Introduction

The development of biomolecular systems for computational tasks is a promising area in bioengineering and biosensor techniques. Using modified protein molecules as functional components of such systems enables the creation of next-generation devices based on the principles of biocomputing. In this study, we explored approaches to synthesizing dual-modified proteins with controlled surface characteristics and their potential application in implementing logical operations.

Materials and Methods

Dual-modified proteins were synthesized through the controlled sequential conjugation of test proteins, bovine serum albumin, and gelatin with low-molecular-weight compounds such as chloramphenicol and biotin, using carbodiimide chemistry. Low-molecular-weight substances were dissolved in a mixed buffer system with dimethyl sulfoxide, and their carboxyl groups were activated by a carbodiimide reagent. The activated compounds were then added to a protein solution in borate buffer, maintaining a precise molar ratio of 1:37:12 to ensure proper structural organization. This step allowed for an equilibrium distribution of surface charges, optimizing molecular interactions. The entire process was meticulously monitored using a label-free optical biosensor system based on spectral-phase interferometry (SPI). The final conjugates were diluted in a phosphate buffer and stored at 4 °C.

Results and Discussion

This study investigated the potential of using the obtained modified protein molecules to perform computational tasks, exemplified by the logical operations “YES” and “NOT.” By adding low-molecular-weight substances to the protein solution in a specific sequence during conjugation, the surface characteristics of the resulting product could be tailored. The steric properties of the surface determine the interaction pattern of the conjugate with other molecules in the solution, enabling it to reproduce specific reactions in a defined environment. These reactions, representing the output signals of a logical operator (logical “0” or “1”), were recorded using the SPI method and digitized.

Conclusions

This study demonstrates the potential of dual-modified proteins for use in biocomputing systems. Future work will focus on expanding the range of logical operations and optimizing the synthesis of dual-modified proteins to enhance their reproducibility and performance in biocomputing systems.