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Biology subjects

Byrne, M. J.

Publications and source records attributed to Byrne, M. J..

4 recordsLinked to original sources

Computational design of developable therapeutic antibodies: efficient traversal of binder landscapes and rescue of escape mutations

Developing therapeutic antibodies is a challenging endeavour, often requiring large-scale screening to produce initial binders, that still often require optimisation for developability. We present a computational pipeline for the discovery and design of therapeutic antibody candidates, which incorporates physics- and AI-based methods for the generation, assessment, and validation of developable candidate antibodies against diverse epitopes, via efficient few-shot experimental screens. We demonstrate that these orthogonal methods can lead to promising designs. We evaluated our approach by experimentally testing a small number of candidates against multiple SARS-CoV-2 variants in three different tasks: (i) traversing sequence landscapes of binders, we identify highly sequence dissimilar antibodies that retain binding to the Wuhan strain, (ii) rescuing binding from escape mutations, we show up to 54% of designs gain binding affinity to a new subvariant and (iii) improving developability characteristics of antibodies while retaining binding properties. These results together demonstrate an end-to-end antibody design pipeline with applicability across a wide range of antibody design tasks. We experimentally characterised binding against different antigen targets, developability profiles, and cryo-EM structures of designed antibodies. Our work demonstrates how combined AI and physics computational methods improve productivity and viability of antibody designs.

bioinformatics↗

Dynamic assembly of pentamer-based protein nanotubes

The molecular mechanisms and the geometrical theory underlying the polymorphic behavior of protein cages provide a basis for designing ones with the desired morphology and assembly properties. We show here that a circularly permuted cage-forming enzyme can controllably assemble into a variety of hollow spherical and cylindrical structures composed entirely of pentamers. A dramatic cage-to-tube transformation is facilitated by an untethered -helix domain that prevents the 3-fold symmetry interaction and imparts a torsion between the building blocks. The unique double- and triple-stranded helical arrangements of subunits are mathematically optimal tiling patterns for this type of pentamer. These structural insights afford guidelines for the design of customized protein nanotubes for smart delivery and nanoreactor systems.

bioengineering↗

The cryoEM structure of the Hendra henipavirus nucleoprotein reveals insights into paramyxoviral nucleocapsid architectures

We report the first cryoEM structure of the Hendra henipavirus nucleoprotein in complex with RNA, at 3.5 [A] resolution, derived from single particle analysis of homotetradecameric RNA-bound N protein rings exhibiting D14 symmetry. The structure of the HeV N protein adopts the common bi-lobed paramyxoviral N protein fold; the N-terminal and C-terminal globular domains are bisected by an RNA binding cleft containing six RNA nucleotides and are flanked by the N-terminal and C-terminal arms, respectively. In common with other paramyxoviral nucleocapsids, the lateral interface between adjacent N and N+1 protomers involves electrostatic and hydrophobic interactions mediated primarily through the N-terminal arm and globular domains with minor contribution from the C-terminal arm. However, the HeV N multimeric assembly uniquely identifies an additional interaction between N+1 and N-1 protomers. The model presented here broadens the understanding of RNA-bound paramyxoviral nucleocapsid architectures and provides a platform for further insight into the molecular biology of HeV, as well as the development of antiviral interventions.

microbiology↗

Structure of a Plant-Specific Partitivirus Capsid Reveals a Novel Coat Protein Architecture with a Hypervariable Protrusion

Persistent plant viruses may be the most common viruses in wild plants. A growing body of evidence for mutualism between such viruses and their hosts, suggests that they play an important role in ecology and agriculture. Here we present the structure of a plant-specific partitivirus capsid at 2.9 [A] resolution by Cryo-EM. Structural features, including the T=1 arrangement of 60 coat protein dimers, are shared with fungal partitiviruses and the picobirnavirus lineage of dsRNA viruses. However, the topology of the capsid is markedly different with protrusions emanating from, and partly comprising, the binding interface of coat protein dimers. We show that a disordered region at the apex of the protrusion is not required for capsid assembly and represents a hypervariable site characteristic of the plant-specific partitiviruses. These results suggest a structural basis for the acquisition of additional functions by partitivirus coat proteins that enables mutualistic relationships with diverse plant hosts.

microbiology↗