Photoconversion and Fluorescence Properties of a Red/Green-Type Cyanobacteriochrome AM1_C0023g2 That Binds Not Only Phycocyanobilin But Also Biliverdin.
Photoconversion and Fluorescence Properties of a Red/Green-Type Cyanobacteriochrome AM1_C0023g2 That Binds Not Only Phycocyanobilin But Also Biliverdin.
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DOI：
10.3389/fmicb.2016.00588
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发表时间：
2016
影响因子：
5.2
通讯作者：
Narikawa R
中科院分区：
文献类型：
--
作者：
Fushimi K;Nakajima T;Aono Y;Yamamoto T;Ni-Ni-Win;Ikeuchi M;Sato M;Narikawa R
蓝藻色素（CBCRs）与红/远红响应光敏色素有远亲关系。红/绿型cbcr广泛分布于各种蓝藻中。红/绿型cbcr与藻蓝胆素（PCB）共价结合，呈现红/绿可逆光转化。近年来的研究表明，含有叶绿素d的蓝细菌Acaryochloris marina中的一些红/绿型cbcr不仅能与PCB共价结合，还能与胆绿素（BV）共价结合。结合bv的cbcr表现出远红/橙色可逆光转换。在这里，我们从A. marina中鉴定出另一种CBCR (AM1_C0023g2)，它不仅能与PCB共价结合，还能以高结合效率结合BV，尽管BV发色团在尿素存在下是不稳定的。用Gly替代Ser334导致bv结合全蛋白的产量显著提高，从而确保突变蛋白为未来开发光遗传开关提供了良好的平台。我们还成功地检测了含有pcb结合AM1_C0023g2的哺乳动物细胞的近红外荧光，其荧光量子产率为3.0%。在这里，pcb结合的全蛋白被显示为未来荧光探针发展的平台。
Cyanobacteriochromes (CBCRs) are distantly related to the red/far-red responsive phytochromes. Red/green-type CBCRs are widely distributed among various cyanobacteria. The red/green-type CBCRs covalently bind phycocyanobilin (PCB) and show red/green reversible photoconversion. Recent studies revealed that some red/green-type CBCRs from chlorophyll d-bearing cyanobacterium Acaryochloris marina covalently bind not only PCB but also biliverdin (BV). The BV-binding CBCRs show far-red/orange reversible photoconversion. Here, we identified another CBCR (AM1_C0023g2) from A. marina that also covalently binds not only PCB but also BV with high binding efficiencies, although BV chromophore is unstable in the presence of urea. Replacement of Ser334 with Gly resulted in significant improvement in the yield of the BV-binding holoprotein, thereby ensuring that the mutant protein is a fine platform for future development of optogenetic switches. We also succeeded in detecting near-infrared fluorescence from mammalian cells harboring PCB-binding AM1_C0023g2 whose fluorescence quantum yield is 3.0%. Here the PCB-binding holoprotein is shown as a platform for future development of fluorescent probes.