Su Min-Shih, Kao Ya-Ting
Department of Biological Science and Technology, College of Engineering Bioscience, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan.
Institute of Bioinformatics and Systems Biology, College of Engineering Bioscience, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan.
ACS Omega. 2025 Aug 6;10(32):35595-35603. doi: 10.1021/acsomega.5c01397. eCollection 2025 Aug 19.
Fatty acid photodecarboxylase (FAP) was recently discovered in microalgae and is a photoenzyme that harvests sunlight to convert long-chain fatty acids to hydrocarbons. The hydrophobicity of the substrates and photoproducts strongly affects the stability of FAP studies. Here, we incorporated zeolitic imidazole frameworks (ZIFs) as structural protecting cages and characterized FAP (FAP) in ZIFs. Due to the preparation conditions and the surface properties, ZIFs with a hydrophobic surface (ZIF-8) form a cluster-like packed morphology, and ZIFs with a hydrophilic surface (ZIF-90) form a hexagon-like morphology. However, both ZIFs compress FAP and lead to a more hydrophobic active-site environment and fewer active-site water molecules. The ZIF-90 cages enhance the FAP activity at higher temperature conditions. Upon irradiation, FAP undergoes energy deactivation and photoinactivation, and these processes compete with each other. In both ZIF cages, the deactivation processes of the excited FAP are slightly enhanced, resulting from the bent cofactor conformation. Although the ZIFs provide protective confinement to stabilize the enzyme structures when structural destruction originates from molecular fragmentation casing by photoinduced radical reactions, such protective effects are limited.
脂肪酸光脱羧酶（FAP）最近在微藻中被发现，是一种利用阳光将长链脂肪酸转化为碳氢化合物的光酶。底物和光产物的疏水性强烈影响FAP研究的稳定性。在此，我们将沸石咪唑框架（ZIFs）作为结构保护笼，并对ZIFs中的FAP进行了表征。由于制备条件和表面性质，具有疏水表面的ZIFs（ZIF-8）形成簇状堆积形态，而具有亲水表面的ZIFs（ZIF-90）形成六边形形态。然而，两种ZIFs都会压缩FAP，导致活性位点环境更疏水，活性位点水分子减少。ZIF-90笼在较高温度条件下增强了FAP活性。光照时，FAP会发生能量失活和光失活，且这些过程相互竞争。在两种ZIF笼中，激发态FAP的失活过程略有增强，这是由弯曲的辅因子构象导致的。尽管当结构破坏源于光诱导自由基反应引起的分子碎片化时，ZIFs提供了保护性限制以稳定酶结构，但这种保护作用是有限的。
