Long Range Electrons

Biological electron trance reactions, however, differ from similar reactions involving small metal complexes. Perhaps the close obvious of these distinctions is the distance over which the transport surpasss. Typically, LRET involves rapid electrontransport over 10 A or greater. In the last few years, considerable research has been focused on the various parameters which control the process. Important factors which have been investigated include the chase: electron path, extent of heme exposure, orientation of the heme, and solvent set up (6:10607). This paper reviews data relating to the potential outcomes of electron graftral distance, reaction driving force, reorganization energy, and protein structure on spacious footslog electron transport, and then discusses these factors with regard to their general significance.

The accompaniment of LRET has been verified by a number of different authors. In experiments involving cyanometmyoglobin and metmyoglobin, King et al. (1992) demonst investd that electron convert can occur over distances greater than 20 A (6:10607). In addition, Dadak et al. (1992) examined electrontransfer between several protein macromolecules which exhibit yearnlived phosphorescence (i.e., parvalbumin, aldolase, and liver-colored alcohol dehydrogenase) to a protein with a measurable redox effect (i.e., cytochrome c) (2:34). The investigation fou

3. Farver, O.; Pecht, I. Long range intramolecular electron transfer in azurins. Journal of the American Chemical Society. 114:57645767; 1992.

4. Farvor, O.; Skov, L. K.; Van de Kamp, M.; Canters, G. W.; Pecht, I. The effect of driving force on intramolecular electron transfer in proteins: studies on atomic number 53site mutated azurins. Journal of the American Chemical Society. 399403; 1992.

6. King, B. C.; Hawkridge, F. M.; Hoffman, B. M. Electrochemical studies of cyanometmyoglobin and metmyoglobin: implications for longrange electron transfer in proteins. Journal of the American Chemical Society. 114:1060310608; 1992.

Two factors which could affect these electron-transfer reactions include protein structure and conferreracceptor distance. Lee et al.

(1992) examine how protein structure might influence the rate or path of an LRET process. Using a synthetic leucine vigor dimer, the researchers found evidence for LRET along an alphahelix. The LRET system active consisted of a pulse radiolytically initiated electrontransfer from tyrosine to a tryptophan radical. Lee et al. (1992) observed that when the two redox partners were held apart by an alphahelix, the LRET rate measured was not identical to that of a nonhelical structure. In fact, an estimated linear extrapolation from higher to lower temperatures suggested that the LRET rate in the leucine zipper is almost one order of magnitude bumper-to-bumper than the electrontransfer rate in the random curl up at the same low temperature. Additionally, Lee et al. (1992) examined electron transfer in the peptide, 17(Aib)n, and found that the rate constant for its electrontransfer reactions depended exponentially on aminoacid separation (7:291). This data, however, is in direct conflict with that of another study. Conrad et al. (1992) used seven cytochrome c derivatives, each with a single, covalently attached Co(diAMsar) cage complex, to analyze the effect of donoracceptor distance on L
Order your essay at Orderessay and get a 100% original and high-quality custom paper within the required time frame.