Tryptophan 19 residue is the origin of bovine β-lactoglobulin fluorescence

- β-Lactoglobulin Trp 19 residue is the sole fluorescence emitter.
- Fluorescence intensity decay of Trp 19 residue is best described with three lifetimes.
- Lifetimes are independent of the protein state (monomeric or dimeric).
- Addition of calcofluor white does not induce an emission red shift.
- Binding of calcofluor white occurs in proximity to Trp 19 residue.