Study of glycated human serum albumin in non-enzymatic glycation process based on MIR/NIR spectroscopy

Abstract

Non-enzymatic glycation of human serum albumin (HSA) is implicated in diabetes mellitus, its complications, and neurodegenerative diseases. This complex process yields diverse products across various stages, yet traditional assays lack the capability to characterize early and intermediate glycation phases effectively. Infrared spectroscopy, encompassing near-infrared (NIR) and mid-infrared (MIR) regions, offers insights into molecular vibrations and has gained traction in studying protein-molecule interactions. Our study employed NIR and MIR spectroscopy to monitor the glycation of HSA induced by 50 mM glucose over five weeks, establishing quantitative models for glycated HSA. NIR analysis revealed that HSA produced the highest amount of fructosamine at 3 weeks, while five characteristic peaks 4768 cm⁻¹, 5644 cm⁻¹, 5982 cm⁻¹, 7012 cm⁻¹, 7143 cm⁻¹ were found. Meanwhile, MIR spectroscopy further revealed the peaks 675 cm⁻¹, 1517 cm⁻¹, 1685 cm⁻¹, 1792 cm⁻¹, and 1840 cm⁻¹, which reflected the degree of glycation of HSA. A robust quantitative model, integrating NIR and MIR data, demonstrated high predictive accuracy (R²c = 0.9994, R²p = 0.9524, RMSEP = 1.59 mmol/L) and reliability (RPD = 3.35). This research not only elucidates HSA glycation levels but also pioneers a novel quantification methodology for glycated HSA.