Precision-Engineered Nano-Electrospray Emitters Enhance Ionization Efficiency for Trap-Assisted Direct Infusion Mass Spectrometry: Application in Plasma Alzheimer’s Disease Proteomics

ABSTRACT: Shotgun direct infusion mass spectrometry (DI-MS) enables high-throughput proteomics. Yet, its performance critically depends on nanospray emitter quality. We present here precision-engineered nanospray emitters with an optimized 4-degree emitter tip angle, designed for sensitive, reproducible, user friendly, and compatible across mass spectrometry platforms that demonstrated enhanced ionization efficiency and spray stability, showing a 21-fold improvement in protein identification rates compared to commercial designs. Using both digested HeLa cell protein extracts and plasma samples from Alzheimer's disease (AD) patients, and controls, where the 14 most high-abundant proteins were depleted, we performed a comprehensive DI-MS protein identification and precise quantification using both Orbitrap Exploris 480 (OE480) and Orbitrap Astral mass spectrometers. We consistently identified and quantified over 160 proteins in AD plasma samples in 4 min DI-MS runs, with superior reproducibility (CV < 15%) and sensitivity on the Orbitrap Astral. Our analysis revealed several unreported disease-associated protein signatures, while confirming known AD biomarkers, with C5, C4BPA, and FAM135B as the protein combination with the highest potential as AD plasma biomarkers for the detection of the disease. The enhanced performance of these standardized engineered nanospray emitters over the established DI-MS workflow establishes a robust and scalable platform for high-throughput clinical proteomics.

INSTRUMENT(S): Orbitrap Exploris 480

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Blood Plasma

DISEASE(S): Alzheimer's Disease

SUBMITTER: Ana Montero Calle  

LAB HEAD: Rodrigo Barderas

PROVIDER: PXD061608 | Pride | 2025-07-20

REPOSITORIES: Pride