Errors of this magnitude can play havoc with any attempt to compare assignments between proteins or to structurally interpret chemical shifts.
Identifying which proteins are mis-assigned or improperly referenced can be challenging, as can correcting the errors once they are found.
The SHIFTCOR program was designed to assist with identifying and fixing these chemical shift referencing problems.
[2] The SHIFTCOR program was originally used to construct a database of properly re-referenced protein chemical shift assignments called RefDB.
[1] RefDB is a web-accessible database of more than 2000 correctly referenced protein chemical shift assignments.