Abstract：
In this study, β-1,3-xylanase (Xyl3088) was designed and prepared by constructing the expression vector plasmid and expressing and purifying the fusion protein. β-1,3-xylo-oligosaccharides were obtained through the specific enzymatic degradation of β-1, 3-xylan from Caulerpa lentillifera. The enzymolysis conditions were established and optimized as follows: Tris-HCl solution 0.05 mol/L, temperature of 37 °C, enzyme amount of 250 μL, and enzymolysis time of 24 h. The oligosaccharides\' compositions and structural characterization were identified by thin-layer chromatography (TLC), ion chromatography (IC) and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS). The IC50 values for scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethyl-benzothiazoline-p-sulfonic acid (ABTS+), and superoxide anion radical (•O2-) were 13.108, 1.258, and 65.926 mg/mL for β-1,3-xylo-oligosaccharides, respectively, and 27.588, 373.048, and 269.12 mg/mL for β-1,4-xylo-oligosaccharides, respectively. Compared with β-1,4-xylo-oligosaccharides, β-1,3-xylo-oligosaccharides had substantial antioxidant activity and their antioxidant effects were concentration dependent. β-1,3-xylo-oligosaccharides also possessed a stronger anti-inflammatory effect on RAW 264.7 cells stimulated by lipopolysaccharide (LPS) than β-1,4-xylo-oligosaccharides. At a working concentration of 100 μg/mL, β-1,3-xylo-oligosaccharides inhibited the release of NO and affected the expression of IL-1β, TNF-α, and other proteins secreted by cells, effectively promoting the release of pro-inflammatory mediators by immune cells in response to external stimuli and achieving anti-inflammatory effects. Therefore, β-1,3-xylo-oligosaccharides are valuable products in food and pharmaceutical industries.
摘要：
在这项研究中,通过构建表达载体质粒，并表达和纯化融合蛋白，设计并制备了β-1,3-木聚糖酶（Xyl3088）。β-1,3-低聚木糖是通过对扁豆中的β-1,3-木聚糖的特异性酶降解获得的。建立并优化了酶解条件:Tris-HCl溶液0.05mol/L,温度为37°C，酶量为250μL，酶解时间为24h。通过薄层色谱（TLC）鉴定寡糖的组成和结构表征，离子色谱(IC)和液相色谱电喷雾串联质谱(LC-ESI-MS)。清除1,1-二苯基-2-吡啶酰肼(DPPH)的IC50值，2,2-偶氮-双-3-乙基-苯并噻唑啉-对-磺酸(ABTS+),β-1,3-低聚木糖的超氧阴离子自由基（•O2-）分别为13.108、1.258和65.926mg/mL，分别,β-1,4-低聚木糖分别为27.588、373.048和269.12mg/mL，分别。与β-1,4-低聚木糖相比，β-1,3-低聚木糖具有明显的抗氧化活性，其抗氧化作用取决于浓度。β-1,3-低聚木糖对脂多糖（LPS）刺激的RAW264.7细胞也具有比β-1,4-低聚木糖更强的抗炎作用。在100μg/mL的工作浓度下，β-1,3-低聚木糖抑制NO的释放,影响IL-1β的表达,TNF-α,和细胞分泌的其他蛋白质，有效促进免疫细胞响应外界刺激释放促炎介质，达到抗炎作用。因此,β-1,3-低聚木糖在食品和制药工业中是有价值的产品。
