Department of Integrative Biology, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
Department of Biomedical Sciences, College of Health and Sciences, Qatar University, Doha, Qatar.
Metab Brain Dis. 2018 Oct;33(5):1443-1457. doi: 10.1007/s11011-018-0251-1. Epub 2018 May 27.
The NF1 gene encodes for neurofibromin protein, which is ubiquitously expressed, but most highly in the central nervous system. Non-synonymous SNPs (nsSNPs) in the NF1 gene were found to be associated with Neurofibromatosis Type 1 disease, which is characterized by the growth of tumors along nerves in the skin, brain, and other parts of the body. In this study, we used several in silico predictions tools to analyze 16 nsSNPs in the RAS-GAP domain of neurofibromin, the K1444N (K1423N) mutation was predicted as the most pathogenic. The comparative molecular dynamic simulation (MDS; 50 ns) between the wild type and the K1444N (K1423N) mutant suggested a significant change in the electrostatic potential. In addition, the RMSD, RMSF, Rg, hydrogen bonds, and PCA analysis confirmed the loss of flexibility and increase in compactness of the mutant protein. Further, SASA analysis revealed exchange between hydrophobic and hydrophilic residues from the core of the RAS-GAP domain to the surface of the mutant domain, consistent with the secondary structure analysis that showed significant alteration in the mutant protein conformation. Our data concludes that the K1444N (K1423N) mutant lead to increasing the rigidity and compactness of the protein. This study provides evidence of the benefits of the computational tools in predicting the pathogenicity of genetic mutations and suggests the application of MDS and different in silico prediction tools for variant assessment and classification in genetic clinics.
NF1 基因编码神经纤维瘤蛋白,该蛋白广泛表达,但在中枢神经系统中表达最高。NF1 基因中的非同义单核苷酸多态性(nsSNP)与 1 型神经纤维瘤病有关,其特征是肿瘤沿着皮肤、大脑和身体其他部位的神经生长。在这项研究中,我们使用了几种计算预测工具来分析神经纤维瘤 Ras-GAP 结构域中的 16 个 nsSNP,预测 K1444N(K1423N)突变是最具致病性的。野生型和 K1444N(K1423N)突变体之间的比较分子动力学模拟(MDS;50ns)表明静电势发生了显著变化。此外,RMSD、RMSF、Rg、氢键和 PCA 分析证实了突变体蛋白的柔性丧失和紧凑度增加。此外,SASA 分析表明,RAS-GAP 结构域核心的疏水性和亲水性残基与突变结构域表面之间发生了交换,这与二级结构分析一致,表明突变蛋白构象发生了显著改变。我们的数据得出结论,K1444N(K1423N)突变导致蛋白刚性和紧凑度增加。本研究为计算工具在预测遗传突变的致病性方面的应用提供了证据,并表明 MDS 和不同的计算预测工具可用于遗传诊所中的变体评估和分类。