Research Center for Applied Microbiology, National Research and Innovation Agency (BRIN), Jl. Raya Bogor, Km. 46, Cibinong, Bogor 16911, Indonesia; School of Chemistry and Molecular Bioscience, University of Queensland, Chemistry Bld, 68 Cooper Rd, Brisbane, QLD 4072, Australia; Department of Biotechnology, Faculty of Food Technology, Bina Nusantara University, Anggrek Jl. Kebon Jeruk Raya No. 27, Kebon Jeruk, West Jakarta 11530, Indonesia.
Research Center for Applied Microbiology, National Research and Innovation Agency (BRIN), Jl. Raya Bogor, Km. 46, Cibinong, Bogor 16911, Indonesia.
Int J Biol Macromol. 2024 Jan;254(Pt 2):127781. doi: 10.1016/j.ijbiomac.2023.127781. Epub 2023 Nov 2.
A novel l-arabinose isomerase (L-AI) from Arthrobacter psychrolactophilus (Ap L-AI) was successfully cloned and characterized. The enzyme catalyzes the isomerization of d-galactose into a rare sugar d-tagatose. The recombinant Ap L-AI had an approximate molecular weight of about 258 kDa, suggesting it was an aggregate of five 58 kDa monomers and became the first record as a homo-pentamer L-AI. The catalytic efficiency (k/Km) and Km for d-galactose were 0.32 mM min and 51.43 mM, respectively, while for l-arabinose, were 0.64 mM min and 23.41 mM, respectively. It had the highest activity at pH 7.0-7.5 and 60 °C in the presence of 0.250 mM Mn. Ap L-AI was discovered to be an outstanding thermostable enzyme that only lost its half-life value at 60 °C for >1000 min. These findings suggest that l-arabinose isomerase from Arthrobacter psychrolactophilus is a promising candidate for d-tagatose mass-production due to its industrially competitive temperature.
一种新型的来自嗜冷节杆菌（Arthrobacter psychrolactophilus）的 l-阿拉伯糖异构酶（L-AI）被成功克隆并进行了表征。该酶催化 d-半乳糖异构化为稀有糖 d-塔格糖。重组 Ap L-AI 的近似分子量约为 258 kDa，表明它是由五个 58 kDa 单体聚合而成，这是首次记录为同型五聚体 L-AI。该酶对 d-半乳糖的催化效率（k/Km）和 Km 分别为 0.32 mM·min 和 51.43 mM，而对 l-阿拉伯糖的 k/Km 和 Km 分别为 0.64 mM·min 和 23.41 mM。在 0.250 mM Mn 存在下，该酶在 pH 7.0-7.5 和 60°C 时具有最高活性。Ap L-AI 被发现是一种出色的耐热酶，在 60°C 下半衰期超过 1000 分钟才会丧失。这些发现表明，来自嗜冷节杆菌的 l-阿拉伯糖异构酶由于其具有工业竞争力的温度，是大规模生产 d-塔格糖的有前途的候选酶。
