scholarly journals High resolution crystal structures of the receptor-binding domain of Clostridium botulinum neurotoxin serotypes A and FA

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4552 ◽  
Author(s):  
Jonathan R. Davies ◽  
Gavin S. Hackett ◽  
Sai Man Liu ◽  
K. Ravi Acharya
Keyword(s):  
Receptor Binding ◽  
Clostridium Botulinum ◽  
Toxin Production ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Crystal Forms ◽  
Multiple Receptors ◽  
Botulinum Neurotoxins ◽  
Translocation Domain ◽  
Existing Structure

The binding specificity of botulinum neurotoxins (BoNTs) is primarily a consequence of their ability to bind to multiple receptors at the same time. BoNTs consist of three distinct domains, a metalloprotease light chain (LC), a translocation domain (HN) and a receptor-binding domain (HC). Here we report the crystal structure of HC/FA, complementing an existing structure through the modelling of a previously unresolved loop which is important for receptor-binding. Our HC/FA structure also contains a previously unidentified disulphide bond, which we have also observed in one of two crystal forms of HC/A1. This may have implications for receptor-binding and future recombinant toxin production.

scholarly journals Investigating Early Events in Receptor Binding and Translocation of Colicin E9 Using Synchronized Cell Killing and Proteolytic Cleavage

2008 ◽  
Vol 190 (12) ◽  
pp. 4342-4350 ◽  
Author(s):  
Ying Zhang ◽  
Mireille N. Vankemmelbeke ◽  
Lisa E. Holland ◽  
David C. Walker ◽  
Richard James ◽  
...  
Keyword(s):  
Cell Surface ◽  
Receptor Binding ◽  
Distal Region ◽  
Cell Killing ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Cleavage Sites ◽  
E Coli ◽  
Translocation Domain ◽  
Colicin E9

ABSTRACT Enzymatic colicins such as colicin E9 (ColE9) bind to BtuB on the cell surface of Escherichia coli and rapidly recruit a second coreceptor, either OmpF or OmpC, through which the N-terminal natively disordered region (NDR) of their translocation domain gains entry into the cell periplasm and interacts with TolB. Previously, we constructed an inactive disulfide-locked mutant ColE9 (ColE9s-s) that binds to BtuB and can be reduced with dithiothreitol (DTT) to synchronize cell killing. By introducing unique enterokinase (EK) cleavage sites in ColE9s-s, we showed that the first 61 residues of the NDR were inaccessible to cleavage when bound to BtuB, whereas an EK cleavage site inserted at residue 82 of the NDR remained accessible. This suggests that most of the NDR is occluded by OmpF shortly after binding to BtuB, whereas the extreme distal region of the NDR is surface exposed before unfolding of the receptor-binding domain occurs. EK cleavage of unique cleavage sites located in the ordered region of the translocation domain or in the distal region of the receptor-binding domain confirmed that these regions of ColE9 remained accessible at the E. coli cell surface. Lack of EK cleavage of the DNase domain of the cell-bound, oxidized ColE9/Im9 complex, and the rapid detection of Alexa Fluor 594-labeled Im9 (Im9AF) in the cell supernatant following treatment of cells with DTT, suggested that immunity release occurred immediately after unfolding of the colicin and was not driven by binding to BtuB.

scholarly journals Characterization of the Antibody Response to the Receptor Binding Domain of Botulinum Neurotoxin Serotypes A and E

2005 ◽  
Vol 73 (10) ◽  
pp. 6998-7005 ◽  
Author(s):  
Michael R. Baldwin ◽  
William H. Tepp ◽  
Christina L. Pier ◽  
Marite Bradshaw ◽  
Mengfei Ho ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Clostridium Botulinum ◽  
Binding Domain ◽  
Classical Type ◽  
Enzyme Linked Immunosorbent Assay ◽  
Receptor Binding Domain ◽  
Binding Domains ◽  
C Terminus ◽  
Neutralizing Capacity

ABSTRACT Clostridium botulinum neurotoxins (BoNTs) are the most toxic proteins for humans. The current clostridial-derived vaccines against BoNT intoxication have limitations including production and accessibility. Conditions were established to express the soluble receptor binding domain (heavy-chain receptor [HCR]) of BoNT serotypes A and E in Escherichia coli. Sera isolated from mice and rabbits immunized with recombinant HCR/A1 (rHCR/A1) from the classical type A-Hall strain (ATCC 3502) (BoNT/A1) and rHCR/E from BoNT serotype E Beluga (BoNT/EB) neutralized the homologous serotype of BoNT but displayed differences in cross-recognition and cross-protection. Enzyme-linked immunosorbent assay and Western blotting showed that α-rHCR/A1 recognized epitopes within the C terminus of the HCR/A and HCR/E, while α-rHCR/E recognized epitopes within the N terminus or interface between the N and C termini of the HCR proteins. α-rHCR/EB sera possessed detectable neutralizing capacity for BoNT/A1, while α-rHCR/A1 did not neutralize BoNT/E. rHCR/A was an effective immunogen against BoNT/A1 and the Kyoto F infant strain (BoNT/A2), but not BoNT serotype E Alaska (BoNT/EA), while rHCR/EB neutralized BoNT/EA, and under hyperimmunization conditions protected against BoNT/A1 and BoNT/A2. The protection elicited by rHCR/A1 to BoNT/A1 and BoNT/A2 and by rHCR/EB to BoNT/EA indicate that immunization with receptor binding domains elicit protection within sub-serotypes of BoNT. The protection elicited by hyperimmunization with rHCR/E against BoNT/A suggests the presence of common neutralizing epitopes between the serotypes E and A. These results show that a receptor binding domain subunit vaccine protects against serotype variants of BoNTs.

Destabilizing the Structural Integrity of SARS-CoV2 Receptor Proteins by Curcumin Along with Hydroxychloroquine: An Insilco Approach for a Combination Therapy

2020 ◽  
Author(s):  
Akhileshwar Srivastava ◽  
Divya Singh
Keyword(s):  
Binding Energy ◽  
Combination Therapy ◽  
Receptor Binding ◽  
Structural Integrity ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Receptor Proteins ◽  
Main Protease ◽  
The Stability ◽  
Therapeutic Activities

Presently, an emerging disease (COVID-19) has been spreading across the world due to coronavirus (SARS-CoV2). For treatment of SARS-CoV2 infection, currently hydroxychloroquine has been suggested by researchers, but it has not been found enough effective against this virus. The present study based on in silico approaches was designed to enhance the therapeutic activities of hydroxychloroquine by using curcumin as an adjunct drug against SARS-CoV2 receptor proteins: main-protease and S1 receptor binding domain (RBD). The webserver (ANCHOR) showed the higher protein stability for both receptors with disordered score (<0.5). The molecular docking analysis revealed that the binding energy (-24.58 kcal/mol) of hydroxychloroquine was higher than curcumin (-20.47 kcal/mol) for receptor main-protease, whereas binding energy of curcumin (<a>-38.84</a> kcal/mol) had greater than hydroxychloroquine<a> (-35.87</a> kcal/mol) in case of S1 receptor binding domain. Therefore, this study suggested that the curcumin could be used as combination therapy along with hydroxychloroquine for disrupting the stability of SARS-CoV2 receptor proteins

Role of key point Mutations in Receptor Binding Domain of SARS-CoV-2 Spike Glycoprotein

2020 ◽  
Vol 20 ◽  
Author(s):  
Bipin Singh
Keyword(s):  
Receptor Binding ◽  
Point Mutations ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Spike Glycoprotein ◽  
Angiotensin Converting Enzyme 2 ◽  
Recent Outbreak ◽  
Novel Coronavirus ◽  
Genomic Similarity

: The recent outbreak of novel coronavirus (SARS-CoV-2 or 2019-nCoV) and its worldwide spread is posing one of the major threats to human health and the world economy. It has been suggested that SARS-CoV-2 is similar to SARSCoV based on the comparison of the genome sequence. Despite the genomic similarity between SARS-CoV-2 and SARSCoV, the spike glycoprotein and receptor binding domain in SARS-CoV-2 shows the considerable difference compared to SARS-CoV, due to the presence of several point mutations. The analysis of receptor binding domain (RBD) from recently published 3D structures of spike glycoprotein of SARS-CoV-2 (Yan, R., et al. (2020); Wrapp, D., et al. (2020); Walls, A. C., et al. (2020)) highlights the contribution of a few key point mutations in RBD of spike glycoprotein and molecular basis of its efficient binding with human angiotensin-converting enzyme 2 (ACE2).

scholarly journals Ivermectin Docks to the SARS-CoV-2 Spike Receptor-binding Domain Attached to ACE2

In Vivo ◽  
2020 ◽  
Vol 34 (5) ◽  
pp. 3023-3026 ◽  
Author(s):  
STEVEN LEHRER ◽  
PETER H. RHEINSTEIN
Keyword(s):  
Receptor Binding ◽  
Binding Domain ◽  
Receptor Binding Domain
Sign in / Sign up

Export Citation Format

Share Document