Fig. 2.

Effect of CN2-Cbi and vitamin B₁₂ on sGC activity. A, structural formulae of dicyanocobinamide (top panel) and vitamin B₁₂ or B₁₂-containing cofactors (bottom panel). Underlined ligands are for the B₁₂ vitamer, and italicized ligands are for the cofactors. B, concentration-response curve to dicyanocobinamide (♦), cyanocobalamin (Vit B12, □), and hydroxycobalamin (Vit B12a, ▵) determined using the [α-³²P]GTP assay. Data are means ± S.D. of three independent experiments performed in triplicate. *, p < 0.05 versus vitamin B₁₂. C, comparison of concentration-response curve to dicyanocobinamide (♦) and cobalamine (▵). Data are means ± S.D. of two independent experiments performed in triplicate. *, p < 0.05.