The isoelectric point or pI of a protein corresponds to the solution pH at which the net surface charge is zero. In the denatured state, the pI depends solely on a protein’s amino acid composition.

Since the earliest days of solution biochemistry, the pI has been recorded and reported. Literature reports of pI abound.

The protein isoelectric point database (PIP-DB) has collected and collated this legacy data to provide an increasingly comprehensive database for comparison and benchmarking purposes.

For questions and comments, contact Dr Darren Flower.