Discerna Technologies
•  Protein Arrays

One of the major technical challenges in proteomics is maintaining the fold and functionality of proteins once immobilised on array surfaces. Discerna is addressing this challenge directly by using two novel, cell-independent protein expression systems. Synthesis of protein directly from DNA eliminates time-consuming and laborious protein expression and purification, creates protein arrays ‘on demand' and addresses the problem of fluctuating protein stability over time.

The Protein Array systems created and patented by Discerna are
•  PISA (Protein In Situ Arrays)
•  DAPA (DNA Array to Protein Array): the generation on demand of pure protein arrays in a single reaction.

PISA

PISA employs a coupled transcription / translation approach that differentiates Discerna's cell free protein expression technologies. Proteins are synthesised directly from their encoding DNA, whereby they become immediately attached to the array surface through an engineered tag sequence. Discerna has designed a double hexa-histidine sequence tag with high intrinsic affinity for divalent cations such as nickel. Protein synthesis on a Ni-NTA slide allows each protein to immediately become attached to the surface upon translation; hence ‘protein in situ array.' PISA may be conducted in a multiparallel fashion and is essentially applicable to any protein, including those that are difficult to express by conventional methods. PISA has been used to synthesise and display arrays of 384 different proteins, demonstrating the feasibility of this method even at proteome scale.

DAPA

DAPA has been developed to produce protein arrays directly from immobilised DNA arrays, thereby generating multiple copies of a protein array from an individual DNA template. DAPA differs from PISA , where DNA is spotted with the cell free system onto the Ni-NTA slide for single use.

A prototype of the instrumentation supporting DAPA has been developed at Discerna.

Multiparallel protein synthesis and solid phase capture generates multiple arrays of proteins from repeat use of the same DNA array template. Discerna has successfully created DAPA arrays for a diverse range of proteins and is now developing proteome-scale arrays for the study of protein-protein interactions.