Lysine Molecules Research Articles

Hydration properties of DNA-lysine gels by microwave dielectric measurements as a function of temperature.

Dielectric measurements by a cavity perturbation method at 10 GHz in the temperature range from -20 degrees C to +45 degrees C are reported for aqueous gels of herring sperm DNA in the presence of 1 or 3 lysine molecules per nucleotide. Measurements for lysine-water and DNA-water systems are also reported. The experimental results can be accounted for by the presence of interfacial water, with dielectric properties different from those of bulk water, and are analyzed in terms of a three component equation (solute molecules, interfacial water and bulk water) to calculate hydration parameters of the systems. The lysine molecule is found to coordinate a particular number of water molecules, in agreement with the literature. The specific hydration of DNA is reduced by the presence of lysine, indicating a direct interaction between the polyion and the aminoacid: a decrease to about 50% was observed at a ratio of one molecule of lysine per nucleotide. A suggestion is made that the interaction is mainly electrostatic in nature.

13C-NMR, 1H-NMR and gas-chromatography mass-spectrometry studies of the biosynthesis of 13C-enriched L-lysine by Brevibacterium flavum.

The basic metabolic pathways of lysine biosynthesis in Brevibacterium flavum, a strain which excretes excessive amounts of L-lysine, have been followed by using two 13C-labeled precursors. 13C- and 1H-NMR spectroscopies in conjunction with gas chromatography mass spectrometry (GC-MS) have revealed the various metabolic pathways leading to L-[13C]lysine. Discrete metabolic pathways give rise to distinct labeling patterns. L-Lysine resulting from [1-13C]glucose fermentation is relatively specifically labeled: L-[3,5-13C]lysine is the main product. Experimental and theoretical approaches based on the 13C-enrichment values of intracellular glutamate, a major intermediate metabolite, allowed us to assess the relative contribution of the major metabolic pathways forming lysine. The labeling pattern of glutamate reflects the isotope distribution in 2-oxoglutarate. When [2-13C]acetate is used as the sole carbon source in the culture, the energy-producing steps of the Krebs cycle are essential. The higher activity of the Krebs cycle, when endogenous carbohydrates are exhausted from the culture, is indicated by the increased 13C enrichment in C-1 of lysine and reveal a high content of isotopomers of four, five and six 13C atoms in the lysine molecule, pointing out that the four-carbon intermediates of the cycle are being derived from the glyoxylate shunt pathway. Such a phenomenon does not occur in glucose fermentation. GC-MS analyses of 13C enrichments and isotopomer distributions in metabolites and end products are in good agreement with the predicted contribution of each metabolic pathway. This new methodological approach of combined NMR and GC-MS has been demonstrated to be applicable to various other metabolic studies.

Electrophysiology of l-lysine entry across the brush-border membrane of Necturus intestine

Microelectrode measurements of apical membrane potentials ( V a) in absorptive cells of isolated Necturus intestine showed that, in the presence or absence of external Na +, 10 mM lysine added to the mucosal medium caused rapid depolarization followed by slower repolarization of V a. In Na +-free media the effects of 10 mM lysine on V a were abolished by 10 mM leucine which alone had no effect on V a under these conditions. This indicates that uncoupled electrodiffusion of lysine plays little or no role in lysine entry across the brush-border membrane. When external Na + was > 10 mM the maximum depolarization of V a ( ΔV′ a) induced by [Lys] ranging from 5 to 30 mM was a simple saturable function of [Lys]. In Na +-free media, the relationship between ΔV′ a and [Lys] was biphasic. At first, ΔV′ a increased with increasing [Lys] reaching a maximum at 10 mM lysine. When [Lys] was further increased, ΔV′ a declined progressively to reach zero or near zero values. A single transport pathway model is proposed to account for rheogenic lysine entry across the brush-border membrane in the presence and absence of Na +. This postulates an amino acid transporter in the membrane with two binding sites. One is an amino acid site specific for the α-amino-α-carboxyl group. The other is a Na + site. Neutral amino acids (e.g. leucine) compete with lysine for the amino acid site. The Na + site has some affinity for the ε-amino group of lysine. When external Na + is high the Na + site is essentially ‘saturated’ with Na + and formation of a mobile complex between an amino acid and the transporter depends in a saturable fashion on amino acid concentration. In Na +-free media or in media containing low [Na +]; (i) at low external [Lys] the ε-amino group of a lysine molecule (simultaneously attached to the amino acid site) interacts with the Na + site to form a mobile complex, (ii) as external [Lys] is increased, attachment of different lysine molecules to each site of an increasing number of transporters to form nontransported or poorly transported complexes results in substrate inhibition of the rheogenic lysine transport process.

Utilization of L-lysine and L-arginine by the diatomPhaeodactylum tricornutum

The rate of growth ofPhaeodactylum tricornutum Bohlin with L-lysine as sole nitrogen source is about half that with ammonium or nitrate, and only one of the two nitrogen atoms in the lysine molecule appears to be used for growth. The organism cannot grow heterotrophically with lysine as carbon source. The rate of lysine metabolism is slow and most of that utilized is incorporated into protein, this process being faster in light than in darkness. The dark incorporation of lysine-carbon into protein is stimulated by addition of ammonium, whereas incorporation in light is unaffected. Arginine-carbon is also mainly incorporated into protein. Light has little effect on this incorporation, and addition of ammonium decreases it both in light and darkness. There is no appreciable conversion of the carbon of either amino acid to carbon dioxide. Although, under anaerobiosis, lysine is taken up and accumulated, negligible metabolism of lysine occurs.

Intercalation of primary diamines and amino acid in the layer structure oxide HTiNbO 5

The intercalation of primary diamines in the layer structure HTiNbO 5 has been studied. This intercalation is quantitative and reversible: ten compounds have been synthesized corresponding to the general formula NH 3(CH 2) n NH( 3(TiNbO 5) 2 with n = 2–10 and 12. For each composition, two forms have been observed according to the temperature of synthesis, called low temperature (l.t.) and high temperature (h.t.), respectively. The X-ray diffraction study of these compounds shows that they are orthorhombic, with a and b parameters close to those of HTiNbO 5. The l.t. and h.t. forms differ one from another by the value of the c parameter which characterizes the spacing between the (TiNbO 5) layers. The values of the c parameters are interpreted in terms of a transversal orientation of the diamine chains with respect to the (TiNbO 5) layers. The transition l.t. áh h.t. is explained by a conformational change of the diamine involving the formation either of gauche bonds or of kinks. The intercalation of an amino acid, lysine, is also quantitative and characterized by the intercalation of one mole per proton leading to the formulation ▪ the greater value of the c parameter observed for this compound results from the formation of hydrogen bonds between the lysine molecules, which ensure the cohesion of the structure.

The preparation and crystal structure analysis of a 2:1 complex between L-lysine and copper(II) chloride

The crystal structure of bis(L-lysine)Cu(II) chloride dihydrate has been determined by X-ray analysis. The complex crystallizes in the monoclinic space group P2 1, with cell dimensions a = 5.189(1), b = 16.988(3), c = 11.482(2) Å, β = 93.57(1)°. The position of the Cu atom was found from a Patterson synthesis, the remaining atoms were located with DIRDIF. The structure was refined by least-squares to R = 0.060 and R w = 0.065 for 2637 observed reflections. The copper(II) atom has an essentially square planar coordination with the two lysine molecules chelated via the carboxy oxygen and the α-amino nitrogen. However the two chlorine atoms form weak interactions with the metal to complete a strongly tetragonally elongated six-fold coordination. The two aliphatic chains have rather different geometries and are extended in a zig-zag mode. Extensive hydrogen bonding links the complex and the water molecules together.

Crystal structure of the amino acid-vitamin complex lysine pantothenate

L-Lysine d-pantothenate, a 1:1 amino acid-vitamin complex, crystallizes in the monoclinic space group P2 1 with a = 8.883(2), b = 16.218(5), c = 10.024(2) A ̊ and β = 106.6(2)° . The structure has been solved by direct methods and refined to an R value of 0.053 for 1868 observed reflections. The zwitterionic positively charged lysine molecules in the structure assume the sterically most favourable conformation with an all- trans side chain trans to the α-carboxylate group. The pantothenate anion has a somewhat folded conformation stabilised by an intramolecular bifurcated hydrogen bond. The unlike molecules aggregate into separate alternating layers. The molecules in the lysine layers form a head-to-tail sequence parallel to the a-axis. The interactions which hold the adjacent layers together include those between the side chain amino group of lysine and the carboxylate group in the pantothenate anion. The geometry of these interactions is such that each carboxylate group is sandwiched between two amino groups in a periodic arrangement of alternating carboxylate and amino groups.

Mobilities of poly-L-lysine molecules in low-salt solutions

We have studied the ordinary–extraordinary phase transition of poly-L-lysine solutions using the techniques of quasielastic light scattering (QELS), electrophoretic light scattering (ELS), and fluorescence photobleaching recovery (FPR). Polymer of molecular weight 90 kg/mol was examined in aqueous solutions at a concentration of 1 g polymer/l. The apparent mutual diffusion coefficient, as measured by QELS, was observed to increase sharply by an order of magnitude (from 0.8 to 7×10−7 cm2/s) as the KCl concentration was increased from 2 to 5 mM, in agreement with previous reports by Schurr and co-workers. On the other hand, the tracer diffusion coefficient (measured by FPR) varies only by about 50% (from 4 to 6×10−7 cm2/s) in a broader trend over the range from 0 KCl to 10 mM KCl. The electrophoretic mobility (measured by ELS) mirrors the change in the tracer diffusion coefficient (from 1.9 to 2.6 μm cm/V s). The ELS and FPR data indicate that poly-L-lysine exists primarily as a random coil with little restriction of translational motion due to intermolecular interactions. The QELS data must then be interpreted in terms of fluctuation mobilities whose lifetimes are not characteristic of the motion of individual molecules.

Radioimmunoassay of class-specific antibodies (RIACA): Chicken antibodies to DNP

A radioimmunological method for the quantitation of class-specific antibodies has been developed. The method allows the quantitation of nanogram per ml concentrations of IgG- and IgM-anti-DNP antibodies without any physical or chemical pretreatment of the sample. The principle of the method is the same as in the radioimmunoassay of class-specific antibodies (RIACA) against BSA (Viljanen et al., 1975) developed recently by us. DNP was coupled covalently to a cyanogen bromide activated paper disk with the augmentation of lysine molecule. anti-DNP antibodies were allowed to react with the coupled DNP and then quantitated by their capacity to bind 125I-labeled anti-chicken-μ or anti-chicken-γ. The inter-assay variation coefficients ranged from 8.1 to 14.7% and the mean standard deviations of duplicate determinations were about 11%. The combination of this method with the exact immunoradiometric quantitation of the total serum IgM and IgG, and with an immunoabsorption technique, makes possible to quantitate class-specific antibodies in weight units.

X-ray studies on crystalline complexes involving amino acids. I. Crystal structure of L-lysine L-aspartate

Lysine aspartate, C 6 H 15 N 2 O 2 ·C 4 H 6 NO 4 , a crystalline complex or lysine and aspartic acid, crystallizes in the monoclinic space group P2 1 with two formula units in a unit cell of dimensions a = 5.539 (3), b = 7.848 (4), c = 15.324 (I5) A, β = 99.1 (I)°. The structure was solved by direct methods and Fourier techniques and refined to an R value of 0.069 for 1134 photographically observed reflexions. The dimensions and the conformation of the lysine molecule are similar to those observed in lysine mono-hydrochloride dihydrate. The side-chain carboxyl group of the aspartate ion is deprotonated unlike that in L- and DL-aspartic acid. The bond lengths and angles in the aspartate ion, except those in the side-chain carboxylate group, are comparable with those in L- and DL-aspartic acid. Considerable differences, however, exist in the conformation of the molecule in these structures. The crystal structure of lysine aspartate consists of alternating layers, one layer comprising lysine molecules and the other, aspartate ions. The two layers are interconnected primarily by hydrogen bonds between the side-chain amino group of lysine and carboxylate oxygen atoms belonging to neighbouring aspartate ions.

Alkylamine-dependent oxidation and oxygenation of α-monoamino acids by lysine monooxygenase

Lysine monooxygenase, a pseudomonad flavoprotein, was almost inactive with an α-monoamino acid as substrate, but the addition of an alkylamine, a counterpart of the fragmented lysine molecule, caused marked oxygen consumption. The rate of oxygen consumption was examined and compared with various combinations of α-monoamino acids and alkylamines. Hydrogen peroxide was formed and the corresponding α-keto acid was produced from each amino acid. In most cases, the hydrogen peroxide formation was nearly equal to the oxygen consumption. In some other cases, however, the oxygen consumption exceeded the hydrogen peroxide formation, and the production of an acid amide in addition to the α-keto acid was qualitatively demonstrated. Thus, both an oxidative deamination and an oxygenative decarboxylation of the same substrate occurred concomitantly, although the ratio of the two types of reaction varied with different combinations of amino acids and alkylamines. Alkylamines at higher concentrations competitively inhibited the lysine oxygenation, whereas lower concentrations of alkylamines stimulated the lysine oxygenation by decreasing the sigmoidicity of the saturation curve for lysine. These results suggest a dual function of the alkylamine; i.e., the interaction with the active site as a fragment of substrate and the effect on the regulatory property of the enzyme.

A Polarized Infrared and X-Ray Study of Lysine-Vermiculite

AbstractLysine and vermiculite form a stable, ordered, interlamellar complex which has a well defined superlattice structure with respect to the ab-plane of vermiculite. The lysine molecules lie at a low angle to the silicate surfaces and establish a double layer network between such surfaces. I.R. and chemical data for the complex are given. The possible role of hydrogen bonds in linking the system together is considered.

The designation of the major guinea-pig neural lobe protein as a neurophysin.

SUMMARY [35S]Cysteine was injected intracisternally into guinea-pigs and 5 h later the soluble proteins of the neural lobe were subjected to electrophoresis on starch and polyacrylamide. In both systems approximately 80% of the total radioactivity was recovered in a single peak with an electrophoretic mobility corresponding to the position of the major protein component. The proteins present in the guinea-pig neural lobe were extracted in 0·1 m-HCl. Fractionation of the protein—neurohypophysial hormone complex on Sephadex G-75 resulted in the isolation of a protein which cross-reacted immunologically with an antiserum raised against porcine neurophysin II. The protein designated a neurophysin contained one molecule of lysine, isoleucine and tyrosine per molecule of protein. It contained no histidine or methionine and its minimum molecular weight was estimated as 8436 by amino acid analysis.

Role of Lysine in Carnitine Biosynthesis in Neurospora crassa

Abstract Neurospora crassa lysine auxotroph strain 33933 was grown on a carnitine-free synthetic medium with either dl-[6-14C]lysine (Experiment 1), or dl-[1-14C]lysine (Experiment 2) together with 0.2 mm dl-lysine sufficient for ample growth. Carnitine was then purified from mycelial extracts of the mold by ion exchange chromatography and examined for radioactivity. In Experiment 1, radioactivity derived from [6-14C]lysine was incorporated into carnitine without dilution; and the radioactivity in such carnitine could not be dissociated from carnitine following thin layer chromatography. In contrast, radioactivity from dl-[1-14C]lysine, Experiment 2, was not detected in biosynthesized carnitine. These data thus provide evidence for the direct involvement of a portion of the lysine molecule in carnitine biosynthesis in N. crassa. A rationale for a lysine:carnitine-precursor:product relationship is offered in terms of recently discovered e-N-methyl lysine derivatives.

Carboxymethylation of Sperm Whale Myoglobin in the Dissolved State

Abstract Sperm whale ferrimyoglobin was treated with 0.2 m sodium bromoacetate at pH 6.8 to test the accessibility for alkylation of certain residues, particularly those of histidine. After a plateau had been reached in the reaction process, the product was shown to retain native properties. Electrophoretically, it was free of unmodified material and contained four main components apparently differing by unit gradations of net charge. The most fully studied preparation contained 5.3, 4.6, 1.3, 0.9, and 17.9 residues per molecule of histidine, 1,3-dicarboxymethylhistidine, 3-carboxymethylhistidine, 1-carboxymethylhistidine, and lysine, respectively. The methionine content was not affected. The aminoterminal valyl residue was largely alkylated. Assignment of histidyl residues according to the derivatives identified in peptide fragments was made according to the method of the preceding paper in the series (Hugli, T. E., and Gurd, F. R. N., J. Biol. Chem., 245, 1930 (1970)). The following residues were recovered as unmodified histidine: 24, 36, 82, 93, and 97. The other residues were isolated in various states of alkylation. The results establish a considerable number of points of similarity between the reactivity patterns in solution and in the crystalline state. Most points of contrast with the results of alkylation in the crystalline states can be ascribed to the absence of neighboring lattice molecules. However, the fact that residue 36 becomes unreactive when the protein passes from the crystalline to the dissolved state implies a distinct structural change controlling the accessibility of the residue to the alkylating agent.

The biosynthesis of desmosine and isodesmosine II. Incorporation of specifically labeled lysine into desmosine and isodesmosine

1. 1.|The incorporation of radioactivity into desmosine and isodesmosine from [I- 14C]lysine and [6- 14C]lysine was studied using chick embryo aortae in tissue culture. 2. 2.|The side chain attached to the pyridinium nitrogen in desmosine and iso-desmosine was liberated in the form of lysine by the action of strong alkali. 3. 3.|After the incorporation of radioactivity into desmosine and isodesmosine from [I- 14C]lysine and from [6- 14C]lysine, one-fourth of the total activity of desmosine as well as isodesmosine was found to be present in the side chain attached to the pyridinium nitrogen. 4. 4.|The distribution of radioactivity in the carboxyl carbons of desmosine and isodesmosine was studied with the use of the ninhydrin reaction. 5. 5.|Almost all the activity incorporated into desmosine and isodesmosine from [I- 14C]lysine was found to be present in the carboxyl carbons. 6. 6.|No activity could be detected in the carboxyl carbons of desmosine and iso-desmosine after the incorporation of radioactivity from [6- 14C]lysine. 7. 7.|All the observations support the hypothesis that 4 lysine molecules condense to form a desmosine or isodesmosine molecule.

The Biosynthesis of Desmosine and Isodesmosine

The biosynthesis of desmosine and isodesmosine was studied with chick embryo aortas in tissue culture. Radioactivity was incorporated into desmosine and isodesmosine when uniformly labeled lysine-14C was added to the medium, but no activity could be incorporated into these amino acids from aspartic acid-14C, glutamic acid-14C, or threonine-14C. The labeled desmosine and isodesmosine obtained after the incorporation of radioactivity from lysine-14C were subjected to the action of strong sodium hydroxide solutions. This treatment liberates the pyridinium nitrogen along with its side chain in the form of lysine. The lysine thus liberated from the labeled desmosine or isodesmosine was found to contain one-fourth of the total activity of the parent compound. The distribution of radioactivity in the carboxyl carbons of these compounds was also studied. These results strongly support the hypothesis that 4 lysine molecules condense to form 1 desmosine or isodesmosine molecule.

Détermination de la dimension des molécules de poly- L-γ-glutamate de benzyle et de poly- L-∈-carbobenzoxy-lysine par des méthodes hydrodynamiques—effets de la flexibilité

Recently, the mass per unit length of poly- γ -benzyl- L -glutamate (PBLG) molecules in dimethylformamide solution was determined by low-angle X-ray scattering. The value obtained is close to that of the 3 10 -helix, though the results of light-scattering and hydrodynamic measurements have been so far interpreted as arising from an α-helical structure which is less elongated. It is possible to resolve this contradiction by recalling that the X-rays measure the particles on a small scale while the other methods measure the over-all dimensions. This can lead to error if a theoretical model of a rigid particle is employed and, in fact, the molecules are not perfectly rigid. In this work, the dimensions of PBLG and of poly-∈-carbobenzoxy- L -lysine (PCBL) molecules are determined according to the usual hydrodynamic analysis from Brownian diffusion constant ( D ) and viscosity ([ η ]) data. The distance between two successive residues projected on the helical axis ( h ) is then calculated. Its systematic variation with molecular weight M clearly indicates flexibility of the molecules. Extrapolation of these data to zero molecular weight allows the determination of the real value of h , which is found to be about 1·9 A. In spite of the uncertainty of the extrapolation, this result supports the existence of a helix more elongated than the α-helix. In addition, criteria of rigidity are denned for rod-like particles of constant diameter. The M 2 /[η] versus log M plot appears very sensitive to any flexibility and shows that the PCBL molecules are much more flexible than the PBLG molecules. On the other hand, the DM versus log M plot remains linear for both polypeptides, which seems to indicate that, to some extent, the Brownian diffusion is insensitive to flexibility. The slope of this latter plot provides thus a direct measurement of the mass per unit length and the h value is found again to be about 1·9 A for PBLG as well as for PCBL molecules. Finally, it is pointed out that only this new analysis of hydrodynamic measurements gives results in good agreement with those found by low-angle X-ray scattering determinations.

La protéine lysante II de la rate du lapin III. détermination des aminoacides N- et C-terminaux

By applying Sanger's flurodinitrobenzene method to the lytic protein II of the spleen of the rabbit, and submitting also this protein to the action of carboxypeptidase, it was possible to show that, as the lysozyme of hen's egg, the lytic protein II of the spleen of the jrabbit is formed by a unique peptidic chain having one molecule of lysine as N-terminal and one molecule of leucine as C-terminal amino acid.

Compounds Synthesized from Proteins and Carcinogenic Hydrocarbons

Introduction The artificial protein antigens obtained by the chemical combination of proteins with diazotized substituted benzenes (Landsteiner and Lampl, 1) and with phenyl isocyanate (Hopkins and Wormall, 2–4) exhibit immunological characteristics which are dependent on the “determinant group” attached to the protein. The demonstration of carcinogenesis from pure hydrocarbons suggested the possibility of forming similar antigens with the carcinogenic substance as the “determinant group.” The development of the malignant state might then be brought into the realm of immunology. Further importance is added to such an approach by the recent synthesis of methylcholanthrene from desoxycholic acid and from cholic acid and by the demonstration of the carcinogenic activity of some of the naturally occurring hormones. Specific immunological response to such substances might then be proved of interest to the problem of spontaneous carcinogenesis. In this paper, a report is given of the synthesis of antigens consisting of protein with the carcinogenic 1:2:5:6-dibenzanthracene and other related non-carcinogenic hydrocarbons as the determinant groups. Their properties have been studied by chemical and serologic methods. Some preliminary notes on the biological activity of these compounds are included. The method of Hopkins and Wormall (2) was selected for the preparation of the “protein-hydrocarbon compounds” because the synthesis of the isocyanates of the higher aromatic hydrocarbons proved more feasible than the diazotization of their amines. Anthranyl isocyanate (m.p. 75–75.5† corr.) and 1:2:5:6-dibenzanthranyl isocyanate (m.p. 181–181.5† corr.) were synthesized and identified (Creech and Franks, 5). 2 Hopkins and Wormall ( 2 ) consider that the isocyanates react mainly with the epsilon amino group of the lysine molecules of the protein. Tyrosine also may be involved in the coupling reaction. However, the terminology of Hopkins and Wormall will be employed in this article and the “protein-hydrocarbon compounds” will be named anthranyl-carbamido-proteins and dibenzanthranyl-carbamido-proteins. 3