Inter-Domain interactions Slow BoNT/A's onset of action.

Despite sharing ∼ 43 % sequence identity and structurally similar individual domains, botulinum neurotoxin (BoNT) serotypes A and E have differences in their properties and domain positioning. BoNT/E has a faster onset of action than BoNT/A. This difference is proposed to be due to conformational differences between BoNT/E and the other BoNT serotypes.

Replacement of the Mouse LD Assay for Determination of the Potency of AbobotulinumtoxinA with a Cell-Based Method in Both Powder and Liquid Formulations.

Botulinum neurotoxins (BoNTs) are important therapeutic agents. The in vivo median lethal dose (LD) assay has been commonly used to measure the potency of BoNT commercial preparations. As an alternative, we developed cell-based assays for abobotulinumtoxinA in both powder (Dysport, Azzalure) and liquid (Alluzience) formulations using the in vitro BoCell system.

Elucidation of critical pH-dependent structural changes in Botulinum Neurotoxin E.

Botulinum Neurotoxins (BoNT) are the most potent toxins currently known. However, they also have therapeutic applications for an increasing number of motor related conditions due to their specificity, and low diffusion into the system. Although the start- and end- points for the BoNT mechanism of action are well-studied, a critical step remains poorly understood.

An efficient system for bioconjugation based on a widely applicable engineered O-glycosylation tag.

Bioconjugates are an important class of therapeutic molecules. To date, glycan-based metabolic glycoengineering has had limited use in this field, due to the complexities of the endogenous glycosylation pathway and the lack of an glycosylation consensus sequence. Here, we describe the development of a versatile on-demand glycosylation system that uses a novel, widely applicable 5 amino acid glycosylation tag, and a metabolically engineered UDP-galactose-4-eperimase (GALE) knock-out cell line.

Investigating the Structural Compaction of Biomolecules Upon Transition to the Gas-Phase Using ESI-TWIMS-MS.

Collision cross-section (CCS) measurements obtained from ion mobility spectrometry-mass spectrometry (IMS-MS) analyses often provide useful information concerning a protein's size and shape and can be complemented by modeling procedures. However, there have been some concerns about the extent to which certain proteins maintain a native-like conformation during the gas-phase analysis, especially proteins with dynamic or extended regions. Here we have measured the CCSs of a range of biomolecules including non-globular proteins and RNAs of different sequence, size, and stability.