Evaluation of glycation reaction of ovalbumin with dextran: Glycation sites identification by capillary liquid chromatography coupled with tandem mass spectrometry

Molecular mechanisms for stabilizing biologics in the solid state

Protein drugs exhibit challenges of biophysical and biochemical instability due to their structural complexity and rich dynamics. Solid-state biologics aim to enhance stability by increasing molecular rigidity within the formulation matrix, representing a primary category of drug products alongside sterile liquid formulations. Understanding the molecular mechanisms behind the stabilization and destabilization of protein drugs, influenced by formulation composition and drying processes, provides scientific rationale for drug product design. This review aims to elaborate on the two primary models of water-to-sugar substitution and matrix vitrification, respectively, via thermodynamic and kinetic stabilization. It offers an up-to-date review of experimental investigations into these hypotheses, specifically elucidating protein structure and protein-excipient interactions at the molecular level, molecular dynamics across a broad range of motion regimes, and microscopic attributes such as protein-sugar and protein-salt miscibility and microenvironmental acidity, in relevant liquid, frozen, and solid states, using advanced biophysical techniques for solid-state analysis. Moreover, we discuss how these mechanistic understandings facilitate the investigation and prediction of critical stability behaviors and enables the design of solid biological drug products.

Cyclic Continuous Glycation Enhanced Dispersibility of Myofibrillar Protein: Reaction Efficiency and Sites Modification

Reaction efficiency in glycation lacks sufficient attention, leading to the waste of process costs. Cyclic continuous glycation (CCG) is an effective approach to accelerate covalent binding between myofibrillar protein (MP) and glucose. This study elucidated that CCG promoted the exposure of reactive glycated sites in MP with full unfolding of secondary and tertiary structures. Notably, the glycation rate was significantly increased by 65.43%. Physicochemical properties indicated that MP-glucose conjugates with high graft degree exhibited favorable solubility, dispersibility, and thermal stability. Furthermore, proteomics was applied to reveal the glycated sites and products in glycoconjugates of MP. Glycation preferentially acted on the tails of the myosin heavy chain. The glucosylation modification on the head region was enhanced by CCG contributing to the inhibition of the head-head interaction. Overall, this study systematically clarifies the mechanism of CCG, providing a theoretical basis for the application of glycation in innovative meat products.

A microfluidic approach for rapid and continuous synthesis of glycoprotein-imprinted nanospheres

Many strategies have been reported for the preparation of glycoproteins imprinted polymers, but they take a long time and cannot produce imprinted polymers continuously. Herein, a microfluidic synthesis approach was developed to make glycoproteins imprinted nanospheres rapidly and continuously. By using ovalbumin as a model template and a synthesized phenylboronic acid-tagged silane reagent as the functional monomer, the synthetic conditions including the polymerization contents, the flow rate and the microfluidic reactor size were comprehensively studied. Under the optimized conditions, the glycoprotein imprinted nanospheres could be synthesized rapidly (<2 h), and exhibited high specificity with cross-reactivity factors of 1.3 (ovotransferrin), +∞ (horse-radish peroxidase), 5.1 (β-lactoglobulin) and 101 (bovine serum albumin). The kinetic and equilibrium binding behaviors, reusability and potential applications of the glycoprotein imprinted nanosphere were investigated. Such microfluidic synthesis strategy can be easily extended to produce other target glycoproteins imprinted nanospheres, as well as non-glycoproteins by using suitable functional monomers.