms for 50% inhibition) ligand. Apo- and holo-forms of HLf and BLf both inhibited more than 80%, while mucin caused approx. 50% inhibition of the HLf binding. Various other proteins (including transferrin) or carbohydrates did not block the binding. Two HLf-binding proteins with an estimated molecular masses of 40 kDa and 30 kDa were identified in a boiled-cell-envelope preparation, while the unboiled cell envelope demonstrated a short-ladder pattern at the top of the separating gel and a second band at approx. 60 kDa position. These data establish a specific interaction of Lf and the Lf-binding proteins seem to be porins in A. hydrophila.
采用¹²⁵I标记的蛋白结合试验检测了乳铁蛋白（Lf）与嗜水气单胞菌（n = 28）的相互作用。人乳铁蛋白（HLf）和牛乳铁蛋白（BLf）的平均结合百分值分别为13.4±2.0（标准误）和17.5±2.7（标准误）。在嗜水气单胞菌嗜水亚种的模式菌株CCUG 14551中对Lf结合进行了表征。HLf和BLf的结合在2小时内达到完全饱和。未标记的HLf和BLf以剂量依赖性方式取代¹²⁵I-HLf的结合，并且异源配体（50%抑制时为1微克）比同源配体（50%抑制时为10微克）更有效地实现取代。HLf和BLf的脱辅基形式和全蛋白形式均抑制超过80%，而粘蛋白引起约50%的HLf结合抑制。各种其他蛋白质（包括转铁蛋白）或碳水化合物均不阻断结合。在煮沸的细胞包膜制剂中鉴定出两种估计分子量分别为40 kDa和30 kDa的HLf结合蛋白，而未煮沸的细胞包膜在分离胶顶部显示出短梯状条带，在约60 kDa位置有第二条带。这些数据证实了Lf的特异性相互作用，并且Lf结合蛋白似乎是嗜水气单胞菌中的孔蛋白。
