A synthetic analogue for the active site of plant-type ferredoxin: Two different coordination isomers by a four-Cys-containing [20]-peptide
✍ Scribed by Norikazu Ueyama; Satoru Ueno; Akira Nakamura; Keishiro Wada; Hiroshi Matsubara; Shin-Ichiro Kumagai; Shumpei Sakakibara; Tomitake Tsukihara
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1992
- Tongue
- English
- Weight
- 917 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
The ( FezSz ) '+ complex of an artificial 20-peptide ligand, Ac-Pro-Tyr-Ser-Cys-Arg-Ala-Gly-Ala-Cys-Ser-Thr-Cys-Ala-Gly-Pro-Leu-Leu-Thr-Cys-Val-NHz, containing an invariant Cys-A-B-C-D-Cys-X-Y-Cys (A, B, C, D, X, Y = amino acid residues) fragment of planttype ferredoxins was synthesized by a ligand exchange method with [ Fez& ( S-t-Bu),] '-.
'H-nmr spectroscopic and electrochemical data of the complex indicate the presence of two coordination isomers. One of them having a Cys-X-Y-Cys bridging coordination to the two Fe(II1) ions, has the (FezSZ)*' core environment similar to those of the denatured plant-type ferredoxins and exhibits a positive shifted redox potential at -0.64 V vs saturated colonel electrode (SCE) in N,N-dimethylformamide (DMF) . Another isomer with the Cys-A-B-C-D-Cys bridging coordination shows a negative redox potential at -0.96 V vs SCE in DMF.