ABSTRACT Macrolides represent a clinically important class of antibiotics that block protein synthesis by interacting with the large ribosomal subunit. The macrolide binding site is composed primarily rRNA. However, mode interaction macrolides rRNA and exact location drug have yet to be described. A new antibiotics, known as ketolides, show improved activity against organisms developed resistance previously used macrolides. biochemical reasons for increased potency ketolides remain unknown....

Many enzymes can self-assemble into higher-order structures with helical symmetry. A particularly noteworthy example is that of nitrilases, in which oligomerization dimers spiral homo-oligomers a requirement for their enzymatic function. Nitrilases are widespread nature where they catalyze the hydrolysis nitriles corresponding carboxylic acid and ammonia. Here, we present Cryo-EM structure, at 3 Å resolution, C-terminal truncate nitrilase from Rhodococcus sp. V51B assembles filaments. The...

Multifunctionality is a common trait of many natural proteins and peptides, yet the rules to generate such multifunctionality remain unclear. We propose that defining some protein/peptide functions are compatible. To explore this hypothesis, we trained computational method predict cell-penetrating peptides at sequence level learned antimicrobial DNA-binding compatible with our predictor. Based on finding, expected designing for CPP activity may render AMP activities. test prediction,...

Pseudomonas aeruginosa is an opportunistic bacterium associated with healthcare infections in intensive care units, ventilator-associated pneumonia, surgical site and burns. This causes 75% of death burned patients, since it can develop a persistent biofilm infections, express several virulence factors antibiotic-resistance mechanisms. Some these are proteases such as elastase alkaline protease, or toxic metabolites pyocyanin one the few microorganisms able to produce cyanide, which inhibits...

The amino acid sequence of triosephosphate isomerase from Trypanosoma brucei , cruzi and Leishmania mexicana have an identity 68 %. Using the numbering system for T. enzyme, in their aligned sequences, leishmanial enzymes cysteine residues at positions 14, 40, 117 126. has 40 126, a valine residue position 117. Dithionitrobenzoic methylmethane thiosulfonate inhibited three enzymes, but was more than 100‐fold sensitive. sensitivity wild type to reagents equal that Cys117Val Val117Cys mutant...

Homodimeric triosephosphate isomerases from Trypanosoma cruzi (TcTIM) and brucei (TbTIM) have markedly similar catalytic properties 3-D structures; their overall amino acid sequence identity is 68% 85% in interface residues. Nonetheless, active dimer formation guanidinium chloride unfolded monomers faster more efficient TcTIM than TbTIM. The enzymes thus provide a unique opportunity for exploring the factors that control of dimers. kinetics reactivation at different protein concentrations...

The gene that encodes for triosephosphate isomerase from Trypanosoma cruzi was cloned and sequenced. In T. cruzi, there is only one isomerase. enzyme has an identity of 72% 68% with brucei Leishmania mexicana, respectively. active site residues are conserved: out the 32 conform interface dimeric brucei, 29 conserved in enzyme. expressed Escherichia coli purified to homogeneity. Data electrophoretic analysis under denaturing techniques filtration showed a homodimer. Some its structural...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnzyme catalysis in organic solvents with low water content at high temperatures. The adenosinetriphosphatase of submitochondrial particlesGeorgina Garza-Ramos, Alberto Darszon, M. Tuena de Gomez-Puyou, and A. Gomez-PuyouCite this: Biochemistry 1990, 29, 3, 751–757Publication Date (Print):January 23, 1990Publication History Published online1 May 2002Published inissue 23 January...

The reactivation of the homodimeric enzyme triosephosphate isomerase (TPI) was studied in reverse micelles. denatured conventional aqueous mixtures with guanidine hydrochloride and transferred to micelles formed cetyltrimethylammonium bromide, hexanol, n ‐octane water. In transfer step, TPI monomers distributed single micelles, diluted more than 100 times. Under optimal conditions, 100% activity could be recovered. rate appearance catalytic increased concentration protein, which indicated...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalysis and thermostability of mitochondrial F1-ATPase in toluene-phospholipid-low-water systemsGeorgina Garza-Ramos, Alberto Darszon, M. Tuena de Gomez-Puyou, A. Gomez-PuyouCite this: Biochemistry 1989, 28, 8, 3177–3182Publication Date (Print):April 18, 1989Publication History Published online1 May 2002Published inissue 18 April 1989https://pubs.acs.org/doi/10.1021/bi00434a010https://doi.org/10.1021/bi00434a010research-articleACS...

Plant ALDH10 enzymes are aminoaldehyde dehydrogenases (AMADHs) that oxidize different ω-amino or trimethylammonium aldehydes, but only some of them have betaine aldehyde dehydrogenase (BADH) activity and produce the osmoprotectant glycine (GB). The latter possess alanine cysteine at position 441 (numbering spinach enzyme, SoBADH), while those ALDH10s cannot (BAL) isoleucine this position. Only plants contain A441- C441-type isoenzymes accumulate GB in response to osmotic stress. In work we...

The possibility of using non‐conserved amino acid residues to produce selective inhibition homologous enzymes from different species has been further explored with triosephosphate isomerase. S ‐phenyl‐ p ‐toluenethiosulfonate (MePhSO 2 ‐SPh), which produces phenyl disulfides accessible Cys residues, inhibits the activity rabbit is due derivatization one five effect MePhSO ‐SPh on isomerase Saccharomyces cerevisiae, Escherichia coli , chicken and Schizosaccharomyces pombe was also determined....

The effect of urea and guanidine hydrochloride (GdmCl) on the activity heart lactate dehydrogenase, glycerol-3-phosphate hexokinase, inorganic pyrophosphatase, glyceraldehyde-3-phosphate dehydrogenase was studied in low-water systems. Most experiments were made a system formed with toluene, phospholipids, Triton X-100, water range that varied over 1.0-6.5% (by vol.) [Garza-Ramos, G., Darszon, A., Tuena de Gómez-Puyou, M. & A. (1990) Biochemistry 29, 751-757]. In such conditions at saturating...

Hunter-killer peptides combine two activities in a single polypeptide that work an independent fashion like many other multi-functional, multi-domain proteins. We hypothesize emergent functions may result from the combination of or more protein domain and could be mechanism selected nature to form moonlighting designed using mechanisms proposed involved evolution such molecules (i.e., mutate non-functional residues use natively unfolded peptides). observed our exhibited together rendered new...

In the interface of homodimeric triosephosphate isomerase from Trypanosoma brucei (TbTIM) and cruzi (TcTIM), one cysteine each monomer forms part intersubunit contacts. The relatively slow derivatization these cysteines by sulfhydryl reagents induces progressive structural alterations abolition catalysis [Garza-Ramos et al. (1998) Eur. J. Biochem. 253, 684−691]. Derivatization 5,5-dithiobis(2-nitrobenzoate) (DTNB) methylmethane thiosulfonate (MMTS) was used to probe if events at catalytic...

To gain insight into the mechanisms of enzyme catalysis in organic solvents, x-ray structure some monomeric enzymes solvents was determined. However, it remained to be explored whether oligomeric proteins is also amenable such analysis. The field acquired new perspectives when proposed that nonaqueous media could reveal binding sites for principle represent starting point drug design. Here, a crystal dimeric triosephosphate isomerase from pathogenic parasite Trypanosoma cruzi soaked and...

Many aldehyde dehydrogenases (ALDHs) have potential potassium-binding sites of as yet unknown structural or functional roles. To explore possible K(+)-specific effects, we performed comparative studies on the tetrameric betaine dehydrogenase from Pseudomonas aeruginosa (PaBADH) and dimeric BADH spinach (SoBADH), whose activities are K(+)-dependent K(+)-independent, respectively, although both enzymes contain sites. Size exclusion chromatography, dynamic light scattering, far- near-UV...

Abstract Gold, silver, and copper small nanoparticles (NPs), with average size ≈ 2 nm, are synthesized afterward protected l ‐ d ‐cysteine, demonstrating emergence of chiroptical activity in the wavelength range 250–400 nm for all three metals respect to bare ligands alone. Silver‐cysteine (Ag‐Cys) NPs display higher anisotropy factor, whereas gold‐cysteine (Au‐Cys) show optical signatures slightly more displaced visible range. A larger number circular dichroism (CD) bands smaller intensity,...

In homodimeric triosephosphate isomerase from Trypanosoma brucei (TbTIM), cysteine 14 of each the two subunits forms part dimer interface. This residue is central for catalysis and stability TbTIM. Cys14 was changed to other 19 amino acids determine characteristics that must have yield catalytically competent stable enzymes. C14A, C14S, C14P, C14T, C14V TbTIMs were essentially wild type in activity stability. Mutants with Asn, Arg, Gly had low activities stabilities. The mutants less than 1%...

The guanidine hydrochloride-induced conformational transitions of glycosomal triosephosphate isomerase (TIM) were monitored with functional, spectroscopic, and hydrodynamic measurements. equilibrium folding pathway was found to include two intermediates (N(2) ↔I(2) ↔2M↔2U). According this model, the stability parameters TIM are as follows: ΔG(I2-N2) = 5.5 ± 0.6, ΔG(2M-I2) =19.6 1.6, ΔG(2U-2M) 14.7 3.1 kcal mol(-1) . I(2) state is compact (α(SR) 0.8); it able bind...

Saccharomyces cerevisiae triosephosphate isomerase (yTIM) is a dimeric protein that shows noncoincident unfolding and refolding transitions (hysteresis) in temperature scans, phenomenon indicative of the slow forward backward reactions native-unfolded process. Thermal scans suggest no stable intermediates appear yTIM. However, reported evidence points to presence residual structure denatured monomer at high temperature.Thermally yTIM showed clear trend towards formation aggregation-prone,...

The effect of urea and guanidine hydrochloride (GdmCl) on the activity lactate dehydrogenases from heart muscle was studied in standard water mixtures reverse micelles formed with n ‐octane, hexanol, cetyltrimethylammonium bromide a concentration that ranged over 2.5–6.0% (by vol.). In all GdmCl (0.15–0.75 M) (0.5–3.0 inhibited enzymes at non‐saturating pyruvate concentrations. At concentrations proved inhibitory for enzyme due to formation ternary enzyme‐NAD‐pyruvate complex, increased...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDeamidation of Triosephosphate Isomerase in Reverse Micelles: Effects Water on Catalysis and Molecular Wear TearGeorgina Garza-Ramos, M. Tuena de Gomez-Puyou, A. K. Umit Yuksel, Robert W. GracyCite this: Biochemistry 1994, 33, 22, 6960–6965Publication Date (Print):June 7, 1994Publication History Published online1 May 2002Published inissue 7 June 1994https://pubs.acs.org/doi/10.1021/bi00188a027https://doi.org/10.1021/bi00188a027research-articleACS...