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. Author manuscript; available in PMC: 2009 Feb 1.
Published in final edited form as: Biochim Biophys Acta. 2007 Dec 15;1777(2):227–237. doi: 10.1016/j.bbabio.2007.11.011

Table 1.

Effect of PROXYL Spin Label at Different Positions in Subunit a on Trp Indole Resonancea.

PROXYL Position Other Mutations W39 W111 W186 W216 W231 W232 W235 W241 W254 W186 & W241
118 - 1 <0.10 ncb - 0.91 0.98 0.99 ncb - 1.00
123 - 1 0.88 ncb - 0.96 1.12 1.15 ncb - 0.93
206 F254W 1 1.36 ncb - 1.01 1.05 1.12 ncb 1.14 0.85
218 - 1 ncc ncb - <0.10 1.22 1.09 ncb - 1.03
222 - 1 ncc 1.05 - <0.10 <0.10 <0.10 <0.10 - 0.65
223 - 1 1.07 ncb - <0.10 <0.10 <0.10 ncb - 0.59
223 W186F 1 1.23 - - <0.10 <0.10 <0.10 <0.10 - -
247 - 1 1.39 ncb - 0.53 1.13 0.79 ncb - 1.01
248 Y216W 1 1.18 ncb 0.75 0.74 0.84 0.89 ncb - 0.58
249 - 1 1.08 ncb - 0.27 0.82 <0.10 ncb - 0.76
254 - 1 0.82 ncb - 0.78 1.03 1.07 ncb - 0.99
256 - 1 0.95 ncb - 1.08 0.94 1.10 ncb - 1.08
a

The signals of Trp indole NH are expressed as ratio of peak volumes before and after reducing the spin label with phenylhydrazine. The signal of W39 that showed no obvious line broadening in any of the experiments was used to normalize the peak volumes in the reduced and oxidized samples.

b

nc, not calculated. Due to overlap of the W186 and W241 signals in most spectra, the relative peak volumes of the individual W186 and W241 resonances could not be calculated. The ratio of the combined peak volumes are given in the last column of the table.

c

nc, not calculated. Signal splitting upon addition of phenylhydrazine was observed with several of the W111 samples making the peak volume measurements unreliable (see Fig. 4 for examples).