Table 1.
Post-translational modifications of human serum albumin detected after exposure of HSA to breast cancer cells
| PTM* | Peptide | Position (peptide) | Position (site) | MCF7 | MDA-MB-231 | MDA-MB-468 | Water | Medium |
|---|---|---|---|---|---|---|---|---|
| 6FMNC | CCTESLVNR | 500-508 | C501 | Yes | Yes | Yes | ||
| DEAME | CASLQK | 224-229 | Q228 | Yes | Yes | Yes | ||
| METH | YICENQDSISSK | 287-298 | C289 | Yes | Yes | Yes | ||
| DEAME | ADLAKYICENQDSISSK | 282-298 | Q292 | Yes | Yes | |||
| ACET | HPYFYAPELLFFAKR | 169-183 | K182 | Yes | ||||
| MYRI | LVRPEVDVMCTAFHDNEETFLKK | 139-161 | K160 | Yes | ||||
| PHOS | AEFAEVSK | 250-257 | S256 | Yes | Yes | |||
| PHOS | YICENQDSISSKLK | 287-300 | S294, S296, S297 | Yes | ||||
| PHOS | AAFTECCQAADK | 187-198 | T190 | Yes | ||||
| PALM | AVMDDFAAFVEKCCK | 570-584 | C582, C583 | Yes | Yes | |||
| ACET | EQLKAVMDDFAAFVEK | 566-581 | K569 | Yes | Yes | |||
| CYSP | CCKHPEAK | 461-468 | C462 | Yes | Yes | |||
| METH | ADLAKYICENQDSISSK | 282-298 | K286 | Yes | Yes | |||
| MYRI | AAFTECCQAADK | 187-198 | C192, C193 | Yes | Yes |
MCF7 are conditionally tumorigenic, and less aggressive as compared to invasive and highly tumorigenic MDA-MB-231 and MDA-MB-468 cells. PTMs in HSA that was solubilized in water or medium are shown to indicate the presence of these PTMs in HSA from healthy individuals (Water), and no impact on these PTMs of the chemicals in the cell culture medium (Medium). In bold and underlined are indicated modified amino acids. “Yes” indicates detection of a peptide, “-”indicates absence of a peptide. A peptide position in HSA sequence is indicated.
* 6FMNC, S-6-FMN cysteine modification; DEAME, deamidation followed by methylation; METH, methylation; ACET, acetylation; MYRI, myristoylation; PHOS, phosphorylation; PALM, palmytoylation; CYSP, cysteine persulfide modification.