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bioRxiv · 10.64898/2026.06.15.732414

Enzyme-Linked Cycloaddition Assay (ELCA) for rapid, ultra-sensitive monitoring of secreted sialoglycoproteins

Lundstrom, J.·Yang, J.·Bojar, D.
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Abstract

Glycosylation of proteins is central to cell signaling, immune function, and pathogen interactions, yet existing methods for monitoring glycan changes require specialized instrumentation and primarily report on membrane-anchored, rather than secreted, glycoproteins, with a slow turnover. Here, we present the Enzyme-Linked Cycloaddition Assay (ELCA), a click chemistry-based platform for ultra-sensitive detection and semi-quantitative analysis of secreted sialoglycoproteins. By metabolically incorporating an azide-modified sialic acid into newly synthesized glycoproteins and capturing labeled material via strain-promoted cycloaddition, ELCA quantifies aggregate sialylation using a microplate reader-compatible, ELISA-like workflow. We demonstrate that the secreted glycoproteome responds rapidly to pharmacological perturbation, with changes detectable within hours. Benchmarking against common glycosylation inhibitors and profiling cytokine-driven macrophage polarization further establishes ELCAs sensitivity and temporal resolution. Compatible with serum-containing conditions and requiring no specialized instrumentation, ELCA provides a broadly accessible tool for rapid, cost-effective monitoring of secreted glycoprotein dynamics.

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Lundstrom, J., Yang, J., Bojar, D.. 2026-06-18. Enzyme-Linked Cycloaddition Assay (ELCA) for rapid, ultra-sensitive monitoring of secreted sialoglycoproteins. https://doi.org/10.64898/2026.06.15.732414

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