Introduction

Experimental

Sample

• Kadcyla®
• lEnhertu®
  -HER2-targeted ADC consisting of trastuzumab and cytotoxic drug
• Herceptin® (trastuzumab)
  – HER2-targeted antibody therapeuticHerceptin and Kadcyla are registered trademarks of Genentech inc.
  Enhertu is a registered trademark of Daiichi Sankyo.

  Instrument

Results

pH STABILITY

CD  spectra were obtained at pH 2, 3, 5, 7, 10, 11, and 12 and converted into MRE (molar residue ellipticity) spectra for normalization.

• Secondary structure compositions were estimated from the MRE spectra using BeStSel, a high-performance secondary structure determination algorithm developed by Dr. József Kardos and Dr. András Micsonai (https://bestsel.elte.hu)^(2-6).
• The difference in fraction between pH 7 and each pH was plotted. Between pH 3 and pH 10, each structure composition seems to remain, however, strand and others compositions shows a significant change at pH 2, 11, and 12.

HEAT STABILITY

CD spectra were obtained while changing the temperature from 25 ºC to 95 ºC by 1 ºC interval and converted to MRE spectra for normalization.

Melting temperature (Tm) was estimated from the denaturation curve to check the thermal stability. The denaturation curve was obtained by plotting the CD signal at 203 nm which is characteristic of β-strand.

• Secondary structure compositions were estimated from the MRE spectra using BeStSel (https://bestsel.elte.hu)^(2-5).
• lThe difference in fraction between 25 ºC and each temperature was plotted. As the temperature increases, the strand decreases and the others increases. The way how the Δ fraction changes is different in Herceptin® compared to Kadcyla® and Enhertu®.

References

Poster Session at PEGS Boston 2025 (The Essential Protein & Antibody Engineering Summit, May 12 – 16, 2025, in Boston, MA, USA)
Satoko Suzuki^1,2, Ai Yamane¹, Yasuo Horiguchi¹, Taiji Oyama¹, Hidetsugu Tabata³, Takehiko Wada², András Micsonai⁴, József Kardos⁴, Ken-ichi Akao<sup>1

1</sup>JASCO Corporation, Hachioji, Tokyo 192-8537, Japan,
²Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan,
³Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan,
⁴ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Budapest H-1117, Hungary

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