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arXiv 0705.1490q-bio.BMq-bio.QM
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单点突变对蛋白质稳定性变化的三态预测

A three-state prediction of single point mutations on protein stability changes

Emidio Capriotti, Piero Fariselli, Ivan Rossi, Rita Casadio

摘要:

蛋白质结构研究的一个基本问题是突变在多大程度上影响蛋白质的稳定性。这个问题可以从顺序和/或结构开始解决。在蛋白质组学和基因组学研究中,预测蛋白质单点突变后的稳定性自由能变化(DDG)也可以帮助注释过程。实验SSG值受标准偏差测量的不确定性影响。大多数DDG值几乎为零(约32%的DDG数据集范围为-0.5至0.5 Kcal/mol),并且对于同一突变,DDG的值和符号可能为正或负,模糊了突变与预期DDG值之间的关系。为了克服这个问题,我们描述了一种新的预测因子,其区分3种突变类别:不稳定突变(DDG<-0.5 Kcal/mol)、稳定突变(DDG>0.5 Kcal/mol)和中性突变(-0.5<=DDG<=0.5 Kcal/mol)。在本文中,支持向量机从蛋白质序列或结构之间的稳定,不稳定和中性突变的区别。我们根据三态分类系统对所有可能的替换进行排名,并表明我们的预测器的总体准确度高达52%,当从序列信息开始执行时,蛋白质结构为58%,平均值相关系数分别为0.30和0.39。这些值比随机预测值高出约20%。

英文摘要:

A basic question of protein structural studies is to which extent mutations affect the stability. This question may be addressed starting from sequence and/or from structure. In proteomics and genomics studies prediction of protein stability free energy change (DDG) upon single point mutation may also help the annotation process. The experimental SSG values are affected by uncertainty as measured by standard deviations. Most of the DDG values are nearly zero (about 32% of the DDG data set ranges from -0.5 to 0.5 Kcal/mol) and both the value and sign of DDG may be either positive or negative for the same mutation blurring the relationship among mutations and expected DDG value. In order to overcome this problem we describe a new predictor that discriminates between 3 mutation classes: destabilizing mutations (DDG<-0.5 Kcal/mol), stabilizing mutations (DDG>0.5 Kcal/mol) and neutral mutations (-0.5<=DDG<=0.5 Kcal/mol). In this paper a support vector machine starting from the protein sequence or structure discriminates between stabilizing, destabilizing and neutral mutations. We rank all the possible substitutions according to a three state classification system and show that the overall accuracy of our predictor is as high as 52% when performed starting from sequence information and 58% when the protein structure is available, with a mean value correlation coefficient of 0.30 and 0.39, respectively. These values are about 20 points per cent higher than those of a random predictor.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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