**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Mitsuki Nakao, Department of Biomedical Laboratory Sciences, Graduate School of Health Sciences, Kumamoto University, Japan

**Main Body of the Abstract**
Background:
Laser microdissection (LMD)-liquid chromatography tandem mass spectrometry (LC-MS/MS) is a powerful tool to identify amyloid precursor protein from formalin-fixed paraffin-embedded (FFPE) tissue sections. However, it sometime fails to identify sufficient amounts of amyloid precursor protein, due to serum and extracellular-matrix proteins contamination or small amount of amyloid. The purpose of this study was to evaluate the usefulness of adding information of amino acid modifications affected by formalin fixation on database search, to increase a number of detected peptides derived from amyloid precursor protein.
Material & Methods:
Twenty FFPE samples (AL, ATTR, AEFEMP1, AApoAI) were evaluated. LMD (Leica) and LC-MS/MS (Thermo Fisher Scientific) were performed for identification of amyloid precursor protein from FFPE tissue sections. On database search, +12 Da (Phe, His, Lys, Arg, Trp, Tyr) modification information was set as dynamic modification. The relative abundances were calculated by using a normalised spectral factor (NSAF).
Results:
(1) The relative value of amyloid precursor protein was increased in 16 (80%) cases. (2) Number of detected peptides derived from amyloid precursor protein was increased in 19 (95%) cases. (3) Coverage of amyloid precursor protein was increased or remained unchanged in 18 (90%) cases.
Summary & Conclusion:
Adding information of amino acid modifications affected by formalin fixation on database search, might be useful for proteomic typing of amyloidosis.



**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Mitsuki Nakao, Department of Biomedical Laboratory Sciences, Graduate School of Health Sciences, Kumamoto University, Japan

**Main Body of the Abstract**
**Background**:
Laser microdissection (LMD)-liquid chromatography tandem mass spectrometry (LC-MS/MS) is a powerful tool to identify amyloid precursor protein from formalin-fixed paraffin-embedded (FFPE) tissue sections. However, it sometime fails to identify sufficient amounts of amyloid precursor protein, due to serum and extracellular-matrix proteins contamination or small amount of amyloid. The purpose of this study was to evaluate the usefulness of adding information of amino acid modifications affected by formalin fixation on database search, to increase a number of detected peptides derived from amyloid precursor protein.
**Material & Methods**:
Twenty FFPE samples (AL, ATTR, AEFEMP1, AApoAI) were evaluated. LMD (Leica) and LC-MS/MS (Thermo Fisher Scientific) were performed for identification of amyloid precursor protein from FFPE tissue sections. On database search, +12 Da (Phe, His, Lys, Arg, Trp, Tyr) modification information was set as dynamic modification. The relative abundances were calculated by using a normalised spectral factor (NSAF).
**Results**:
(1) The relative value of amyloid precursor protein was increased in 16 (80%) cases. (2) Number of detected peptides derived from amyloid precursor protein was increased in 19 (95%) cases. (3) Coverage of amyloid precursor protein was increased or remained unchanged in 18 (90%) cases.
**Summary & Conclusion**:
Adding information of amino acid modifications affected by formalin fixation on database search, might be useful for proteomic typing of amyloidosis.



Evaluation of adding information of amino acid modifications affected by formalin fixation on proteomic typing of amyloidosis PC10 (#51)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.