Tyrosine Cross-Links:  Molecular Basis of Gluten Structure and Function

2001 ◽  
Vol 49 (5) ◽  
pp. 2627-2632 ◽  
Author(s):  
Katherine A. Tilley ◽  
Rachel E. Benjamin ◽  
Katherine E. Bagorogoza ◽  
B. Moses Okot-Kotber ◽  
Om Prakash ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Structure And Function ◽  
Cross Links ◽  
And Function ◽  
Gluten Structure

scholarly journals Exotoxins of Staphylococcus aureus

2000 ◽  
Vol 13 (1) ◽  
pp. 16-34 ◽  
Author(s):  
Martin M. Dinges ◽  
Paul M. Orwin ◽  
Patrick M. Schlievert
Keyword(s):  
Staphylococcus Aureus ◽  
Toxic Shock Syndrome ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Food Poisoning ◽  
Structure And Function ◽  
Toxic Shock ◽  
The Family ◽  
Toxic Shock Syndrome Toxin ◽  
And Function

SUMMARY This article reviews the literature regarding the structure and function of two types of exotoxins expressed by Staphylococcus aureus, pyrogenic toxin superantigens (PTSAgs) and hemolysins. The molecular basis of PTSAg toxicity is presented in the context of two diseases known to be caused by these exotoxins: toxic shock syndrome and staphylococcal food poisoning. The family of staphylococcal PTSAgs presently includes toxic shock syndrome toxin-1 (TSST-1) and most of the staphylococcal enterotoxins (SEs) (SEA, SEB, SEC, SED, SEE, SEG, and SEH). As the name implies, the PTSAgs are multifunctional proteins that invariably exhibit lethal activity, pyrogenicity, superantigenicity, and the capacity to induce lethal hypersensitivity to endotoxin. Other properties exhibited by one or more staphylococcal PTSAgs include emetic activity (SEs) and penetration across mucosal barriers (TSST-1). A detailed review of the molecular mechanisms underlying the toxicity of the staphylococcal hemolysins is also presented.

Structure of CD20 in complex with the therapeutic monoclonal antibody rituximab

Science ◽  
2020 ◽  
Vol 367 (6483) ◽  
pp. 1224-1230 ◽  
Author(s):  
Lionel Rougé ◽  
Nancy Chiang ◽  
Micah Steffek ◽  
Christine Kugel ◽  
Tristan I. Croll ◽  
...  
Keyword(s):  
Structural Model ◽  
Structure And Function ◽  
Antigen Binding ◽  
Surface Markers ◽  
Cell Surface Markers ◽  
Therapeutic Monoclonal Antibody ◽  
Cross Links ◽  
Cell Membrane Protein ◽  
And Function ◽  
Cluster Of Differentiation

Cluster of differentiation 20 (CD20) is a B cell membrane protein that is targeted by monoclonal antibodies for the treatment of malignancies and autoimmune disorders but whose structure and function are unknown. Rituximab (RTX) has been in clinical use for two decades, but how it activates complement to kill B cells remains poorly understood. We obtained a structure of CD20 in complex with RTX, revealing CD20 as a compact double-barrel dimer bound by two RTX antigen-binding fragments (Fabs), each of which engages a composite epitope and an extensive homotypic Fab:Fab interface. Our data suggest that RTX cross-links CD20 into circular assemblies and lead to a structural model for complement recruitment. Our results further highlight the potential relevance of homotypic Fab:Fab interactions in targeting oligomeric cell-surface markers.

A stochastic roadmap method to model protein structural transitions

Robotica ◽  
2015 ◽  
Vol 34 (8) ◽  
pp. 1705-1733 ◽  
Author(s):  
Kevin Molloy ◽  
Rudy Clausen ◽  
Amarda Shehu
Keyword(s):  
Protein Structure ◽  
Molecular Basis ◽  
Structure And Function ◽  
Structural Transitions ◽  
Simulation Framework ◽  
Human Disorders ◽  
Model Protein ◽  
And Function ◽  
The Impact

SUMMARYEvidence is emerging that the role of protein structure in disease needs to be rethought. Sequence mutations in proteins are often found to affect the rate at which a protein switches between structures. Modeling structural transitions in wildtype and variant proteins is central to understanding the molecular basis of disease. This paper investigates an efficient algorithmic realization of the stochastic roadmap simulation framework to model structural transitions in wildtype and variants of proteins implicated in human disorders. Our results indicate that the algorithm is able to extract useful information on the impact of mutations on protein structure and function.

scholarly journals Structure and function of aerotolerant, multiple-turnover THI4 thiazole synthases

2021 ◽  
Author(s):  
Jaya Joshi ◽  
Qiang Li ◽  
Jorge D. Garcia-Garcia ◽  
Bryan J. Leong ◽  
You Hu ◽  
...  
Keyword(s):  
Active Site ◽  
Molecular Basis ◽  
Structure And Function ◽  
Comparative Genomic ◽  
Aerobic Conditions ◽  
Single Turnover ◽  
Metal Cofactor ◽  
Catalytic Metal ◽  
And Function ◽  
Sulfur Donor

Plant and fungal THI4 thiazole synthases produce the thiamin thiazole moiety in aerobic conditions via a single–turnover suicide reaction that uses an active–site Cys residue as sulfur donor. Multiple turnover (i.e. catalytic) THI4s lacking an active–site Cys (non–Cys THI4s) that use sulfide as sulfur donor have been characterized—but only from archaeal methanogens that are anaerobic, O2–sensitivehyperthermophiles from sulfide–rich habitats. These THI4s prefer iron as cofactor. A survey of prokaryote genomes uncovered non–Cys THI4s in aerobic mesophiles from sulfide–poor habitats, suggesting that multiple–turnover THI4 operation is possible in aerobic, mild, low–sulfide conditions. This was confirmed by testing 23 representative non–Cys THI4s for complementation of an Escherichia coli ΔthiG thiazole auxotroph in aerobic conditions. Sixteen were active, and more so when intracellular sulfidelevel was raised by supplying Cys, demonstrating that they function in the presence of O2 at mild temperatures and indicating they use sulfide or a sulfide metabolite as sulfur donor. Comparative genomic evidence linked non–Cys THI4s with proteins from families that bind, transport, or metabolize cobalt or other heavy metals. The crystal structure of the aerotolerant bacterial Thermovibrio ammonificans THI4 was determined to probe the molecular basis of aerotolerance. The structure suggested no large deviations compared to the structures of THI4s from O2–sensitive methanogens but is consistent with an alternative catalytic metal. Together with complementation data, the use of cobalt rather than iron was supported. We conclude that catalytic THI4s can indeed operate aerobically and that the metal cofactor inserted is a likely natural determinant of aerotolerance.

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