02001nas a2200205   4500008004100000022001400041245008200055210006900137260011000206300001400316490000700330520119600337100002401533700002501557700002501582700002601607700002601633700002001659856011601679       2015                        eng d  a1463-907600aThermodynamic and kinetic characterization of transmembrane helix association0 aThermodynamic and kinetic characterization of transmembrane heli  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcNOV  a1390-13980 v173 a<p>The transient dimerization of transmembrane proteins is an important event in several cellular processes and computational methods are being increasingly used to quantify their underlying energetics. Here, we probe the thermodynamics and kinetics of a simple transmembrane dimer to understand membrane protein association. A multi-step framework has been developed in which the dimerization profiles are calculated from coarse-grain molecular dynamics simulations, followed by meso-scale simulations using parameters calculated from the coarse-grain model. The calculated value of Delta G(assoc) is approx. -20 kJ mol(-1) and is consistent between three methods. Interestingly, the meso-scale stochastic model reveals low dimer percentages at physiologically-relevant concentrations, despite a favorable Delta G(assoc). We identify generic driving forces arising from the protein backbone and lipid bilayer and complementary factors, such as protein density, that govern self-interactions in membranes. Our results provide an important contribution in understanding membrane protein organization and linking molecular, nano-scale computational studies to meso-scale experimental data.</p>1 aPawar, Aiswarya, B.1 aDeshpande, Sneha, A.1 aGopal, Srinivasa, M.1 aWassenaar, Tsjerk, A.1 aAthale, Chaitanya, A.1 aSengupta, Durba  uhttps://library.ncl.res.in/content/thermodynamic-and-kinetic-characterization-transmembrane-helix-association-002311nas a2200241   4500008004100000022001400041245008800055210006900143260000800212300001100220490000800231520148500239653001601724653001801740653003901758653003101797653003001828100002501858700002401883700002601907700002001933856011601953       2020                        eng d  a0009-308400aLipid-dependent conformational landscape of the ErbB2 growth factor receptor dimers0 aLipiddependent conformational landscape of the ErbB2 growth fact  cAUG  a1049110 v2303 a<p>Altered lipid metabolism has been linked to cancer development and progression. Several roles have been attributed to the increased saturation and length of lipid acyl tails observed in tumors, but its effect on signaling receptors is still emerging. In this work, we have analyzed the lipid dependence of the ErbB2 growth factor receptor dimerization that plays an important role in the pathogenesis of breast cancer. We have performed coarse-grain ensemble molecular dynamics simulations to comprehensively sample the ErbB2 monomer-dimer association. Our results indicate a dynamic dimer state with a complex conformational landscape that is modulated with increasing lipid tail length. We resolve the native N-terminal ``active'' and C-terminal ``inactive'' conformations in all membrane compositions. However, the relative population of the N-terminal and C-terminal conformers is dependent on length of the saturated lipid tails. In short-tail membranes, additional non-specific dimers are observed which are reduced or absent in long-tailed bilayers. Our results indicate that the relative population as well as the structure of the dimer state is modulated by membrane composition. We have correlated these differences to local perturbations of the membrane around the receptor. Our work is an important step in characterizing ErbB dimers in healthy and diseased states and emphasize the importance of sampling lipid dynamics in understanding receptor association.</p>
10aErbB2 dimer10aLipid effects10aMartini coarse-grained simulations10aMembrane protein structure10aTransmembrane association1 aGopal, Srinivasa, M.1 aPawar, Aiswarya, B.1 aWassenaar, Tsjerk, A.1 aSengupta, Durba  uhttps://library.ncl.res.in/content/lipid-dependent-conformational-landscape-erbb2-growth-factor-receptor-dimers