Table 2.

Model data for multiple descriptor tyrosine nitration predictions.

Data Set	Model		Descriptor	Threshold Valueb	Reward or Penaltyc	Score fractiond
	Descriptors	Qualitya
In vivo	3	0.779	abs_relative_distance_to_closest_negative_amino_acid_heteroatom	0.220	−3	0.333
			abs_relative_distance_to_closest_positive_amino_acid_heteroatom	0.450	−4	0.444
			distance_to_sidechain_SER_THR_TYR_O	10.1	2	0.222
In vitro	3	0.828	abs_relative_distance_to_closest_negative_amino_acid_heteroatom	1.02	−2	0.286
			abs_relative_distance_to_closest_positive_amino_acid_heteroatom	0.463	−2	0.286
			distance_to_neutral_sidechain	3.91	−3	0.429
All	3	0.809	abs_relative_distance_to_closest_negative_amino_acid_heteroatom	1.02	−4	0.444
			abs_relative_distance_to_closest_positive_amino_acid_heteroatom	0.452	−3	0.333
			sterics8	75.5	−2	0.222
	4	0.845	abs_relative_distance_to_closest_negative_amino_acid_heteroatom	0.599	−7	0.333
			abs_relative_distance_to_closest_positive_amino_acid_heteroatom	0.434	−6	0.286
			distance_to_backbone	3.54	−5	0.238
			nitration_gain	−75.1	3	0.143

^aQuality score of model: $\mathit{\text{Model Quality}}=\sqrt{\frac{\mathit{\text{TP}}}{\mathit{\text{TP}}+\mathit{\text{FN}}}*\frac{\mathit{\text{TN}}}{\mathit{\text{TN}}+\mathit{\text{FP}}}}$, where TP=true positives, FP=false positives, TN=true negatives and FN=false negatives.

^bIf descriptor value exceeds the threshold, the ^creward or penalty will be assessed to the model.

^dScore fraction represents the relative significance of that descriptor to the overall model.