Various missense mutations in the VHL gene have been reported among patients with familial bilateral pheochromocytoma. However, the p.Arg82Leu mutation in the VHL gene described here among patients with familial bilateral pheochromocytoma, has never been reported previously in a germline configuration. Interestingly, long-term follow-up of these patients indicated that the mutation might have had little impact on the normal function of the VHL gene, since all of them have remained asymptomatic. We further attempted to correlate this information with the results obtained by in silico analysis of this mutation using SIFT, PhD-SNP SVM profile, MutPred, PolyPhen2, and SNPs&amp;GO prediction tools. To gain, new mechanistic insight into the structural effect, we mapped the mutation on to 3D structure (PDB ID 1LM8). Further, we analyzed the structural level changes in time scale level with respect to native and mutant protein complexes by using 12 ns molecular dynamics simulation method. Though these methods predict the mutation to have a pathogenic potential, it remains to be seen if these patients will eventually develop symptomatic disease. © 2013 John et al.

George Priya Doss C

Department of Integrative Biology

School of Bio Sciences and Technology

Vellore Campus

John A.M

C. G.P.D

Ebenazer A

Seshadri M.S

Nair A

Rajaratnam S

Pai R.

Fulltext

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

PLoS ONE

We examined 25 breast tumor samples for somatic mutations in exon 20 and exon 9 of PIK3CA gene in South Indian population. Genomic DNA was isolated and amplified for PIK3CA gene, followed by direct sequencing of purified polymerase chain reaction products. We identified PI3K3CA mutations in 5 of 25 (20%), including four of the mutations in p.H1047R and one in p.H1047L. Nucleotide base substitution A to G (c.3140A &gt; G) and A to T (c.3140A &gt; T) results in p.H1047R and p.H1047L mutation in exon 20 of PIK3CA gene. We did not observe any mutation in exon 9 of PIK3CA gene. Furthermore, we investigated the effect of mutations on protein structure and function by the combination of sequence and structure-based in silico prediction methods. This determined the underlying relationship between the mutation and its phenotypic effects. Next step, we complemented by molecular dynamics simulation analysis (30 ns) of native and mutant structures that measured the effect of mutation on protein structure. The obtained results support that the application of computational methods helps predict the biological significance of mutations. © 2015 Taylor and Francis.

Journal of Biomolecular Structure and Dynamics

Deciphering the impact of somatic mutations in exon 20 and exon 9 ofPIK3CAgene in breast tumors among Indian women through molecular dynamics approach

von Willebrand disease (VWD) is an autosomal inherited disorder related to trauma-related bleeding in affected people. VWD results from deficiency of von Willebrand factor (VWF) - a glycoprotein involved in hemostasis and carrier for factor VIII (FVIII). Mutations in A1 domain of von Willebrand factor (VWD) gene are exceptionally polymorphic and associated with adhesion movement, clearance, and binding properties that could be interfaced with thrombosis. To address this issue, we implemented in silico prediction algorithms, namely, SIFT, PolyPhen 2.0, I-Mutant 3.0, SNAP, Align GVGD, PhD-SNP, SNPs&amp;GO, and MutPred to classify the variants as pathogenic and affecting protein stability. Based on prediction scores, four variants, namely, P1266L, H1268D, C1272R, and C1272F, were predicted as highly deleterious from a pool of 72 nsSNPs/variants in A1 domain of VWD belonging to type 2A and 2B. Upon literature survey, amino acid substitution (P → L) at position 1266 is involved in improving the connection with platelets, substitution (C → F) at position 1272 results in extreme bleeding in patients, and substitution (H → D) at position 1268 disturbs the salt bridge scaffold were considered for further analysis. Through molecular dynamic simulation analysis over a period of 100 ns showed that four mutations near N-terminal region bring about a change in structure and function of the native VWD protein. © 2016 Elsevier Inc. All rights reserved.

Advances in Protein Chemistry and Structural Biology Personalized Medicine

Role of von Willebrand Factor—A1 Domain Variants P1266L, H1268D, C1272R, and C1272F in VWD

Oncogenic mutations in phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) are the most frequently reported in association with various forms of cancer. Several studies have reported the significance of hotspot mutations in a catalytic subunit of PIK3CA in association with breast cancer. Mutations are frequently observed in the highly conserved region of the kinase domain (797-1068 amino acids) of PIK3CA are activating or gain-of-function mutations. Mutation in codon 1047 occurs in the C-terminal region of the kinase domain with histidine (H) replaced by arginine (R), lysine (L), and tyrosine (Y). Pathogenicity and protein stability predictors PhD-SNP, Align GVGD, HANSA, iStable, and MUpro classified H1047R as highly deleterious when compared to H1047L and H1047Y. To explore the inhibitory activity of Wortmannin toward PIK3CA, the three-dimensional structure of the mutant protein was determined using homology modeling followed by molecular docking and molecular dynamics analysis. Docking studies were performed for the three mutants and native with Wortmannin to measure the differences in their binding pattern. Comparative docking study revealed that H1047R-Wortmannin complex has a higher number of hydrogen bonds as well as the best binding affinity next to the native protein. Furthermore, 100 ns molecular dynamics simulation was initiated with the docked complexes to understand the various changes induced by the mutation. Though Wortmannin was found to nullify the effect of H1047R over the protein, further studies are required for designing a better compound. As SNPs are major genetic variations observed in disease condition, personalized medicine would provide enhanced drug therapy. © 2016 Elsevier Inc. All rights reserved.

Investigating the Inhibitory Effect of Wortmannin in the Hotspot Mutation at Codon 1047 of PIK3CA Kinase Domain

Fanconi anemia (FA) is an autosomal recessive human disease characterized by genomic instability and a marked increase in cancer risk. The importance of FANCD1 gene is manifested by the fact that deleterious amino acid substitutions were found to confer susceptibility to hereditary breast and ovarian cancers. Attaining experimental knowledge about the possible disease-associated substitutions is laborious and time consuming. The recent introduction of genome variation analyzing in silico tools have the capability to identify the deleterious variants in an efficient manner. In this study, we conducted in silico variation analysis of deleterious non-synonymous SNPs at both functional and structural level in the breast cancer and FA susceptibility gene BRCA2/FANCD1. To identify and characterize deleterious mutations in this study, five in silico tools based on two different prediction methods namely pathogenicity prediction (SIFT, PolyPhen, and PANTHER), and protein stability prediction (I-Mutant 2.0 and MuStab) were analyzed. Based on the deleterious scores that overlap in these in silico approaches, and the availability of three-dimensional structures, structure analysis was carried out with the major mutations that occurred in the native protein coded by FANCD1/BRCA2 gene. In this work, we report the results of the first molecular dynamics (MD) simulation study performed to analyze the structural level changes in time scale level with respect to the native and mutated protein complexes (G25R, W31C,W31R in FANCD1/BRCA2-PALB2, and F1524V, V1532F in FANCD1/BRCA2-RAD51). Analysis of the MD trajectories indicated that predicted deleterious variants alter the structural behavior of BRCA2-PALB2 and BRCA2-RAD51 protein complexes. In addition, statistical analysis was employed to test the significance of these in silico tool predictions. Based on these predictions, we conclude that the identification of disease-related SNPs by in silico methods, in combination with MD approach has the potential to create personalized tools for the diagnosis, prognosis, and treatment of diseases. The methods reviewed here generated a considerable amount of valuable data, but also the need for further validation. © Springer Science+Business Media New York 2014

Cell Biochemistry and Biophysics

An Integrated in Silico Approach to Analyze the Involvement of Single Amino Acid Polymorphisms in FANCD1/BRCA2-PALB2 and FANCD1/BRCA2-RAD51 Complex

Single amino acid substitutions (SAPs) belong to a class of SNPs in the coding region, which alter the protein function during the translation process. Storage of more information regarding SAPs in public databases will soon become a major hurdle in characterizing the functional SAPs. In such a demanding era, biology has to rely on bioinformatics, which can work its way through to solve the problems at hand by cutting huge amount of time and resources that are otherwise wasted. Here, we describe an overview of the existing repositories of variant databases and computational methods in predicting the effects of functional SAPs on protein stability, structure, function, drug response, and protein dynamics. This chapter will inspire many biologists with a greater promise in identifying the functional SAPs at the structural level, thereby understanding the molecular effects that are critical for personalized medicine diagnosis, prognosis, and treatment for diseases. © 2014 Elsevier Inc.

Advances in Protein Chemistry and Structural Biology

Computational Approaches and Resources in Single Amino Acid Substitutions Analysis Toward Clinical Research

Disease Markers

BRCA1andBRCA2Unclassified Variants and Missense Polymorphisms in Algerian Breast/Ovarian Cancer Families

Human Molecular Genetics

Integrative genomic analysis reveals somatic mutations in pheochromocytoma and paraganglioma

Proteins: Structure, Function, and Bioinformatics

A missense mutation in CLIC2 associated with intellectual disability is predicted by in silico modeling to affect protein stability and dynamics

Annals of Oncology

Unclassified variants in BRCA genes: guidelines for interpretation

BMC Bioinformatics

Protein structure analysis of mutations causing inheritable diseases. An e-Science approach with life scientist friendly interfaces

p.Arg82Leu von Hippel-Lindau (VHL) Gene Mutation among Three Members of a Family with Familial Bilateral Pheochromocytoma in India: Molecular Analysis and In Silico Characterization

Journal	PLoS ONE
Publisher	Public Library of Science (PLoS)
ISSN	19326203
Open Access	Yes