Table 3.

Values of dihedral angles (θ₁ and θ₁-120°) and ρ_C^π B″(mT) calculated from reported β-methylene hydrogen HFCs (a_β^H (1) and a_β^H (2) in mT) for l-tryptophan radicals in proteins.

Protein- Radical	l-tryptophan	free	a(1)	a(2)	Θ 1	Θ 1- 120	ρCπ B″	Reference
B. adusta VPd			2.25	1.88	−25.4	−145.4	2.77	7
E coli CCPb			0.75	0.46	56.0	−64.0	2.41	4
E. coli RNR R2 Y122Fc			2.76	1.38	−13.3	−133.3	2.92	31
E. coli RNR R2 Y122F Wac			2.83	1.36	−12.4	−132.4	2.98	27
E. coli RNR Y122Wc			2.80	1.30	−11.7	−131.7	2.93	32
E. coli RNRd			2.75	1.38	−13.4	−133.4	2.92	31
Human SODd			0.13	1.43	77.3	−42.7	2.63	33
M. tuberculosis KatG			1.60	0.10	40.8	−79.2	2.81	34
Mouse RNR R2 Y177Wd			2.25	0.15	15.6	−104.4	2.43	31
Mouse RNR R2 Y177Wd			2.25	0.15	15.6	−104.4	2.43	35
Mouse RNR Y177Wd			2.25	1.50	−19.9	−139.9	2.55	35
P. erygii VPc			2.60	1.15	−10.6	−130.6	2.70	8
E. coli RNR R2 Y122F Wbc,e			0.20	1.60	75.4	−44.6	3.15	27
Yeast CCPb,e			0.44	0.72	63.9	−56.1	2.30	5
Bovine CCOa,b			0.41	0.67	64.0	−56.0	2.14	5
Bovine CCO pH= 8.5a,b			0.43	0.62	63.0	−57.0	2.09	5

^aAssignments questioned by Svistunenko⁶ and this work (irregular ρ_C^π B″ values)

^bCation radical

^cNeutral radical with H-bonded proton

^dNeutral radical

^eIrregular ρ_C^π B″ values for unknown reasons

Abbreviations: VP, versatile peroxidase; CCP, cytochrome C peroxidase; RNR, ribonucleotide reductase; SOD, superoxide dismutase; KatG, catalase-peroxidase; CcO, cytochrome c oxidase