Gan Weiqiong, Gao Feng, Xing Keke, Jia Minze, Liu Haiping, Gong Weimin
Key Laboratory of RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People's Republic of China.
Center for Chemical Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300457, People's Republic of China.
Acta Crystallogr F Struct Biol Commun. 2015 Apr;71(Pt 4):381-7. doi: 10.1107/S2053230X15003921. Epub 2015 Mar 20.
The FAOD/FPOD family of proteins has the potential to be useful for the longterm detection of blood glucose levels in diabetes patients. A bottleneck for this application is to find or engineer a FAOD/FPOD family enzyme that is specifically active towards α-fructosyl peptides but is inactive towards other types of glycated peptides. Here, the crystal structure of fructosyl peptide oxidase from Eupenicillium terrenum (EtFPOX) is reported at 1.9 Å resolution. In contrast to the previously reported structure of amadoriase II, EtFPOX has an open substrate entrance to accommodate the large peptide substrate. The functions of residues critical for substrate selection are discussed based on structure comparison and sequence alignment. This study reveals the first structural details of group I FPODs that prefer α-fructosyl substrates and could provide significant useful information for uncovering the mechanism of substrate specificity of FAOD/FPODs and guidance towards future enzyme engineering for diagnostic purposes.
FAOD/FPOD蛋白家族有潜力用于糖尿病患者血糖水平的长期检测。该应用的一个瓶颈是找到或设计一种对α-果糖基肽具有特异性活性但对其他类型糖化肽无活性的FAOD/FPOD家族酶。在此，报道了土生尤尼青霉素（EtFPOX）果糖基肽氧化酶的晶体结构，分辨率为1.9 Å。与之前报道的阿玛多里酶II结构不同，EtFPOX具有开放的底物入口以容纳大的肽底物。基于结构比较和序列比对讨论了对底物选择至关重要的残基的功能。这项研究揭示了偏好α-果糖基底物的I类FPOD的首个结构细节，并可为揭示FAOD/FPOD的底物特异性机制以及未来用于诊断目的的酶工程提供重要有用信息。
