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The metalloprotease (Mpl) of Listeria monocytogenes is a thermolysin-like protease that mediates the maturation of a broad-range phospholipase C, whose function contributes to the ability of this food-borne bacterial pathogen to survive intracellularly. Mpl is made as a proprotein that undergoes maturation by proteolytic cleavage of a large N-terminal prodomain. In this study, we identified the N terminus of mature Mpl and generated Mpl catalytic mutants to investigate the mechanism of Mpl maturation. We observed that Mpl activity was a prerequisite for maturation, suggesting a mechanism of autocatalysis. Furthermore, using a strain of L. monocytogenes expressing both the wild-type form and a catalytic mutant form of Mpl simultaneously, we determined that in vivo maturation of Mpl occurs exclusively by an intramolecular autocatalysis mechanism.

Research has been conducted on the cyclometalated Pt(thpy)(CO)(Cl) monomers where thpy is 2-(2'-thienylpyridinate). The emitting triplet state of these monomers has been investigated via the use of the optically detected magnetic resonance spectroscopy and high-resolution optical spectroscopy and the results are reported.

Research has been conducted on the carbaporphyrins. The reaction of these compounds with silver(I) acetate in methanol-CH (sub)2 Cl (sub)2 has produced silver(III) complexes and the details are reported.

Research has been conducted on the sterically hindered and unhindered alkyl nitriles and on benzyl and phenyl nitriles. The hydrolysis of these nitriles to carboxamides has been catalyzed via zinc(II)/ketoxime combination and the results are reported.

Research has been conducted on the organometallic compounds. The organolithium reagent addition to corannulene has been investigated and the route to 1-alkyl-1,2-dihydrocorannulenes has been developed and is described.

Research has been conducted on the ruthenium(II) organometallic antitumor complex. The reactions of this complex with amino acid L-cysteine in aqueous solution have been investigated and the details are reported.

Research has been conducted on the bacterial plasmid-encoded organomercury lyase. The protein and solvent components of this lyase-mediated protonolysis of pi-hydroxymercuribenzoate have been investigated via the study of lyase's cysteine residues and the kinetic activity and turnover abilities of the mutant and wild type enzymes and the details are reported.

Research has been conducted on the catalytic asymmetric acyl halide-aldehyde cyclocondensation reaction. The implementation of the reaction design is described and the results indicate that the reaction strategy allows to employ differentially substituted organocuprates in the 4-substituted 2-oxetanone ring opening.

Research has been conducted on the soluble poly- and dinuclear transition metal alkynyl complexes. The design and isolation of these complexes have been carried out and the results indicate that they are ideal building blocks for the luminescent organometallic oligomer and metal-based functional material construction.

Research has been conducted on the noncentrosymmetric infinite coordination networks. The crystal-engineering methods developed for the synthesis of these networks used as second-order nonlinear optical materials are described.

Research has been conducted on the coordinated water ligands. The labile nature of these ligands has been investigated in organometallic aqua complexes via substitution reactions with incoming ligands and the results are reported.

The authors review the publications on biological methylation. The topics of interest include bioalkylation, metalloids' methylation, arsenic methylation, antimony biomethylation and enzymology of biomethylation.

The authors review the publications on organometallic complexes of the rare-earth metals. The topics of interest include hydrido complexes, chalcogenido complexes and hydrocarbyl complexes, their synthesis, structure, properties and applications.

Research has been conducted on the bifunctionalized ligand. The reactivity of this ligand has been investigated for the organic and organometallic synthesis and the selective preparation of these organometallic systems is reported.

The authors review the publications on organonitrile transformations. The topics of interest include C-C bond formation, metal-mediated alcohol-nitrile coupling and hydrolysis of organonitriles which involves metal complexes.

The author reviews the publications on the preparation of the enantiomerically pure planar chiral organometallics. The topics of interest include diastereoselective complexation induced by proximal chirality, by chiral auxiliaries and by displacing preexisting chirality.

The author reviews the publications on the surface chemistry of silicon and germanium, group (IV) semiconductors. The topics of interest include silicon- and germanium-carbon bond formation on these semiconducting surfaces.

The metallorganic chemical vapor deposition method was successfully used to synthesize pure Ti[O.sub.2] and [Nd.sup.3+]-, [Pd.sup.2+]-, [Pt.sup.4+]-, and [Fe.sup.3+]-doped Ti[O.sub.2] nanoparticles. Polycrystalline Ti[O.sub.2] structure was verified with x-ray diffraction, which showed typical characteristic anatase reflections without any separate dopant-related peaks. Transmission electron microscopy observations confirmed the existence of homogeneously distributed 22 [+ or -] 3 nm Ti[O.sub.2] nanoparticles. The particle size remained the same for the doped samples. The doping level of transition metals was kept at [approximately equal to] 1 atomic percent, which was determined by x-ray photoelectron spectra and energy dispersive x-ray spectroscopy. The effects of different types of dopants on the photocatalytic activity were revealed by the degradation of 2-chlorophenols with an UV light source. The photocatalytic efficiency was remarkably enhanced by the introduction of [Pd.sup.2+] and [Nd.sup.3+]. [Nd.sup.3+]-doped Ti[O.sub.2] showed the largest enhancement. However, [Pt.sup.4+] changed the 2-chlorophenol degradation rate only slightly, and [Fe.sup.3+] was detrimental to this process. These effects were related to the position of the dopants in the nanoparticles and the difference in their ionic radii with respect to that of [Ti.sup.4+].

Research has been conducted on the organomercurial compounds. The preparation of these compounds from 2-bromobenzaldehyde and their characterization via the use of elemental analysis, NMR and infrared spectroscopy are discussed.

Research has been conducted on the coupling reaction which involves allenic and propargylic palladium species. The regioselectivity controlling factors for this reaction have been verified and the details are presented.

Research has been conducted on the pipecolic acid derivatives. The asymmetric synthesis of these derivatives from the functionalized beta-amino alcohols has been carried out and the reactions between the unsaturated organilithium reagents and oxazolidines have been explored.

Research has been conducted on the neutral mixed-cage molecules E (sub)4 X (sub)3 (E= P, As; X= S, Se). The synthesis and characterization of rhenium(I) derivatives of P (sub)4 S (sub)3 and P (sub)4 Se (sub)3 which exist as Re-nu (super)1 -P (sub)apical and Re-nu (super)1 -P (sub)basal coordination isomers in solution have been carried out and the results indicate that P (sub)4 X (sub)3 molecule is sandwiched between organometallic fragments.

Research has been conducted on the anthracene derivatives with the 2,2,6,6-tetramethyl-1-piperidinyloxy radicals. The preparation of these derivatives has been carried out and the results of the photodimerization reaction are reported.

Research has been conducted on the tert-butanesulfinyl aldimines and ketimines which serve as precursors in the 1,2-amino alcohol synthesis. The general protocols for the unbranched alkyl, branched alkyl and aryl organometallic reagent addition to N-sulfinyl aldimines and ketimines are described.

Research has been conducted on the coumarins. The combinatorial synthesis of the coumarin library carried out under mild conditions in utilizing silyl linker based macrobeads as solid supporters has been developed and described.

Research has been conducted on the bridging phosphine ligand 2,6-bis(diphenylphosphino)pyridine (L). The use of this ligand in the synthesis of the neutral organometallic ligand {Fe(CO) (sub)4} (sub)2 (mu-L) has been carried out and the results exhibit eclipsed and staggered conformations in the crystalline forms.

Research has been conducted on the stannylated oxazolines. The addition of these oxazolines to the bromonaphthoquinones at the carbonyl group vicinal to the bromine atom has been investigated and the results are presented.

Research has been conducted on the alkoxythiophenes which represent subunits for the synthesis of the thermotropic liquid crystals by the palladium-catalyzed cross-coupling reactions and organometallic derivatization. The synthesis of these alkoxythiophenes has been carried out and the results are reported.

Research has been conducted on the imines derived from naphthalene-1-carbaldehyde and acyclic alpha,beta-unsaturated aldehydes. The reaction of these imines with the organolithium reagents has been investigated and the results indicate that it depends on the characteristic nature of the imine nitrogen atom substituent.

Research has been conducted on the arylsulfonylhydrazones. The reaction of the arylsulfonylhydrazones of aldehydes and ketones with alpha-metalated sulfones has been investigated with respect to developing a practical olefination method, and the results are discussed.

Research has been conducted on the open-chain cyclic diketons. The reaction of these diketons with specific omega-alkenyl organometallics has been examined and the results indicate that this reaction leads to 1,2-diols bonded to terminal olefinic chains.

Research has been conducted on the organometallic cyclobutadieno-fused dehydroannulenes. The synthesis, spectroscopic and structural characterization of these dehydroannulenes have been investigated and the use of the strategy developed by Vollhardt and Youngs has been described.

Research has been conducted on the organometallic rhenium species. The use of bis(trimethylsilyl) peroxide as an oxidant in place of aqueous hydrogen peroxide in replacing these compounds by inorganic rhenium oxides is discussed.

Research has been conducted on the sulfonimines. The reaction of these sulfonimines with crotyl bromide and indium in aqueous media that gave alpha-crotylation products has been investigated and the results are presented.

Research has been conducted on the dialkyl-substituted allyl chloride derivatives. The regioselective palladium-catalyzed coupling reactions of these derivatives with allylstannanes and benzylidenemalonitrile that give functionalized 1,7-octadienes have been investigated and discussed.

Iron acquisition by seven strains of heterotrophic marine bacteria from a number of siderophore-iron complexes has been studied to evaluate the importance of siderophores for iron nutrition. Desferrioxamine B and marine siderophores partly purified from iron-limited cultures were considered. Iron dissolved in seawater binds to strong organic complexes with stability constants similar to those of microbial iron chelates. Results indicate bacteria may rely on siderophores to gain iron in situ.

Wave packet propagations on CASSCF/CCI potentials have been used to study the photodissociation dynamics of H2Fe(C0)4. Calculations for the electronic ground and excited states were made. A semiquantitative mechanism was proposed for the photodissocition of the title molecule. Nonradiationless transitions to a low-lying triplet state occured in picosecond time, with low probability, indicating the minor role of triple states in the early stages of photodissociation.

Anion photoelectron spectroscopy was used to study the electronic structure of metallocarbohedrenes Msub8Csub12 (M = Ti, V, Cr, Zr, Nb). The electron affinities of the metallocarbohedrenes were metal dependent and increased from Tisub8Csub12 to Crsub8Csub12. The Zrsub8Csub12 and Nbsub8Csub12 electronic structures were similar to Tisub8Csub12 and Vsub8Csub12. Molecular orbital schemes derived from a tetracapped tetrahedral Msub8Csub12 cluster can be used to qualitatively interpret all the spectra.

Analysis of the influence of a selenoorganic compound, ebselen on infarct size in a canine coronary artery occlusion-reperfusion model shows that ebselen causes a decrease in myocardial-reperfusion injury and reduces the infarct size. The infarct size reduction by ebselen correlates to the decrease in myeloperoxidase activity in ischemic myocardium and rise in reduced glutathione levels. Ebselen treatment has no effect on the regional myocardium, reduced glutathione levels, the regional myocardial blood flow and hemodynamic parameters involved in the experimental studies.

Research has been conducted on the bifunctional carboranes. The method developed to synthesize bifunctional metal complexes is described and the results indicate that the bifunctional derivatives can be used as synthons for the preparation of the organometallic radiopharmaceuticals.

Research has been conducted on the organo-metal compound transmetalation. The hypothesis that Grignard reagents undergo transmetalation as the organo-zinc compounds has been tested and the results are discussed.

Research has been conducted on the olefins. The oxidative cyclization of 1,4-dienes which has led to the olefins' selective oxidative cleavage to produce carboxylic acids is described.

Research has been conducted on the organometallic compounds. The model complexes used in investigating the ring-opening transformations mediated by the organometallic compounds are discussed.

A study on the targets and mechanisms of action of gold complexes to counter rheumathoid arthritis demonstrated that mild oxidation of gold-sulfur complexes produces gold clusters and disulfide by way of an electron-transfer mechanism that occurs with unexpected n values. These results suggest an oxidative reactivity for gold-sulfur centers that has not been previously recognized. Furthermore, the oxidative reactivity of gold-sulfur complexes suggests some exciting possibilities for the biochemistry of gold.

Novel dendrons and dendrimers have interacting ferrocenyl units were constructed. The silicon-bridged biferrocene was the key dendritic wedge for the synthesis of the new dendrimers, prepared by reaction of ferrocenyllithium with vinylmethyldichlorosilane. The results show that dendritic structures having electronically communicated organometallic units, can be built using a simple convergent approach.