比率型近红外荧光探针检测小鼠体内半胱氨酸

Ratiometric Near Infrared Fluorescent Probe for Detecting Cysteine in Living Mice

半胱氨酸(Cys)是20种天然氨基酸中唯一含有还原性硫醇基团的氨基酸,在蛋白质合成、解毒和代谢等生理过程中起着关键作用,与许多疾病密切相关。本工作设计了一种具有细胞膜定位功能、可特异性识别Cys的荧光探针Cy-B。在乙醇/4-羟乙基哌嗪乙磺酸缓冲溶液(体积比1∶4,pH 7.4)中,随着Cys浓度增加,探针在808 nm处的荧光发射信号强度(I_(808nm))逐渐减弱,同时在635 nm处的荧光发射信号强度(I_(635nm))逐渐增强,以I_(635nm)/I_(808nm)构建比率荧光信号可实现对Cys的定量检测。得益于Cy-B近红外发射的优势,探针可应用于小鼠体内Cys含量的比率型检测。

Cysteine(Cys)is the only amino acid containing reductive thiol group among 20 kinds of natural amino acids,which plays a key role in protein synthesis,detoxification and metabolism and is closely associated with many diseases.Therefore,we designed a fluorescent probe Cy-B with the ability of cell membrane localization to specifically recognize Cys.In the EtOH/2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid(HEPES)buffer solution(VEtOH/VHEPES=1∶4,pH 7.4),the fluorescence intensity at 808 nm(I_(808 nm))gradually decreased with the increase of Cys concentration,accompanied with the enhanced fluorescence signal at 635 nm(I_(635 nm)).The ratio signal of I_(635nm)/I_(808nm)elevated with a[Cys]-dependent manner,achieving the detection of Cys.Benefiting from the NIR emission,this probe can be successfully applied for ratiometric detection of Cys in living mice.