透明质酸（Hyaluronic acid, HA）是一种由二糖重复单元构成的高分子酸性粘多糖，近年来发现其低分子结构具有独特的生物学活性，可广泛应用于医疗、保健和化妆品等领域，因而寻求低分子量HA的合成方式受到了研究者的关注。透明质酸合成酶是生物法合成HA的核心酶，目前的研究大多局限在高分子量HA合成酶，但因缺乏相应的酶源，对低分子量HA合成酶的研究鲜有报道。本项目以自主挖掘的新型低分子量HA合成酶BcHAS为研究对象，通过与已知高分子量合成酶SeHAS进行生物信息学分析比较，采用基因重排等方式，获取影响HA聚合度的关键结构域，挖掘出BcHAS的特定位点关键氨基酸残基对HA聚合度的影响规律，阐明生物合成HA聚合度的调控机理。本研究预期结果将实现对特定低分子量HA的高效定向合成，为其它类似生物高分子的分子量调控研究提供良好的科学基础和方法借鉴。

Hyaluronic acid (HA) is a high molecular acidic mucopolysaccharide composed of disaccharide repeat units. In recent years, it has been found that its low molecular structure has unique biological activity and can be widely used in medical, health care and cosmetics fields Therefore, the search for a low molecular weight HA synthesis method has attracted the attention of researchers. Hyaluronic acid synthase is the core enzyme for biosynthesis of HA. However, most of the current researches are limited to high-molecular-weight HA synthase, and there are few reports on low-molecular-weight HA synthase due to the lack of corresponding enzyme sources. In this project, the new low-molecular-weight HA synthase, BcHAS, was discovered and researched independently. Through the bioinformatics analysis and comparison with the well-known high-molecular-weight synthase, SeHAS, gene rearrangement was used to obtain the key structure affecting the degree of HA polymerization domain, to excavate the influence of key amino acid residues at specific sites of BcHAS on the degree of HA polymerization, and clarify the regulation mechanism of HA degree of biosynthesis. The results of this study are expected to achieve efficient targeted synthesis of specific low-molecular-weight HA and provide a good scientific basis and method for the molecular weight regulation of other similar biopolymers.