Turboid Proximity Labeling

TurboID couples biotin activation to ATP-dependent chemistry that produces reactive biotin intermediates. These short-lived intermediates label proteins in the surrounding molecular neighborhood, creating covalent biotin attachments rather than relying on a stable protein complex during isolation. Because labeling depends on proximity, the resulting protein set reflects the local environment around the engineered ligase.

Covalent attachment gives each labeled protein a durable biotin tag that can be recognized by streptavidin. This separation between the labeling event and later identification allows the local protein neighborhood to be captured as a molecular record, after which mass spectrometry determines which proteins carry the tag. The tag therefore connects proximity with analyte recovery.

Rapid labeling enables researchers to examine protein neighborhoods over relatively short experimental windows. Instead of viewing only a prolonged or fixed state, investigators can compare local protein environments during different stages of infection or immune activation. This time-resolved capability is especially useful when signaling complexes or host-pathogen interfaces change as cellular conditions evolve.

A typical workflow positions the engineered ligase at a protein, organelle, or cellular compartment of interest, then supplies biotin and ATP so nearby proteins receive covalent tags. Researchers isolate the labeled material through streptavidin-based capture and identify the recovered proteins by mass spectrometry. The final protein list represents the molecular neighborhood associated with the ligase location.

The method is suited to living-cell experiments in which researchers need information from complex cellular environments. It can examine protein neighborhoods around defined proteins, organelles, or compartments without restricting the question to a purified molecular system. This makes it useful for mapping local molecular organization under biologically relevant conditions, including infection and immune activation.

In these fields, TurboID can map host-pathogen interfaces and identify proteins near infection-associated molecular regions. It can also characterize immune signaling complexes and compare how their surrounding protein neighborhoods change during immune activation. By combining proximity labeling with mass spectrometry, researchers obtain protein-level information about dynamic cellular responses in the relevant biological context.