Hello, I had recently collected and solved the phases for a protein molecule using CCP4 and the ShelXCDE SAD method in it. What I was wondering was that the peaks for the three SE incorporated methionines are there as expected, but there is one peak scored roughly as the second largest where the disulfide is based on ShelXD's HA search algorithm. This data was collected at 0.97960 Angstroms which is close to the peak Xray absorption edge for Se but does anyone know if a disulfide has any absorption edge overlapping here?
