Principle of Label Transfer in Protein Interaction Analysis

The core of the label transfer method involves transferring a label from one protein (typically referred to as the "bait") to another interacting protein (referred to as the "prey"). This method leverages the photosensitive properties of crosslinkers, which form covalent bonds between two interacting proteins when exposed to light at a specific wavelength.

 

1. Labeling Reaction

First, the bait protein reacts with a label transfer reagent (such as a radioactive, fluorescent, or biotin-labeled compound) to form a stable labeled complex. The key to this step is selecting an appropriate label reagent to ensure effective binding and stability on the bait protein.

 

2. Protein Interaction

The labeled bait protein is then incubated with the prey protein in vitro, forming a protein complex. At this stage, stable or transient interactions may occur between the bait and prey proteins.

 

3. Crosslinking Reaction

Upon exposure to ultraviolet light, the photosensitive portion of the crosslinker is activated, forming a covalent bond with the prey protein. This process links the bait and prey proteins together, transferring the label to the prey protein.

 

4. Label Transfer and Detection

Finally, the crosslinker’s spacer arm is cleaved, releasing the bait protein from the complex, completing the label transfer. The prey protein, now carrying the label that was originally on the bait protein, can be identified and quantified using appropriate detection methods (such as Western blot, radioactivity analysis, or fluorescence detection).

 

Applications of Label Transfer Method

The label transfer method is widely used in exploring protein interactions, with particular advantages in studying weak and transient interactions. It can discover new protein interactions, validate proteins identified by other methods, and analyze complex protein assemblies. Additionally, the label transfer method is extensively applied in the study of nucleic acid-protein interactions.

 

By understanding the principles and mechanisms, researchers can apply this technique more effectively to uncover the complexities of protein interactions. MtoZ Biolabs provides integrate label transfer protein interaction analysis service.