To: Professor Pauling
From: Walt Schroeder
Subject: Number of Isoleucine Residues Per Molecule of Hemoglobin
In the paper which described the analysis of hemoglobins, we stated that the minimum
molecular weight of both proteins must be about 67,000 because there is only one isoleucine
residue per molecule of thus weight but we did not comment further on this point.
Recently, I have wondered whether we should not have called more attention to this
fact because it does not show that in human Hb any dissociation by urea or in very
dilute solution must result in dissimilar fragments. Dr. Corey and I think that a
short to the JACS which stresses this result might be worthwhile.
However, in looking up literature for this note I have been unable to find any statement
which suggests that hemoglobin might disassociate into identical fragments of half
or quarter molecular weight or that the molecule might contain four identical peptide
chains & coincide with the four hemes although both Dr. Corey and I fell that we have
heard or read such statements.
Do you think that such a note would be advisable and are you aware of any published
statements such as I have described?