Dear abrf
I am currently manually synthesising a 62AA peptide which
has 4 methionines and I am 50 cycles into this beast. I have checked by
cleaving a small resin sample to see how it is going at 10 cycle intervals.
I have seen a gradual increase in Met[O] until it is now the major product
( plus diMet{o})in the crude mass spec at 50 cycles. My question is does
anyone have a bulletproof method that will convert the Met[O] back to Met. I
have found in the past that if the oxidation occurs readily in a peptide,
then DTT at 37C will convert the Met[O] back to Met but other times it is
quite intractable . The peptide has also got Cys and Trp which make it
sensitive to some of the methods I have seen in the literature. Please does
anyone have any suggestions.
Denis Scanlon
AUSPEP PTY.LTD.
P.O.Box 806 Parkville
Vic. 3052 AUSTRALIA
Phn: + 613 9328 1211
Fax: +613 9326 8810
This archive was generated by hypermail 2b29 : Thu May 18 2000 - 09:47:35 EDT