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Lactoferrin interaction with Actinobacillus actinomycetemcomitans.

K R Alugupalli·S Kalfas·S Edwardsson·A S Naidu
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Abstract

The interaction of lactoferrin with Actinobacillus actinomycetemcomitans was examined in a 125I-labeled protein binding assay. The binding of human and bovine lactoferrins reached maximum within 1 h. Lactoferrin binding to the bacterium was pH-dependent and reversible. Scatchard analysis indicated the existence of two different types of binding sites on the bacterium, one with a high affinity constant k alpha approximately 8.8 x 10(-7) M) and the other with a low one (k alpha approximately 1.8 x 10(-6) M). Bacteria in the exponential phase of growth showed higher binding than cells in the stationary phase. Bacteria grown in medium containing serum and/or lysed erythrocytes bound lactoferrin to a lesser extent. Heat-inactivated serum, lysed erythrocytes and other proteins such as mucin and laminin inhibited lactoferrin binding to A. actinomycetemcomitans in a competitive binding assay. Sodium dodecyl sulfate polyacrylamide-gel electrophoresis and Western blot analysis of the cell envelope as well as the outer membrane of A. actinomycetemcomitans revealed lactoferrin-reactive protein bands at 29 kDa and 16.5 kDa. The 29-kDa band displayed a heat-modifiable lactoferrin-reactive form with a molecular weight of 34 kDa. Neither proteinase K-treated cell envelope nor lipopolysaccharide of this bacterium showed reactivity with lactoferrin. These data suggests a specific interaction of lactoferrin with outer membrane proteins of A. actinomycetemcomitans.

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Aggregatibacter actinomycetemcomitansAnimalsBacterial Outer Membrane ProteinsBinding, CompetitiveCattleElectrophoresis, Polyacrylamide GelFibrinogenFibronectinsHorsesHumansHydrogen-Ion ConcentrationLactoferrinLamininMucinsProtein BindingJournal Article

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K R Alugupalli, S Kalfas, S Edwardsson, A S Naidu. 1995. Lactoferrin interaction with Actinobacillus actinomycetemcomitans.. https://doi.org/10.1111/j.1399-302x.1995.tb00115.x

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Aggregatibacter actinomycetemcomitans↗
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Aggregatibacter actinomycetemcomitans↗