Abstract: | The magnetic susceptibility of the acetazolamide complex of human Co(II) carbonic anhydrase B was measured between 1.4 and 160 K. From the temperature dependence of the paramagnetic contribution of Co(II) a g-value of 2.23 +/- 0.02 and a zero-field splitting of (33 +/- 1) cm-1 were estimated. The effective number of Bohr magnetons as T leads to 0 is 3.35 in excellent agreement with the number (3.38) calculated from the apparent g'-values of the EPR spectrum at 16 K. Extrapolation to high temperatures gave an effective number of Bohr magnetons of 4.32. |