透明质酸酶是一类能够降解透明质酸的酶,在医学领域具有广泛的应用。在这项研究中,海洋细菌弧菌。ZG1,可以降解HA,被隔离,导致发现了两种新的透明质酸裂解酶,Vhylzx1和Vhylzx2,通过基因组测序和生物信息学分析。这些裂解酶属于多糖裂解酶-8家族。Vhylzx1和Vhylzx2特异性降解HA,在35°C时具有最高活性,pH5.7和50°C,pH7.1。Vhylzx1和Vhylzx2是内型酶,可以将HA完全降解为不饱和二糖。序列同源性评估和定点诱变表明,Vhylzx1的催化残基是Asn231,His281和Tyr290,而Vhylzx2的催化残基是Asn227,His277和Tyr286。此外,这项研究使用共有序列来增强Vhylzx2突变体的比活性。值得注意的是,突变体V564I,N742D,L619F,和D658G使比活性增加2.4、2.2、1.3和1.2倍。这些特性对于进一步的基础研究和应用是有用的,在制备具有生物活性的透明质酸寡糖方面具有广阔的应用前景。
Hyaluronidases are a class of enzymes that can degrade hyaluronic acid and have a wide range of applications in the medical field. In this study, the marine bacterium Vibrio sp. ZG1, which can degrade HA, was isolated, leading to the discovery of two novel hyaluronan lyases, Vhylzx1 and Vhylzx2, through genome sequencing and bioinformatic analysis. These lyases belong to the polysaccharide lyase-8 family. Vhylzx1 and Vhylzx2 specifically degrade HA, with highest activity at 35 °C, pH 5.7 and 50 °C, pH 7.1. Vhylzx1 and Vhylzx2 are endo-type enzymes that can fully degrade HA into unsaturated disaccharides. Sequence homology assessment and site-directed mutagenesis revealed that the catalytic residues of Vhylzx1 are Asn231, His281, and Tyr290, and that the catalytic residues of Vhylzx2 are Asn227, His277, and Tyr286. Moreover, this study used consensus sequences to enhance the specific activity of Vhylzx2 mutants. Notably, the mutants V564I, N742D, L619F, and D658G increases the specific activity by 2.4, 2.2, 1.3, and 1.2-fold. These characteristics are useful for further basic research and applications, and have a promising application in the preparation of biologically active hyaluronic acid oligosaccharides.