02200nas a2200253 4500008004100000022001400041245010400055210006900159260000800228300001200236490000800248520136000256653003201616653003101648653000901679653002301688653002101711653000801732100002101740700002101761700002001782700001801802856012601820 2019 eng d a0022-263100aDifferential dynamics underlying the Gln27Glu population variant of the beta(2)-adrenergic receptor0 aDifferential dynamics underlying the Gln27Glu population variant cOCT a499-5070 v2523 a

The beta (2)-adrenergic receptor (beta (2)AR) is a membrane-bound G-protein-coupled receptor and an important drug target for asthma. Clinical studies report that the population variant Gln27Glu is associated with a differential response to common asthma drugs, such as albuterol, isoproterenol and terbutaline. Interestingly, the 27th amino acid is positioned on the N-terminal region that is the most flexible and consequently the least studied part of the receptor. In this study, we probe the molecular origin of the differential drug binding by performing structural modeling and simulations of the wild-type (Gln) and variant (Glu) receptors followed by ensemble docking with the ligands, albuterol, isoproterenol and terbutaline. In line with clinical studies, the ligands were observed to interact preferentially with the Glu variant. Our results indicate that the Glu residue at the 27th position perturbs the network of electrostatic interactions that connects the N-terminal region to the binding site in the wild-type receptor. As a result, the Glu variant is observed to bind better to the three ligands tested in this study. Our study provides a structural basis to explain the variable drug response associated with the 27th position polymorphism in the beta (2)AR and is a starting step to identify genotype-specific therapeutics.

10abeta(2)-Adrenergic receptor10aG-protein-coupled receptor10aGPCR10amolecular dynamics10aPharmacogenetics10aSNP1 aBhosale, Sumedha1 aNikte, Siddhanta1 aSengupta, Durba1 aJoshi, Manali uhttps://library.ncl.res.in/content/differential-dynamics-underlying-gln27glu-population-variant-beta2-adrenergic-receptor02242nas a2200241 4500008004100000022001400041245013700055210006900192260000900261300001200270490000800282520138800290653002301678653002401701653002801725653003401753653002601787100001701813700000501830700002001835700002001855856012501875 2021 eng d a0006-291X00aDynamic coupling analysis on plant sesquiterpene synthases provides leads for the identification of product specificity determinants0 aDynamic coupling analysis on plant sesquiterpene synthases provi cJAN  a107-1140 v5363 a

Sesquiterpene synthases catalyse cyclisation of farnesyl pyrophosphate to produce diverse sesquiterpenes. Despite utilising the same substrate and exhibiting significant sequence and structural homology, these enzymes form different products. Previous efforts were based on identifying the effect of divergent residues present at the catalytic binding pocket on the product specificity of these enzymes. However, the rationales deduced for the product specificity from these studies were not generic enough to be applicable to other phylogenetically distant members of this family. To address this problem, we have developed a novel approach combining sequence, structural and dynamical information of plant sesquiterpene synthases (SSQs) to predict product modulating residues (PMRs). We tested this approach on the SSQs with known PMRs and also on sesquisabinene synthase 1 (SaSQS1), a SSQ from Indian sandalwood. Our results show that the dynamical sectors of SSQs obtained from molecular dynamics simulation and their hydrophobicity and vicinity indices together provide leads for the identification of PMRs. The efficacy of the technique was tested on SaSQS1 using mutagenesis. To the best of our knowledge, this is a first technique of this kind which provides cues on PMRs of SSQs, with divergent phylogenetic relationship. (C) 2020 Elsevier Inc. All rights reserved.

10amolecular dynamics10aProduct specificity10aSesquiterpene synthases10aStatistical coupling analysis10aX-ray crystallography1 aSingh, Sneha1 a1 aSengupta, Durba1 aKulkarni, Kiran uhttps://library.ncl.res.in/content/dynamic-coupling-analysis-plant-sesquiterpene-synthases-provides-leads-identification02291nas a2200265 4500008004100000022001400041245012300055210006900178260000800247300001100255490000900266520140300275653003201678653003101710653000901741653002301750653002101773653000801794100002101802700001901823700001901842700001801861700002001879856012601899 2021 eng d a1570-963900aLoss of a water-mediated network results in reduced agonist affinity in a beta(2)-adrenergic receptor clinical variant0 aLoss of a watermediated network results in reduced agonist affin cAPR a1406050 v18693 a

The beta(2)-adrenergic receptor (beta(2)AR) is a member of the G protein-coupled receptor (GPCR) family that is an important drug target for asthma and COPD. Clinical studies coupled with biochemical data have identified a critical receptor variant, Thr164Ile, to have a reduced response to agonist-based therapy, although the molecular mechanism underlying this seemingly ``non-deleterious'' substitution is not clear. Here, we couple molecular dynamics simulations with network analysis and free-energy calculations to identify the molecular determinants underlying the differential drug response. We are able to identify hydration sites in the transmembrane domain that are essential to maintain the integrity of the binding site but are absent in the variant. The loss of these hydration sites in the variant correlates with perturbations in the intra-protein interaction network and rearrangements in the orthosteric ligand binding site. In conjunction, we observe an altered binding and reduced free energy of a series of agonists, in line with experimental trends. Our work identifies a functional allosteric pathway connected by specific hydration sites in beta(2)AR that has not been reported before and provides insight into water-mediated networks in GPCRs in general. Overall, the work is one of the first step towards developing variant-specific potent and selective agonists.

10abeta(2)-Adrenergic receptor10aG protein coupled receptor10aGPCR10amolecular dynamics10aPharmacogenetics10aSNP1 aNikte, Siddhanta1 aSonar, Krushna1 aTandale, Aditi1 aJoshi, Manali1 aSengupta, Durba uhttps://library.ncl.res.in/content/loss-water-mediated-network-results-reduced-agonist-affinity-beta2-adrenergic-receptor02172nas a2200265 4500008004100000022001400041245007500055210006900130260000900199300001100208490000800219520135600227653001101583653001201594653003101606653002301637653001801660653002001678100002101698700002001719700001901739700002401758700002001782856010401802 2023 eng d a0167-732200aSurface-induced demixing of self-assembled isomeric mixtures of citral0 aSurfaceinduced demixing of selfassembled isomeric mixtures of ci cJUL  a1218030 v3813 a

The self-assembly of organic molecules and their interactions with metal surfaces have been of considerable interest, both for developing novel functional materials and for understanding fundamental design principles of nanostructures. In this study, we investigate the solution and surface-induced self-assembly of two stereoisomers of citral molecules (geranial and neral) using atomistic molecular dynamics simulations. We demonstrate that the morphology of the aggregates in water is concentration dependent (ranging from distorted spherical to slab-like aggregates) but independent of isomer effects. The isomeric mixtures of citral indicate homogeneous mixing based on differential density maps and high values of Shannon entropy. Interestingly, surface-confinement of citral aggregates on a Cu(111) surface leads to phase segregation and demixing of the two isomers that is more apparent in the surface-bound monolayer in comparison to the adjacent layers. Positional ordering and formation of domains are observed over a series of isomeric citral mixtures with varying compositions, as indicated by high differential density and low values of Shannon entropy. Our work provides new insights into molecular self-assembly of organic molecules in nanostructures and metal-organic overlayers.(c) 2023 Elsevier B.V. All rights reserved.

10aCitral10aIsomers10aMetal-organic interactions10amolecular dynamics10aSelf-assembly10aShannon entropy1 aSaraf, Deepashri1 aPrakash, Shikha1 aPinjari, Aadil1 aPujari, Bhalchandra1 aSengupta, Durba uhttps://library.ncl.res.in/content/surface-induced-demixing-self-assembled-isomeric-mixtures-citral