Extraction, purification and physicochemical properties of a novel lectin from Laetiporus sulphureus mushroom

Technological conditions for extracting Laetiporus sulphureus lectin (LSL) were optimized through an orthogonal experiment. LSL, with a relative agglutinating activity of 259.90 ± 7.47 UH/mg protein, was successfully obtained, and its structure was characterized. Results indicated that the novel 52.0 kDa LSL was rich in aspartic acid, glutamic acid, leucine, and threonine, and its secondary structure mainly presented alpha-helix, beta-sheet, beta-turn, and random-coil conformation. Moreover, its relative agglutinating activity was inhibited by alpha-lactose and beta-lactose. Meanwhile, d-maltose, d-glucose, d-fructose, d-mannose, and d-xylose did not exert this effect. The obtained LSL showed resistance to acid and alkali and demonstrated moderate thermostability, and its relative agglutinating activity was reduced by Fe3+ and Al3+ ions. Meanwhile, Ca2+, Mg2+, Zn2+, and Mn2+ ions had no inhibitory effects.