TABLE 1.

Intrinsic fluorescence properties of PDI mutants

Protein	Barycentric mean wavelength (λm)a	Shifts in λmb	Ksvc
	nm	nm	m−1
b′x	343.8		0.92 ± 0.05 (n = 3)
I272A b′x	340.5	−3.3	1.03 ± 0.02 (n = 2)
L343A b′x	349.6	+5.8	2.14 ± 0.06 (n = 2)d
W111F/W390F PDI	348.7		0.84 ± 0.21 (n = 6)
W111F/W390F/I272A PDI	346.8	−1.9	0.92 ± 0.22 (n = 5)
W111F/W390F/L343A PDI	350.0	+1.3	1.52 ± 0.17 (n = 4)d
W111F abb′x	345.6		0e
W111F/I272A abb′x	342.9	−2.7	0e
W111F/L343A abb′x	347.0	+1.4	1.26 ± 0.05 (n = 3)d

^a The barycentric mean wavelength between 310 and 400 nm was calculated as λ_m = ΣF(λ)×(λ)/ΣF(λ), where F(λ) is the fluorescence intensity at wavelength λ (29).

^b Difference of λ_m of I272A or L343A mutants minus λ_m of the corresponding background proteins. −, blue shift; +, red shift.

^c Data were expressed as the mean ± S.D.

^d p < 0.001.

^e No quenching detectable.