In article <3upe58$ko4 at ixnews7.ix.netcom.com>
mesalvu at ix.netcom.com (Michael Salvucci) writes:
> Does anyone know of a method (or computer program) for accurately
> determining the concentration of a protein from the A280 and the
> sequence (i.e., the number of tyr & trp residues).
Take a look at the 1989 paper by Gill and von Hippel (Anal. Biochem.,
182, 319-326) which uses the number of tyr, trp, and cys to calculate
the extinction coefficient at 280. They get within 5% for most
proteins.
Good luck,
David Gottfried