. Author manuscript; available in PMC: 2020 Mar 20.

Published in final edited form as: J Am Chem Soc. 2019 Mar 7;141(11):4678–4686. doi: 10.1021/jacs.8b13610

Table 1.

PmoD paramagnetic spectroscopic features.

Paramagnet	g_x, g_y, g_z	Cu A_z (MHz)	¹⁴N₁ A_x,y, A_z (MHz)^§	¹⁴N₂^* A_x,y, A_z (MHz)^§	Cys-C_β ¹H₁ A_x,y, A_z^∇ (MHz)	Cys-C_β ¹H₂ A_x,y,z (MHz)
Cu_A	2.01, 2.05, 2.13	141	+17, +16.5	+16, +16.5	+14.5, +17	~4.5
Type 2 Cu₁	−, −, 2.23	610
Type 2 Cu₂	−, −, 2.20	545

¹⁴N₂ shows resolved quadrupole splitting at the high field extreme, 3P = 2.3 MHz.

^§

¹⁴N hyperfine couplings assumed to be positive, as necessitated by the fact that they are directly-coordinated in-plane Cu ligands (with respect to the Cu₂[S(Cys)]₂ core).

^∇

To determine the sign of A_{Cys–C_β¹H₁}, we conducted pulsed ENDOR saturation recovery (PESTRE)³¹ measurements (Figure S7). Such measurements indicate that for PmoD, A_{Cys–C_β¹H₁} > 0, consistent with past characterization of other Cu_A centers.^21,32