Table 1.

Effects of substitution of residue 148 on the GFP

Mutant	Absorbance band(nm)		Emission banda(nm)		pKa	Quantum yieldb
	A	B	A	B		A	B
S65T	394	489	459/508	510	5.95±0.02c	0.02±0.01	0.67±0.01
S65T/H148N	393	488	459/510	511	6.37±0.02	0.01±0.01	0.45±0.02
S65T/H148E	397	484	460/510	511	7.17±0.05	0.04±0.01	0.24±0.02
S65T/H148D	415	487	510	510	7.95±0.02c	0.21±0.04	0.32±0.03
H148D	400	469	503	505	> 10.4	0.15±0.02	0.40±0.02
wild type GFP	395	475	460/509	505	N.A.	0.75±0.03	0.75±0.03

^aThe emission maxima resulting from excitation at the peak of either absorbance band A or B.

^bQuantum yields of bands A and B were measured at pH 4.5 or 5 and 11, respectively.

^cTaken from reference (17)