克氏螯虾壳聚糖抗菌的作用靶位  

Target site for the antibacterial action of chitosan from red swamp crayfish

作　　者：郑铁生[1] 朱旭明[2] 张燕玲[3] 

机构地区：[1]江苏大学基础医学与医学技术学院,江苏省镇江市212013 [2]南京医科大学附属无锡市人民医院检验科,江苏省无锡市214023 [3]天津医科大学检验系,天津市300070

出　　处：《世界华人消化杂志》2009年第25期2585-2588,共4页World Chinese Journal of Digestology

基　　金：高校基金资助项目;No.2291270004~~

摘　　要：目的:研究克氏螯虾壳聚糖抗菌的作用靶位,探讨其抗菌机制.方法:用5(6)-羧-四甲基罗丹明-5-马来酰亚胺标记克氏螯虾壳聚糖,应用标记克氏螯虾壳聚糖与大肠埃希菌及金黄色葡萄球菌在pH5.6,37℃条件下220r/min作用3.5h,观察作用前后上清液中的核酸和蛋白质含量变化,并用激光共聚焦显微镜观察其对细菌的聚集部位.结果:荧光标记克氏螯虾壳聚糖对大肠埃希菌作用前后的上清液中,核酸和蛋白质的含量由作用前的0.00和0.22±0.01升高为1.13±0.06和1.49±0.05(P<0.01);对金黄色葡萄球菌作用前后的上清液中,核酸和蛋白质的含量由作用前的0.03±0.06和0.21±0.02升高为1.00±0.10和0.81±0.01(P<0.01);并且荧光标记克氏螯虾壳聚糖浓度越高,核酸及蛋白质含量也逐渐增高;激光共聚焦显微镜下显示两种实验细菌由表及里的荧光强度逐渐增强.结论:克氏螯虾壳聚糖的抗菌作用靶位,除部分作用于细菌细胞膜外,主要是进入细菌内作用于细胞器.AIM： To investigate the potential target site for the antibacterial action of chitosan from red swamp crayfish and explore its antibacterial mechanism.METHODS： Chitosan from red swamp crayfish was labeled with 5（6）-carboxy-tetramethylrho- damine-5-maleimide. The labeled chitosan was then incubated with Escherichia coli （E.coli） and Staphylococcus aureus （ S.aureus）, respectively. The total protein （TP） and nucleic acid contents in cell-free supernatants of chitosan-treated E.coli and S.aureus were determined. Laser scanning confocal microscopy （LSCM） was used to observe the distribution of fluorescently labeled chitosan in bacteria.RESULTS： Chitosan treatment significantly increased the nucleic acid and TP contents in cell-free supernatants of E.coli （1.13±0.06 vs 0.00 and 1.49±0.05 vs 0.22±0.01, respectively; both P 〈 0.01） and S.aureus （1.00±0.10 vs 0.03±0.06 and 0.81±0.01 vs 0.21±0.02, respectively; both P 〈 0.01） in a concentration-dependent manner. LSCM showed that the fluorescent signal in the bacterial cytoplasm was stronger than that in the bacterial membrane.CONCLUSION： Bacterial cytoplasm is the main target site for the antibacterial action of chitosan from red swamp crayfish.

关 键 词：克氏螯虾壳聚糖 抗菌 核酸 蛋白质 激光共聚焦显微镜 作用靶位 

分 类 号：R96[医药卫生—药理学]