Engineered Arabidopsis Blue Light Receptor LOV Domain Variants with Improved Quantum Yield, Brightness, and Thermostability

• Published in: Journal of agricultural and food chemistry Vol. 67; no. 43; pp. 12037 - 12043
• Main Authors: Ko, Sanghwan, Hwang, Bora, Na, Jung-Hyun, Lee, Jisun, Jung, Sang Taek
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 30.10.2019
• Subjects: Arabidopsis - chemistry; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis - radiation effects; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Flavin Mononucleotide - metabolism; Fluorescence; Light; Protein Domains; Protein Stability; flavin-binding fluorescent protein; quantum yield; fluorescence intensity; directed evolution
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.9b05473

Despite remarkable contribution of green fluorescent protein and its variants for better understanding of various biological functions, its application for anaerobic microorganisms has been limited because molecular oxygen is essential for chromophore formation. To overcome the limitation, we engineered a plant-derived light, oxygen, or voltage (LOV) domain containing flavin mononucleotide for enhanced spectral properties. The resulting LOV variants exhibited improved fluorescence intensity (20 and 70% higher for SH3 and 70% for BR1, respectively) compared to iLOV, an LOV variant isolated in a previous study, and the quantum yields of the LOV variants (0.40 for SH3 and 0.45 for BR1) were also improved relative to that of iLOV (Q = 0.37). In addition to fluorescence intensity, the identified mutations of SH3 enabled an improved thermostability of the protein. The engineered LOV variants with enhanced spectral properties could provide a valuable tool for fluorescent molecular probes under anaerobic conditions.