Hi Andrey, Are you sure it's not PLP? To me that looks like you have confounding aggregation, and PLP in two forms, perhaps only partly incorporated when considering your protein absorbance. Check out the spectra in the paper:
Turning pyridoxal-5'-phosphate-dependent enzymes into thermostable binding proteins: D-Serine dehydratase from baker's yeast as a case study. Biochimie. <http://www.ncbi.nlm.nih.gov/pubmed?term=21896305#> 2012 Feb;94(2):479-86. Cheers, Shane On Fri, Nov 30, 2012 at 11:06 AM, Grishin, Andrey <andrey.gris...@usask.ca>wrote: > ** > Dear CCP4bb users, > > this problem was already discussed many times here and I've read these > discussions before writing. I have a pale yellow protein. The spectrum > contains peaks at 320 and 420. Before we proceed to ICP-OES and > wavelength scans at the synchrotron, may be some of you had a similar > spectrum before? Does not look like FAD, NADH and pyridoxal phosphate. > > Thank you > Andrey Grishin > Postdoctoral Fellow > University of Saskatchewan >