I took the PE/ABD 494 HT course recently and they still add DTT to R4 and
R5 and say that if enough met(o) is present, that it will elute near asn.
They also say that met sulphone elutes near tyr with their latest solvent
system (A3 and B2) on the HT 494.
Dick
>Hello from atypically snowy St. Louis. Met sulfone runs between DMPTU and
>His,
>on PEABI seperations, as indicated in the Mod PTH-AA in Prot Seq booklet
>published by the ABRF in 1993 (If anyone would like a copy please let me
>know).
>Met sulfoxide is reduced back to Met as a result of DTT in the solvents from
>PEABI. You may want to verify that with their tech support as it has been
>five years since I checked with them Re that issue. Have you/they
>considered mass
>spec as an alternative? Finally, I would like to reiterate Greg Grant's
>previous posting Re a second edition of the Mod PTH-AA booklet. We are in
>the process of collecting new information for that endeavor and would
>welcome any
>submission of information on unusual/modified PTH amino acids. We especially
>encourage non PEABI users. Mark.