Key Lab of Ecological Environment Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, China.
College of Chemical Engineering, Qingdao University of Science & Technology, Qingdao, China.
J Sci Food Agric. 2023 Sep;103(12):6095-6104. doi: 10.1002/jsfa.12705. Epub 2023 May 31.
In the present study, the ι-carrageenase gene, Car1293, was obtained from the genome of Microbulbifer sp. YNDZ01, which was isolated from the surface of macroalgae. To date, there are few studies on ι-carrageenase and the anti-inflammatory activity of ι-carrageenan oligosaccharides (CGOS). To enhance our perspective on ι-carrageenase and ι-carrageen oligosaccharides, the sequence, protein structure, enzymatic properties, enzymatic digestion products and anti-inflammatory activity of the gene were investigated.
The gene length of Car1293 is 2,589 bp, encoding an enzyme with 862 amino acids, which shares 34% similarity with any previously reported ι-carrageenase. The spatial structure of Car1293 consists of many α-helices with a β-fold binding module located at its terminus, and eight binding sites were found in the binding module as a result of docking with CGOS-DP4 ligand. The optimum temperature and pH for the activity of recombinant Car1293 toward ι-carrageenan were 50 °C and 6.0, respectively. The hydrolysates of Car1293 are mainly degree of polymerization (DP)8, with minor products showing DP2, DP4, and DP6. The enzymatic hydrolysates CGOS-DP8 showed prominent anti-inflammatory activity, which was greater than that of the positive control l-monomethylarginine in lipopolysaccharide-induced RAW264.7 macrophages. It inhibited nitric oxide production, as well as significantly inhibited tumor necrosis factor-α and interleukin-6 secretion.
The ι-carrageenase sequence encoded by Car1293 is novel and can hydrolyze carrageenan into CGOS-DP8 that has a significant anti-inflammatory effect. The present study fills a gap in the research on the biological activity of oligosaccharides in ι-carrageenan and provides promising data for the development of natural anti-inflammatory agent. © 2023 Society of Chemical Industry.
本研究从分离自大型海藻表面的微球藻属 YNDZ01 基因组中获得 ι-卡拉胶酶基因 Car1293。迄今为止，关于 ι-卡拉胶酶和 ι-卡拉胶低聚糖（CGOS）的抗炎活性研究较少。为了更深入地了解 ι-卡拉胶酶和 ι-卡拉胶低聚糖，对该基因的序列、蛋白质结构、酶学性质、酶解产物和抗炎活性进行了研究。
Car1293 基因长度为 2589bp，编码的酶含有 862 个氨基酸，与任何先前报道的 ι-卡拉胶酶的相似度为 34%。Car1293 的空间结构由许多α-螺旋组成，其末端有一个β-折叠结合模块，通过与 CGOS-DP4 配体对接，在结合模块中发现了 8 个结合位点。重组 Car1293 对 ι-卡拉胶的最适温度和 pH 值分别为 50°C 和 6.0。Car1293 的水解产物主要为聚合度（DP）8，少量产物为 DP2、DP4 和 DP6。酶解产物 CGOS-DP8 表现出显著的抗炎活性，优于阳性对照 LPS 诱导的 RAW264.7 巨噬细胞中的 l-单甲基精氨酸。它抑制一氧化氮的产生，显著抑制肿瘤坏死因子-α和白细胞介素-6 的分泌。
Car1293 编码的 ι-卡拉胶酶序列是新颖的，可以将卡拉胶水解成具有显著抗炎作用的 CGOS-DP8。本研究填补了 ι-卡拉胶中寡糖生物活性研究的空白，为天然抗炎剂的开发提供了有前景的数据。© 2023 化学工业协会。
