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Human prostatic acid phosphatase crystal structures in complex with a phosphate ion and alpha-benzylaminobenzylphosphonic acid reveal the identity of the final intemediate in the catalytic mechanism and determinants of binding ligands within the active site, respectively. The latter explains the enzyme's preference to aromatic substrates.

The X-ray crystal analysis of human c8gamma reveals a typical lipocalin fold forming a calyx and exhibiting a binding site for a small molecule, whose identity is unknown. C8gamma is a subunit of human C8 which in turn a component of the cytolytic membrane attack complex of complement.

Research has been conducted on the thymidylate synthase, a chemotherapy target in colorectal cancer. The crystal structure of the complex between recombinant human thymidylate synthase and raltitrexed has been investigated.

Research has been conducted on the formyltetrahydrofolate synthetase from Moorella thermoacetica, a thermophilic homoacetogen. The crystal structure of this synthetase in complex with cesium and potassium ions has been investigated and the binding position of the monovalent cation has been identified.

Research has been conducted on the Ser 167 of Escherichia coli thymidylate synthase. The kinetic and crystallographic studies of the role of Ser 167 in the catalysis are described.

Research has been conducted on the N (super)10 -formyltetrahydrate synthase structure. Multiwavelength anomalous dispersion scattering by Se-Met residues has been used to solve this structure.

Research has been conducted on the Pseudomonas 7A glutaminase-asparaginase. Results indicate that it catalyzes D and L glutamine and asparagine isomers hydrolysis.

The asymmetric structure and its influence on tbe catalytic mechnaism of enolase was described through structural resolution, refinement and x-ray diffraction studies. The resulting crystal structure was shown to be constituted by two similar subunits. In one unit, the imidazole side chain of His159 was in contact with the phosphate group of the substrate molecule. In the other subunit, the imidazole was separated by water molecules.

The photoinduced reactions of (t-Bu)3In with Et2NSnMe3 and (n-Bu)2NSnMe3 led to the formation of [(t-Bu)2InNEt2] and [(t-Bu)2InN(n-Bu)2], respectively, with typical yields of 75-85%. Crystallographic analysis of the resulting compounds that were formed via alkyltrimethyltin elimination reactions indicated the presence of similar molecular bond lengths and bond angles. Furthermore, the average In-C bond length of the compounds were longer than the average bond length of [(t-Bu)2InN(n-Bu)2]2.

The structural conformation of the Pseudomonas 7A glutaminase-asparaginase was resolved at 1.7 angstrom by molecular replacement method. The active site of the aminohydrolase was identified as the Thr20-Gly40 catalytic loop which is responsible for the enhancement of the hydrolysis of the isomeric forms of glutamine and asparagine. The loop was found bound with a sulfate ion and an ammonium ion in the substrate binding site. Such interaction seems to be responsible for the closed conformation of the compound revealed by crystallography.

Oxazolidine-2-selone chiral derivatizing agents (CDAs) can be used to expand the ability of 77Se nuclear magnetic resonance to detect and evaluate remotely disposed chiral centers of racemic and chiral carboxylic acids and acid chlorides. The enantiomeric excesses can be determined quickly and accurate for chiral molecules using these CDAs. Additionally, the data obtained through coupling these CDAs with carboxylic acids and acid chlorides allows for a clearer understanding of large chemical shift differences based on the (R) and (S)-MTPA selone adducts undergoing an unusual syn/anti event.

The glycolytic enzyme enolase requires two divalent metal ions per active site to catalyze the forming of phosphoenolpyruvate from 2-phospho-D-glycerate by dehydration. The position of site II of the second metal ion, having a lower affinity for Mg2+ ions, is determined and quarter complex structure between the Mn2+ ions and the transition-state analogue phosphonoacetohydroxamate enolase is analyzed. The sequential reaction mechanism explains the enolase inactivity caused by the increase in Mg2+ concentrations.

The inactive conformation of the loop of residues 181-197 which prevents substrate binding was stabilized to demonstrate the replacement of V3L in human thymidylate synthase which affects its kinetic properties and intracellular stability. The mechanism leading to the high [K.sub.m,app] values in the crystal structure of a V3F*FdUMP binary complex could be applied to facilitate the design of compounds acting as allosteric inhibitors of hTS.

The R163K, a variant of human thymidylate synthase (hTS), is designed and expressed, in which the inactive conformation is destabilized. The calculation have shown that the molecular electrostatic potential at cysteine 195 (Cys195) has differed between the subunits of the dimer.

1,3-Propanediphosphonic acid (PDPA) is introduced as an allosteric inhibitor of human thymidylate synthase (hTS). It is shown that PDPA acts by stabilizing an inactive conformer of loop 181-197.

Crystal structures of the ferric H93G myoglobin (Mb) cavity mutant containing either an anionic proximal thiolate sulfur donor or a carboxylate oxygen donor ligand are described at 1.7 and 1.4 Angstrom resolution, respectively. The investigation of the H93G Mb cavity mutant has afforded the first structural evidence that nonimidazole exogenous ligands bind in the proximal ligation site.

Enolase is a dimeric metal-activated metalloenzyme, which uses two magnesium ions per subunit, the strongly bound conformational ion and the catalytic ion that binds to the enzyme-substrate complex inducing catalysis. The crystal structure of the human neuronal enolase-Mg2F2Pi complex (enolase of fluoride/phosphate complex) determined at 1.36 Angstrom resolution shows that the combination of anions effectively mimics an intermediate state in catalysis.

C8g is a 22-kDa subunit of C8, which is one of five proteins that form the cytolytic 'membrane attack complex' (MAC) of complement. C8g is the only lipocalin among the [...]

Thymidylate synthase (TS) is a homodimer of approximately 72 kDa which catalyzes the reductive methylation of 2-deoxyuridine monophosphate (dUMP) using 5,10-methylenetetrahydrofolate ([CH.sub.2][H.sub.4]folate) to form deoxythymidine monophosphate (dTMP) and dihydrofolate ([H.sub.2]folate). [...]