Iron-sulfur proteins high potential

High-potential iron-sulfur proteins (HiPIP) form a family of small (—6-10 kDa) soluble electron transport proteins originally only found in photo synthetic representatives of the proteobacteria (for reviews,... 

Pereira MM, Carita JN, Teixeira M. 1999. Membrane-bound electron transfer chain of the ther-mohalophilic bacterium Rhodothermus marinus Characterization of the iron- sulfur centers from the dehydrogenases and investigation of the high-potential iron- sulfur protein function by in vitro reconstitution of the respiratory chain. Biochemistry 38 1276. 

Note A HiPIP stands for high potential iron sulfur protein, a trivial name to indicate that the reduction potential of this type of small ET proteins is relatively high +0. < +0.5 volts. Formally,... 

Heering, H.A., Bulsink, Y.B.M., Hagen, W.R., and Meyer, T.E. 1995. Reversible superreduction of the cubane [4Fe-4S](3+ 2+ 1+) in the high-potential iron-sulfur protein under non-denaturing conditions EPR spectroscopic and electrochemical studies. European Journal of Biochemistry 232 811-817. 

Hipip high potential iron-sulfur protein. 

This cluster formally contains three iron(III) and one iron(E). It is present in a class of proteins called high potential iron-sulfur proteins (HiPIP). It has also been prepared through oxidation of [(RS)4Fe4S4]2 model compounds [57]. Both in the model compound at low temperatures and in proteins there is electron delocalization on one mixed valence pair [58-62]. Therefore, the polymetallic center is constituted by two iron ions at the oxidation state +2.5 and two iron ions at the oxidation state +3. Hamiltonian (6.20), or a more complicated one [40, 41,43], can be used to describe the electronic structure. Indeed, a delocalization operator is sometimes needed in the Hamiltonian [40,41,43]. Consistently with magnetic Mossbauer data the S M subspin involving the mixed valence pair is 9/2, whereas the S n subspin involving the iron(IH) ions is 4. Mossbauer and EPR data do not exclude % and 3, respectively, for the two pairs [57] in any case, the... 

A. Peptide Model and Simple Thiolate Complexes of High-Potential Iron-Sulfur Proteins... 

CV = cyclic voltammetry Fd = ferredoxin HP = high potential iron-sulfur protein IRP = iron regulatory protein LS3 = l,3,5-tris((4,6-dimethyl-3-mercaptophenyl)thio)-2,4,6-tris(/ -tolylthio)benzene (3-) Rd = rubredoxin SCE = standard calomel electrode tibt = 2,4,6-triisopropylphenyl Tp = tris(pyrazolyl)hydroborate (1-). 

Figure 5 The most commonly encountered FeS centers (a) the monoiron center of rubredoxin, (b) the FeySy cluster of plant-type ferredoxins, (c) the FeySy cluster of Rieske proteins, (d) the Fe3S4 cluster of ferredoxins, and (e) the Fe4 4 cluster of ferredoxins and high potential iron-sulfur proteins (FliPiPs).

Ciurli S, Musiani F. High potential iron-sulfur proteins and their role as soluble electron carriers in bacterial photosynthesis tale of a discovery. Photosynth. Res. 2005 85 115-131. 

High-Potential Iron-Sulfur Protein (HiPIP)... 

High potential iron sulfur protein (Chromatium)... 

HiPIP Formerly used abbreviation for high-potential iron-sulfur protein, now classed as a ferredoxin. An ELECTRON-TRANSFER PROTEIN from photosynthetic and other bacteria, containing a [4FE-4S] CLUSTER which undergoes oxidation-reduction between the [4Fe-4S]2+ and [4Fe-4S]3+ states. 

Hipip — high-potential iron—sulfur protein. 

R Maikin and PJ Aparicio (1975) Identification of a g=1.90 high-potential iron-sulfur protein in chloroplasts. Biochem Biophys Res Commun 63 1157-1160... 

The reported distances are all metal-to-metal measures in the case of metal clusters, the closest metal was chosen. Tunneling times range from a few nanoseconds (12.2 A ET in the high-potential iron sulfur protein from C. vinosum) to 10 milliseconds (26 A ET inP. aeruginosa azurin). 

Carter, C.W. X-Ray Analysis of the High Potential Iron-Sulfur Proteins and Ferredoxins. In Iron-Sulfur Proteins (ed. Lovenberg, W.), Vol. 3, New York, Academic Press 1977, pp. 157-204... 

Heering HA, Bulsink YBM, Hagen WR, Meyer TE (1995) Influence of charge and polarity on the redox potentials of high-potential iron-sulfur proteins - evidence for the existence of 2 groups. Biochemistry 34 14675-14686... 

---