A Solid-Phase Compatible Dialkoxydiphenylsilane (DADPS) Reagent for Chemoproteomics (UCLA Case No. 2023-017)

UCLA researchers in the Department of Biological Chemistry have developed two novel fluorenylmethyl carbamate functionalized dialkoxydiphenylsilane (FMOC-DADPS) reagents that provide unprecedented compatibility with solid-phase chemistry, enabling higher yield and purity in the synthesis of DADPS-based chemoproteomics capture reagents.

BACKGROUND: Mass spectrometry-based chemoproteomics is a powerful technology for functional biology and drug discovery. Standard chemoproteomics workflows rely on cleavable capture reagents, typically incorporating a biotin or desthiobiotin handle connected to the labeled peptide via an enzymatic, chemical, or photochemical cleavable linker. Among all cleavable linkers, the dialkoxydiphenylsilane (DADPS) group has emerged as a preferred motif due to its stability and clean chemical cleavage. However, current synthetic approaches limit the efficient incorporation of DADPS moieties into chemoproteomics capture reagents, particularly when using solid-phase peptide synthesis. Thus, this represents an unmet need to enable the broader application of DADPS linkers in chemoproteomic reagent development.

INNOVATION: UCLA researchers have developed two novel fluorenylmethyl carbamate functionalized DADPS (FMOC-DADPS) reagents that are fully compatible with solid-phase chemistry. Application of these reagents enables the streamlined synthesis of a diverse panel of DADPS-containing chemoproteomics capture reagents with high yield and purity. Application of the FMOC-DADPS reagents in cysteine-targeted chemoproteomics enabled robust identification of numerous unique peptides across thousands of proteins. When isotopically labeled, these reagents enabled proteome-wide mapping of the cysteines modified by cysteine-reactive small molecules with performance comparable or superior to existing methods. The development of these FMOC-DADPS reagents represents a significant advance compared to prior approaches due to both the flexibility and ease of synthesis. The DADPS functionalized capture reagents also affords the high coverage and quantitative nature of the chemoproteomics data.

POTENTIAL APPLICATIONS:

• Rapid and high yielding solid-phase synthesis of FMOC-DADPS or DADPS based reagents
• Any technique that is utilizing DADPS reagents
• A working strategy for optimizing the current workflow of chemoproteomics studies with DADPS reagents

ADVANTAGES:

• Rapid and high yielding solid-phase synthesis of FMOC-DADPS
• The FMOC-DADPS that is in high purity and easy to synthesis guaranteed high performance in chemoproteomics studies
• Increased the coverage and enhanced the quantitative nature of the data of chemoproteomics studies

DEVELOPMENT-TO-DATE: Chemoproteomics studies conducted using the isotopically enriched DADPS reagents enabled the identification of >10,000 unique cysteine containing peptides on >3000 proteins, with >5000 unique ligandable cysteines being discovered. The discovery was summarized as academic paper and submitted for publication.

Related Papers (from the inventors only):

1. Solid-Phase Compatible Silane-Based Cleavable Linker Enables Custom Isobaric Quantitative Chemoproteomics. Nikolas R. Burton, Daniel A. Polasky, Flowreen Shikwana, Samuel Ofori, Tianyang Yan, Daniel J. Geiszler, Felipe da Veiga Leprevost, Alexey I. Nesvizhskii, and Keriann M. Backus. Journal of the American Chemical Society 2023 145 (39), 21303-21318. DOI: 10.1021/jacs.3c05797
2. Yan, T., Palmer, A. B., Geiszler, D. J., Polasky, D. A., Boatner, L. M., Burton, N. R., ... & Backus, K. M. (2022). Enhancing cysteine chemoproteomic coverage through systematic assessment of click chemistry product fragmentation. Analytical chemistry, 94(9), 3800-3810.

Keywords: mass spectrometry, chemoproteomics, drug discovery, capture reagent, dialkoxydiphenylsilane, cleavable linker, FMOC-DADPS