安徽农业科学
安徽農業科學
안휘농업과학
JOURNAL OF ANHUI AGRICULTURAL SCIENCES
2009年
34期
16859-16860,16866
,共3页
荧光探针%小牛胸腺DNA%DNA构象
熒光探針%小牛胸腺DNA%DNA構象
형광탐침%소우흉선DNA%DNA구상
Fluorescence probe%Calf-thymus DNA%DNA conformation
[目的]利用荧光探针法研究铅离子与DNA的作用方式.[方法]采用紫外可见分光光度法检测了DNA的纯度,采用荧光滴定法研究了铅离子对DNA构象的影响.[结果]随着铅离子的加入,DNA-EB复合物的荧光强度逐渐降低.在DNA-EB体系中加入铅离子后,荧光强度随着铅离子浓度的增加而降低,且荧光峰位略有红移.按生物分子的荧光寿命τ0为10 ns计算,DNA-EB与铅离子的双分子猝灭常数分别为1.01×10~(13)和4.0×10~(14) L/(mol·s),二者均大于生物分子的最大动态猝灭常数2.0 ×10~(10)L/(mol·s),说明由铅离子引起的DNA-EB的荧光猝灭属于静态猝灭.根据斜率和外推截距计算出DNA-EB与猝灭剂的解离常数为1.13×10~(-5) mol/L.铅离子与DNA-EB的结合位点为5.56,结合常数为1.51×10~(29).[结论] 铅离子容易与DNA结合,引起DNA构象的变化.
[目的]利用熒光探針法研究鉛離子與DNA的作用方式.[方法]採用紫外可見分光光度法檢測瞭DNA的純度,採用熒光滴定法研究瞭鉛離子對DNA構象的影響.[結果]隨著鉛離子的加入,DNA-EB複閤物的熒光彊度逐漸降低.在DNA-EB體繫中加入鉛離子後,熒光彊度隨著鉛離子濃度的增加而降低,且熒光峰位略有紅移.按生物分子的熒光壽命τ0為10 ns計算,DNA-EB與鉛離子的雙分子猝滅常數分彆為1.01×10~(13)和4.0×10~(14) L/(mol·s),二者均大于生物分子的最大動態猝滅常數2.0 ×10~(10)L/(mol·s),說明由鉛離子引起的DNA-EB的熒光猝滅屬于靜態猝滅.根據斜率和外推截距計算齣DNA-EB與猝滅劑的解離常數為1.13×10~(-5) mol/L.鉛離子與DNA-EB的結閤位點為5.56,結閤常數為1.51×10~(29).[結論] 鉛離子容易與DNA結閤,引起DNA構象的變化.
[목적]이용형광탐침법연구연리자여DNA적작용방식.[방법]채용자외가견분광광도법검측료DNA적순도,채용형광적정법연구료연리자대DNA구상적영향.[결과]수착연리자적가입,DNA-EB복합물적형광강도축점강저.재DNA-EB체계중가입연리자후,형광강도수착연리자농도적증가이강저,차형광봉위략유홍이.안생물분자적형광수명τ0위10 ns계산,DNA-EB여연리자적쌍분자졸멸상수분별위1.01×10~(13)화4.0×10~(14) L/(mol·s),이자균대우생물분자적최대동태졸멸상수2.0 ×10~(10)L/(mol·s),설명유연리자인기적DNA-EB적형광졸멸속우정태졸멸.근거사솔화외추절거계산출DNA-EB여졸멸제적해리상수위1.13×10~(-5) mol/L.연리자여DNA-EB적결합위점위5.56,결합상수위1.51×10~(29).[결론] 연리자용역여DNA결합,인기DNA구상적변화.
[Objective] The purpose was to research the action mode of lead ions and DNA by fluorescent probe method.[Method] The purity of DNA was detected by UV-vis spectrophotometry and the influence of lead ions on DNA conformation was researched by fluorescence titration.[Result] The fluorescence intensity of DNA-EB compound was decreased gradually along with the addition of lead ions.After the lead ions were added into DNA-EB system,the fluorescence intensity was decreased as the concn.of lead ions was increased and the fluorescent peak-position was a little red shifted.The fluorescence lifetime τ_0 of biological molecular was 10 ns,it was calculated out according to this that the double-molecular quenching constants of DNA-EB and lead ions were 1.01×10~(13) and 4.0×10~(14) L/(mol·s) resp.,both of them were bigger than the maximum dynamic quenching constant,which was 2.0 ×10~(10) L/(mol·s),indicating that the fluorescent quenching induced by lead ions of DNA-EB belong to statistic quenching.According slope and extrapolation intercept,it was calculated out that the dissociation constant of DNA-EB and quencher was 1.13×10~(-5) mol/L.The binding site of lead ions on DNA-EB was 5.56 and their binding constant was 1.51×10~(29).[Conclusion]It was easy for lead ions to combine with DNA and induce the change of DNA conformation.
