Some time ago
we asked about protein descriptor services on the web - the long and short of it is that, there really wasn't anything that fit our needs, so we wrote one. Given a sequence it returns a long vector of descriptors, things like hydrophobicity, fraction of each amino acid, pI, and a whole bunch of other stuff. If there is interest, we could open this up as a web service - so return a JSON or XML object in real time (and for UniProt sequences have these precalculated). There will be some licensing issues for some of the descriptors, but I'm sure we can sort something out.
