Discovery of Self-Labeling Miniproteins

Technology

This technology uses self-labeling mini-proteins to attach functional labels or small molecules to a protein-of-interest. Self-labeling proteins work by first making a fusion protein that combines the protein-of-interest with the self-labeling protein. The self-labeling portion of the fusion protein is then reacted with a substrate that contains a label such as a fluorophore, pull-down-tag, or small molecule. The self-labeling nature of the fusion protein means that molecular biology investigators can easily interchange the label to perform many different kinds of assays. Previous self-labeling protein technologies, such as CLIP or Halo tags, are bulky (>100 amino acids) and therefore frequently disrupt the functionality of the target protein. In contrast, the self-labeling mini-proteins of this invention are small (<30 amino acids), which minimizes their impact on the structure and function of the target protein. Additionally, the mini-protein reaction with the substrate is highly specific, so only proteins containing the tag are labeled.

Problem Addressed

Protein labels, such as fluorophores, dyes, pull-down tags, or small molecules are frequently used to research protein characteristics. However, current labeling strategies have significant limitations including lack of label interchangeability, difficulty specifically targeting the protein of interest, or relying on bulky protein tags that can disrupt the structure, function, and localization of the labeled protein.

Advantages

• Highly-specific self-labeling mini-protein sequences
• Interchangeable labeling through substrate choice
• Less than half the size of existing self-labeling protein tags, which minimizes disruption of the protein of interest

Publications

Evans, Ethan D., and Bradley L. Pentelute. "Discovery of a 29-Amino-Acid Reactive Abiotic Peptide for Selective Cysteine Arylation." ACS Chemical Biology, 13 (2018): 527-532. doi: 10.1021/acschembio.7b00520.