Fernández Michael, Caballero Julio
Molecular Modeling Group, Center for Biotechnological Studies, University of Matanzas, Matanzas, C.P. 44740, Cuba.
J Mol Graph Model. 2006 Dec;25(4):410-22. doi: 10.1016/j.jmgm.2006.02.005. Epub 2006 Feb 28.
Bayesian-regularized genetic neural networks (BRGNNs) were used to model the binding affinity (IC(50)) for 128 non-peptide antagonists for the human luteinizing hormone-releasing hormone (LHRH) receptor using 2D spatial autocorrelation vectors. As a preliminary step, a linear dependence was established by multiple linear regression (MLR) approach, selecting the relevant descriptors by genetic algorithm (GA) feature selection. The linear model showed to fit the training set (N=102) with R(2)=0.746, meanwhile BRGNN exhibited a higher value of R(2)=0.871. Beyond the improvement of training set fitting, the BRGNN model overcame the linear one by being able to describe 85% of test set (N=26) variance in comparison with 73% the MLR model. Our non-linear QSAR model illustrates the importance of an adequate distribution of atomic properties represented in topological frames and reveals the electronegativities, masses and polarizabilities as the most influencing atomic properties in the structures of the heterocycles under analysis for having an appropriate LHRH antagonistic activity. Furthermore, the ability of the non-linear selected variables for differentiating the data was evidenced when total data set was well distributed in a Kohonen self-organizing map (SOM).
采用贝叶斯正则化遗传神经网络(BRGNNs),利用二维空间自相关向量对128种人促黄体生成素释放激素(LHRH)受体非肽拮抗剂的结合亲和力(IC(50))进行建模。作为初步步骤,通过多元线性回归(MLR)方法建立线性相关性,利用遗传算法(GA)特征选择来选择相关描述符。线性模型对训练集(N = 102)的拟合度为R(2)=0.746,而BRGNN的R(2)值更高,为0.871。除了提高训练集的拟合度外,BRGNN模型还克服了线性模型,与MLR模型73%的拟合度相比,它能够描述测试集(N = 26)85%的方差。我们的非线性定量构效关系(QSAR)模型说明了拓扑框架中原子性质适当分布的重要性,并揭示了电负性、质量和极化率是所分析杂环结构中具有适当LHRH拮抗活性的最具影响力的原子性质。此外,当总数据集在Kohonen自组织映射(SOM)中分布良好时,证明了非线性选择变量区分数据的能力。