Role of stabilization centers in 4 helix bundle proteins

2002 ◽  
Vol 48 (2) ◽  
pp. 320-326 ◽  
Author(s):  
M. Fuxreiter ◽  
I. Simon
Keyword(s):  
Stabilization Centers ◽  
Helix Bundle

scholarly journals Synergic Role of Nucleophosmin Three-helix Bundle and a Flanking Unstructured Tail in the Interaction with G-quadruplex DNA

2014 ◽  
Vol 289 (31) ◽  
pp. 21230-21241 ◽  
Author(s):  
Alessandro Arcovito ◽  
Sara Chiarella ◽  
Stefano Della Longa ◽  
Adele Di Matteo ◽  
Carlo Lo Sterzo ◽  
...  
Keyword(s):  
Quadruplex Dna ◽  
Helix Bundle ◽  
G Quadruplex

scholarly journals Role of loop-helix interactions in stabilizing four-helix bundle proteins.

1992 ◽  
Vol 89 (16) ◽  
pp. 7315-7319 ◽  
Author(s):  
K. C. Chou ◽  
G. M. Maggiora ◽  
H. A. Scheraga
Keyword(s):  
Helix Bundle ◽  
Four Helix Bundle ◽  
Helix Interactions

scholarly journals Role of Cysteine Residues in Structural Stability and Function of a Transmembrane Helix Bundle

2001 ◽  
Vol 276 (42) ◽  
pp. 38814-38819 ◽  
Author(s):  
Christine B. Karim ◽  
M. Germana Paterlini ◽  
Laxma G. Reddy ◽  
Gregory W. Hunter ◽  
George Barany ◽  
...  
Keyword(s):  
Structural Stability ◽  
Transmembrane Helix ◽  
Cysteine Residues ◽  
Helix Bundle ◽  
And Function

scholarly journals Extension of a Three-Helix Bundle Domain of Myosin VI and Key Role of Calmodulins

2011 ◽  
Vol 100 (12) ◽  
pp. 2964-2973 ◽  
Author(s):  
Yanxin Liu ◽  
Jen Hsin ◽  
HyeongJun Kim ◽  
Paul R. Selvin ◽  
Klaus Schulten
Keyword(s):  
Myosin Vi ◽  
Helix Bundle

scholarly journals Structural and functional characterization of human and murine C5a anaphylatoxins

2014 ◽  
Vol 70 (6) ◽  
pp. 1704-1717 ◽  
Author(s):  
Janus Asbjørn Schatz-Jakobsen ◽  
Laure Yatime ◽  
Casper Larsen ◽  
Steen Vang Petersen ◽  
Andreas Klos ◽  
...  
Keyword(s):  
Complement Activation ◽  
Functional Characterization ◽  
Functional Assay ◽  
Helix Bundle ◽  
Wide Range ◽  
A Cell ◽  
Four Helix Bundle ◽  
G Protein Coupled

Complement is an ancient part of the innate immune system that plays a pivotal role in protection against invading pathogens and helps to clear apoptotic and necrotic cells. Upon complement activation, a cascade of proteolytic events generates the complement effectors, including the anaphylatoxins C3a and C5a. Signalling through their cognate G-protein coupled receptors, C3aR and C5aR, leads to a wide range of biological events promoting inflammation at the site of complement activation. The function of anaphylatoxins is regulated by circulating carboxypeptidases that remove their C-terminal arginine residue, yielding C3a-desArg and C5a-desArg. Whereas human C3a and C3a-desArg adopt a canonical four-helix bundle fold, the conformation of human C5a-desArg has recently been described as a three-helix bundle. Here, the crystal structures of an antagonist version of human C5a, A8Δ71–73, and of murine C5a and C5a-desArg are reported. Whereas A8Δ71–73adopts a three-helix bundle conformation similar to human C5a-desArg, the two murine proteins form a four-helix bundle. A cell-based functional assay reveals that murine C5a-desArg, in contrast to its human counterpart, exerts the same level of activition as murine C5a on its cognate receptor. The role of the different C5a conformations is discussed in relation to the differential activation of C5a receptors across species.

scholarly journals Atomistic basis of opening and conduction in mammalian inward rectifier potassium (Kir2.2) channels

2019 ◽  
pp. jgp.201912422 ◽  
Author(s):  
Eva-Maria Zangerl-Plessl ◽  
Sun-Joo Lee ◽  
Grigory Maksaev ◽  
Harald Bernsteiner ◽  
Feifei Ren ◽  
...  
Keyword(s):  
Md Simulations ◽  
Inward Rectifier ◽  
Ion Conduction ◽  
Helix Bundle ◽  
Kir Channel ◽  
Channel Opening ◽  
Spontaneous Wetting ◽  
Pore Lining ◽  
Crossing Point

Potassium ion conduction through open potassium channels is essential to control of membrane potentials in all cells. To elucidate the open conformation and hence the mechanism of K+ ion conduction in the classic inward rectifier Kir2.2, we introduced a negative charge (G178D) at the crossing point of the inner helix bundle, the location of ligand-dependent gating. This “forced open” mutation generated channels that were active even in the complete absence of phosphatidylinositol-4,5-bisphosphate (PIP2), an otherwise essential ligand for Kir channel opening. Crystal structures were obtained at a resolution of 3.6 Å without PIP2 bound, or 2.8 Å in complex with PIP2. The latter revealed a slight widening at the helix bundle crossing (HBC) through backbone movement. MD simulations showed that subsequent spontaneous wetting of the pore through the HBC gate region allowed K+ ion movement across the HBC and conduction through the channel. Further simulations reveal atomistic details of the opening process and highlight the role of pore-lining acidic residues in K+ conduction through Kir2 channels.

scholarly journals Connexons Coupling to Gap Junction Channel: Potential Role for Extracellular Protein Stabilization Centers

Biomolecules ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 49
Author(s):  
László Héja ◽  
Ágnes Simon ◽  
Zsolt Szabó ◽  
Julianna Kardos
Keyword(s):  
Gap Junction ◽  
Homology Model ◽  
Specific Protein ◽  
Protein Stabilization ◽  
Interface Formation ◽  
Stabilization Centers ◽  
Gap Junction Channel ◽  
Channel Potential ◽  
Specific Inhibitors

Connexin (Cx) proteins establish intercellular gap junction channels (Cx GJCs) through coupling of two apposed hexameric Cx hemichannels (Cx HCs, connexons). Pre- and post-GJ interfaces consist of extracellular EL1 and EL2 loops, each with three conserved cysteines. Previously, we reported that known peptide inhibitors, mimicking a variety of Cx43 sequences, appear non-selective when binding to homomeric Cx43 vs. Cx36 GJC homology model subtypes. In pursuit of finding potentially Cx subtype-specific inhibitors of connexon-connexon coupling, we aimed at to understand better how the GJ interface is formed. Here we report on the discovery of Cx GJC subtype-specific protein stabilization centers (SCs) featuring GJ interface architecture. First, the Cx43 GJC homology model, embedded in two opposed membrane bilayers, has been devised. Next, we endorsed the fluctuation dynamics of SCs of the interface domain of Cx43 GJC by applying standard molecular dynamics under open and closed cystine disulfide bond (CS-SC) preconditions. The simulations confirmed the major role of of the unique trans-GJ SC pattern comprising conserved (55N, 56T) and non-conserved (57Q) residues of the apposed EL1 loops in the stabilization of the GJC complex. Importantly, clusters of SC patterns residing close to the GJ interface domain appear to orient the interface formation via the numerous SCs between EL1 and EL2. These include central 54CS-S198C or 61CS-S192C contacts with residues 53R, 54C, 55N, 197D, 199F or 64V, 191P, respectively. In addition, we revealed that GJC interface formation is favoured when the psi dihedral angle of the nearby 193P residue is stable around 180° and the interface SCs disappear when this angle moves to the 0° to −45° range. The potential of the association of non-conserved residues with SC motifs in connexon-connexon coupling makes the development of Cx subtype-specific inhibitors viable.

Role of Buried Polar Residues in Helix Bundle Stability and Lipid Binding of Apolipophorin III:  Destabilization by Threonine 31†

Biochemistry ◽  
2005 ◽  
Vol 44 (24) ◽  
pp. 8810-8816 ◽  
Author(s):  
Paul M. M. Weers ◽  
Wazir E. Abdullahi ◽  
Jamie M. Cabrera ◽  
Tzu-Chi Hsu
Keyword(s):  
Lipid Binding ◽  
Helix Bundle ◽  
Apolipophorin Iii ◽  
Polar Residues

scholarly journals The role of stabilization centers in protein thermal stability

2016 ◽  
Vol 471 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Csaba Magyar ◽  
M. Michael Gromiha ◽  
Zoltán Sávoly ◽  
István Simon
Keyword(s):  
Thermal Stability ◽  
Stabilization Centers ◽  
Protein Thermal Stability
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