2008 Nobel Prize in Chemistry
Reason for Award
for the discovery and development of the green fluorescent protein, GFP
Laureates
Japan
United States of America
United States of America
Explanation
Scientists studying why certain jellyfish glow discovered a special protein called GFP. When blue or ultraviolet light shines on GFP, the protein lights up bright green all by itself. By attaching GFP to a gene and putting it into a cell, researchers can see exactly where that cell is and what it is doing just by looking through a microscope. This helps doctors find diseased cells or check if a medicine is working. Although the protein originally came from a jellyfish, it is now used in laboratories all over the world. It even shows up in glow-in-the-dark toys and aquarium fish that shine at night. Thanks to GFP, scientists have a new “green flashlight” that lets them peek inside the mysteries of living things.
Related Keywords
Green Fluorescent Protein
1. GFP is an autofluorescent protein originally isolated from the jellyfish Aequorea victoria that emits green light when excited by UV or blue light. 2. The chromophore is buried inside a 238-amino-acid β-barrel, shielding it from quenchers and providing high photostability. 3. Because no external cofactors are required, GFP can be expressed in virtually any organism, making it ideal for biological imaging. 4. Gene fusions allow visualization of specific proteins or promoter activities, establishing GFP as a standard tool for studying cell dynamics. 5. Engineering has produced numerous variants with altered colors, photo-switchability, and sensing capabilities, vastly broadening its research applications.
Bioluminescence
1. Bioluminescence is the production of visible light by living organisms through enzyme-catalyzed reactions, common in marine species and insects. 2. In the jellyfish, GFP acts within a complementary system by absorbing blue light emitted from the photoprotein aequorin and re-emitting green light. 3. Unlike luciferase systems, GFP requires no exogenous substrate, making their experimental uses distinct yet complementary. 4. Ecologically, bioluminescence is believed to aid in predator avoidance, prey attraction, and intra-species communication. 5. Modern research combines GFP with luciferase reporters to optimize imaging sensitivity and multiplexing in vivo.
Chromophore
1. A chromophore is the chemical moiety in a molecule that absorbs and emits light, giving the molecule its color. 2. In GFP, the chromophore forms spontaneously from residues Ser65-Tyr66-Gly67 to create an imidazolinone structure. 3. Buried inside the β-barrel, it is isolated from solvent, boosting quantum yield and photostability. 4. Amino-acid mutations alter π-conjugation length and electron donation, permitting fine tuning of excitation and emission spectra. 5. The surrounding hydrogen-bond network and proton wire modulate pH sensitivity and photo-switching behavior, critical for sensor design.
Live-cell Imaging
1. Live-cell imaging refers to real-time observation of dynamic processes in cultured cells or whole organisms. 2. GFP tags enable tracking of protein localization and movement without fixation or staining. 3. When coupled with confocal or two-photon microscopy, high-resolution 3-D visualization is achievable even in deep tissues. 4. Techniques such as FRET and FRAP allow quantification of protein-protein interactions and diffusion rates. 5. Live-cell imaging underpins diverse applications, including drug screening, immune-response analysis, and neural-circuit mapping.
Spectral Variants
1. Spectral variants are engineered GFP-like proteins whose excitation and emission wavelengths differ due to amino-acid substitutions. 2. Variants such as CFP, YFP, and mCherry, produced by Tsien and others, enable true multicolor analysis. 3. Wavelength shifts facilitate simultaneous visualization of several proteins and the design of efficient FRET pairs. 4. Many variants are optimized for monomericity and brightness, reducing cytotoxicity and aggregation issues. 5. Newly developed spectral variants, combined with genome editing and optogenetics, accelerate the dissection of complex biological systems.