| Autor: |
Eggset, G., Bjørnsdottir, R., Leifson, R. McQueen, Arnesen, J. A., Coucheron, D. H., Jørgensen, T. Ø. |
| Předmět: |
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| Zdroj: |
Journal of Fish Diseases; Jan1994, Vol. 17 Issue 1, p17-29, 13p |
| Abstrakt: |
Extracellular haemolytic activities of Aeromonas salmonicida ssp. salmonicida to salmon red blood cells were shown to be due to different forms of the membrane-active enzyme glycerophospholipid:cholesterol acyltransferase (GCAT). About 10% of the total haemolytic activity was due to a high molecular mass complex of LPS and GCAT (mol. mass >1000kDa), containing 35-50% neutral sugars and 1.5-2.0% protein. Some haemolytic activity (30-40% of total), corresponding to 5–70 kDa by gel filtration, also contained GCAT-activity and may represent aggregated forms of GCAT. However, about 50% or more of the haemolytic activity was due to a protein of 26kDa free GCAT. Rabbit antibodies to GCAT neutralized the haemolytic activity of both GCAT and GCAT-EPS. A transposon-produced serine protease negative mutant of the same A. salmonicida strain showed reduced haemolytic activity. The mutant produced a 38-kDa GCAT proform of low haemolytic activity. The proform was processed by autogenous serine protease to a highly haemolytic 26-kDa molecule with pi 6.3, similar to GCAT of the parent strain. The weakly haemolytic GCAT-LPS analogue of the mutant strain did not contain detectable amounts of the 26-kDa molecule and was not activated by proteases. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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