Hi All I had a soaked crystal with NADP; and the crystal diffracted to 2.5A. I was looking for NADP at its binding site, I came up with wierd density which I could not fit with any end of NADP. The density is upto 3.5 A in Fo-Fc map; and is spherical long enough to put nicotine. But the density is not flat.
I found some density at the surface (which is not the typical binding site for NADP), where I can fit the two phophate groups as well as two sugar rings next to each phophate. But I do not see any density either Nicotine part or the nucleotide part. The crystal grown in pH 8.0. I guess NADP may undergo hydrolysis at pH 8.0 resulting in ADP and nicotine; I failed to fit these products as well. Has anyone experienced like this? and your suggestions are welcome Thank you Sajid
