Table 1 In vitro assessment of trastuzumab degradation sites
Storage duration/temperature | RM/−80 °C | 1 d/37 °C/ PBS pH 7.4 | 7 d/37 °C/ PBS pH 7.4 | 12 d/37 °C/ PBS pH 7.4 | 1 d/37 °C/ serum in vitro | 7 d/37 °C/ serum in vitro | 12 d/37 °C/ serum in vitro |
|---|---|---|---|---|---|---|---|
LC–MS peptide mapping [%] | |||||||
LC-Asn-30 | |||||||
LC-deamid-30 | 8.0 (±0.1) | 12.4 (±0.2) | 32.2 (±0.2) | 45.4 (±0.5) | 13.5 (±0.2) | 43.4 (±0.7) | 66.2 (±0.6) |
HC-Asn-55 | |||||||
HC-deamid-55 | 2.0 (±0.2) | 2.3 (±0.1) | 4.5 (±0.1) | 6.3 (±0.1) | 2.4 (±0.1) | 5.9 (±0.2) | 10.3 (±0.3) |
HC-Asp-102 | |||||||
HC-isoAsp-102 | 6.5 (±0.2) | 8.2 (±0.3) | 13.6 (±0.5) | 18.3 (±0.5) | 7.3 (±0.2) | 13.7 (±0.9) | 17.7 (±0.2) |
HC-Asn-387,392,393 | |||||||
HC-deamid-387,392,393 | 1.0 (±0.1) | 1.7 (±0.1) | 5.1 (±0.2) | 7.3 (±0.2) | 1.8 (±0.1) | 7.5 (±0.1) | 13.6 (±0.5) |
CEC | |||||||
% Acidic | 23.6 (±0.2) | 27.1 (±0.5) | 62.8 (±0.1) | 78.1 (±0.3) | 36 (±0.2) | 80.2 (±0.5) | 96.3 (±0.1) |
% Main | 69.1 (±0.5) | 61.5 (±1.2) | 29.3 (±0.5) | 16.1 (±0.5) | 56.0 (±0.5) | 15.9 (±1.4) | 2.8 (±0.1) |
% Basic | 6.3 (±0.1) | 6.4 (±0.1) | 7.1 (±0.1) | 5.7 (±0.1) | 6.9 (±0.1) | 3.8 (±0.3) | 0.9 (±0.1) |
SEC | |||||||
% Fragments | 0.2 (±0.1) | 0.2 (±0.1) | 0.2 (±0.1) | 0.3 (±0.1) | 0.2 (±0.1) | 1.5 (±0.3) | 1.8 (±0.4) |
% Monomer | 99 (±0.1) | 98.9 (±0.2) | 98.7 (±0.2) | 97.5 (±0.9) | 99.1 (±0.2) | 96.1 (±0.4) | 95.8 (±0.4) |
% Aggregates | 0.9 (±0.1) | 0.9 (±0.1) | 1.1 (±0.2) | 2.2 (±0.9) | 0.7 (±0.1) | 2.4 (±0.2) | 2.3 (±0.2) |
SPR | |||||||
% Target binding | 100 (±1) | 98 (±1) | 90 (±1) | 84 (±1) | 97 (±1) | 83 (±1) | 72 (±1) |
