Atypical Asparagine Deamidation of NW Motif Significantly Attenuates the Biological Activities of an Antibody Drug Conjugate.

Asparagine deamidation is a post-translational modification (PTM) that converts asparagine residues into iso-aspartate and/or aspartate. Non-enzymatic asparagine deamidation is observed frequently during the manufacturing, processing, and/or storage of biotherapeutic proteins. Depending on the site of deamidation, this PTM can significantly impact the therapeutic's potency, stability, and/or immunogenicity.

Multiplex Bioanalytical Methods for Comprehensive Characterization and Quantification of the Unique Complementarity-Determining-Region Deamidation of MEDI7247, an Anti-ASCT2 Pyrrolobenzodiazepine Antibody-Drug Conjugate.

Deamidation, a common post-translational modification, may impact multiple physiochemical properties of a therapeutic protein. MEDI7247, a pyrrolobenzodiazepine (PBD) antibody-drug conjugate (ADC), contains a unique deamidation site, N102, located within the complementarity-determining region (CDR), impacting the affinity of MEDI7247 to its target. Therefore, it was necessary to monitor MEDI7247 deamidation status in vivo.

A scalable and robust cationic lipid/polymer hybrid nanoparticle platform for mRNA delivery.

mRNA based gene therapies hold the potential to treat multiple diseases with significant advantages over DNA based therapies, including rapid protein expression and minimized risk of mutagenesis. However, successful delivery of mRNA remains challenging, and clinical translation of mRNA therapeutics has been limited. This study investigated the use of a lipid/polymer hybrid (LPH) nanocarrier for mRNA, designed to address key delivery challenges and shuttle mRNA to targeted tissues.

A single homogeneous assay for simultaneous measurement of bispecific antibody target binding.

Bispecific antibodies (BsAbs) are engineered to simultaneously bind two different antigens, and offer promising clinical outcomes for various diseases. The dual binding properties of BsAbs may enable superior efficacies and/or potencies compared to standard monoclonal antibodies (mAbs) or combination mAb therapies. Characterizing BsAb binding properties is critical during biotherapeutic development, where data is leveraged to predict efficacy and potency, assess critical quality attributes and improve antibody design.

Melanopsin mediates light-dependent relaxation in blood vessels.

Melanopsin (opsin4; Opn4), a non-image-forming opsin, has been linked to a number of behavioral responses to light, including circadian photo-entrainment, light suppression of activity in nocturnal animals, and alertness in diurnal animals. We report a physiological role for Opn4 in regulating blood vessel function, particularly in the context of photorelaxation. Using PCR, we demonstrate that Opn4 (a classic G protein-coupled receptor) is expressed in blood vessels.

Chronic sazetidine-A maintains anxiolytic effects and slower weight gain following chronic nicotine without maintaining increased density of nicotinic receptors in rodent brain.

Chronic nicotine administration increases the density of brain α4β2* nicotinic acetylcholine receptors (nAChRs), which may contribute to nicotine addiction by exacerbating withdrawal symptoms associated with smoking cessation. Varenicline, a smoking cessation drug, also increases these receptors in rodent brain. The maintenance of this increase by varenicline as well as nicotine replacement may contribute to the high rate of relapse during the first year after smoking cessation.

Chronic sazetidine-A at behaviorally active doses does not increase nicotinic cholinergic receptors in rodent brain.

Chronic nicotine administration increases α4β2 neuronal nicotinic acetylcholine receptor (nAChR) density in brain. This up-regulation probably contributes to the development and/or maintenance of nicotine dependence. nAChR up-regulation is believed to be triggered at the ligand binding site, so it is not surprising that other nicotinic ligands also up-regulate nAChRs in the brain.

A new radioligand binding assay to measure the concentration of drugs in rodent brain ex vivo.

We have developed a new radioligand binding assay method to measure the concentration of nonradiolabeled drugs in the brain ex vivo. This new method fuses the concepts of standard competition and saturation binding assays and uses a transformed version of the Cheng-Prusoff equation (Biochem Pharmacol 22:3099-3108, 1973) to calculate the drug concentration. After testing the validity of this method, we demonstrated its utility by measuring the brain concentration of sazetidine-A, a newly developed nicotinic receptor ligand, and its elimination rate after a single subcutaneous administration.

Endogenously expressed muscarinic receptors in HEK293 cells augment up-regulation of stably expressed α4β2 nicotinic receptors.

Nicotine-induced up-regulation of neuronal nicotinic receptors (nAChRs) has been known and studied for more than 25 years. Other nAChR ligands can also up-regulate nAChRs, but it is not known if these ligands induce up-regulation by mechanisms similar to that of nicotine. In this study, we compared up-regulation by three different nicotinic agonists and a competitive antagonist of several different nAChR subtypes expressed in HEK293 cells.

Effects of chronic nicotine on heteromeric neuronal nicotinic receptors in rat primary cultured neurons.

Nicotine increases the number of neuronal nicotinic acetylcholine receptors (nAChRs) in brain. This study investigated the effects of chronic nicotine treatment on nAChRs expressed in primary cultured neurons. In particular, we studied the chronic effects of nicotine exposure on the total density, surface expression and turnover rate of heteromeric nAChRs.