Table 1.

Quenching parameters in KI^a

Conditions	KSV (M−1)
pH 6.5	3.6 ± 0.3
6 M GdmCl	4.0 ± 0.2
6 M urea	4.4 ± 0.3

^a Errors are data fit errors to Eq. 1. The constants were obtained by fitting of fluorescence intensity at 338 nm versus concentration of quenching agent (similar constants were obtained by fitting the intensities at 335, 336, and 337 nm; data not shown). Experiments were carried out at 298 K, pH 6.5, 10 mM phosphate buffer.