Dear all, I have a peptide crystal structure at 0.97 Å that contains two surface exposed Methionine. The CE atoms of both MET have a suspiciously high b-factor >40 and a positive density. In addition, the sulfur atom SD has a large negative density (b-factor ~23).
I initially suspected that the MET may have oxidized to MET-sulfoxide and tried to model only the MET-sulfoxide. This again resulted in negative density. I think that the peptides might be partly oxidized which brings me to my question. Is there a way to model both MET and MET-sulfoxide into the density much like alternate conformation with options to refine their respective occupancies. best wishes, Abhishek ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
