Please note that the content of this book primarily consists of articles
available from Wikipedia or other free sources online. Yellow
Fluorescent Protein (YFP) is a genetic mutant of green fluorescent
protein, derived from Aequorea victoria. Its excitation peak is 514nm
and its emission peak is 527nm. Like green fluorescent protein (GFP), it
is a useful tool in cell and molecular biology, usually explored using
fluorescence microscopy. Three improved versions of YFP are Citrine,
Venus, and Ypet. They have reduced chloride sensitivity, faster
maturation, and increased brightness (product of the extinction
coefficient and quantum yield). Typically, yellow FPs serve as the
acceptor for genetically-encoded FRET sensors of which the most likely
donor FP is mCFP (monomeric cyan FP). The red-shift relative to GFP is
caused by a Pi-Pi stacking interaction as a result of the T203Y
mutation, which essentially increases the polarizability of the local
chromophore environment as well as providing additional electron density
into the chromophore.
