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J F Biellmann

Publications and source records attributed to J F Biellmann.

At least 37 records · Page 2Linked to original sources
PubMed1989

Squalene epoxide cyclase and microemulsion.

Squalene epoxide cyclase was extracted from microsomal preparations of rat liver using anionic, cationic and non-ionic microemulsions. The anionic microemulsion was the best with respect to protein solubilisation, extracted cyclase activity and stability of this activity over time. The activity assay showed cyclase activity to be higher in anionic microemulsion than in buffer in the presence of surfactant. Calcium chloride in the anionic microemulsion had a stabilising effect and less total protein seemed to be extracted.

Animals↗
PubMed1989

X-ray analysis of D-xylose isomerase at 1.9 A: native enzyme in complex with substrate and with a mechanism-designed inactivator.

The structures of crystalline D-xylose isomerase (D-xylose ketol-isomerase; EC 5.3.1.5) from Streptomyces rubiginosus and of its complexes with substrate and with an active-site-directed inhibitor have been determined by x-ray diffraction techniques and refined to 1.9-A resolution. This study identifies the active site, as well as two metal-binding sites. The metal ions are important in maintaining the structure of the active-site region and one of them binds C3-O and C5-O of the substrate forming a six-membered ring. This study has revealed a very close contact between histidine and C1 of a substrate, suggesting that this is the active-site base that abstracts a proton from substrate. The mechanism-based inhibitor is a substrate analog and is turned over by the enzyme to give a product that alkylates this same histidine, reinforcing our interpretation. The changes in structure of the native enzyme, the enzyme with bound substrate, and the alkylated enzyme indicate that the mechanism involves an "open-chain" conformation of substrate and that the intermediate in the isomerization reaction is probably a cis-ene diol because the active-site histidine is correctly placed to abstract a proton from C1 or C2 of the substrate. A water molecule binds to C1O and C2O of the substrate and so may act as a proton donor or acceptor in the enolization of a ring-opened substrate.

Aldose-Ketose Isomerases↗
PubMed1987

Enzyme and organic solvents: horse liver alcohol dehydrogenase in non-ionic microemulsion: stability and activity.

In a microemulsion made with Triton X-100, the stability of the enzymatic activity was higher than in ionic microemulsions. The stability increased with water content. The kinetic constants (Michaelis constant of NAD+ and maximum velocity) were close to those found in the previously studied microemulsions. The Michaelis constant of NAD+ expressed with respect to the buffer volume was higher than in water. The pH dependence of the kinetic constants in this microemulsion was determined. The activity determined by NAD+ reduction decreased with water content, whereas the redox activity determined via butanol oxidation coupled to retinal reduction was only slightly reduced.

Alcohol Dehydrogenase↗
PubMed1987

Crystallization and preliminary X-ray study of pig lens aldose reductase.

Crystals of pig lens aldose reductase have been grown from polyethylene glycol solutions at pH 6.2 and analysed by X-ray diffraction. Two crystal forms were obtained. The first belongs to space group P1 with unit cell dimensions a = 81.3 A, b = 85.9 A, c = 56.6 A, alpha = 102.3 degrees, beta = 103.3 degrees, gamma = 79.0 degrees, with four molecules in the unit cell related by a 222 non-crystallographic symmetry. The second crystal form is hexagonal. The space group is P6(2)22 with a = b = 101 A, c = 257 A and two molecules in the asymmetric unit. Both forms are suitable for X-ray structure analysis to better than 3 A resolution.

Aldehyde Reductase↗
PubMed1987

Enzymes and microemulsions. Activity and kinetic properties of liver alcohol dehydrogenase in ionic water-in-oil microemulsions.

The activity and the kinetic properties of horse liver alcohol dehydrogenase have been studied in water-in-oil microemulsions containing sodium dodecyl sulfate (SDS) or hexadecyl trimethylammonium bromide (CTAB), 1-butanol or 1-pentanol or 1-hexanol or t-butanol, water and cyclohexane alone or with octane. In the anionic microemulsions (i.e. containing sodium dodecyl sulfate), the enzyme quickly lost its activity, but was efficiently protected by the coenzyme and some adenine nucleotides. In the cationic microemulsions (i.e. containing hexadecyl trimethylammonium bromide), the enzyme activity was more stable and with higher alcohols was stable for at least 20 min. The Michaelis constant of NAD+ calculated with respect to the water content was nearly constant and higher than in water. The maximum velocity in anionic microemulsions depends on the water content whereas in cationic microemulsions, the maximum velocity did not show a clear dependence on the water content and was close to the maximum velocity found in water. The pH dependence of Km and Vmax in these microemulsions was similar to that observed in water. The kinetic data for a hydrophobic substrate, cinnamyl alcohol, showed that this alcohol partitions between the pseudo-phases and thus the apparent Michaelis constant and the concentration at which substrate-excess inhibition appeared were increased. The catalytic properties of the enzyme in microemulsions were illustrated by the preparative reduction of cinnamaldehyde with cofactor recycling. The rate determination of NAD+ reduction and of 1-butanol/cinnamaldehyde redox reaction showed that at low water content (2.8%), the NAD+ reduction rate was close to zero whereas the redox reaction rate was about half of the rate at higher water content. Probably at low water content the coenzyme binding-dissociation rates are reduced much more than the binding-dissociation rates of the substrates and the rates of the ternary complex interconversion. The cationic microemulsions seemed to be very favorable medium for enzyme activity, the tetraalkyl ammonium surfactant causing less denaturation than the anionic detergent dodecyl sulfate.

1-Propanol↗
PubMed1986

Dependence of the substrate specificity and kinetic mechanism of horse-liver alcohol dehydrogenase on the size of the C-3 pyridinium substituent. 3-Benzoylpyridine-adenine dinucleotide.

The kinetic mechanism and the substrate specificity of liver alcohol dehydrogenase are changed when 3-benzoylpyridine-adenine dinucleotide is used as coenzyme. Only primary alcohols are substrates of the enzyme and with ethanol the mechanism becomes rapid-equilibrium random bi-bi. According to model building experiments on a graphic display, the benzoyl group partially enters the substrate binding site, whereas the essential interactions between coenzyme and enzyme are preserved. This restraint on the substrate binding site provides a molecular explanation for the observed dependence between coenzyme and substrate chemical structures.

Alcohol Dehydrogenase↗
PubMed1986

Designed inhibitors of horse liver alcohol dehydrogenase. Effect of active-site metal ion substitution.

3-(p-Butoxyphenyl)propionamide, -thioamide and -hydrazide and the formamide of p-butoxybenzylamine were tested as inhibitors of cadmium(II) and cobalt(II) active-site substituted alcohol dehydrogenase. The results agree with a direct coordination of these inhibitors except for the hydrazide to the active-site metal ion, in the enzyme-NADH-inhibitor complex. The hydrazide might be situated at some distance from the metal ion without a direct coordination bond.

Alcohol Oxidoreductases↗
PubMed1984

Suicide inactivation of fructose-1,6-bisphosphate aldolase.

2-Keto-4,4,4-trifluorobutyl phosphate (HTFP) was prepared from 3,3,3-trifluoropropionic acid. HTFP acts as an irreversible inhibitor of rabbit muscle aldolase: the loss of activity was time dependent and the inactivation followed a pseudo-first-order process. Values of 1.4 mM for the dissociation constant and 2.3 X 10(-2) s-1 for the reaction rate constant were determined. The kinetic constants do not depend on the enzyme concentration. No effect of thiols on the inactivation rate was detected. Only 1-2 mol of fluoride ions was liberated per inactivated subunit, indicative of a low partition ratio. Dihydroxyacetone phosphate protected the enzyme against the inactivation in a competitive manner, and glyceraldehyde 3-phosphate protected as if it formed a condensation product with HTPF. 5,5'-Dithiobis(2-nitrobenzoic acid) thiol titration showed the loss of one very reactive thiol group per enzyme subunit after inactivation. All those observations seem to agree with a suicide substrate inactivation of aldolase by HTPF.

Animals↗
PubMed1984

Reaction of the Z isomer of 4-trans-(N,N-dimethylamino)cinnamaldoxime with the liver alcohol dehydrogenase-oxidized nicotinamide adenine dinucleotide complex.

The Z isomer of 4-trans-(N,N-dimethylamino)-cinnamaldoxime, (Z)-DMOX (lambda maxH2O 354 nm), forms a ternary complex with NAD+ and equine liver alcohol dehydrogenase. The 3-acetyl (3-acetyl-PdAD+), 3-thiocarboxamide (3-thio-NAD+), 3-iodo (io3PdAD+) and nicotinamide mononucleotide (NMN+) analogues of NAD+ also form ternary complexes with enzyme and (Z)-DMOX. These complexes are characterized by large red-shifts in the UV-visible spectrum of bound (Z)-DMOX (lambda max 428 nm for the NAD+ complex) and new spectral bands in the 280-340-nm region associated with the pyridine moieties of NAD+ and the NAD+ analogues. The ternary enzyme-NAD+-(Z)-DMOX complex is weakly fluorescent (lambda ex 430 nm; lambda em max 505 nm) and strongly quenches the residual tryptophan fluorescence of the enzyme-NAD+ binary complex. (Z)-DMOX binds with high affinity to the enzyme-NAD+ complex (Kd less than or equal to 4 X 10(-9) M at pH 8.75 and 25 degrees C), and similarly high affinities were found for the 3-acetyl-PdAD+, 3-thio-NAD+, and io3PdAD+ complexes. Binding is much weaker to the enzyme-NMN+ complex. The active site specifically substituted Co(II), Ni(II), Cu(II), and Cd(II) enzyme derivatives and the enzyme species lacking any metal ion at the active site (apoenzyme) also form ternary complexes with (Z)-DMOX in which the DMOX UV-visible spectrum is red-shifted (ranging from 43 to 83.5 nm). The complexes formed with the Zn(II) and Co(II) enzymes are characterized by relatively high affinities for (Z)-DMOX and by spectra that are independent of pH over the range 6-10. The affinity of the apoenzyme-NAD+ complex for (Z)-DMOX is much lower, and the spectrum of the complex is pH dependent with lambda max = 430 nm at pH 7 and lambda max = 397 nm at pH 10. The rate of (Z)-DMOX dissociation from the apoenzyme complex was found to be approximately 10(3)-fold greater than the rates observed for the metal ion substituted enzymes. The 280-340-nm spectral bands appear to result from the dihydropyridine moieties of covalent adducts formed between (Z)-DMOX and NAD+ and the NAD+ analogues. The large red-shifts of the (Z)-DMOX spectrum result from the bonding of the oxime nitrogen to a strong electrophilic center (either the active site zinc ion or the nicotinamide ring of NAD+.)(ABSTRACT TRUNCATED AT 400 WORDS)

Alcohol Dehydrogenase↗
PubMed1983

Properties of horse liver alcohol dehydrogenase modified by the affinity label 3-chloroacetylpyridine-adenine dinucleotide.

The reactive analogue of NAD+, CPAD+, was incorporated in the horse liver alcohol dehydrogenase (EC 1.1.1.1) linearly with its inactivation, to stoichiometry, with no apparent subunit interaction. No hydride transfer could take place in the modified enzyme, nor the interaction of trans-4-N,N-dimethylaminocinnamaldehyde with its reduced form, indicating an impairment of the accessibility to the catalytic zinc atom. The labeling in the enzyme, alkylated by [carbonyl-14C]CPAD+ was not stable, with a half-life of 32 h.

Affinity Labels↗
PubMed1983

Applicability of the induced-fit model to glyceraldehyde-3-phosphate dehydrogenase from sturgeon muscle. Study of the binding of oxidized nicotinamide adenine dinucleotide and nicotinamide 8-bromoadenine dinucleotide.

A new method of calculation, based on a direct fitting of the protein fluorescence intensity observed upon coenzyme binding (H.-P. Lutz, unpublished results), is used to study the negative cooperative behavior of glyceraldehyde-3-phosphate dehydrogenase from sturgeon muscle. The calculation procedure simultaneously elaborates data obtained for four different protein concentrations, and it is able to compare different models by computing the minimal and critical sum of squares. Using this approach, it is shown that the induced-fit model [Koshland, D. E., Jr., Nemethy, G., & Filmer, D. (1966) Biochemistry 5,365] and the dimer of dimer model [Malhotra, O. P., & Bernhard, S. A. (1968) J. Biol. Chem. 243, 1243-1252] can both be applied for explaining the negative cooperativity observed upon coenzyme binding to sturgeon glyceraldehyde-3-phosphate dehydrogenase. In addition to the progressive modification of the binding affinity during ligand binding, different maximal fluorescence quenchings for the binding steps must be postulated; and furthermore, the binding capability decreases by decreasing the protein concentration. The fact that the induced-fit model can also be applied is rather in contradiction with the view generally accepted of a dimer of dimer structure of sturgeon glyceraldehyde-3-phosphate dehydrogenase. By use of the same approach, nicotinamide 8-bromoadenine dinucleotide is shown to bind to glyceraldehyde-3-phosphate dehydrogenase from sturgeon in a negative cooperative manner.

Animals↗
PubMed1983

New inhibitors of alcohol dehydrogenase: studies in vivo and in vitro in the rat.

Two compounds bearing an amide group, p-butoxyphenol acetamide (BPA) and N-(p-butoxybenzyl)formamide (BBF) were studied as inhibitors of alcohol dehydrogenase (ADH) and their action compared with that of 4-methyl-pyrazole (4-MP), a known inhibitor of this enzyme. In vitro studies on pure horse liver ADH showed that BPA and BBF were noncompetitive inhibitors with respect to ethanol and that their Ki values were 22 and 0.14 micrometer, respectively. The apparent Ki values of BPA and BBF for rat liver ADH were found to be 90 and 2.3 micrometers, respectively (noncompetitive inhibition). Several in vivo experiments were carried out in the rat. Administration intraperitoneally of the substance (460 mumol/kg) 1 hr before intraperitoneal injection of alcohol (2 g/kg body weight) led to a significant decrease in ethanol catabolism. Injection of the substances at 460 mumol/kg brought about a decrease in rat liver ADH activity, but the activity of mitochondrial aldehyde dehydrogenase was only decreased in animals treated with BBF.

Acetamides↗
PubMed1982

Properties of the charge-transfer transition observed in glyceraldehyde-3-phosphate dehydrogenase from sturgeon muscle alkylated by 3-chloroacetylpyridine--adenine dinucleotide. Characterisation of the modified amino acid.

An absorption band at 340 nm is shown to be formed concomitantly with the covalent bond between the affinity label 3-chloroacetylpyridine--adenine dinucleotide (clac3PdAD+) and glyceraldehyde-3-phosphate from sturgeon. This band corresponds to a charge-transfer transition. Its intensity depends upon the pH and the ionic strength but is almost independent of the nature of the anions present in the medium. The pH dependence shows an inflection point at pH 7.1. This result suggests the participation of a residue with a pKa of 7.1 within the active site of the enzyme in the formation of this transition. Using various techniques, the amino acid alkylated by clac3PdAD+ is shown to be the essential Cys-149, thus excluding the participation of this residue in the formation of the charge-transfer transition. On the other hand, the modification of Cys-153 seems not to affect this charge-transfer band. Other possible donors are proposed, such as the invariant His-176 or Tyr-317 residues. These amino acids might be implicated in the formation of the Racker band.

Affinity Labels↗
PubMed1982

Inactivation of yeast alcohol dehydrogenase by a reactive coenzyme analogue: 3-chloroacetyl pyridine adenine dinucleotide.

Yeast alcohol dehydrogenase is very rapidly and irreversibly inactivated by 3-chloroacetyl pyridine adenine dinucleotide, a reactive NAD+-analogue (Biellmann et al., 1974, FEBS Lett. 40, 29-32). Kinetic investigations with this compound, and structurally related compounds, show that this inactivation, against which NAD+ provides a complete protection, corresponds to an affinity label. The incorporation of the coenzyme analogue correlates linearly with the enzyme inactivation, the total inactivation corresponding to one mole of inactivator per coenzyme binding site. The pH-dependence of the inactivation rates of the enzyme by this coenzyme analogue and by its reduced form reflects exactly the pH variation of their respective dissociation constants. In spite of a good stability of the label in the non denatured inactivated enzyme, no modified amino-acid residue could be identified. Considering the affinity of this analogue for yeast alcohol dehydrogenase and the strict steric requirements of this enzyme towards its ligands, the nature of the inactivation reaction as well as different possibilities of the loss of the label in the inactivated enzyme are discussed.

Affinity Labels↗
PubMed1982

Affinity labeling of glyceraldehyde-3-phosphate dehydrogenase from sturgeon and Bacillus stearothermophilus by 3-chloroacetylpyridine--adenine dinucleotide. Kinetic studies.

The inactivation of glyceraldehyde-3-phosphate dehydrogenase from Bacillus stearothermophilus and sturgeon by 3-chloroacetylpyridine--adenine dinucleotide, which is not active as a coenzyme, obeys pseudo-first-order kinetics. The mechanism of inactivation corresponds to an affinity label. Four moles of inactivator are incorporated per mole of tetramer for both enzymes. All the kinetic results strongly support the idea that neither enzyme exhibits negative cooperativity for the non-covalent binding of 3-chloroacetylpyridine--adenine dinucleotide. NAD+ strongly protects both glyceraldehyde-3-phosphate dehydrogenases from inactivation. In the presence of NAD+, the inactivation process seems also to exhibit pseudo-first-order kinetics. The fact that each kinetic experiment can be described by only one pseudo-first-order rate constant is unexpected. The results of thiol titration are in favor of the modification of the essential Cys-149, although another thiol group per monomer, probably Cys-153, becomes titratable on both native alkylated enzymes. This latter result suggests that the alkylation of the Cys-149 by the 3-chloroacetylpyridine--adenine dinucleotide should affect the tertiary structure of these enzymes.

Affinity Labels↗
PubMed1981

5-Methylnicotinamide-adenine dinucleotide. Kinetic investigation with major and minor isoenzymes of liver alcohol dehydrogenase and structural determination of its binary complex with alcohol dehydrogenase.

5-Methylnicotinamide-adenine dinucleotide and 3-cyano-5-methylpyridine-adenine dinucleotide was prepared from 5-methylthionicotinamide-adenine dinucleotide by chemical conversion. The 5-methylthionicotinamide-adenine dinucleotide was obtained by enzymic transglucosidation. Model compounds ascertained the structure. None of the dinucleotides methylated at C-5 was active with the major isoenzyme EE of horse liver alcohol dehydrogenase, but activity with 5-methylnicotinamide-adenine dinucleotide was measured with the minor isoenzymes. The binding of 5-methylnicotinamide-adenine dinucleotide to liver alcohol dehydrogenase, investigated by X-ray diffraction methods to 0.37-nm resolution, occurs with the pyridinium ring away from the active site as previously described for 3-iodopyridine-adenine and pyridine-adenine dinucleotides. A general conclusion on the use of inhibitors as tools for exploration of the active site is drawn.

Alcohol Oxidoreductases↗