【摘要】 借助于电子顺磁共振波谱仪（EPR）探测了多变鱼腥藻中 Mn²⁺含量的变化。较高浓度的 CaCl₂和 Ca（NO₃）,处理引起藻体中结合态 Mn 的游离和藻的放氧活性的下降。当结合Mn 游离量达57％时,放氧活性降为零。MgCl₂处理的效果小于 CaCl₂。较高浓度的 MnCl₂像 EGTA 一样抑制藻的放氧。与对照比较,在 CaCl₂、MgCl₂和 MnCl₂处理下藻体的低温荧光发射光谱发生变化,波长686nm处的肩消失,F₁₃₀/F₆₉₅比值下降。本文对光合放氧复合物中离子间可能在其结合位点上发生竞争性取代作用进行了讨论。更多还原

【Abstract】 The changes of Mn²⁺ contents in Anabacna variabilis were probed by EPR.Treatments with CaCl₂ and Ca （NO₃）₂ at high concentrations induced the release of bound Mn and the decrease of oxygen-evolving activity of the cyanobacterium.When the release percentage of bound Mn reached up to 57%,the oxygen-evolving activity decreased to zero.MgCl₂ treat- ment resulted in less effectiveness than CaCl₃ MnCl-2 at high concentration inhibited cyanobac- terial oxygen evolution,as the indication of EGTA.In the comparision with control the low temperature fluorescence emission spectra of the cyanobacterium treated by CaCl₂,MgCl₂ and MnCl₂ changed with the shoulder disappearance at 686nm and the decline of ratio of F₇₃₀/F₆₉₅ The possible competitive substitutions among ions at their binding sites in oxygen-evolving complex were discussed.更多还原