Table 1.
Measured molecular mass values for NISTmAb RM 8671 and non-originator lots NS0-59, NS0-60, and NS0-66.
| Observed Mass (Da) |
|||||
|---|---|---|---|---|---|
| Proteoform | Theoretical Mass (Da)a | RM 8671 | NS0-59 | NS0-60 | NS0-66 |
| G0F/G0F – GlcNAc | 147833.9 | 147838.0 | 147841.0 | ND | 147841.8 |
| G0F/G1F – GlcNAc | 147996.1 | 148000.4 | ND | ND | ND |
| G0F/G0F | 148037.2 | 148044.1 | 148043.9 | 148044.9b | 148042.9 |
| G0F/G0F + S1 | 148124.2 | ND | 148128.2 | 148124.5 | 148127.7 |
| G0F/G0F + K* | 148165.3 | 148164.0 | 148166.0 | 148173.1b | 148170.3 |
| G0F/G1F | 148199.3 | 148205.4 | 148207.7b | 148205.7 | 148205.0 |
| G0F/G1F + S2 | 148286.4 | ND | 148298.0b | 148298.8b | 148299.8b |
| G0F/G1F + K* | 148327.5 | 148324.2 | 148329.9 | 148329.6 | 148330.4 |
| G1F/G1F | 148361.4 | 148368.3 | 148370.0b | 148367.6 | 148367.5 |
| G1F/G1F + S3 | 148448.5 | ND | 148461.1b | 148456.8b | 148460.3b |
| G1F/G1F + K* | 148489.6 | 148485.6 | 148491.6 | 148492.2 | 148488.3 |
| G1F/G2F | 148523.6 | 148528.9 | 148528.5 | 148527.8 | 148521.3 |
| G1F/G2F + S4 | 148610.7 | ND | 148626.9b | 148620.9b | 148622.0b |
| G1F/G2F + K* | 148651.8 | 148657.1 | ND | 148652.0 | 148651.2 |
| G2F/G2F | 148685.7 | 148689.3 | 148688.6 | 148688.9 | ND |
| G2F/G2F + S5 | 148772.8 | ND | 148788.0b | 148784.9b | 148788.0 |
| G2F/G2F + Hex | 148847.7 | 148847.4 | ND | 148848.2 | ND |
a. Theoretical values include 16 disulfide bonds, two N-terminal pyroglutamic acids, and no C-terminal Lys (K), unless otherwise noted. Theoretical values were calculated using the NIST Mass and Fragment calculator. Peaks labeled with a * indicate presence of a C-terminal lysine on the previous glycoform. Peaks labeled with a number of S1–5 indicate the presence of a partially uncleaved serine of the leader peptide. Glycan assignments were made based on putative compositions expected from the glycan biosynthetic pathway.
b. Peak assignments for these indicated peaks were made despite mass errors in excess of 50 ppm. See supplementary Table S2 for calculated mass errors. ND, not detected.