How is the intensity of fluorescence in GFP affected?

The intensity of fluorescence in GFP is influenced by multiple factors including pH, temperature, and the protein's environment.

When considering pH, it affects the ionization state of amino acid residues within the protein structure, which can alter the absorbance of the chromophore responsible for fluorescence. Variations in temperature can influence the kinetics of molecular motion and stability of the protein, potentially affecting the quantum yield of fluorescence. Furthermore, the protein's environment, such as interactions with other molecules or changes in the local polarity, can also impact the fluorescence output.

In contrast, the effects of temperature, pH, and environmental interactions together explain why solely focusing on one aspect, such as temperature alone or GFP concentration only, fails to capture the comprehensive influences on fluorescence intensity. Thus, recognizing the synergy of these factors is essential for understanding how fluorescence is modulated in GFP.