scholarly journals The use of prosthetic groups for synthesis of addressed RFLP molecules for positron emission tomography

2021 ◽  
pp. 84-86
Author(s):  
A.V. Ozerskay ◽  
◽  
K.V. Belugin ◽  
O.N. Badmaev ◽  
◽  
...  
Keyword(s):  
Solid Phase ◽  
Cyclic Ketones ◽  
Automatic Synthesis ◽  
New Methods ◽  
Repeat Proteins ◽  
Positron Emission ◽  
Her 2 ◽  
Ankyrin Repeat Proteins ◽  
Prosthetic Groups ◽  
Psma Inhibitor

The aim of the research. An intensive research is underway to create new methods for the synthesis of fl uorine-18 labeled radiopharmaceuticals. Th e aim of this work is to select iodoaliphatic carboxylic acids and esters for radiopharmaceuticals labeling. Material and methods. A simple way to obtain z-yodalifi c carbonic acids and complex esters from commercially available cyclic ketones has been developed. Automatic synthesis of 18F-fl uoroproprostatic groups and 18F fl uoride peptide agents is successfully carried out using new original materials and various purifi cation methods with solid phase cartridges Results. In further work, it is planned to use diff erent 18F-fl uoroproproprostatic groups for synthesis with various peptide agents. Conclusion. Based on these compounds 18F-fl uoroproproprostatic groups were synthesized. Octreotid as an analogue of somatostatin, the non-immunoglobulin-specifi c frame proteins (designed ankyrin repeat proteins) for targeted imaging of tumor cells hyperexpressing Her-2/neu, and prostate-specifi c membrane antigen (PSMA) inhibitor are signifi cant peptide agents.

An optimised and standardised test to determine the presence of the protozoa Cryptosporidium and Giardia in water

2000 ◽  
Vol 41 (7) ◽  
pp. 103-110 ◽  
Author(s):  
G. Stanfield ◽  
E. Carrington ◽  
F. Albinet ◽  
B. Compagnon ◽  
N. Dumoutier ◽  
...  
Keyword(s):  
Solid Phase ◽  
Immunomagnetic Separation ◽  
Ferric Sulphate ◽  
Preliminary Assessment ◽  
New Methods ◽  
European Water ◽  
Conventional Analysis ◽  
Time Savings ◽  
Initial Recovery ◽  
Microscopic Counting

With funding from the European Commission, a consortium of members of the European Water Research Institutes is carrying out a programme of work with the objective of optimising and standardising a method for determining the presence in water of (oo)cysts of Cryptosporidium and Giardia. Each of the stages of the conventional analysis procedure (initial concentration, recoveryand identification and enumeration) are being investigated and the relative merits of existing and new methods are being assessed. Newly developed filters (Envirochek and Filta-Max) have been shown to be more efficient for initial recovery of (oo)cysts from water than the previously used Cuno cartridge filters. In addition, for the analysis of raw waters, flocculationwith ferric sulphate has been shown to give recoveries similar to the Envirochek and Filta Max. Modern purification systems such as immunomagnetic separation have also been assessed and found to offer some advantages over flotation although optimisation of the latter has brought improved efficiency. Preliminary assessment of solid phase cytometry has indicated that this technique could offer significant time savings compared to conventional microscopic counting. The results of the study will be used to propose a revised standard method to CEN.

Designed Ankyrin Repeat Proteins as Novel Binders for Ultrasound Molecular Imaging

2021 ◽  
Author(s):  
Alexandra Kosareva ◽  
Mukesh Punjabi ◽  
Amanda Ochoa-Espinosa ◽  
Lifen Xu ◽  
Jonas V. Schaefer ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Ankyrin Repeat ◽  
Repeat Proteins ◽  
Ultrasound Molecular Imaging ◽  
Ankyrin Repeat Proteins

scholarly journals Thermostable designed ankyrin repeat proteins (DARPins) as building blocks for innovative drugs

2021 ◽  
Author(s):  
Johannes Schilling ◽  
Christian Jost ◽  
Ioana Mariuca Ilie ◽  
Joachim Schnabl ◽  
Oralea Buechi ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Building Blocks ◽  
Ankyrin Repeat ◽  
Internal Repeat ◽  
Repeat Proteins ◽  
Repeat Domain ◽  
Ankyrin Repeat Proteins ◽  
Classical Immunoglobulin ◽  
Dynamics Simulations ◽  
Innovative Drugs

AbstractDesigned Ankyrin Repeat Proteins (DARPins) are a class of antibody mimetics with a high and mostly unexplored potential in drug development. They are clinically validated and thus represent a true alternative to classical immunoglobulin formats. In contrast to immunoglobulins, they are built from solenoid protein domains comprising an N-terminal capping repeat, one or more internal repeats and a C-terminal capping repeat. By using in silico analysis and a rationally guided Ala-Scan, we identified position 17 of the N-terminal capping repeat to play a key role for the overall protein thermostability. The melting temperature of a DARPin domain with a single full-consensus internal repeat was increased by about 8°C to 10°C when the original Asp17 was replaced by Leu, Val, Ile, Met, Ala or Thr, as shown by high-temperature unfolding experiments at equilibrium. We then transferred the Asp17Leu mutation to various backgrounds, including different N- and C-terminal capping repeats and clinically validated DARPin domains, such as the VEGF-binding ankyrin repeat domain of abicipar pegol. In all cases, the proteins remained monomeric and showed improvements in the thermostability of about 8°C to 16°C. Thus, the replacement of Asp17 seems to be generically applicable to this drug class. Molecular dynamics simulations show that the Asp17Leu mutation reduces electrostatic repulsion and improves van-der-Waals packing, rendering the DARPin domain less flexible and more stable. Interestingly, such a beneficial Asp17Leu mutation is present in the N-terminal caps of three of the five DARPin domains of ensovibep, a SARS-CoV-2 entry inhibitor currently in clinical development. This mutation is likely responsible, at least in part, for the very high melting temperature (>90°C) of this promising anti-Covid-19 drug. Overall, such N-terminal capping repeats with increased thermostability seem to be beneficial for the development of innovative drugs based on DARPins.

Imaging Enterobacterales infections in patients using pathogen-specific positron emission tomography

2021 ◽  
Vol 13 (589) ◽  
pp. eabe9805
Author(s):  
Alvaro A. Ordonez ◽  
Luz M. Wintaco ◽  
Filipa Mota ◽  
Andres F. Restrepo ◽  
Camilo A. Ruiz-Bedoya ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Solid Phase ◽  
Multidrug Resistant ◽  
Sterile Inflammation ◽  
Emission Tomography ◽  
Whole Body ◽  
Hamster Model ◽  
Positron Emission ◽  
Pet Ct

Enterobacterales represent the largest group of bacterial pathogens in humans and are responsible for severe, deep-seated infections, often resulting in sepsis or death. They are also a prominent cause of multidrug-resistant (MDR) infections, and some species are recognized as biothreat pathogens. Tools for noninvasive, whole-body analysis that can localize a pathogen with specificity are needed, but no such technology currently exists. We previously demonstrated that positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-d-sorbitol (18F-FDS) can selectively detect Enterobacterales infections in murine models. Here, we demonstrate that uptake of 18F-FDS by bacteria occurs via a metabolically conserved sorbitol-specific pathway with rapid in vitro 18F-FDS uptake noted in clinical strains, including MDR isolates. Whole-body 18F-FDS PET/computerized tomography (CT) in 26 prospectively enrolled patients with either microbiologically confirmed Enterobacterales infection or other pathologies demonstrated that 18F-FDS PET/CT was safe, could rapidly detect and localize Enterobacterales infections due to drug-susceptible or MDR strains, and differentiated them from sterile inflammation or cancerous lesions. Repeat imaging in the same patients monitored antibiotic efficacy with decreases in PET signal correlating with clinical improvement. To facilitate the use of 18F-FDS, we developed a self-contained, solid-phase cartridge to rapidly (<10 min) formulate ready-to-use 18F-FDS from commercially available 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) at room temperature. In a hamster model, 18F-FDS PET/CT also differentiated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia from secondary Klebsiella pneumoniae pneumonia—a leading cause of complications in hospitalized patients with COVID-19. These data support 18F-FDS as an innovative and readily available, pathogen-specific PET technology with clinical applications.

scholarly journals Rigid fusions of designed helical repeat binding proteins efficiently protect a binding surface from crystal contacts

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Patrick Ernst ◽  
Annemarie Honegger ◽  
Floor van der Valk ◽  
Christina Ewald ◽  
Peer R. E. Mittl ◽  
...  
Keyword(s):  
Protein Design ◽  
Binding Proteins ◽  
Peptide Binding ◽  
Binding Mode ◽  
Equilibrium Structure ◽  
Repeat Proteins ◽  
Binding Surface ◽  
Crystal Contacts ◽  
Armadillo Repeat ◽  
Ankyrin Repeat Proteins

Abstract Designed armadillo repeat proteins (dArmRPs) bind extended peptides in a modular way. The consensus version recognises alternating arginines and lysines, with one dipeptide per repeat. For generating new binding specificities, the rapid and robust analysis by crystallography is key. Yet, we have previously found that crystal contacts can strongly influence this analysis, by displacing the peptide and potentially distorting the overall geometry of the scaffold. Therefore, we now used protein design to minimise these effects and expand the previously described concept of shared helices to rigidly connect dArmRPs and designed ankyrin repeat proteins (DARPins), which serve as a crystallisation chaperone. To shield the peptide-binding surface from crystal contacts, we rigidly fused two DARPins to the N- and C-terminal repeat of the dArmRP and linked the two DARPins by a disulfide bond. In this ring-like structure, peptide binding, on the inside of the ring, is very regular and undistorted, highlighting the truly modular binding mode. Thus, protein design was utilised to construct a well crystallising scaffold that prevents interference from crystal contacts with peptide binding and maintains the equilibrium structure of the dArmRP. Rigid DARPin-dArmRPs fusions will also be useful when chimeric binding proteins with predefined geometries are required.

Arpp/Ankrd2, a member of the muscle ankyrin repeat proteins (MARPs), translocates from the I-band to the nucleus after muscle injury

2007 ◽  
Vol 129 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Yoshiyuki Tsukamoto ◽  
Naoki Hijiya ◽  
Shinji Yano ◽  
Shigeo Yokoyama ◽  
Chisato Nakada ◽  
...  
Keyword(s):  
Muscle Injury ◽  
Ankyrin Repeat ◽  
Repeat Proteins ◽  
Ankyrin Repeat Proteins
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