Iron–sulfur cluster

Structure of [Fe4S4(SMe)4]2−, a synthetic analogue of 4Fe–4S cofactors.[1]

Iron–sulfur clusters are molecular ensembles of iron and sulfide. They are most often discussed in the context of the biological role for iron–sulfur proteins, which are pervasive.[2] Many Fe–S clusters are known in the area of organometallic chemistry and as precursors to synthetic analogues of the biological clusters. It is supposed that the last universal common ancestor had many iron-sulfur clusters.[3]

In biology

See also: iron–sulfur protein

Iron–sulfur clusters occur in many biological systems, often as components of electron transfer proteins. The ferredoxin proteins are the most common Fe–S proteins in nature. They feature either 2Fe–2S or 4Fe–4S centers. They occur in all branches of life.[4]

Fe–S clusters can be classified according to their Fe:S stoichiometry [2Fe–2S], [4Fe–3S], [3Fe–4S], and [4Fe–4S].[5] The [4Fe–4S] clusters occur in two forms: normal ferredoxins and high potential iron proteins (HiPIP). Both adopt cuboidal structures, but they utilize different oxidation states. They are found in all forms of life.[6]

The relevant redox couple in all Fe–S proteins is Fe(II)/Fe(III).[6]

Many clusters have been synthesized in the laboratory with the formula [Fe4S4(SR)4]2−, which are known for many R substituents, and with many cations. Variations have been prepared including the incomplete cubanes [Fe3S4(SR)3]3−.[7]

Synthetic Fe–S clusters

Structure of the hydrated ammonium salt of [Fe4S3(NO)7]−.

Synthetic Fe–S clusters are laboratory-prepared coordination compounds or chains, often designed to mimic the structural, electronic, or chemical properties of biological Fe–S clusters.

Roussin's black anion, [Fe4S3(NO)7]−, described in 1858, is the first synthetic Fe-S cluster.[8] It has the geometry of an incomplete cubane-type cluster with C3v symmetry. The dark colour of the complex is attributed to a number of charge-transfer interactions.[9] Since the 1970s, many of these Fe-S clusters have been described.[10][11] A key property of Fe–S clusters is their ability to undergo redox.

Organometallic clusters

Organometallic Fe–S clusters include the sulfido carbonyls with the formula Fe2S2(CO)6, H2Fe3S(CO)9, and Fe3S2(CO)9. Compounds are also known that incorporate cyclopentadienyl ligands, such as (C5H5)4Fe4S4.[12]

Figure. Illustrative synthetic Fe–S clusters. From left to right: Fe3S2(CO)9, [Fe3S(CO)9]2−, (C5H5)4Fe4S4, and [Fe4S4Cl4]2−.

Inorganic materials

Structure of potassium dithioferrate, which features infinite chains of Fe(III) centers.

In maquettes and artificial proteins

It is possible to incorporate Fe–S clusters into maquettes (smaller minimal functional proteins designed from biological proteins) and artificial proteins, often abbreviated to MAPs. The first examples of Fe–S MAPs emerged in the early 1970s, as a means to mimic naturally occurring iron-containing proteins like rubredoxins. These contained [Fe(S-Cys)4] motifs.[10] Further research into [4Fe–4S] MAPs has led to the development of ambidoxins: de novo maquettes that consist of 12 residues with the sequence X-Cys-X2-Cys-X2-Cys-X2-Cys-X (X = Arg, Lys), which can successfully perform hundreds of redox cycles. However, Fe–S MAPs are limited by their lower solubility and exposed Fe–S cluster core that is susceptible to degradation by solvents.[10][11][13]

See also

References

  1. ^ Axel Kern; Christian Näther; Felix Studt; Felix Tuczek (2004). "Application of a Universal Force Field to Mixed Fe/Mo−S/Se Cubane and Heterocubane Clusters. 1. Substitution of Sulfur by Selenium in the Series [Fe4X4(YCH3)4]2–; X = S/Se and Y = S/Se". Inorg. Chem. 43 (16): 5003–5010. doi:10.1021/ic030347d. PMID 15285677.
  2. ^ Lippard, S. J. and Berg, J. M. (1994). "Principles of Bioinorganic Chemistry". University Science Books: Mill Valley, CA. ISBN 0-935702-73-3.
  3. ^ Weiss, Madeline C., et al. (2016). "The physiology and habitat of the last universal common ancestor." Nature Microbiology 1 (9): 1–8.
  4. ^ Johnson, D. C.; Dean, D. R.; Smith, A. D.; Johnson, M. K. (2005). "Structure, function, and formation of biological iron-sulfur clusters". Annual Review of Biochemistry. 74 (1): 247–281. doi:10.1146/annurev.biochem.74.082803.133518. PMID 15952888.
  5. ^ Lill, Roland (2015). "Issue of iron-sulfur protein". Biochimica et Biophysica Acta (BBA) - Molecular Cell Research. 1853 (6): 1251–1252. doi:10.1016/j.bbamcr.2015.03.001. PMC 5501863. PMID 25746719.
  6. ^ a b Fisher, N (1998). "Intramolecular electron transfer in [4Fe–4S)]". The EMBO Journal: 849–858.
  7. ^ Rao, P. V.; Holm, R. H. (2004). "Synthetic Analogues of the Active Sites of Iron-Sulfur Proteins". Chem. Rev. 104 (2): 527─559. doi:10.1021/Cr020615+. PMID 14871134.
  8. ^ Butler, Anthony R. (July 1982). "The chemist Z. Roussin (1827-94)". Journal of Chemical Education. 59 (7): 549. Bibcode:1982JChEd..59..549B. doi:10.1021/ed059p549.
  9. ^ Jaworska, Maria; Stasicka, Zofia (March 2006). "Structure and UV–vis spectroscopy of roussin black salt [Fe4S3(NO)7]−". Journal of Molecular Structure. 785 (1–3): 68–75. Bibcode:2006JMoSt.785...68J. doi:10.1016/j.molstruc.2005.09.030.
  10. ^ a b c Boncella, Amy E.; Sabo, Emily T.; Santore, Robert M.; Carter, Jens; Whalen, Jaclyn; Hudspeth, Jesse D.; Morrison, Christine N. (2022-02-15). "The expanding utility of iron-sulfur clusters: Their functional roles in biology, synthetic small molecules, maquettes and artificial proteins, biomimetic materials, and therapeutic strategies". Coordination Chemistry Reviews. 453 214229. doi:10.1016/j.ccr.2021.214229. ISSN 0010-8545.
  11. ^ a b Waser, Valerie; Ward, Thomas R. (2023-11-15). "Aqueous stability and redox chemistry of synthetic [Fe4S4] clusters". Coordination Chemistry Reviews. 495 215377. doi:10.1016/j.ccr.2023.215377. ISSN 0010-8545.
  12. ^ Ogino, H.; Inomata, S.; Tobita, H. (1998). "Abiological Iron-Sulfur Clusters". Chem. Rev. 98 (6): 2093–2122. doi:10.1021/cr940081f. PMID 11848961.
  13. ^ "Synthetic Iron-Sulfur Clusters". Mougel Group - Bioinspired Molecules and Materials. Retrieved 2026-01-07.
allikas: https://en.wikipedia.org/wiki/Iron_sulfur_cluster