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Izadi, S.

Publications and source records attributed to Izadi, S..

2 recordsLinked to original sources

Molecular Surface Descriptors to Predict Antibody Developability

Understanding the molecular surface properties of monoclonal antibodies (mAbs) is crucial for determining their function, affinity, and developability. Yet, robust methods to accurately represent the key structural and biophysical features of mAbs on their molecular surface are still limited. Here, we introduce MolDesk, a set of molecular surface descriptors specifically designed for predicting antibody developability characteristics. We assess the performance of these descriptors by directly benchmarking their correlations with an extensive array of in vitro and in vivo data, including viscosity at high concentration, aggregation, hydrophobic interaction chromatography (HIC), human pharmacokinetic (PK) clearance, Heparin retention time, and polyspecificity. Additionally, we investigate the sensitivity of these surface descriptors to methodological nuances, such as the choice of interior dielectric constant for electrostatic potential calculations, residue-level hydrophobicity scales, initial antibody structure models, and the impact of conformational sampling. Based on our benchmarking analysis, we propose six in silico developability rules that leverage these molecular surface descriptors and demonstrate their superior ability to predict the clinical progression of therapeutic antibodies compared to established models like TAP. 1

bioinformatics↗

Divining Deamidation and Isomerization in Therapeutic Proteins: Effect of Neighboring Residue

Deamidation of asparagine (ASN) and isomerization of aspartic acid (ASP) residues are among the most commonly observed spontaneous post-translational modifications (PTMs) in proteins. Understanding and predicting a protein sequences propensity for such PTMs can help expedite protein therapeutic discovery and development. In this study, we utilized proton-affinity calculations with semi-empirical quantum mechanics (QM) and {micro}s long equilibrium molecular dynamics (MD) simulations to investigate mechanistic roles of structure and chemical environment in dictating spontaneous degradation of asparagine and aspartic acid residues in 131 clinical-stage therapeutic antibodies. Backbone secondary structure, side-chain rotamer conformation and solvent accessibility were found as three key molecular indicators of ASP isomerization and ASN deamidation. Comparative analysis of backbone dihedral angles along with N-H proton affinity calculations provides a mechanistic explanation for the strong influence of the identity of the n+1 residue on the rate of ASP/ASN degradation. With these findings, we propose a minimalistic physics-based classification model that can be leveraged to predict deamidation and isomerization propensity of therapeutic proteins.

biochemistry↗