Jaeger K E, Kharazmi A, Høiby N
Lehrstuhl für Biologie der Mikroorganismen, Ruhr-Universität, Bochum, Germany.
Microb Pathog. 1991 Mar;10(3):173-82. doi: 10.1016/0882-4010(91)90052-c.
Lipase was isolated from P. aeruginosa by ultrafiltration of sterile-filtered culture supernatant. Gel filtration on Sepharose 4B yielded a broad peak corresponding to a molecular mass range of 100 to 1000 kDa. Electron microscopy of a negatively stained lipase preparation after Sepharose 4B chromatography revealed spherical particles with diameters ranging from 5 to 20 nm. Biochemical characterization and SDS polyacrylamide gel electrophoresis suggested that these particles consisted of protein and carbohydrate including lipopolysaccharide with the major enzyme activity being lipase. Various concentrations of this lipase preparation were preincubated with human peripheral blood neutrophils and monocytes. The chemotaxis and chemiluminescence of these cells were then determined. It was shown that lipase inhibited the monocyte chemotaxis and chemiluminescence, whereas it had no or very little effect on neutrophils. The inhibitory effect was concentration dependent and was abolished by heat treatment of the enzyme at 100 degrees C. Since monocytes are one of the important cells of the host defence system the inhibition of the function of these cells may contribute to the pathogenesis of infections caused by P. aeruginosa.
通过对无菌过滤的培养上清液进行超滤，从铜绿假单胞菌中分离出脂肪酶。在Sepharose 4B上进行凝胶过滤得到一个宽峰，对应于100至1000 kDa的分子量范围。对Sepharose 4B层析后经负染的脂肪酶制剂进行电子显微镜观察，发现直径为5至20 nm的球形颗粒。生化特性分析和SDS聚丙烯酰胺凝胶电泳表明，这些颗粒由蛋白质和碳水化合物组成，包括脂多糖，主要酶活性为脂肪酶。将不同浓度的这种脂肪酶制剂与人外周血中性粒细胞和单核细胞预孵育。然后测定这些细胞的趋化性和化学发光。结果表明，脂肪酶抑制单核细胞趋化性和化学发光，而对中性粒细胞没有或只有很小的影响。这种抑制作用是浓度依赖性的，并且在100℃对酶进行热处理后被消除。由于单核细胞是宿主防御系统的重要细胞之一，这些细胞功能的抑制可能有助于铜绿假单胞菌引起的感染的发病机制。
