理化因子对集胞藻PCC6803溶血素溶血活性的影响

研究了保存温度以及添加稳定剂、氧化剂、还原剂、螯合剂和金属离子对集胞藻(Synechocystis sp. PCC6803)野生型菌株产生的溶血素的溶血活性的影响.结果表明，该溶血素在提取初始仅具有较低的溶血活性，但在提取3～6 d后，溶血活性急剧升高，之后随保存时间延长逐渐降低.-20 ℃低温保存有利于该溶血素活性的维持.添加半胱氨酸盐酸盐、牛血清白蛋白和血红蛋白都能提高其溶血活性，可以作为该溶血素的稳定剂；氧化剂H₂O₂能显著提高其溶血活性，而还原剂β-巯基乙醇、二硫苏糖醇显著抑制其溶血活性，说明该溶血素为非巯基依赖型溶血素.金属离子Ca2+，Co2+，Fe3+，Ni2+，Cu2+，Mn2+和Mg2+均会抑制其溶血活性，仅Zn2+能增加其溶血活性，金属螯合剂EDTA也能增强其溶血活性. 

Effects of Physical and Chemical Agents on the Hemolytic Activity of Hemolysin Produced by Synechocystis sp. PCC6803

The effects of different storage temperatures and addition of various stabilizers, oxidants, reducers, metal ions and chelators on hemolytic activity of the hemolysin produced by wild type strain of Synechocystis sp. PCC6803 were studied. The results showed that the hemolysin only had a low hemolytic activity when it was freshly extracted and, however, the hemolytic activity increased drastically after 3 to 6 days of conservation, then decreased gradually with the time. Low temperature of-20 ℃ favored the sustaining of hemolytic activity. The addition of cysteine monohydrochloride, bovine serum albumin or hemoglobin as stabilizers enhanced the hemolytic activity. The determination that the hemolytic activity was enhanced by oxidant of hydrogen peroxide and inhibited by reducers such as β-mercaptoethanol and dithiothreitol indicated that the hemolysin was anon thiol-activated toxin. In addition, supplement of metal ions of Ca2+, Co2+, Fe3+, Ni2+, Cu2+, Mn2+ and Mg2+ decreased the hemolytic activity, whereas Zn2+ and EDTA increased it significantly.