scholarly journals Proton-Binding Motifs of Membrane-Bound Proteins: From Bacteriorhodopsin to Spike Protein S

2021 ◽  
Vol 9 ◽  
Author(s):  
Ana-Nicoleta Bondar
Keyword(s):  
Hydrogen Bond ◽  
Binding Sites ◽  
Coupled Model ◽  
Protein S ◽  
Specific Protein ◽  
Spike Protein ◽  
Sequence Motifs ◽  
Proton Binding ◽  
Hydrogen Bond Networks ◽  
Membrane Bound

Membrane-bound proteins that change protonation during function use specific protein groups to bind and transfer protons. Knowledge of the identity of the proton-binding groups is of paramount importance to decipher the reaction mechanism of the protein, and protonation states of prominent are studied extensively using experimental and computational approaches. Analyses of model transporters and receptors from different organisms, and with widely different biological functions, indicate common structure-sequence motifs at internal proton-binding sites. Proton-binding dynamic hydrogen-bond networks that are exposed to the bulk might provide alternative proton-binding sites and proton-binding pathways. In this perspective article I discuss protonation coupling and proton binding at internal and external carboxylate sites of proteins that use proton transfer for function. An inter-helical carboxylate-hydroxyl hydrogen-bond motif is present at functionally important sites of membrane proteins from archaea to the brain. External carboxylate-containing H-bond clusters are observed at putative proton-binding sites of protonation-coupled model proteins, raising the question of similar functionality in spike protein S.

An attempt to discriminate catalytic and regulatory proton binding sites in membrane-bound, thiol-reduced chloroplast ATPase

Biochemistry ◽  
1992 ◽  
Vol 31 (17) ◽  
pp. 4239-4247 ◽  
Author(s):  
Marie Valerio ◽  
Yaroslav De Kouchkovsky ◽  
Francis Haraux
Keyword(s):  
Binding Sites ◽  
Proton Binding ◽  
Membrane Bound

scholarly journals How water-mediated hydrogen bonds affect chlorophyll a/b selectivity in Water-Soluble Chlorophyll Protein

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alessandro Agostini ◽  
Elena Meneghin ◽  
Lucas Gewehr ◽  
Danilo Pedron ◽  
Daniel M. Palm ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Binding Sites ◽  
Photophysical Properties ◽  
Water Soluble ◽  
Variable Degree ◽  
Formyl Group ◽  
Hydrogen Bond Networks ◽  
Conformational Freedom ◽  
Chlorophyll Protein ◽  
Hydrogen Bonded

AbstractThe Water-Soluble Chlorophyll Protein (WSCP) of Brassicaceae is a remarkably stable tetrapyrrole-binding protein that, by virtue of its simple design, is an exceptional model to investigate the interactions taking place between pigments and their protein scaffold and how they affect the photophysical properties and the functionality of the complexes. We investigated variants of WSCP from Lepidium virginicum (Lv) and Brassica oleracea (Bo), reconstituted with Chlorophyll (Chl) b, to determine the mechanisms by which the different Chl binding sites control their Chl a/b specificities. A combined Raman and crystallographic investigation has been employed, aimed to characterize in detail the hydrogen-bond network involving the formyl group of Chl b. The study revealed a variable degree of conformational freedom of the hydrogen bond networks among the WSCP variants, and an unexpected mixed presence of hydrogen-bonded and not hydrogen-bonded Chls b in the case of the L91P mutant of Lv WSCP. These findings helped to refine the description of the mechanisms underlying the different Chl a/b specificities of WSCP versions, highlighting the importance of the structural rigidity of the Chl binding site in the vicinity of the Chl b formyl group in granting a strong selectivity to binding sites.

scholarly journals The sequence of human ACE2 is suboptimal for binding the S spike protein of SARS coronavirus 2

2020 ◽  
Author(s):  
Erik Procko
Keyword(s):  
Receptor Binding ◽  
Binding Sites ◽  
Protein S ◽  
Public Health Emergency ◽  
Host Cells ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Sars Coronavirus ◽  
Molecular Events ◽  
Proteins And Peptides

SUMMARYThe rapid and escalating spread of SARS coronavirus 2 (SARS-CoV-2) poses an immediate public health emergency. The viral spike protein S binds ACE2 on host cells to initiate molecular events that release the viral genome intracellularly. Soluble ACE2 inhibits entry of both SARS and SARS-2 coronaviruses by acting as a decoy for S binding sites, and is a candidate for therapeutic, prophylactic and diagnostic development. Using deep mutagenesis, variants of ACE2 are identified with increased binding to the receptor binding domain of S. Mutations are found across the interface, in the N90-glycosylation motif, and at buried sites where they are predicted to enhance local folding and presentation of the interaction epitope. When single substitutions are combined, large increases in binding can be achieved. The mutational landscape offers a blueprint for engineering high affinity proteins and peptides that block receptor binding sites on S to meet this unprecedented challenge.

EVALUATION OF TISSUE STEROID BINDING IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S223-S246 ◽  
Author(s):  
C. R. Wira ◽  
H. Rochefort ◽  
E. E. Baulieu
Keyword(s):  
Protein Binding ◽  
Binding Sites ◽  
Experimental System ◽  
Specific Protein ◽  
Coupling Mechanism ◽  
Target Tissue ◽  
Protein Binding Sites ◽  
Definition Of ◽  
Hormone Specificity

ABSTRACT The definition of a RECEPTOR* in terms of a receptive site, an executive site and a coupling mechanism, is followed by a general consideration of four binding criteria, which include hormone specificity, tissue specificity, high affinity and saturation, essential for distinguishing between specific and nonspecific binding. Experimental approaches are proposed for choosing an experimental system (either organized or soluble) and detecting the presence of protein binding sites. Techniques are then presented for evaluating the specific protein binding sites (receptors) in terms of the four criteria. This is followed by a brief consideration of how receptors may be located in cells and characterized when extracted. Finally various examples of oestrogen, androgen, progestagen, glucocorticoid and mineralocorticoid binding to their respective target tissues are presented, to illustrate how researchers have identified specific corticoid and mineralocorticoid binding in their respective target tissue receptors.

Discovery of Some Antiviral Natural products to fight against Novel Corona Virus (SARS-CoV-2) using Insilico approach

2020 ◽  
Vol 23 ◽  
Author(s):  
Ashish Shah ◽  
Vaishali Patel ◽  
Bhumika Parmar
Keyword(s):  
Binding Affinity ◽  
Protein S ◽  
Docking Studies ◽  
Spike Protein ◽  
Enveloped Viruses ◽  
Bioactivity Prediction ◽  
Corona Virus ◽  
Main Protease ◽  
Antiviral Activities ◽  
Deadly Disease

Background: Novel Corona virus is a type of enveloped viruses with a single stranded RNA enclosing helical nucleocapsid. The envelope consists of spikes on the surface which are made up of proteins through which virus enters into human cells. Until now there is no specific drug or vaccine available to treat COVID-19 infection. In this scenario, reposting of drug or active molecules may provide rapid solution to fight against this deadly disease. Objective: We had selected 30 phytoconstituents from the different plants which are reported for antiviral activities against corona virus (CoVs) and performed insilico screening to find out phytoconstituents which have potency to inhibit specific target of novel corona virus. Methods: We had perform molecular docking studies on three different proteins of novel corona virus namely COVID-19 main protease (3CL pro), papain-like protease (PL pro) and spike protein (S) attached to ACE2 binding domain. The screening of the phytoconstituents on the basis of binding affinity compared to standard drugs. The validations of screened compounds were done using ADMET and bioactivity prediction. Results: We had screened five compounds biscoclaurine, norreticuline, amentoflavone, licoricidin and myricetin using insilico approach. All compounds found safe in insilico toxicity studies. Bioactivity prediction reviles that these all compounds may act through protease or enzyme inhibition. Results of compound biscoclaurine norreticuline were more interesting as this biscoclaurine had higher binding affinity for the target 3CLpro and PLpro targets and norreticuline had higher binding affinity for the target PLpro and Spike protein. Conclusion: Our study concludes that these compounds could be further explored rapidly as it may have potential to fight against COVID-19.

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.

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