FRET based Peptidyl “Turn-On” Fluorescent Sensor for monitoring Cu (II)

초록

Fluorescent probes have revolutionized the study of biological systems and environmental processes by allowing exquisitely sensitive, real-time detection of tagged proteins and probing trace transitional metal ions. Fluorescent switches at the molecular level have attracted considerable attention during recent years because they afford promising properties such as high sensitivity, high resolution, and high contrast. In the last decades, there are several promising examples of chemosensors reported for the selective monitoring Cu (II) due to its valuable significance in biological system and as environmental pollutant. Most of the sensors for monitoring Cu (II) are “Turn-Off” and vanished the fluorescence upon binding. To get over this problem, we designed decapeptide and appended pyrene and coumarin as FRET pair in the N-terminus and C-terminus of the peptide respectively. The FRET mode of signaling was monitored by exciting pyrene at 342 nm with and without metal ions in biological buffer system. The binding affinity, fluorescence response with transition metal ions, alkali and alkaline earth metal ions and selectivity for Cu (II) over these ions was studied. To investigate the FRET efficiency and validity of this sensing system, the peptides with only single dye at N-terminus and C-terminus was also studied.