Predicted and observed fibrinogen chain masses in 21 healthy subjects
| Fibrinogen chain/phosphorylation state* . | Sialylation state† . | Common polymorphisms . | Predicted mass, Da‡ . | Observed mass, mean (SD) . |
|---|---|---|---|---|
| Aα | ||||
| 312A | 66 102 | 66 101 (4) | ||
| 312T | 66 132 | 66 134 (4) | ||
| 1 | 312A | 66 182 | 66 180 (5) | |
| 1 | 312T | 66 212 | 66 214 (4) | |
| 2 | 312A | 66 262 | 66 259 (4) | |
| 2 | 312T | 66 292 | 66 293 (4) | |
| Bβ | ||||
| 1 | 448K | 54 185 | 54 182 (2) | |
| 1 | 448R | 54 213 | 54 213 (3) | |
| 2 | 448K | 54 476 | 54 473 (2) | |
| 2 | 448R | 54 504 | 54 504 (3) | |
| γ | ||||
| 1 | 48 368 | 48 381 (3) | ||
| 2 | 48 659 | 48 672 (3) |
| Fibrinogen chain/phosphorylation state* . | Sialylation state† . | Common polymorphisms . | Predicted mass, Da‡ . | Observed mass, mean (SD) . |
|---|---|---|---|---|
| Aα | ||||
| 312A | 66 102 | 66 101 (4) | ||
| 312T | 66 132 | 66 134 (4) | ||
| 1 | 312A | 66 182 | 66 180 (5) | |
| 1 | 312T | 66 212 | 66 214 (4) | |
| 2 | 312A | 66 262 | 66 259 (4) | |
| 2 | 312T | 66 292 | 66 293 (4) | |
| Bβ | ||||
| 1 | 448K | 54 185 | 54 182 (2) | |
| 1 | 448R | 54 213 | 54 213 (3) | |
| 2 | 448K | 54 476 | 54 473 (2) | |
| 2 | 448R | 54 504 | 54 504 (3) | |
| γ | ||||
| 1 | 48 368 | 48 381 (3) | ||
| 2 | 48 659 | 48 672 (3) |
Denotes the number of phosphate groups (80 Da each) attached to the chain.
Denotes the number of sialic acid groups (291 Da each) attached to the chain.
Predicted masses of the fibrinogen chains16 were used to identify predominant LC-MS peaks that would be expected in a normal population. These include nonphosphorylation, monophosphorylation, and diphosphorylation of the Aα chain; monosialylation and disialylation of the Bβ and γ chains; and the common polymorphisms Aα T312A and Bβ R448K, which have allele frequencies of 24% and 15%, respectively, in healthy subjects.9