Biology subjects

Burley, G. A.

Publications and source records attributed to Burley, G. A..

3 recordsLinked to original sources

bioRxiv2024

A first insight into the developability of an IgG3: A combined computational and experimental approach

Immunoglobulin G 3 (IgG3) monoclonal antibodies (mAbs) are high value scaffolds for developing novel therapies. Despite their wide-ranging therapeutic potential, IgG3 physicochemical properties and developability characteristics remain largely under-characterised. Protein-protein interactions elevate solution viscosity in high-concentration formulations impacting physico-chemical stability, manufacturability, and injectability of mAbs. Therefore, in this manuscript, the key molecular descriptors and biophysical properties of a model anti-IL-8 IgG1 and its IgG3 ortholog are characterised. A computational and experimental framework was applied to measure molecular descriptors impacting on their downstream developability. Findings from this approach underpin a detailed understanding of the molecular characteristics of IgG3 mAbs as potential therapeutic entities. This work is the first report examining the manufacturability of IgG3 for high concentration mAb formulations. While poorer conformational and colloidal stability, and elevated solution viscosity was observed for IgG3, future efforts controlling surface potential through sequence-engineering of solvent-accessible patches can be used to improve biophysical parameters that dictate mAb developability.

bioengineering↗

bioRxiv2024

Enhancing viscosity control in antibody formulations: A framework for the biophysical screening of mutations targeting solvent-accessible hydrophobic and electrostatic patches

The formulation of high-concentration monoclonal antibody (mAb) solutions in low dose volumes for autoinjector devices poses challenges in manufacturability and patient administration due to elevated solution viscosity. In the current study, we present a systematic experimental framework for the computational screening of molecular descriptors to guide the design of mutants with modified viscosity profiles accompanied by experimental evaluation. Our observations using a model anti-IL8 antibody reveal that the reduction in viscosity is influenced by the location of hydrophobic interactions, while targeting positively charged patches in mAb1 leads to the most significant viscosity increase compared to the wild-type mAb. We conclude that existing in silico predictions of physicochemical properties exhibit poor correlation with experimental parameters for antibodies with suboptimal developability characteristics, emphasizing the necessity for comprehensive case-by-case evaluations of mAbs. This approach aids in the rational design of mAbs with tailored solution viscosities, ensuring improved manufacturability and patient convenience in self-administration scenarios.

bioengineering↗

bioRxiv2022

Biosynthesis of aurodox, a Type III secretion system inhibitor from Streptomyces goldiniensis

The global increase in antimicrobial-resistant infections means that there is a need to develop new antimicrobial molecules and strategies to combat the issue. Aurodox is a linear polyketide natural product that is produced by Streptomyces goldiniensis, yet little is known about aurodox biosynthesis or the nature of the biosynthetic gene cluster (BGC) that encodes its production. To gain a deeper understanding of aurodox biosynthesis by S. goldiniensis, the whole genome of the organism was sequenced, revealing the presence of an 87 kb hybrid Polyketide Synthase/Non-Ribosomal Peptide Synthetase (PKS/NRPS) BGC. The aurodox BGC shares significant homology with the kirromycin BGC from S. collinus T{upsilon} 365; however, the genetic organisation of the BGC differs significantly. The candidate aurodox gene cluster was cloned and expressed in a heterologous host to demonstrate that it was responsible for aurodox biosynthesis and disruption of the primary PKS gene (aurAI) abolished aurodox production. These data support a model whereby the initial core biosynthetic reactions involved in aurodox biosynthesis follow that of kirromycin. Cloning aurM* from S. goldiniensis and expressing this in the kirromycin producer S. collinus T{upsilon} 365 enabled methylation of the pyridone group, suggesting this is the last step in biosynthesis. This methylation step is also sufficient to confer the unique Type III Secretion System inhibitory properties to aurodox. ImportanceEnterohaemorrhagic Escherichia coli (EHEC) is a significant global pathogen for which traditional antibiotic treatment is not recommended. Aurodox inhibits the ability of EHEC to establish infection in the host gut through the specific targeting of the Type III Secretion System, whilst circumventing the induction of toxin production associated with traditional antibiotics. These properties suggest aurodox could be a promising anti-virulence compound for EHEC, which merits further investigation. Here, we have characterised the aurodox biosynthetic gene cluster from Streptomyces goldiniensis and have established the key enzymatic steps of aurodox biosynthesis that give rise to the unique anti-virulence activity. These data provide the basis for future chemical and genetic approaches to produce aurodox derivatives with increased efficacy and the potential to engineer novel elfamycins.

microbiology↗