英语翻译Interactions with DNA.The changes of the electronicabsorption spectrum of 3 as a function of ct-DNAconcentration were used to estimate the DNA bindingconstant,Kb (Figure S4 in the Supporting Information).34Hypochromic shifts were observed
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英语翻译Interactions with DNA.The changes of the electronicabsorption spectrum of 3 as a function of ct-DNAconcentration were used to estimate the DNA bindingconstant,Kb (Figure S4 in the Supporting Information).34Hypochromic shifts were observed
英语翻译
Interactions with DNA.The changes of the electronic
absorption spectrum of 3 as a function of ct-DNA
concentration were used to estimate the DNA binding
constant,Kb (Figure S4 in the Supporting Information).34
Hypochromic shifts were observed at 365 and 457 nm
with a slight bathochromic shift (∼2 nm) for 10.4 μM3 in
the presence of up to 71.5 μM ct-DNA,resulting in Kb=
2.0 \2 106 M-1 (s=1.62) fitted as previously described in
detail.34 The DNA binding constant measured for 3 is
similar to values reported for 2 (106-107 M-1) and for
related DNA intercalating complexes,with values that
are several magnitudes greater than that of the nonintercalator
1 (700 M-1).48-50 As listed in Table 1,only a
modest (1.1-fold) luminescence enhancement is observed
for 10 μM3 upon the addition of 100 μMct-DNA (5mM
Tris,50 mM NaCl,pH=7.5),a result that is strikingly
different from that of the “light-switch” 2 under similar
experimental conditions.12 As previously reported,no
observable luminescence changes in 1 were detected upon
the addition of ct-DNA.51
The ethidium bromide stained agarose gel imaged in
Figure 6 compares the DNA photocleavage of 1-3 upon
irradiation (λirr g 455 nm,tirr = 15 min).Lane 1 shows
the migration of pUC18 alone kept in the dark as a control,
which is composed mostly of unreacted supercoiled
plasmid (formI).Without irradiation,no apparent
DNA cleavage is observed in lanes 2,4,and 6 for
complexes 1-3,respectively.Lanes 5 and 7 show theDNA photocleavage of 2 and 3,respectively,indicating
greater reactivity of 3 compared to 2 under similar
experimental conditions.This result is consistent with
the greater quantum yield of the sensitized 1O2 production
of 3 (Φ1O2
=0.76) relative to that of 2 (Φ1O2
=0.16)
measured in CH3OH.Although 1 has a greater quantum
yield for the production of 1O2 (0.81),negligible
DNAphotocleavage is observed under similar conditions
(lane 3).The difference in DNA photocleavage between
1 and 3 can be explained by the weak electrostatic DNA
binding of the former and tight intercalation of the latter.
The oxygen dependence of the DNA photocleavage by
3 was further investigated,and the results are shown in
Figure S5 in the Supporting Information.Lanes 3 and
4 (Figure S5 in the Supporting Information) show greater
DNA photocleavage by 3 in D2O compared to H2O,
in agreement with the longer lifetime of 1O2 in the
former.52 Additionally,negligible DNA cleavage by 3
was observed under deoxygenated conditions (lane 5,
Figure S5 in the Supporting Information).These findings
suggest that the DNA photocleavage of 3 is primarily
mediated by 1O2.
英语翻译Interactions with DNA.The changes of the electronicabsorption spectrum of 3 as a function of ct-DNAconcentration were used to estimate the DNA bindingconstant,Kb (Figure S4 in the Supporting Information).34Hypochromic shifts were observed
与DNA的相互作用.3的电子吸收谱随t0-DNA浓度的数变化被用来估算DNA结合常数Kb(支持信息中的图S4)34.在365和457nm处观察到了减色漂移,伴随着在存在直到71.5μM ct-DNA时10.4μM 3稍向红的漂移,导致了符合前面详细描述的Kb=2.0×106M-1(s=1.62)34.对3测得的DNA结合常数类似于对2报行的值(106~107 M-1)和对于有关DNA插入络合物报行的值,其数值比非插入剂1的值(700 M-1)大几个数量级48-50.如表1所列的那样,对于10μM 3来说,在添加100μM ct-DNA(5mM Tris,50mM NaCl,pH=7.5)时只观察到适度的(1.1倍)发光增强,这是一个与“光开关”2在类似实验条件下明显不同的结果12.如以前报行过的那样,在添加ct-DNA时在1中监测不到可观察到的发光变化51.
成像在图6中的溴乙锭着色的琼脂糖凝胶比较了在辐照下1-3的DNA光断裂(λirr≥455nm,tirr=15min).第1行示出了作为对照的单独保持在黑暗中的pUC18的迁移,这大多是由未反应的超螺旋质体(形式1)组成的.在没有辐照的情况下,分别代表络合物1-3的第2、4、6行没有观察到明显的DNA断裂.第5和第7行分别示出了2和3的DNA光断裂,表明了在类似的实验条件下相比于2来说,3有较大的反应性.这一结果与络合物3在CH3OH中测得的致敏1O2产生 相对于2 的较高量子效率相符合.
虽然1对致敏1O2的产生有较大的量子效率(0.81),但是在类似的条件下观察到的DNA断裂可以忽略不计(第3行).1和3之间在DNA断裂上的差别可以用前者较弱的静电DNA结合和后者紧的插入来解释.用3的DNA光断裂与氧的相关性做了进一步的研究,结果示于了支持信息中的图S5.第3行和第4行(支持信息中的图S5)表明,用3,在D2O中相比于H2O中有较大的DNA光断裂,与1O2在前者中有较长的寿命相一致52.此外,在去氧条件下观察到3的DNA断裂可以忽略不计(第5行,支持信息中的图S5).这些发现告诉我们,3的DNA光断裂主要由1O2起作用.
与DNA的相互作用。 3浓度为1克拉- DNA的功能的变化对电子吸收光谱来估计DNA的结合常数,Kb的辅助资料(在图中四).34减色变化,观察在365和457 nm处有轻微的DNA红移为71.5μM的克拉移(最多〜2纳米)的10.4μM3的存在,导致= 2.0 Kb的106的M - 1(第= 1.62)的安装以前detail.34描述为3 DNA测定结合常数的值是类似报道2(106-...
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与DNA的相互作用。 3浓度为1克拉- DNA的功能的变化对电子吸收光谱来估计DNA的结合常数,Kb的辅助资料(在图中四).34减色变化,观察在365和457 nm处有轻微的DNA红移为71.5μM的克拉移(最多〜2纳米)的10.4μM3的存在,导致= 2.0 Kb的106的M - 1(第= 1.62)的安装以前detail.34描述为3 DNA测定结合常数的值是类似报道2(106-107的M - 1)和相关DNA插层复合物与值是1(nonintercalator数的幅度大于700的M - 1).48-50表1所列,只有少量(1.1倍)观察到发光的增强后10μM3100增补μMct - DNA的(5毫米的Tris,50 mM的氯化钠,pH值= 7.5),这一结果是惊人的报告从不同以往的“光开关类似”2根据实验conditions.12作为没有明显的变化,一经发现发光分别为6的CT图的加法在DNA.51的溴化乙锭染色的琼脂糖凝胶成像比较光断裂后,照射1-3的DNA(λirr克455 nm处,tirr = 15分钟)。巷1显示,仅在pUC18质粒控制迁移保存在一个黑暗的其中大部分是由未反应的超螺旋质粒(formI)。没有辐射,没有观察到明显的DNA切割线在二,四,六为配合1-3分别。拉纳5日和7显示theDNA光断裂2和第3,分别3,显示更大的反应相比,在相同的实验条件2。这一结果是Φ1O2符合致敏1O2生产更大量子产量的3(Φ1O2= 0.76),2相(= 0.16)测定甲醇。虽然1具有更大的生产1O2量子产量为(0.81),是微不足道DNAphotocleavage)3巷观察类似条件下(。的DNA差异在1至3光断裂可以解释由弱静电的DNA结合前和紧后插由3光断裂DNA的氧的依赖性进一步调查,结果显示在图中五的支持信息。通道3和4(图五的证明资料)显示光断裂3至水更大的DNA的重水相比,3协议与较长的寿命由1O2在former.52微不足道切割DNA此外,无氧条件下观察(5巷,图中五的证明资料)。
这些结果表明,3介导的光断裂DNA的主要是由1O2。
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与DNA相互作用。这个变化的电子
吸收光谱的ct-DNA 3功能
浓度是用来估计DNA约束力
常数,科比在支持(图S4).34信息
在Hypochromic变化进行观察和457纳米365
有轻微的bathochromic转移(∼2海里)μM3 104
在场的情况下,ct-DNA 71.5μM,导致Kb =
...
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与DNA相互作用。这个变化的电子
吸收光谱的ct-DNA 3功能
浓度是用来估计DNA约束力
常数,科比在支持(图S4).34信息
在Hypochromic变化进行观察和457纳米365
有轻微的bathochromic转移(∼2海里)μM3 104
在场的情况下,ct-DNA 71.5μM,导致Kb =
106 M-1(s = 0 1.62安装在先前描述
detail.34 DNA结合常数测量为3
类似的106-107文献值(2),M-1
相关的脱氧核糖核酸(DNA),与价值的良机
有几种大小比nonintercalator吗
1(700 M-1).48-50列在表1,只有一个
谦虚(1.1-fold)发光的提高是观察
10μM3在增加100μMct-DNA(5毫米
三、50毫米,pH = 7.5),这是很大的变化
不同的电灯开关了“2”在相似的
先前报道的实验conditions.12,没有
可见的光变化检测1
ct-DNA.51的
ethidium溴化的染色琼脂成像
图6 photocleavage脱氧核糖核酸(DNA)的1-3比较
λirr g -照射,tirr = 15分钟纳米)。道1所示
pUC18运移的单独蒙在鼓里作为一种控制,
unreacted组成的supercoiled吗
质粒(formI)。无辐射,没有明显的
观察DNA乳沟小路2、4、6
1-3复合体。5至7显示theDNA巷2和3 photocleavage分别注明
更大的3比2反应在相似的
实验条件。这个结果是一致的
更有意思的1O2量子产量生产
3(Φ1O2
= 0.76)相对于2(Φ1O2
= 0.16)。
在CH3OH测量。尽管有更大的量子理论
产量生产1O2(0.81),可以忽略不计
DNAphotocleavage类似条件下观察
(莱恩)。photocleavage脱氧核糖核酸(DNA)之间的差异
1和3可以解释这样的弱静电的DNA
前者的约束和紧身夹层后者。
氧依赖性的photocleavage脱氧核糖核酸(DNA)
三是进一步调查,结果显示
人物的证明资料。“三、车道
4(图S5在支持信息)具有更大
3在D2O DNA photocleavage相比H2O,
在协议1O2一生的时间越长
另外,former.52微不足道的脱氧核糖核酸(DNA)由3。乳沟
deoxygenated条件下观察(五巷,
人物的证明资料)S5阶段。这些发现
建议photocleavage脱氧核糖核酸(DNA)的3为主
1O2介导的。
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