Design of Analytical Methods for Protein Adsorption Characteristics at Material Interfaces

Nonspecific adsorption of proteins onto solid surfaces is a fundamental phenomenon in interface science, influencing the physicochemical properties and functional performance of materials in bioanalytical applications. In this study, we developed a common characterization technique for nonspecific reaction factors to provide a foundation for the rational control of specific protein interactions and the development of novel blocking agents, enabling tailored surface engineering strategies. Proteins adsorbed onto insoluble carriers, using magnetic particles as the model system, were explored from approximately 24,000 human proteins and subsequently characterized in silico. Statistical analysis revealed common features of highly adsorptive proteins, including distinct clustering of specific amino acid residues, such as arginine (Arg) and alanine. Adsorption was governed by structural flexibility and charge distribution, particularly in denatured regions. These findings support the hypothesis that protein charge blockiness, resulting from Arg residues in highly mobile denatured regions, affects adsorption. Comprehensive analyses, combining protein array-based interaction profiling and in silico characterization, provided new insights into the molecular mechanisms underlying protein-surface interactions. This methodology facilitates the rational design of advanced blocking agents and surface modifications to control protein adsorption and is applicable to a wide range of materials beyond magnetic particles. Overall, this work advances the understanding of nonspecific adsorption at biomaterial interfaces and contributes to the development of tailored surface engineering strategies in interface science.