We have developed a class of binding proteins, called avimers, to overcome the limitations of antibodies and other immunoglobulin-based therapeutic proteins. Avimers are evolved from a large family ...of human extracellular receptor domains by in vitro exon shuffling and phage display, generating multidomain proteins with binding and inhibitory properties. Linking multiple independent binding domains creates avidity and results in improved affinity and specificity compared with conventional single-epitope binding proteins. Other potential advantages over immunoglobulin domains include simple and efficient production of multitarget-specific molecules in Escherichia coli, improved thermostability and resistance to proteases. Avimers with sub-nM affinities were obtained aganist five targets. An avimer that inhibits interleukin 6 with 0.8 pM IC50 in cell-based assays is biologically active in two animal models.
We have developed a novel fluorescence-based homogeneous binding assay for high-throughput screening of chemical compounds. In this assay, a Cy5- or Cy5.5-labeled ligand binds to receptor immobilized ...on a particle, either a bead or a cell. The resulting localized signal can be detected by a modified microvolume fluorimeter (MVF). When a molecule which competes with the labeled ligand is present, the localized fluorescence on cells or beads is reduced. Image processing software enumerates events and analyzes fluorescence intensity. We describe MVF assays for the IL-1 and IL-5 receptors. Using synthetic peptides with a range of affinities for the IL-1 receptor, we obtained IC50 data consistent with those determined by radioligand binding assays. Because the image processing software can discriminate among events with different diameters, we were able to develop a multiplex assay, in which the IL-1R and IL-5R assays were carried out in the same well with each receptor immobilized on a different size of bead. IC50 values generated in the multiplex assay for ligands specific to each receptor were comparable to those determined independently. Finally, similar IC50 values were obtained in a 16-μl volume in an 864-well plate. This homogeneous, nonradioactive, miniaturizable, and multiplex-capable assay holds much promise for screening of combinatorial libraries and compound collections.
This book explores the interplay between International Law and Chemical, Biological, Radio-Nuclear (CBRN) risks. An all-hazards approach is adopted to cover events of intentional, accidental and ...natural origin, and international obligations are presented according to the phases of the emergency management cycle, including prevention, preparedness, response and recovery.
The endocrine hormone FGF21 has attracted considerable interest as a potential therapeutic for treating diabetes and obesity. As an alternative to the native cytokine, we generated bispecific Avimer ...polypeptides that bind with high affinity and specificity to one of the receptor and coreceptor pairs used by FGF21, FGFR1c and beta-Klotho. These Avimers exhibit FGF21-like activity in in vitro assays with potency greater than FGF21. In a study conducted in obese male cynomolgus monkeys, animals treated with an FGFR1c/beta-Klotho bispecific Avimer showed improved metabolic parameters and reduced body weight comparable to the effects seen with FGF21. These results not only demonstrate the essential roles of FGFR1c and beta-Klotho in mediating the metabolic effects of FGF21, they also describe a first bispecific activator of this unique receptor complex and provide validation for a novel therapeutic approach to target this potentially important pathway for treating diabetes and obesity.
Water without borders? Bakker, Karen; Cohen, Alice; Norman, Emma S
Water without borders?,
2013, 20131030, 2019, 2013, 2013-10-30
eBook
Water without Borders?is designed to help readers develop a balanced understanding of the most pressing shared water issues between Canada and the United States.
The endocrine hormone FGF21 has attracted considerable interest as a potential therapeutic for treating diabetes and obesity. As an alternative to the native cytokine, we generated bispecific Avimer ...polypeptides that bind with high affinity and specificity to one of the receptor and coreceptor pairs used by FGF21, FGFR1c and beta -Klotho. These Avimers exhibit FGF21-like activity in in vitro assays with potency greater than FGF21. In a study conducted in obese male cynomolgus monkeys, animals treated with an FGFR1c/ beta -Klotho bispecific Avimer showed improved metabolic parameters and reduced body weight comparable to the effects seen with FGF21. These results not only demonstrate the essential roles of FGFR1c and beta -Klotho in mediating the metabolic effects of FGF21, they also describe a first bispecific activator of this unique receptor complex and provide validation for a novel therapeutic approach to target this potentially important pathway for treating diabetes and obesity.
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