PT  - JOURNAL ARTICLE
AU  - Fan Pu
AU  - Scott A. Ugrin
AU  - Andrew J. Radosevich
AU  - David Chang-Yen
AU  - James W. Sawicki
AU  - Nari N. Talaty
AU  - Nathaniel L. Elsen
AU  - Jon D. Williams
TI  - High Throughput Intact Protein Analysis Using Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry
AID  - 10.1101/2021.11.08.467755
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.11.08.467755
4099  - http://biorxiv.org/content/early/2021/12/18/2021.11.08.467755.short
4100  - http://biorxiv.org/content/early/2021/12/18/2021.11.08.467755.full
AB  - Mass spectrometry (MS) is the primary analytical tool used to characterize proteins within the biopharmaceutical industry. Electrospray ionization (ESI) coupled to liquid chromatography is the gold standard technique for intact protein analysis. However, speed limitations prevent analysis of large sample numbers (>1000) in a day. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) MS, an ambient ionization MS technology, has recently been established as a platform for high throughput small molecule analysis. Here we report the application of such system for intact protein analysis. Up to 150 kDa proteins are detectable on a high throughput IR-MALDESI-MS system and we have evaluated how matrix affects signal. The system can analyze up to 22 protein samples in a second. Protein autophosphorylation, compound binding kinetics and compound modifications to a probe protein are demonstrated as applications. Top-down protein sequencing was conducted to identify a cysteine modification site. Two plate-based high throughput sample cleanup methods were coupled to IR-MALDESI-MS to enable analysis of samples containing high amounts of salts and buffers without compromising speed.Competing Interest StatementThe work was enabled by the AbbVie Postdoc Program. All authors are employees of AbbVie. The design, study conduct, and financial support for this research were provided by AbbVie. AbbVie participated in the interpretation of data, review, and approval of the publication.