A Simple Method to Determine Electrospray Response Factors of Noncovalent Complexes
A Simple Method to Determine Electrospray Response Factors of Noncovalent Complexes
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DOI：
10.1021/ac900785m
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发表时间：
2009-08-15
影响因子：
7.4
通讯作者：
De Pauw, Edwin
中科院分区：
文献类型：
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作者：
Gabelica, Valerie;Rosu, Frederic;De Pauw, Edwin
用电喷雾-质谱法对非共价化合物进行定量研究需要测定每个物种的相对响应值。本文提出的确定电喷雾响应因子的方法是基于(1)内标和(2)应用于一个结合伙伴M的质量平衡方程，对于该结合伙伴M，在电喷雾质谱图中检测到不同的络合物M(X)L(Y)。使用一组提供络合物之间不同比例的实验(例如，滴定实验中的不同配体浓度或动力学实验中的不同时间点)来产生一组独立的线性方程，该线性方程可以使用简单的矩阵代数来求解，以求出每个M(X)L(Y)络合物相对于内标的响应因子。Ne响应因子可用于确定平衡离解常数或用于反应动力学的定量监测。第一个是通过对DNA配体复合体的研究来说明的，在那里我们证明了微小的沟槽结合或插层都不会显著地影响DNA响应因子。第二个例子是端粒G-四链dGGG(TTAGGG)(3)与其互补链的结合动力学研究，其中响应因子允许校正四链的相对响应。和长双工，并获得独立于源调谐电势的可重现的缔合速率常数。
The quantitative study of noncovalent complexes by electrospray mass spectrometry requires the determination of the relative response of each species. The method proposed here to determine the electrospray response factors is based on the use of (1) an internal standard and (2) the mass balance equation applied to one binding partner M, for which different complexes M(x)L(y) are detected in the electrospray mass spectra. A set of experiments providing various ratios between the complexes (e.g., different ligand concentrations in a titration experiment or different time points in a kinetics experiment) is used to generate a set of independent linear equations that can be solved using simple matrix algebra to find the response factors of each M(x)L(y) complex relative to that of the internal standard. ne response factors can then be used to determine equilibrium dissociation constants or for the quantitative monitoring of reaction kinetics. The first is illustrated with a study of DNA-ligand complexes, where we show that neither minor groove binding nor intercalation dramatically affects the DNA response factor. The second is illustrated with a study of the association kinetics of the telomeric G-quadruplex dGGG(TTAGGG)(3) with its complementary strand, where the response factors allow correcting for the relative response of the quadruplex. and the long duplex and obtaining reproducible association rate constants independently of the source tuning potentials.