A semisynthetic fluorescent sensor protein for glutamate

Area of Science:

• Biochemistry
• Neuroscience
• Molecular Biology

Background:

• Glutamate is a major excitatory neurotransmitter in the central nervous system.
• Accurate measurement of extracellular glutamate is crucial for understanding neuronal function and dysfunction.
• Existing glutamate sensing methods have limitations in sensitivity, localization, or invasiveness.

Purpose of the Study:

• To develop a novel, highly sensitive fluorescent sensor for extracellular glutamate.
• To enable real-time, ratiometric monitoring of glutamate concentrations on cell surfaces.
• To provide a new tool for neurobiological research investigating glutamatergic signaling.

Main Methods:

• Semisynthesis of a genetically encoded fluorescent protein sensor.
• Characterization of sensor spectral properties (excitation and emission wavelengths).
• Demonstration of ratiometric sensing of glutamate on the surface of living cells.

Main Results:

• The sensor exhibits glutamate-dependent fluorescence emission between 550 and 700 nm upon excitation at 547 nm.
• A significant ratiometric change of 1.56 was observed on cells.
• The sensor demonstrated high sensitivity to changes in extracellular glutamate concentration.

Conclusions:

• The developed fluorescent glutamate sensor is effective for extracellular sensing.
• Its high sensitivity and specific localization make it a valuable tool for neurobiology.
• This sensor facilitates advanced studies of glutamatergic neurotransmission in physiological and pathological conditions.