There are a couple of things that sometimes affect this:
1. CO atom types. If you have CO atoms picked, analysis is often quite
fussy about having them already typed as CO rather than just given a
resonance. I've been meaning to write a macro to type the 13C dim of
all HNCO & HNCACO peaks to C, but Tim can probably give us chapter and
verse in about three lines of code.
2. aliasing. For Gly, Ser & maybe Thr where your N is aliased, since
analysis uses the BMRB database values to calculate the likelihood of
being a particular residue type, an aliased N shift will result in a
poor match. Good practice is to always record 15N HSQCs at a couple of
different 15N sweepwidths so you can easily identify the aliased peaks.
--
Dr. Brian O. Smith ---------------------- B Smith at bio gla ac uk
Division of Molecular & Cellular Biology,
Faculty of Biomedical & Life Sciences,
Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK.
Tel: 0141 330 5167/6459/3089 Fax: 0141 330 4600
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