Hydrogen-bond networks between the C-terminus and Arg from the first α-helix stabilize photoprotein molecules

2014 ◽  
Vol 13 (3) ◽  
pp. 541 ◽  
Author(s):  
Elena V. Eremeeva ◽  
Ludmila P. Burakova ◽  
Vasilisa V. Krasitskaya ◽  
Alexander N. Kudryavtsev ◽  
Osamu Shimomura ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
C Terminus ◽  
Hydrogen Bond Networks ◽  
Α Helix

Conformational Changes of the Wild-Type hIAPP and the S20P Mutant in Water Revealed by Molecular Dynamics Simulations

2011 ◽  
Vol 396-398 ◽  
pp. 1554-1557
Author(s):  
Mian Wang ◽  
Jian Yi Wang
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bond ◽  
Conformational Changes ◽  
Amyloid Fibrils ◽  
Helical Structure ◽  
Wild Type ◽  
Hydrogen Bond Interaction ◽  
Hydrogen Bond Networks ◽  
Α Helix ◽  
Dynamics Simulations

Conformational changes of wild-type (WT) hIAPP and the S20P mutant in explicit water are investigated using molecular dynamics. In the whole simulation, WT shows compacter structure and has more hydrogen-bond networks than S20P. The residues 14-18 in WT is always maintained as a helical structure which is stabilized by the hydrogen bond between Ser20 and NH group of His18, and the other regions in WT partially loosen from α-helix structures into the coil structures. The S20P mutant in a shortage of hydrogen-bond interaction unfolds faster than WT. This work provides insight into the specific conformation of IAPP which is associated with the generation of amyloid fibrils.

High proton conductivity in a nickel(ii) complex and its hybrid membrane

2019 ◽  
Vol 48 (6) ◽  
pp. 2190-2196 ◽  
Author(s):  
Shuai-Liang Yang ◽  
Yue-Ying Yuan ◽  
Fei Ren ◽  
Chen-Xi Zhang ◽  
Qing-Lun Wang
Keyword(s):  
Hydrogen Bond ◽  
Proton Conductivity ◽  
Hybrid Membrane ◽  
Water Molecules ◽  
Hybrid Membranes ◽  
High Proton Conductivity ◽  
High Proton ◽  
Hydrogen Bond Networks

A novel 2D nickel(ii) complex (1) has been successfully synthesized using a 2,2′-bipyridyl, polycarboxylsulfonate ligand H4SBTC and Ni2+ ions. Owing to the presence of abundant water molecules, hydrogen bond networks and other protons, 1 and its hybrid membranes demonstrate high proton conductivity.

scholarly journals The Unique Structure of Haemophilus influenzae Protein E Reveals Multiple Binding Sites for Host Factors

2012 ◽  
Vol 81 (3) ◽  
pp. 801-814 ◽  
Author(s):  
Birendra Singh ◽  
Tamim Al-Jubair ◽  
Matthias Mörgelin ◽  
Marjolein M. Thunnissen ◽  
Kristian Riesbeck
Keyword(s):  
Haemophilus Influenzae ◽  
Disulfide Bridge ◽  
Lung Epithelial Cells ◽  
Binding Region ◽  
Content Type ◽  
Bacterial Surface ◽  
Hydrogen Bonding Pattern ◽  
Functional Regions ◽  
C Terminus ◽  
Α Helix

ABSTRACTHaemophilus influenzaeprotein E (PE) is a multifunctional adhesin involved in direct interactions with lung epithelial cells and host proteins, including plasminogen and the extracellular matrix proteins vitronectin and laminin. We recently crystallized PE and successfully collected X-ray diffraction data at 1.8 Å. Here, we solved the structure of a recombinant version of PE and analyzed different functional regions. It is a dimer in solution and in the asymmetric unit of the crystals. The dimer has a structure that resembles a flattened β-barrel. It is, however, not a true β-barrel, as there are differences in both the hydrogen-bonding pattern and the shape. Each monomer consisted of a 6-stranded antiparallel β-sheet with a rigid α-helix at the C terminus tethered to the concave side of the sheet by a disulfide bridge. The laminin/plasminogen binding region (residues 41 to 68) is exposed, while the vitronectin binding region (residues 84 to 108) is partially accessible in the dimer. The dimerized PE explains the simultaneous interaction with laminin and vitronectin. In addition, we found this unique adhesin to be present in many bacterial genera of the familyPasteurellaceaeand also orthologues in other, unrelated species (Enterobacter cloacaeandListeria monocytogenes). Peptides corresponding to the surface-exposed regions PE 24 to 37, PE 74 to 89, and PE 134 to 156 were immunogenic in the mouse. Importantly, these peptide-based antibodies also recognized PE at the bacterial surface. Taken together, our detailed structure of PE explains how this important virulence factor ofH. influenzaesimultaneously interacts with host vitronectin, laminin, or plasminogen, promoting bacterial pathogenesis.

Thermoplastic polydimethylsiloxane with l ‐phenylalanine‐based hydrogen‐bond networks

2017 ◽  
Vol 135 (24) ◽  
pp. 45419 ◽  
Author(s):  
Shunsuke Tazawa ◽  
Atsushi Shimojima ◽  
Tomoki Maeda ◽  
Atsushi Hotta
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bond Networks

Reconstitution of human atlastin fusion activity reveals autoinhibition by the C terminus

2021 ◽  
Vol 221 (2) ◽  
Author(s):  
Daniel Crosby ◽  
Melissa R. Mikolaj ◽  
Sarah B. Nyenhuis ◽  
Samantha Bryce ◽  
Jenny E. Hinshaw ◽  
...  
Keyword(s):  
Network Formation ◽  
Fusion Activity ◽  
Amphipathic Helix ◽  
Alternate Splicing ◽  
Charge Reversal ◽  
Splice Isoforms ◽  
C Terminus ◽  
Splice Isoform ◽  
Inhibitory Domain ◽  
Α Helix

ER network formation depends on membrane fusion by the atlastin (ATL) GTPase. In humans, three paralogs are differentially expressed with divergent N- and C-terminal extensions, but their respective roles remain unknown. This is partly because, unlike Drosophila ATL, the fusion activity of human ATLs has not been reconstituted. Here, we report successful reconstitution of fusion activity by the human ATLs. Unexpectedly, the major splice isoforms of ATL1 and ATL2 are each autoinhibited, albeit to differing degrees. For the more strongly inhibited ATL2, autoinhibition mapped to a C-terminal α-helix is predicted to be continuous with an amphipathic helix required for fusion. Charge reversal of residues in the inhibitory domain strongly activated its fusion activity, and overexpression of this disinhibited version caused ER collapse. Neurons express an ATL2 splice isoform whose sequence differs in the inhibitory domain, and this form showed full fusion activity. These findings reveal autoinhibition and alternate splicing as regulators of atlastin-mediated ER fusion.

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