Effects of Peptide Ligands

Chelating Effects of Peptide Ligands A. Rubredoxin Peptide Model Complexes 

The difference in redox potential and in thermal stability between native rubredoxin and the simple model complexes has been suggested to be brought about by the different protein environments (18). This is as yet unproved, however. The amino acid sequences of many rubredoxins isolated from various sources have been determined, as shown in Fig. 5 (19). A sequence around the Fe active site, Cys-X-Y-Cys, is an invariant fragment and primarily determines the chemical and physical properties. For example, C. pasteurianum rubredoxin has such sequences, Cys6-Thr-Val-Cys9 and Cys39-Pro-Leu-Cys42. 

Studies of the synthesis of Fe(II) complexes of oligopeptides containing the two invariant Cys-X-Y-Cys fragments have been carried out to 

Clostridium pasteunanum Peptost reptococcus elsdenii Micrococcus aerogenes 

The Redox Potentials of the Fe(II)/L L Peptide Model Complexes in Me2SO 

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