Department of Integrated Biomedical and Life Sciences, Korea University, Seoul 02841, South Korea.
Transdisciplinary Major in Learning Health Systems, Department of Integrated Biomedical and Life Sciences, Korea University, Seoul 02841, South Korea.
Enzyme Microb Technol. 2022 Nov;161:110113. doi: 10.1016/j.enzmictec.2022.110113. Epub 2022 Aug 17.
Isoflavonoids are of great interest due to their human health-promoting properties, which have resulted in studies on exploiting these phytochemicals as hotspots in diverse bio -industries. Biocatalytic glycosylation of isoflavonoid aglycones to glycosides has attracted marked interests because it enable the biosynthesis of isoflavonoid glycosides with high selectivity under mild conditions, and also provide an environmentally friendly option for the chemical synthesis. Thus, these inspired us to exploit new flexible and effective glycosyltransferases from microbes for making glycosides attractive compounds that are in high demand in several industries. Most recently, we have reported the functional characterization of a bacterial-origin recombinant glycosyltransferase (MeUGT1). Herein, more detailed kinetic characteristics of this biocatalyst, using a number of glycosyl donor substrates, were examined for further investigation of its biocatalytic applicability, enabling it feasible to biosynthesize new glycosides; phenoxodiol-4'-O-α-glucuronide, phenoxodiol-4'-O-α-(2''-N-acetyl)glucosaminide, phenoxodiol-4'-O-α-galactoside, phenoxodiol-4'-O-α-(2''-N-acetyl)galactosaminide and phenoxodiol-4'-O-α-(2''-deoxy)glucoside. The thorough kinetic analyses revealed that while the recombinant enzyme can utilize, albeit with different substrate preference and catalytic efficiency, a total five different nucleotide sugars as glycosyl donors, exhibiting its promiscuity towards glycosyl donors. This is the first report that a recombinant glycosyltransferase MeUGT1 that can regio-specifically glycosylate C4'-hydroxyl function of semi-synthetic phenoxodiol isoflavene to biosynthesize a series of unnatural phenoxodiol-4'-O-α-glycosides.
异黄酮因其对人体健康的促进作用而备受关注，这促使人们研究利用这些植物化学物质作为多个生物产业的热点。异黄酮苷元的生物催化糖基化已成为热点，因为它可以在温和条件下高选择性地合成异黄酮糖苷，而且为化学合成提供了一种环保的选择。因此，这些激发了我们从微生物中开发新的灵活有效的糖基转移酶，用于制造糖苷，使具有高需求的糖苷成为有吸引力的化合物，这些糖苷在多个行业中都有需求。最近，我们报道了一种细菌来源的重组糖基转移酶（MeUGT1）的功能特征。在此，我们用一些糖基供体底物进一步研究了这种生物催化剂的详细动力学特征，以进一步研究其生物催化适用性，使其能够可行地生物合成新的糖苷；苯并二氢吡喃-4'-O-α-葡萄糖醛酸苷、苯并二氢吡喃-4'-O-α-(2''-N-乙酰)葡萄糖胺、苯并二氢吡喃-4'-O-α-半乳糖苷、苯并二氢吡喃-4'-O-α-(2''-N-乙酰)半乳糖胺和苯并二氢吡喃-4'-O-α-(2''-脱氧)葡萄糖苷。彻底的动力学分析表明，尽管重组酶可以利用，尽管具有不同的底物偏好和催化效率，但可以利用总共五种不同的核苷酸糖作为糖基供体，表现出对糖基供体的混杂性。这是第一个报道，一种重组糖基转移酶 MeUGT1 可以区域特异性地糖基化半合成苯并二氢吡喃异黄酮的 C4'-羟基，生物合成一系列非天然苯并二氢吡喃-4'-O-α-糖苷。
