Question

Question 3. (5 marks) Plastocyanin is a copper containing redox enzyme and the copper shuttles between the Cu(I) and Cull) oxidation states. The crystal structures for both Cu(II)- and Cu(l)-plastocyanin have been determined and these show very little change in the Cu-coordination geometry, despite the change in oxidation state. Importantly, the Cu-coordination geometry is neither that preferred by Cu(II) (square-planar) or by Cu(l) (tetrahedral), rather it is in between - trigonal pyramidal (or distorted tetrahedral). Explain how these features are consistent with the Entatic state and facilitate rapid electron transfer?

Answer 1