| Autor: |
Ronald Nachum, Stuart E. Siegel, Stanley W. Watson |
| Rok vydání: |
1980 |
| Předmět: |
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| Zdroj: |
Journal of Invertebrate Pathology. 36:382-388 |
| ISSN: |
0022-2011 |
| DOI: |
10.1016/0022-2011(80)90042-7 |
| Popis: |
Bactericidal activity of heat-derived (60°C) extracts of Limulus amoebocyte lysate (LAL) was found to be inhibited by low molar (10 to 100 m m ) concentrations of the monovalent cations Na + and K + . The protective effect of Na + was shown to be species dependent and inversely proportional to the sensitivity of the test microorganism as determined by bactericidal titer. The effect of Na + (100 m m ) on bactericidal activity in whole (unheated) LAL, when assayed against a sensitive species ( Escherichia coli ), was negligible and in direct contrast to data obtained when using 60°C extracts of LAL. Increasing the concentration of Na + to reflect levels in L. polyphemus blood (400 to 500 m m ) afforded only minimal protection for sensitive bacterial species. These data suggested that whole LAL may contain a heat-labile substance (protein?) capable of binding Na + , obviating the inhibitory effect of Na + on bactericidal activity. Further evidence for the existence of this cation-binding substance was obtained when 55°C extracts of LAL were found refractory to Na + concentrations which totally abolished bactericidal activity in 60°C extracts. The mechanism of Na + inhibition of bactericidal activity and the role of the cation-binding substance in L. polyphemus host defense against bacterial invasion and dissemination is discussed. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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