929706-89-8Relevant academic research and scientific papers
18F-Labeled wild-type annexin V: Comparison of random and site-selective radiolabeling methods
Perreault, Amanda,Knight, James C.,Wang, Monica,Way, Jenilee,Wuest, Frank
, p. 65 - 74 (2016)
Early stage apoptosis is characterized by the externalization of phosphatidylserine (PS) from the inner leaflet of the plasma membrane to the outer periphery. Consequently, PS represents an excellent target for non-invasive imaging of apoptosis by positron emission tomography. Annexin V is a 36 kDa protein which binds with high affinity to PS. Radiolabeling of wild-type annexin V with fluorine-18 (18F) can be accomplished via random acylation of 23 amine groups (22 lysine residues and one N-terminal amine) with [18F]SFB or site-specific alkylation reaction on cysteine residue at position 315 with maleimide-containing prosthetic groups like [18F]FBEM. The effect upon random and site-directed 18F labeling of annexin V was studied with EL4 mouse lymphoma cells. Both, randomly and site-selectively radiolabeled annexin V demonstrated comparable binding to apoptotic EL4 cells. This finding suggests that the 18F radiolabeling method has no significant effect on the ability of 18F-labeled wild-type annexin V to bind PS in apoptotic cells.
Design and Synthesis of an Easily Obtainable Maleimide Reagent N-[2-(4-[18F]fluoro-N-methylbenzenesulfonamido)ethyl]maleimide ([18F]FBSEM) to Radiolabel Thiols in Proteins
Fujita, Yuji,Murakami, Yoshihiro,Noda, Akihiro,Miyoshi, Sosuke
, p. 642 - 648 (2017)
An easily obtainable thiol-selective labeling reagent [18F]FBSEM (N-[2-(4-[18F]fluoro-N-methylbenzenesulfonamido)ethyl]maleimide) was developed. The advantage of the design is that the precursor and [18F]FBSEM have the same backbone and backbone construction is not required; in contrast, known thiol-specific labeling reagents do require backbone construction, and this is thought to be the cause of their complicated synthesis. [18F]FBSEM was successfully obtained in higher yield (25%) and in a simpler way (two fluorination and deprotection steps in 65 min) than the widely used [18F]FBEM (N-[2-(4-[18F]fluorobenzamide)ethyl]maleimide). The labeling efficacy of [18F]FBSEM was confirmed by conjugation with glutathione. [18F]FBSEM is a promising labeling agent for proteins.
Preliminary biological evaluation of 18F-FBEM-Cys-annexin V a novel apoptosis imaging agent
Lu, Chunxiong,Jiang, Quanfu,Hu, Minjin,Tan, Cheng,Yu, Huixin,Hua, Zichun
, p. 4902 - 4914 (2015/05/27)
A novel annexin V derivative (Cys-Annexin V) with a single cysteine residue at its C-terminal has been developed and successfully labeled site-specifically with 18F-FBEM. 18F-FBEM was synthesized by coupling 18F-fluorobenzoic acid (18F-FBA) with N-(2-aminoethyl)maleimide using optimized reaction conditions. The yield of 18F-FBEM-Cys-Annexin V was 71.5% ± 2.0% (n = 4, based on the starting 18F-FBEM, non-decay corrected). The radiochemical purity of 18F-FBEM-Cys-Annexin V was >95%. The specific radioactivities of 18F-FBEM and 18F-FBEM-Cys-Annexin V were >150 and 3.17 GBq/μmol, respectively. Like the 1st generation 18F-SFB-Annexin V, the novel 18F-FBEM-Cys-Annexin V mainly shows renal and to a lesser extent, hepatobiliary excretion in normal mice. In rat hepatic apoptosis models a 3.88 ± 0.05 (n = 4, 1 h) and 10.35 ± 0.08 (n = 4, 2 h) increase in hepatic uptake of 18F-FBEM-Cys-Annexin V compared to normal rats was observed after injection via the tail vein. The liver uptake ratio (treated/control) at 2 h p.i. as measured via microPET correlated with the ratio of apoptotic nuclei in liver observed using TUNEL histochemistry, indicating that the novel 18F-FBEM-Cys-Annexin V is a potential apoptosis imaging agent.
Fully automated synthesis and coupling of [18F]FBEM to glutathione using the iPHASE FlexLab module
Ackermann, Uwe,Plougastel, Lucie,Wichmann, Christian,Goh, Yit Wooi,Yeoh, Shinn Dee,Poniger, Stan S.,Tochon-Danguy, Henri J.,Scott, Andrew M.
, p. 115 - 120 (2014/03/21)
Site-specific radiolabelling of peptides or antibodies using [ 18F]FBEM is often preferred over non-site-specific radiolabelling with [18F]SFB because it does not affect the affinity of the antibody to its target. Unfortunately, the synthesis of [18F]FBEM and its conjugation to thiol containing macromolecules requires some manual intervention, which leads to radiation exposure of the radiochemist. In this publication, we report on the complete automation of [18F]FBEM production and its subsequent conjugation to glutathione using a slightly modified iPHASE FlexLab module. [18F]FBEM was produced in 1.185 ± 0.168 GBq (15-20%; n = 10; 0.75 ± 0.106 GBq non-decay corrected) with a specific activity of 57 ± 10 GBq/μmol. Radiochemical purity was 97 ± 1% and the synthesis time including HPLC purification and reformulation was 70 min. After evaporation to dryness, [18F]FBEM was conjugated to glutathione in PBS buffer pH 7.4 in quantitative yields. This fully automated method does not require any manual intervention and therefore reduces the radiation exposure to the operator. copy; 2014 John Wiley & Sons, Ltd.
RADIOLABELED AFFIBODY MOLECULES
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, (2008/12/04)
The invention provides a radiolabeled affibody molecule comprising a fragment of an IgG-binding domain of protein A from Staphylococcus aureus, a bifunctional linker, and a radiolabel comprising 18F or 76Br, wherein the bifunctional
