Chitin Purification (CBD-tag)

Proteins can be expressed with a chitin binding domain tag (CBD) or CBD-fusion proteins can be easily constructed using the IMPACT Purification System (NEB #E6901). Fusion of a target protein to CBD permits one-step purification using Chitin resin (NEB #S6651) or Chitin Magnetic Beads (NEB #E8036). The CBD-fusion protein will bind to the chitin resin or beads while other proteins flow through. Removal of the CBD-tag during elution typically yields highly pure, native protein without the use of a protease. Chitin resin, when used with the pTXB1 Vector (NEB #N6707), allows for the isolation of native recombinant proteins possessing a reactive C-terminal thioester that can be used for applications in intein-mediated protein ligation (IPL) and site-specific labeling. Chitin Magnetic Beads enable quick and high throughput, small scale purification of CBD-fusion proteins. Once CBD-fusion proteins are immobilized to the beads they can be used in subsequent experiments to capture (pull down) target proteins from crude cell lysates.