The following amino acids are coded in Benchling as having molecular weights as listed below:

  A: 89.09
  B: 132.65
  C: 121.15
  D: 133.1
  E: 147.13
  F: 165.19
  G: 75.07
  H: 155.16
  I: 131.17
  J: 131.2
  K: 146.19
  L: 131.17
  M: 149.21
  N: 132.12
  O: 255.31
  P: 115.13
  Q: 146.15
  R: 174.2
  S: 105.09
  T: 119.12
  U: 168.06
  V: 117.15
  W: 204.23
  X: 143.7
  Y: 181.19
  Z: 146.75

Notes:

We have lightly modified constants from biopython, to match results from expasy.
These are the average isotopic masses (as opposed to the monoisotopic mass, see http://www.ionsource.com/tutorial/isotopes/slide8.htm).

Molecular weights for B, Z are non-standard and were reverse engineered from
http://web.expasy.org/protparam/. Molecular weights for J and X were taken from Geneious.

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