Jiyoung Mun (CellKey AI Inc.)

Kwang Hoe Kim (CellKey AI Inc.)

Jiyoung Mun (CellKey AI Inc.)

Eun Sun Ji (CellKey AI Inc.)

Bo Su Lee (Naturetech Co., Ltd.)

Se Yeong Jeon (Naturetech Co., Ltd.)

Hye Ryeong Hong (Naturetech Co., Ltd.)

Hyun Jin Kim (Naturetech Co., Ltd.)

Seon Gil Do (Naturetech Co., Ltd.)

Jong Hwan Shin (CellKey AI Inc.)

Kwang Hoe Kim (CellKey AI Inc.)

Proteoglycans are high molecular weight glycoproteins that offer potential health benefits, including the prevention of osteoarthritis, anti-inflammatory effects, enhancement of immune function, and promotion of skin health. Aggrecan, a major proteoglycan with glycosaminoglycan (GAG) chains, presents challenges in quantification due to its highly glycosylated structure. In this study, we aimed to develop a targeted and reproducible quantification method based on core protein-derived peptides, excluding post-translational modifications. Aggrecan was identified from salmon (Oncorhynchus keta) nasal cartilage using liquid chromatography-mass spectrometry (LC-MS), and a multiple reaction monitoring (MRM)-based quantification method was established using stable-isotope-labeled peptides. The developed method achieved a limit of detection (LOD) of 0.0008 µg/mL and a lower limit of quantification (LLOQ) of 0.0025 µg/mL, demonstrating high sensitivity and precision. These results validate the feasibility of core protein-targeted quantification and support the use of this approach in quality control and functional evaluation of salmon cartilage-derived food materials.