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The author has described some formative events in his scientific career and has given a personal introduction to the resonance Raman spectroscopy and its application to metalloproteins.

Combining quantum and molecular mechanics (QM/MM) methods and protein structure prediction algorithms, helix and loop movements were computed along the pathway of CO dissociation from myoglobin (Mb). The principal effect of CO dissociation is shown to be a concerted rotation of the E and F halices, which hold the heme like a clamshell.

A study was conducted about the axial ligation of a corrinoid iron-sulfur protein (CFeSP) that plays a key role in energy generation and cell carbon synthesis by anaerobic microbes, such as methanogenic archaea and acetogenic bacteria. The results obtained demonstrate that the elongation of the Co-OH(sub 2) bond of the CFeSP-bound cofactor was proposed to make the cobalt center more 'Co(super 1+)-like', a requirement to facilitate heterolytic Co-C bond cleavage.

A study based is used to demonstrate that in catechol 1,2-dioxygenase (C12O), an intradiol enzyme, and the catechol binds to the Fe(III) as a dianion. It can be concluded that the basis of the respective regiospecificities of intradiol and extradiol dioxydenase linked to the protonation state of the bidentate-bound catechol in the enzyme/substrate complex.

Early events in the unfolding of apomyoglobin are studied with ultraviolet resonance raman (UVRR) spectroscopy coupled to a laser-induced temperature jump. The result indicates that all of the UVRR signals show a prompt response, within the instrument resolution, which accounts for half of the total relaxation amplitude.

Different UV wavelengths for the resonant Raman excitation of hemoglobin in its two affinity states (Tand R) is explored. Changes in the T - R difference spectra as a function of excitation wavelength are reported.

Ferritins are iron -storage proteins capable of holding up to 4500Fe(Super 3+) ions with in a single water-soluble protein shell made from 24 polypeptide chain. The Glu128Arg/Glu135Arg mutants of Escherichia coli and Rhodobacter capsulatus bacterioferritins are unable to associate into 24-meric structures, with dimmers of polypeptide chains being their stable forms.

Photodegradation of imidazole [ImH], 4-methylimidazole [4MeImH], and histidine during collection of UV resonance Raman [UVRR] spectra is reported. Histine degradation is an insidious problem in protein UVRR spectroscopy because of the weakness of the histidine Raman signals.

The similarities and differences between the active site PKs of Mn-superoxide dismutase and those of Fe-superoxide dismutase are discussed. It is shown that in both oxidation states the metal center is weakly affected through the local dielectric, the active site hydrogen bond network and a loosely bound molecule of H2O.

Results point out that the presence of the heme b and the absence of a metal histidine bond are involved in the the activation of soluble guanylyl cyclase. Further, the metalloprotein porphyrins serve as activators and are bound 4-coordinate to the enzyme, suggesting that the tetrapyrrole conformation is important.

Ultraviolet Resonance Raman Spectroscopy (UVRRS), electronic absorption spectroscopy, and X-ray crystallography are used to probe the nature of the binding of 2,3-dihydroxybiphenyl (DHB) to the extradiol ring-cleavage enzyme, 2,3-dihydroxybiphenyl 1,2-dioxygenase (DHBD; EC 1.13.11.39). The structural data show that the aromatic rings of the enzyme-bound DHB are essentially orthogonal to each other.

Carbon monoxide binding by de novo heme proteins from designed combinatorial libraries is explored.

The results of the DFT (B3LYP) calculations of the structures and force fields of the five spin states of a model deoxyheme (C(sub s) symmetry) are presented. A detailed analysis of low-frequency vibrations and their isotope shifts is given and compared with the experimental resonance Raman spectra.

Researchers from Oak Ridge National Laboratory and the University of Tennessee conducted sorption experiments on pertechnetate using a class of bifunctional strong-base anion-exchange resin sites composed of two trialkyl-ammonium groups

The effect of 13C labelling of tyrosine residues on the static and time-resolved ultraviolet resonance Raman spectra was examined in the effort to understand the allosteric reaction coordinate in hemoglobin. Results demonstrating chain sensitivity are presented.

Solid scintillating fibers, coated with a dual-mechanism bifunctional polymer shown to bind Cs(I) in alkaline solutions, were developed for measurement of (super 137)Cs. The effect of the epoxy-polymer coating thickness on attenuation of the signal from (super 137)Cs was evaluated. After optimal coating conditions were determined, both scintillation fiber and resin functions were retained, producing stable field-ready fibers. Temporal studies were performed to examine the kinetics of (super 137)Cs uptake into the resin. Calibration curves of the fiber response were generated by (beta)-emission from solutions of (super 137)Cs dissolved in 1 M sodium hydroxide. The plots exhibited a linear response over a range of 4-3200 nCi/mL(3.4 x 10(super -10)-2.7 x 10(super -7) M (super 137)Cs), with a limit of detection of 3.65 nCi/mL (approximately 42 parts per trillion (super 137)Cs). The distribution coefficient of Cs was determined to be 490 +/- 50 mL/g from these measurements. Selectivity studies of the resin were performed in the presence of 100 fold excess of Sr(II), A1(III), and nonradioactive Cs(I). Linear calibration plots were obtained in the presence of these potential interferences, but at a reduced sensitivity. The fibers were also used to evaluate the (super 137)Cs content of a mock tank waste sample to show the potential of the fibers in complicated matrixes.

Researchers from Nottingham, UK collected stream water samples to test the presence of organic and sulfuric acid as a result of acid leaching from farmlands in midwestern Finland.

The nature of metal-bound histidine ultraviolet resonance Raman (UVRR) bands in Cu, Zn superoxide dismutase is explored.

Research concerning the reaction between CooA and NO to form a five-coordinate NO-heme has been conducted. The use of electronic absorption and resonance Raman spectroscopies is discussed.

This article presents a analysis of the relation between the use of lead in gasoline and population blood levels from 19 studies from six continents. In 17 of the studies, there are data changes in blood lead levels before and after the changes in use of lead in gasoline. In 11 of the studies, there are data on air lead levels. The analysis of the data suggests that reductions in gasoline lead levels have been a major causal factor in the observed reductions in population blood lead levels at these locations. Tables and cites are included.

Research is presented describing the back-bonding effects which dominate vibrational frequency variations for NO and O2, and CO adducts of heme. The interactions of heme and its bound ligands with the surrounding matrix of protein may explain the activation of small-molecules.

The action of bacterial nitric oxide reductase (NOR) on nitric oxide and nitrous oxide plays an integral role in the completion of the two-electron process undergone by these compounds. NOR is considered a diverged member of the heme-copper oxidase group since it exhibits a distinct electronic absorption spectrum. Experimental data derived from a Pavacocus denitrificans strain suggest that the oxygen reducing activity manifested by heme-copper oxidases is significantly attributed to the substitution of copper for non-heme iron in the dinuclear center.

Resonance Raman (RR) spectroscopy is used to characterize the methylmalonyl-coenzyme A (MM-CoA) mutase, a prototype of adenosylcobalamin- (AdoCbl) dependent isomerase enzymes. The RR spectra suggest that a Co-C tilting is part of the Co-C activation mechanism in MM-CoA mutase. Moreover, the observed RR enhancement patterns are reversed when a bound substrate or product is contained in the enzyme, indicating that the steric forces responsible for the tilting are relieved when the substrate or product is rearranged in the active site.

The vibrational spectra of the mercury thiolate complexes (Hg(SME)3)(super 3-), (Hg(Sbu(super t))3)- and Hg(SCH2CH2NH2)2 are examined using ultraviolet resonance Raman spectroscopy and vibrational analysis. Results from vibrational coordinate mixing provide insight into the variable spectral patterns for the Hg->S proteins and models. The Raman bands for the Hg->S complexes are found to be resonantly enhanced by excitation at UV wavelengths, in resonance with S->Hg charge-transfer excited states.

UV resonance Raman difference spectra between deoxyhemoglobin and ligated contained tryptophan and tyrosine signals which arise from quaternary H-bonds in the T state which were broken in the R state. The H-bonds were unaffected by bis(3,5-dibromosalicyl) fumarate cross-linking at the Lys alpha 99 residues, which prevented dissociation of Hb tetramers to dimers. However, when the pH was lowered from 9.0, or when NaCL was added, intensity diminished for the tyrosine Y8 and tryptophan W3 bands of cross-linked deoxyHb, but not of native deoxyHb.

A study was conducted to analyze a reaction coordinate for the allosteric transition in human hemoglobin based on the static and time-resolved Raman spectroscopy of hemoglobin(sub A) and of the mutant hemoglobin(sub K)(D-alpha-99N). The heme was held between the proximal and distal helices that were tethered using H-bonds. Results indicated that cooperativity in hemoglobin is influenced by interhelical H-bonds that promote the helices to act as levers.

Research was conducted to examine the role of an invariant asparagine (Asn38) residue which forms three H-bonds that could have an important influence in fixing the position of the cysteine ligand, Cys84. PCR-mediated mutagenesis was used to replace the asparagine with leucine, threonine or glutamine to investigate the role of the Asn38 side chain. Results indicate the importance of intermolecular H-bonds adjacent to the binding site of type I Cu proteins.

The nature of heme ligation and its CO activation mechanism were examined via resonance Raman spectra of the CO-responsive transcription factor CooA from Rhodospirillum rubrum. The results suggested that CO-dependent CooA activation works under a novel charge relay mechanism. Reprotonation of Histidine 77 upon ligand displacement by Co takes place in the mechanism. Moreover, displacement of either His 77 of the trans ligand, X was made possible by CO.

The orbital ordering of the cation radicals in beta-substituted porphyrins have been studied using resonance Raman spectroscopy. The obtained spectra is similar to the parent Cu-tetraphenylporphyrins but has extra bands showing a reduction in molecular symmetry from D4h to Cs. Additional Raman spectroscopic data agree with the orbital ordering of these beta-substituted derivatives.

A 'chromophore-in-protein' approach was used to model geometries and resonance Raman (RR) spectra for type 1 copper active sites of plastocyanin and azurin and two azurin site-directed mutants. Geometries and vibrational spectra were calculated using force constants for the Cu coordination group that fits the RR spectra along with the AMBER force field. Under the 'chromophore-in-protein' approximation, a large portion of the protein is included in the calculation but only atoms within a certain distance of the Cu were allowed to vibrate, thus reducing the size and complexity of the calculation while keeping all the protein forces.

Plastocyanin (Pcy) is a prototypical type 1 copper protein mediating long range electron transfer in photosynthetic plant systems. Resonance Raman (RR) spectra for recombinant poplar Pcy isotopically labeled with cystein-CbetaD(sub2) and (super15)N, are reported. Isotope shifts conform the 400cm(sper1-) vibrations, heavily admixed with cystein internal coordinates. The isotope shifts also allow assignments of high-frequency RR bands to internal His87 and Cys84 vibrations.

The horseradish peroxidase (HRP) heme enzyme can catalyze the oxidation of several organic and inorganic compounds, using hydrogen peroxide. It has also been shown to catalyze the hydroxylation of benzene efficiently in the presence of peroxide. Resonance Raman spectroscopy is a sensitive and powerful probe of the heme active site structure in heme enzymes such as HRP.The characterization of ferric HRPPEG and a ferrous carbon monoxide compound of HRPPEG in benzene solution has been undertaken, using resonance Raman spectroscopy.

The successful simulation of Q-band resonant enhancement of the Raman-active vibrations of nickel porphine is demonstrated. Both coordinate-independent and coordinate-dependent contributions to the scattering amplitude are considered. Trends observed in the experimental data which originate owing to interference between A-term and B-term scattering contributions were accurately reproduced. This underscores the reliability of the relative magnitudes and phase of the Condon and non-Condon parameters which are computed at the INDO level as the vibrational properties of the molecule are accounted for.

The Rothamsed Park Grass Experiment served as a viable environmental monitoring sample for conducting archived soil and herbage analysis. It was shown that Rothamsed's sulfur dioxide emission rate is directly related to the area's herbage S concentration. Although the numerical value representing the herbage variable has decreased considerably from 1900 to 1970, the concentration of total and extractable S in the topsoil were insignificant to the area's pollution rate.

Experiments were performed to explore the structural changes in hemoglobin which has altered by deleting the C-terminal residues, Arg alpha141 and Tyr alpha140 from the alpha chain and the His beta146 and Tyr beta145 from the beta chain. Alteration of C-terminal residues resulted to the appearance of high pH of negative difference signals on the ultraviolet resonance Raman spectra. The loss of the C-terminals also affected the strength of the Fe-His bond. Furthermore, a direct association between the Fe-His bond strength and the acidity of the quaternary structure was also observed.

Aspartate side chains were labeled using bacterially expressed hemoglobin to confirm the hypothesis that tyr alpha42 acts as an acceptor and Asp beta99 acts as the donor in the H-bond that stabilizes the T quaternary structure in hemoglobin tetramers. If Asp beta99 is the donor, it was surmised that it was protonated in the T state. Fourier transform infrared evidence suggests that Asp beta99 is not protonated and its carboxylate anion does accept an H-bond from the tyr alpha42 OH.

A study was conducted to analyze the low-lying spin states of iron(II) porphine. Density functional theory was utilized to carry out quantum-chemical computations of molecular potential surfaces. The force field for each spin state was evaluated to determine the frequency of vibrations involving iron motion. Experimental results indicated five modes supporting large amplitude motions of the iron atom.

A study was conducted on the mechanism of an antibody-catalyzed reaction in comparison to that of the corresponding enzyme. The results indicate that the antibody that catalyzes metal insertion into porphyrins and the corresponding enzyme, ferrochelatase, both induce distortion in the porphyrin substrate. However, the antibody-induced distortion is different from the enzyme-induced distortion.

Hemes occur in a wide variety of proteins having diverse functions. Ferrochelatase is a terminal enzyme in heme biosynthesis, catalyzing insertion of ferrous iron in the porphyrin macrocycle. Resonance Raman (RR) spectroscopy was used to investigate the mechanism of yeast ferrochelatase, lacking in iron-sulfur cluster. Results suggest that porphyrin binding to ferrochelatase does not itself cause significant macrocycle distortion, but the presence of Hgsuper2+, significantly alters the structure.

Phenyl-deuterated tyrosine (Tyr-d4) and indole-deuterated tryptophan (Trp-d5) were selectively introduced into hemoglobin (Hb) by expressing the gene in auxotrophic strains of Escherichia coli. Findings showed that the Trp alpha14 contributions to the T - R difference spectrum to be minimal and Trp beta37 was found to be a locus of the W3 difference signal. Also, there is a stronger T-state H-bond between Trp beta37 and Asp alpha94.

Soluble guanylyl cyclase (sGC) is a cytosolic enzyme catalyzing the conversion of guanosine 5'-triphosphate (GTP) to guanosine 3',5'-monophosphate (cGMP). Spectroscopic studies have confirmed that nitric oxide (NO) binds directly to the Fe atome in the hem group, indicating that the resting form of sGC could be five-coordinate FE(II)PPIX(His) or a combination of five-coordinate FE(II)PPIX-(His) and six-coordinate Fe(II)PPIX(His)2.

Resonance Raman studies on Ni(II) and copper(II) 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrin (MOETPP) pi-cation radicals confirmed that CuOETPP+ is an A(sub 2u) cation while NiOETPP+ an A(sub 1u) cation. There was also an observed big change in orbital energies when Ni is substituted with Cu in the MOETPPs which is proposed to be due to the sterically-induced out-of-plane distortion in the MOETPPs and to distortion-induced orbital interactions.

Raman resonance spectroscopy was utilized to assess the structure of RuII octaethyltetraphenylporphyrins (OETPP) and determine bond interactions. Raman spectroscopy indicated the presence of phi-back-bonding effects in the OEP and TPP adducts of RuIITPP(Py)2 and RuIIOEP(Py)2 due to the increased back-donation to the porphyrin unit in the absence of CO. The bonds in the prophyrin ring are also weakened by enhanced back-donation which causes a downward shift in the skeletal modes.