TABLE 1.
Characterization of NH2Y• formation in α:β complexes with various on- and off-pathway mutations
| β:α complex | % NH2Y• (EPR)a |
% NH2Y• (SF UV-vis)a |
first phase kobs (s−1) |
second phase kobs (s−1) |
|---|---|---|---|---|
| wt-β2:Y730NH2Y-α2b | 53 | 39 | 12.8 | 2.5 |
| wt-β2:Y731NH2Y-α2b | 45 | 35 | 19.2 | 2.7 |
| Y356F-β2:Y730NH2Y-α2 | <3% c | <2% c | -- | -- |
| Y356F-β2:Y731NH2Y-α2 | <3% | <2% | -- | -- |
| wt-β2:Y731F/Y730NH2Y-α2 | <3% | <2% | -- | -- |
| wt-β2:Y413NH2Y-α2 | 12 | 8 | 4.8d | 0.5 |
| wt-β2:Y731F/Y413NH2Y-α2 | 7 | 12 | 0.04 | -- |
| Y356F-β2:Y413NH2Y-α2 | <3% | NDe | -- | -- |
a
Y122• converted to NH2Y•, as a percent of the starting [Y122•].
b
Originally reported in reference 15.
c
No conversion detected within our lower limit of detection, approximated to be 3% of the total initial Y122• by EPR and 2% by SF UV-vis spectroscopy.
d
Taken as the average of the rate constants measured at 325 nm and 410 nm.
e
Not determined.