Monte Carlo estimation of errors in 13C-NMR relaxation studies of a DNA oligomer duplex.
Monte Carlo estimation of errors in 13C-NMR relaxation studies of a DNA oligomer duplex.
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DNA 寡聚物双链体 13C-NMR 弛豫研究中误差的蒙特卡罗估计。
DOI：
10.1021/ci00027a002
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Borer,PN
中科院分区：
文献类型：
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作者：
Yu,JQ;Blumenthal,DS;Borer,PN
本文用蒙特卡罗方法对DNA双链体天然丰度~（13）C-NMR弛豫进行了误差分析。在90.6 MHz下对双链DNA五核苷酸[d（TCGCG）] 2重复测量纵向弛豫时间7）和异核NOE。在所有碳上的平均偏差为13%（T1）和9%（NOE）。这些相对偏差用于生成100个关于每种碳的测量平均值的正态分布的T1和NOE值。新版本的MOLDYN，2称为McMOLDYN，已被写入，这是用来生成100个值的T\和NOE与正态分布对应的测量误差;相同的误差分布也适用于测量在125.8 MHz。从McMOLDYN模拟的分布出发，对无模型方法3中的序参量S2和有效内关联时间re进行了优化。McMOLDYN还允许自动输入输出参数S2、re和rm的多组初始猜测。此外，McMOLDYN增加了来自化学位移各向异性的交叉弛豫项，随着光谱仪磁场的提高，交叉弛豫项越来越重要。在优化的两个参数之间，S2具有最小的相对误差，估计平均为15%，这意味着S2是一个定义明确的参数。然而，re的定义非常差，平均相对误差估计为85%;它通常在30-300 ps的范围内。
An analysis of errors has been done with the Monte Carlo method for natural abundance I3C-NMR relaxation studies of a DNA duplex. Repeated measurements of the longitudinal relaxation time, 7), and the heteronuclear NOE were made at 90.6 MHz on the duplexed DNA pentanucleotide,[d (TCGCG)] 2.’The deviations averaged over all carbons were 13% for T\and9% for NOE. These relative deviations were applied to generate100 values of T\and NOE with normal distributions about the measured mean values for each carbon. A new version of MOLDYN, 2 called McMOLDYN, has been written, which was used to generate 100 values of T\and NOE with normal distributions corresponding to the measured errors; the same error distributions were also applied to measurements at 125.8 MHz. The order parameter, S2, and the effective internal correlation time, re, in the Model-Free Approach3 havebeen optimized from the distributions simulated by McMOLDYN. McMOLDYN also permits the automated entry of multiple sets of initial guesses for the output parameters S2, re, and rm. In addition, McMOLDYN adds cross-relaxation terms from chemical shift anisotropy, increasingly important as spectrometer magnetic fields get higher. Between the two parameters optimized, S2 has the smallest relative error, estimated at 15% on average, which means that S2 is a well-defined parameter. However, re is very poorly defined with the average relative error estimated 85%; it is typically found in the range of 30-300 ps.