Investigation of new peptide design, peptide stability and 2D LC-MS/MS for data storage and retrieval with peptides

Abstract

With the amount of data generated growing exponentially, there is an urgent need to develop new storage technology. Peptides have shown great potential as a storage material in the previous study. This study was conducted to improve data storage with peptide sequence and to prove the kinetic stability of peptides for data storage. Two mass spectrometry technologies were used for the quantitative analysis of peptides and de novo peptide sequencing. We have improved the encoding scheme and peptide design based on the previous study to achieve higher capacity, and the successful retrieval of a 1088-bit text file suggested the feasibility of the new encoding scheme. With a new dataset, a 96,224 bits long PNG file, 4095 peptides sequences have been generated using the new encoding scheme. The 4095 peptides will be synthesized and tested in the next step. Additionally, the stability of peptides has been demonstrated in this study. A triple quadrupole mass spectrometer (QqQ-MS) was used for quantitative analysis, and 11 peptides were chosen for the study. Accelerated aging experiments were performed to measure peptide decay kinetics. Our study showed that the half-life of these peptides was within a range of 10 - 100 years at -20℃ without any extra protective measure, and by freeze-drying with trehalose, the half-life at -20℃ could be improved to more than 200 years, which suggested the potential of peptide as the data storage medium. Two-dimensional liquid chromatography (2D-LC) was applied for de novo peptide sequencing to retrieve data. 2D-LC has been reported as a powerful tool applied for protein identification with peptide fingerprinting. In this study, we applied 2D-LC in the peptide-based data storage system to retrieve the information stored in 40 peptides, and the result was compared with that of ultra-performance liquid chromatography (UPLC) and nano-liquid chromatography (nano-LC). Theoretically, separation capacity could be higher with 2D-LC. However, the lower signal-to-noise ratio due to successive dilutions and salt residue caused lower recovery. This study demonstrated the feasibility of peptides used for data storage and clarified the essential need for further research. The findings regarding peptide stability and 2D-LC are expected to have an active role in the development of relevant fields.