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Articles tagged: 15N

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Posted by John Cottrell (November 15, 2018)

The plus one dilemma

There are several common modifications that can add approximately 1 Da to a peptide mass. Even if you have high accuracy data, it can sometimes be difficult to figure out which one is correct.   Delta Lys->Glu substitution 0.947630 Leu->Asn or Ile->Asn substitution 0.958863 Deamidation at N or Asn->Asp substitution 0.984016 Deamidation at Q or Gln->Glu substitution 0.984016 Citrullination at [...]

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Posted by John Cottrell (October 14, 2013)

Modifications round-up, part 2

This is the second of two articles dealing with topics relating to modifications. The first can be found here. Note that Site analysis was covered in an earlier article. Why aren’t amino acid substitutions listed in the search form? Amino acid substitutions are rare and there are lots of them, so the only practical way to use them is in [...]

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