Scott Joshua G, Goddard Julie M
Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA.
Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA.
Int J Biol Macromol. 2025 Apr;302:140390. doi: 10.1016/j.ijbiomac.2025.140390. Epub 2025 Jan 27.
Combined cross-linked enzyme aggregates (Combi-CLEAs) of β-Galactosidase (β-Gal) and Glucose Isomerase (GI) allow the transformation of d-lactose to lactose-fructose syrup through one-pot cascade biocatalytic reactions. Despite its promise, the low thermostability of β-Gal and high-temperature demands for GI limits this application. Trehalose is a protein-stabilizing disaccharide which has been utilized in immobilized enzyme systems to enhance protein thermostability. In this work, trehalose decorated poly (amidoamine) (PAMAM) dendrimers were synthesized at low and high surface coverage levels (10 % and 50 %) and used to stabilize Combi-CLEAs of β-Gal and GI. Addition of trehalose decorated nanostructures to β-Gal and GI Combi-CLEAs enhanced β-Gal performance at elevated temperatures (58.6 % higher activity and 2.26× higher stability) while maintaining GI performance of Combi-CLEAs. The resulting Combi-CLEAs containing trehalose decorated nanostructures retained ~40 % β-Gal activity following 7 consecutive reaction cycles and exhibited GI activity for 5 consecutive reaction cycles. Overall, this study demonstrates the potential of trehalose decorated nanostructures to stabilize proteins at elevated temperatures typical of bioprocessing applications and storage of therapeutics.
β-半乳糖苷酶（β-Gal）和葡萄糖异构酶（GI）的复合交联酶聚集体（Combi-CLEAs）可通过一锅法级联生物催化反应将d-乳糖转化为乳糖-果糖糖浆。尽管有前景，但β-Gal的低热稳定性和GI对高温的要求限制了这种应用。海藻糖是一种蛋白质稳定二糖，已用于固定化酶系统以提高蛋白质热稳定性。在这项工作中，合成了低表面覆盖率和高表面覆盖率（10%和50%）的海藻糖修饰聚（酰胺胺）（PAMAM）树枝状大分子，并用于稳定β-Gal和GI的Combi-CLEAs。向β-Gal和GI Combi-CLEAs中添加海藻糖修饰的纳米结构可提高β-Gal在高温下的性能（活性高58.6%，稳定性高2.26倍），同时保持Combi-CLEAs的GI性能。所得含有海藻糖修饰纳米结构的Combi-CLEAs在连续7个反应循环后保留了约40%的β-Gal活性，并在连续5个反应循环中表现出GI活性。总体而言，本研究证明了海藻糖修饰纳米结构在生物加工应用和治疗剂储存典型的高温下稳定蛋白质的潜力。
