# Integrated Structural and Glycoproteomic Profiling Reveals Protein Conformational Remodeling and Biomarkers Across Alzheimer’s Disease Progression

## TL;DR

This study combines structural and glycoproteomic analysis of blood and spinal fluid to uncover protein changes and potential biomarkers across Alzheimer's disease stages.

## Contribution

The novel integration of structural proteomics and glycoproteomics in matched serum and CSF samples reveals new insights into AD progression and biomarker discovery.

## Key findings

- 54 proteins showed structural changes across Alzheimer's stages, with clusterin and ceruloplasmin altered in both serum and CSF.
- Protein structural changes correlated with N-glycosylation patterns in haptoglobin and kininogen-1, suggesting functional crosstalk.
- Integrated structural and glycoproteomic profiling enhances biomarker discovery and understanding of AD molecular mechanisms.

## Abstract

Alzheimer’s disease (AD) is characterized by progressive
neurodegeneration and protein misfolding, yet the structural dynamics
of proteins and their post-translational modifications during disease
progression remain poorly understood. Here, we present an integrated
structural and glycoproteomic analysis of paired serum and cerebrospinal
fluid (CSF) samples from individuals across three clinical stages:
normal cognition, mild cognitive impairment, and AD. Using limited
proteolysis mass spectrometry (LiP-MS) combined with high-field asymmetric
waveform ion mobility spectrometry and data-independent acquisition,
we identified 54 proteins exhibiting structural alterations, two of
which (clusterin and ceruloplasmin) showed structural changes in both
serum and CSF. Furthermore, our findings reveal potential crosstalk
between protein structural changes and N-glycosylation, supported
by correlations between LiP-derived structural features and glycosylation
patterns in key proteins, such as haptoglobin and kininogen-1. This
study demonstrates that integrating structural proteomics with glycoproteomics
in matched serum and CSF samples enhances biomarker discovery and
provides novel insights into the molecular mechanisms of AD. Our approach
offers a powerful platform for identifying robust, minimally invasive
biomarkers and for understanding post-translational modification-induced
protein remodeling in neurodegenerative diseases.