Purification and Comprehensive Characterization of Two Novel Acidic Glycoproteins from Scorpion with Therapeutic...

Scorpions have long been utilized in traditional medicine for their therapeutic properties, including anti-cancer, analgesic, anti-thrombotic, and immune-modulating properties. This study aimed to optimize extraction conditions, partial purification, structural characterization and biological activity of glycoproteins from the scorpion (Buthus martensii Karsch) body. Under the optimized conditions, the extraction yield of scorpion glycoproteins (SGP's) reached 12.57 ± 0.7%. Subsequently, two novel glycoproteins, SGP-1a and SGP-1b, were isolated through DEAE-52 anion exchange chromatography and Sephadex G-75 gel filtration, with average molecular weights of 46.8 kDa and 10.3 kDa, respectively. Compositional analysis revealed SGP-1a and SGP-1b were rich in monosaccharides (Glu, Gal, Rha) and amino acids (Ser, Lys, Ala, Leu, Arg, Phe), and were characterized as homogeneous acidic protein-bound heteropolysaccharides. FTIR spectrum confirmed that SGP-1a and SGP-1b presence of glycated proteins, β-elimination reaction elucidated that SGP's contained N-glycosidic linkage. According to the CD analysis, SGP-1a contains 7.4% α-helix, 34.1% β-sheet, 13.2% β-turn, 34.6% random coil and SGP-1b contains 4.7% α-helix, 46.8% β-strand, 47.2% random coil. Bioactivity assays demonstrated significant anti-inflammatory activity against COX-2 (IC50: 21.14 ± 1.73 µg/mL for SGP-1a; 18.58 ± 1.54 µg/mL for SGP-1b) Meanwhile, both the SGPs exhibit strong antioxidant activity, the IC₅₀ of SGP-1a and SGP-1b against DPPH, ABTS, and hydroxyl free radicals were 1.75 mg/mL, and 0.79 mg/mL, 1.56 mg/mL, and 0.79 mg/mL, 0.53 mg/mL and 1.69 mg/mL respectively. These findings unveil the molecular basis of BmK's medicinal properties, providing novel leads for anti-inflammatory drug development.