绿藻硫酸鼠李聚糖酶性质研究

Degradase for rhamnan sulfate from green algae and its enzyme characterization

以绿藻硫酸鼠李聚糖为碳源,从青岛海域中筛选到1株可分泌绿藻硫酸鼠李聚糖酶的菌株SC127,通过硫酸铵沉淀、Q-Sepharose Fast Flow离子交换层析和Sephadex G-100凝胶过滤层析等方法对其所产酶进行了分离纯化,并对纯化后的硫酸鼠李聚糖酶性质作了初步研究。研究结果显示:SC127菌株属于假交替单胞菌属(Pseudoalteromonas),所产硫酸鼠李聚糖酶经分离纯化后由SDS-PAGE电泳检验呈单一条带,测得其分子质量为110.6 k Da,此酶最适温度为38℃,最适p H为8,且适用于较广的温度与p H范围。对酶解产物分析表明:该硫酸鼠李聚糖酶可降解硫酸鼠李聚糖得到以聚合度4为主的硫酸鼠李寡糖。

A degradase-producing marine bacterial strain using rhamnan sulfate in green algae as carbon source, named SC127, was isolated from samples of sea area of Qingdao. Degradase at electrophoretic purity grade was obtained from the fermentation broth by ammonium sulfate precipitation, Q-sepharose fast flow ion exchange chromatography and Sephadex G-100 gel filtration chromatography and the characteristics of degradase for rhamnan sulfate were researched. The results showed that the strain was identified as Pseudoalteromonas sp. according to 16S rDNA sequence analysis. The purified degradase for rhamnan sulfate exhibited a single band on SDS-PAGE with a molecular mass of 110.6 kDa and had the maximum activity at 38℃ and pH 8. It could be used in wide ranges of pH and temperature. Analysis on products obtained by the enzymatic reaction showed that the degradase could degrade rhamnan sulfate to obtain sulfated oligosaccharides in which the main degree of polymerization was four.