Showing papers on "Buffer solution published in 1982"

Rapid determination of residual chlorine by flow injection analysis

Abstract: Flow injection determination of residual chlorine in solution has been carried out spectrophotometrically by methyl orange decolorisation and by formation of a yellow complex with o-tolidine. The carrier streams are 0.180 mM methyl orange in pH 2 buffer solution or 0.01 M hydrochloric acid, and 3.0 mMo-tolidinium dichloride (in 2 M hydrochloric acid), respectively. A sampling rate of 288 samples per hour has been obtained with the latter reagent and the detection limit is 0.08 p.p.m. of chlorine. Influence of flow parameters such as flow-rate, tube length and diameter and the effect of interferents on the determination have been investigated. A study of the hyprochlorite-ammonium-o-tolidine reaction system has been performed and a method for the simultaneous determination of NH4+ and OCl– is described.

Affinity chromatography using metal ions

Abstract: A process for the affinity chromatographic separation of at least one biological or related substance from a mixture wherein the at least one biological or related substance is bound to a binding material, having a ligand containing at least one of the groups anthraquinone, phthalocyanine or aromatic azo, in the presence of at least one metal ion selected from the group Ca 2+ , Sr 2+ , Ba 2+ , Al 3+ , Co 2+ , Ni 2+ , Cu 2+ or Zn 2+ . The preferred metal ions are Co 2+ , Ni 2+ and Zn 2+ , with Zn 2+ being particularly preferred. The ligand may be linked directly to the matrix or via a spacer arm. The process may be performed at atmospheric pressure or under pressure, especially high pressure (100-3500 psi). The nature of the contact, washing and eluting solutions depends on the substance to be separated. Generally the contact solution is made up of the substance to be separated and a metal salt dissolved in a buffer solution, while the washing solution comprises the same metal salt dissolved in the same buffer. The eluting solution, may be a buffer solution, either alone or containing a chelating agent or it may be an alkali metal salt or a specific desorbing agent. Alternatively the eluting solution may be a mixture of two or more of these solutions or two or more of these solutions used consecutively.

Responsibility of Hydrogen Peroxide for the Lethality of Resting Escherichia coli B Cells Exposed to Alternating Current in Phosphate Buffer Solution

Abstract: Surviving fractions of Escherichia coli B exposed to an alternating current (AC) of 50 Hz in a phosphate buffer solution of pH 7.0 at 29°C were closely related to the amount of H2O2 formed in cell suspensions. At a definite current density, the amount of H2O2 in the suspensions or in buffer solution without cells increased with increasing AC-exposure time under aerobic conditions. On the other hand, the formation of H2O2 on AC-exposure was not detected under anaerobic conditions. It was considered that H2O2 was formed on the surface of carbon electrodes by AC-electrolytic reduction of dissolved oxygen. The amount of H2O2 formed decreased with increasing concentration of cells suspended or of catalase added to the suspension. When the formation of H2O2 was significantly suppressed, surviving fractions of cells exposed to AC remained almost unchanged. Growth conditions, modifying the intracellular level of catalase of E. coli, affected the sensitivity of cells to AC-exposure.

Method for eliminating glucose dependent Schiff base effect from hemoglobin A1 assay

Abstract: An ion exchange method for the separation of hemoglobin A1 from its Schiff base precursors and from nonglycosylated hemoglobin in a sample of human blood. The known method of lysing the sample, using it to impregnate a weak cation exchange resin, eluting out the glycosylated components with a buffer solution containing from about 0.6 M to about 0.11 M alkali metal ion dissolved therein, and recovering the eluate, is modified by the inclusion of a dihydroxyboryl compound in either the hemolysate, the elution buffer, or both.

Electrophoretic separation of isoenzymes utilizing a stable polyacrylamide system

Abstract: A method for separating isoenzymes is disclosed. The method involves polyacrylamide gel electrophoresis in a buffer solution of a salt of 2-amino-2-methyl-1,3-propanediol at a pH of about 6.4 to 7.3 and an electrolyte buffer of 2-amino-2-methyl-1,3-propanediol taurine at a pH of about 8.0 to 10.0. After separation of the isoenzymes, the amount of individual isoenzymes present is determined.

Thermal Destruction of Vitamin B6 Vitamers in Buffer Solution and Cauliflower Puree

Abstract: Thermal degradation rates of pyridoxal (PL-HCl), pyridoxine (PN-HCl) and pyridoxamine (PM-2 HCl) in 0.1 M phosphate buffer (pH 7.20) were determined over the temperature range 110-145°C using HPLC procedures. Thermal degradation of PM-2 HCl was modelled by a pseudo-first order rate constant. Thermal degradation of PN-HCl and PL-HCl was modelled by a 1.5 order and second order model, respectively. The temperature dependence of all three rate constants could be described by the Arrhenius equation. None of the degradation products from any of the vitamers exhibited antivitamin activity. Thermal degradation rates of vitamin B6 in cauliflower puree were measured over the temperature range 106-138°C and found not to be described by a first-order model. The activation energy was markedly lower in this food system than in the model system and emphasizes the importance of conducting experiments on real food systems. The activation energy is in the range reported for several other water soluble nutrients.

Development of a Reliable Hg-195m-]au-195m Generator for the Production of Au-195m, a Short-lived Nuclide for Vascular Imaging

Abstract: A new mercury-195m (T1/2: 41 hr) leads to gold-195m (T1/2: 30.6 sec) generator suitable for first-pass as well as steady-state radionuclide angiography studies has been developed. The distribution coefficients, Kd, for mercury (Hg-195m) and gold (Au-196), experimentally evaluated on chelating resin Chelex 100, showed this resin to be suitable as the column packing. Mercury-195m in a Trisma buffer solution at pH 7.40 was loaded on a chelating resin Chelex 100 column, together with gold carrier. Au-195m was eluted with an aqueous solution of 5% glucose in a 0.01M Trisma buffer at pH 7.70 (25 degrees C). Chemical assessment of the eluate has ensured that the eluted carrier-free gold is by no means colloidal: 80% is found in an ionic form, 20% as an uncharged species. Safe clinical use for routine diagnosis in humans is possible.

Study on the Micelle Formation of Sodium Deoxycholate

Abstract: The micelle formation of sodium deoxycholate ( NaDC ) in aqueous solution with addition of NaCl and in a buffer solution ( pH = 7.78 ) has been investigated by means of light scattering, circular dichroism, viscosity, density and solubilization of cholesterol. In the both solution systems of the added NaCl and the borate buffer it was clearly seen that the shape and size of aggregate at the lower concentration range are quite different from those at the higher concentration. The time dependence in the size and shape of the aggregate was so remarkable that all experiments had to be made until the systems observed reached their time equilibria. In the system with addition of NaCl the association number of spherical micelle, formed in the relatively higher range of NaDC concentration, increases with increasing the concentration of added NaCl and with lowering temperature. Also the association number in pure water at each temperature was estimated by extrapolating to the zero concentration of NaCl added.

Arylalkanoic acid process improvement

Abstract: In preparing arylalkanoic acids, e.g. ibuprofen or naproxen, via the conversion of the selected α-haloketal derivative of a 1-haloethyl aryl ketone to the haloalkyl ester of the arylalkanoic acid using a zinc salt catalyst the improvement comprising reacting a ring-substituted 6-membered ring ketal of the selected 1-haloethyl C6 -C12 -aryl ketone with a soluble zinc carboxylate salt to form the corresponding 3-haloalkyl arylalkanoic acid ester. The ester is converted to the alkali metal salt of the acid with base in an aqueous/water insoluble organic liquid mixture and the crude salt is converted to the corresponding acid in an aqueous/water insoluble solvent mixture for the acid, the organic solution of the acid is washed with a pH 7.0 to 8.0 buffer solution, and the arylalkanoic acid product is separated from the mother liquor which mother liquor is recycled to the alkali metal arylalkanoate salt forming step of the process to accumulate and recover the arylalkanoic acid values which remained in the mother liquor.

[33] 5-Keto-d-gluconate reductase from Gluconobacter su☐ydans

Abstract: Publisher Summary This chapter describes an assay method for the isolation of 5-keto-D-gluconate reductase from Gluconobacter suboxydans . 5-Keto-D-gluconate reductase catalyzes the reduction of 5-keto-D-gluconate to D-gluconate and occurs only in acetic acid bacteria. It is reduced in the presence of nicotinamide adenine dinucleotide phosphate dehydrogenase (NADPH) to give D-gluconate and nicotinamide adenine dinucleotide phosphate dehydrogenase (NADP). The reaction rate is measured by the decrcase of absorbancc at 340 nm. NADPH oxidation is followed in a recording spectrophotometer at 25°C. The steps involved in the purification procedure discussed are (1) the preparation of cell-free extract, (2) diethylaminoethyl (DEAE)-sephadex column chromatography, (3) affinity chromatography on blue-dextran sepharose, (4) pH gradient chromatography on diethylaminoethyl (DEAE)-sephadex, and (5) crystallization. All operations are carried out at 0–5°C throughout the purification steps, unless otherwise stated. Centrifugations are at 12,000 g for 20 min. The buffer solution used is potassium phosphate, pH 6.0, which is supplemented with 2-mercaptoethanol, sodium D-gluconate, and glycerol.

Effects of salicylate on HCO-3/Cl- exchange across the human erythrocyte membrane.

Abstract: Changes in extracellular pH (pHo) in human red cell suspensions were monitored in a stopped-flow rapid reaction apparatus. A 20% suspension of washed human RBC in saline at pH 7 containing NaHCO3 and extracellular carbonic anhydrase was mixed with an equal volume of buffered saline solution at pH 6.7. Sodium salicylate, when present, was added to both the erythrocyte suspension and the buffer solution. The effects of salicylate in the therapeutic to toxic concentration range on HCO-3/Cl- exchange were studied at 37 degree C. HCO-3/Cl- exchange flux was estimated using the extracellular buffer capacity and the difference between dpHo/dt using a control RBC suspension and that using a suspension of RBC whose anion exchange pathway was markedly inhibited. The results show that salicylate competitively decreases the rate of HCO-3/Cl- exchange, with inhibition increasing as salicylate concentration increases. KI is approximately 2.4 mM. At a salicylate concentration of 10 mM, HCO-3/Cl- exchange under the conditions of our experiments was inhibited by more than 70%. These findings are consistent with the possibility that CO2 transfer in capillary beds in vivo may be diminished in the presence of salicylate due to slowing of red cell HCO-3/Cl- exchange.

Erythrocyte storing solution

Abstract: PURPOSE:An erythrocyte storing solution having improved storage properties, obtained by adding specific subatances to an physiologically isotonic buffer solution. CONSTITUTION:In a storing solution to preserve erythrocyte, glucose and albumin are added to a physiologically isotonic buffer solution [ACD(acid citrate dextrose) solution]. The amount of glucose to the buffer solution is 0.5-2.0w/v%, especially about 1w/v%, and the amount of albumin is 0.25-1.0w/v%, especially about 0.5w/v. Glucose has preventing actions on the hemolyzation of erythrocyte and extremely enhancing the preservating effect of erythrocyte, and albumin further improves the storage properties of erythrocyte by the synergistic actions with glucose.

Process for the recovery of alpha -2-SB-glycoprotein

Abstract: The present invention provides a process for obtaining alpha -2-SB-glycoprotein from physiological solutions thereof by binding to a bindable protein immobilized on an insoluble carrier, wherein the carrier-fixed protein is subsequently washed with a buffer solution of pH 6 to 8.5 and thereafter the alpha -2-SB-glycoprotein is eluted with a buffer solution with a pH of 9 or more and isolated from the eluate.

Composition for testing carious activity

Abstract: PURPOSE:The titled composition, prepared by impregnating an absorbing carrier with a pH indicator and a buffer solution system, and capable of providing the rapid and easy test of the carious activity with a high degree of accuracy. CONSTITUTION:A composition prepared by impregnating an absorbing carrier, e.g. a filter paper or cloth, with a pH indicator system, e.g. metacresol purple or thymol blue, and a buffer solution system, e.g. citric acid or sulfosalicylic acid. The salivary buffering ability can be measured simply by observing the color tone developed on the surface of the composition just after applying one drop of saliva thereto. The dental caries are caused by organic acids, e.g. lactic acid or acetic acid, produced from the decomposition of dietary carbohydrates by the bacteria in the oral cavity, e.g. Streptococcus mutans. The titled composition provides the measurement of the neutralizing ability of the acidic buffer solution system of a sample saliva, and permits the prediction of the tendency of the future occurrence of the dental caries or the further progress of the present dental caries, and is very useful for the oralogy.

チオテノイルトリフルオロアセトンと1,10-フェナントロリンを用いるマンガン(ii)の吸光光度定量

Abstract: Manganese (II) reacted with thiothenoyltrifluoroacetone (STTA) in the presence of 1, 10-phenanthroline (phen) to form a complex, Mn(STTA)2(phen). The complex extracted into xylene had an absorption maximum around 375 nm and the absorbance was stable at least for 24 h. The analytical procedure was as follows: To a sample solution containing less than 15μg of manganese (II), were added each 5 ml of 20 w/v % ammonium acetate solution and 3.0 × 10-4M phen solution. The pH of the mixture was adjusted to 7.3 ±0.3 with ammonia water and the solution was diluted to 50 ml with water. The manganese (II) in the solution was extracted with 10 ml of 3.15 × 10-4 M STTA solution in xylene by shaking for 5 min. The aqueous phase was removed and the organic phase was washed with 10 ml of borax-NaOH buffer solution (pH 11.5) by shaking for 1 min. Then the absorbance of the organic phase was measured at 375 nm against the reagent blank. In the determination of 10 μg of manganese (II), 1.0 μg of zinc (II), cadmium (II), copper (II), and cobalt (II) interfered. However, these (interfering) metal ions were removed by the prelim inary extraction at pH 7.3±0.3 with STTA solution in xylene in the absence of phen, because manganese (II) was not extracted under these conditions. The calibration curve was linear up to 15μg of manganese (II) in 10 ml of the organic phase. The coefficient of variation on the absorbance for 10 μg of manganese (II) was 0.8 %. The molar absorptivity was 3.58× 104 l mol-1 cm-1. The proposed method could be applied to the determination of manganese in aluminum and aluminum alloys with satisfactory results.

Effect of pH on the removal of pyritic sulfur from coal by oxydesulfurization

Abstract: The effect of pH on the removal of pyritic sulfur in air/water chemical coal cleaning was investigated. The pH was varied by adding sulfuric acid or sodium carbonate to a coal-water slurry. The effect of nearb neutral pH ( about7) was determined in a buffer solution of sodium dihydrogen phosphate and disodium hydrogen phosphate. Data were taken in the temperature range of 130 to 190/sup 0/C, oxygen partial pressure of 0.32 to 1.36 MPa, and reaction times up to 3600 s. The rate of pyrite oxidation was found to be minimum at the nearby neutral conditions. Under otherwise identical conditions, the rate of pyrite oxidation was greater in basic pH than in acidi pH. The enhancement in the rate of pyrite oxidation is explained on the basis of electrochemical reactions. Under nearly neutral conditions, the overall reaction is shown to be controlled by the surface reaction, whereas under acidic as well as basic conditions, diffusion of oxygen through the product ash layer as well as the surface chemical reaction seems to be important.

Physiologically active novel substance mutastein and process for its production

Abstract: A physiologically active novel substance designated as Mutastein is disclosed, which has the following specific physiological properties: (1) it has a molecular weight of at least 200,000, and when subjected to gel-filtration with Sephadex G-100 and Sephallose 6B, it will be eluted in the void volume; (2) its ultraviolet spectrum: FIG. 1; (3) its infrared spectrum: FIG. 2; (4) it has a proteinous nature and contains about 10% of saccharide; (5) it is soluble in water and a saline solution, but it will be salted out from a saturated solution containing about 30% of ammonium salfate; and it is insoluble in acetone, ethanol, ethylacetate and benzene, (6) it dissolves in a buffer solution having a pH 7 or over, but it precipitates at a pH of from 3 to 3.5, (7) it is stable when heat-treated at pH 9, at 100° C. for 10 minutes, (8) its elementary analysis: C: about 44%, H: about 7%, and N: about 12%, (9) its color reactions: Phenol-surfuric acid color reaction (orange), and Folin's color reaction (blue). This substance can be prepared by culturing the Mutastein-producing strain belonging to the genus Aspergillus, and isolating the Mutastein from the culture medium.

Double-chain dna bonded to d-glutamic acid-d-lysine copolymer, its preparation and medicine containing the same

Abstract: NEW MATERIAL:Double-chain DNA bonded to D-glutamic acid-D-lysine copolymer The appearance: amorphous white powder; melting point: 263-264 degC (decomp); solubility: soluble in water, 001M phosphoric acid buffer solution and physiological saline; insoluble in methanol, acetone, ethyl acetate; specific rotatory power [alpha]D =+3667; pH: 58-60 (in 12% aqueous solution); color reactions: positive to alpha-naphthol and diphenylamine reactions, negative to Liebermann, Zimmermann and ferric chloride reactions; elementary analyses (%): C 42, H 6, N 13 USE:A remedy for autoimmune diseases such as systemic lupus erythematosus PREPARATION:DNA is treated into double-chain DNA, which is oxidized with an oxidizing agent such as sodium periodate The oxidized product is made to react with D-glutamic acid-D-lysine copolymer and reduced with sodium borohydride or the like to produce the objective compound

Measuring method of superoxide dismutase (sod)

Abstract: PURPOSE:To measure the titled substance easily and well, by reacting a solution containing a combination of the titled substance with a labeling enzyme with a test solution and a solution containing a receptor having the ability to combine with the titled substance in an aqueous medium, and measuring the enzymic activity. CONSTITUTION:A superoxide dismutase is combined with an enzyme, e.g. lipase, alkaline phosphatase or glycerol kinase, and a given amount of the resultant solution containing the combination thereof is reacted with a test solution for determining the superoxide dismutase value, a receptor having a specific bonding property to the superoxide dismutase, e.g. an antibody obtained by sensitizing a different kind of animal with the superoxide dismutase or a solution containing the an antiserum containing the antibody, at about 4 deg.C overnight. The reaction is carried out in an aqueous medium, e.g. a buffer solution. After the reaction, the solid phase is separated from the liquid layer, and the enzymic activity of the solid phase or liquid layer is measured.

Stabilization of l-alpha-glycerol-3-phosphate oxidase

Abstract: PURPOSE: To improve the stability of L-α-glycerol-3-phosphate oxidase in a buffer solution, remarkably, by adding flavin adenine dinucleotide and/or a chelating agent. CONSTITUTION: A buffer solution containing L-α-glycerol-3-phosphate is incorporated with flavin adenine dinucleotide or a chelating agent such as ethylenediaminetetraacetic acid, ethylene glycol ether diamine tetraacetic acid, etc. or their mixture, to obtain a buffer solution having a pH of 5.0W9.0, flavine adenine dinucleotide concentration of 0.01W50mM/1 and chelating agent concentration of 0.1W200mM/1. COPYRIGHT: (C)1984,JPO&Japio

Preparation of solubilizing aqueous solution of water insoluble substance

Abstract: PURPOSE: To obtain the titled transparent and stable solubilizing aqueous solution, by a method wherein a water insoluble substance is added to an aqueous solution containing a nonionic surfactant and the resulting mixture is once heated to a temp. higher than the cloud point of the nonionic surfactant under stirring to be cooled. CONSTITUTION: A water insoluble substance being a fatty substance such as cholesterol ester is added to an aqueous solution containing a nonionic surfactant (e.g., a polyoxyethylene derivative such as polyoxyethylene lauryl ether) and the resulting mixture is once heated to a temp. higher than the cloud point of the nonionic surfactant under stirring and cooled to the cloud point or less while stirring is further continued. Thus obtained aqueous solution is extremely stable and generates no turbidity even if diluted with a buffer solution to lower the concn. thereof or the pH thereof is changed. Therefore, this solution is high in usefulness as a general-purpose standard liquid or a substrate solution of a fatty substance. COPYRIGHT: (C)1983,JPO&Japio

Glycoprotein and remedy for tumor

Abstract: NEW MATERIAL:A glycoprotein having the following properties: Molecular weight: 12,000W17,000. Color reactions: Coloring of the protein by the Lowry reaction, coloring of the peptide bond and the amino acid by the ninhydrin reaction after the hydrolysis with hydrochloric acid and coloring of the saccharide by the phenolsulfurinc acid reaction. Properties and solubility: White powder. Soluble in water and aqueous solution of NaCl, etc. and slightly soluble in benzene, etc. Saccharide content: 27W33%. Isoelectric point: 4.2W7.3. Adsorbable in a 0.01M phosphroric acid buffer solution (7.2pH) by specific fractionation procedures. USE: A remedy for tumors. PROCESS: A glycoprotein (CB x ) having a very powerful and selective cytotoxic action on the tumorous cells and differentiation inductive action on the recovery of the tumorous cells to the normal cells is obtained by subjecting an extract or cultivation supernatant liquid of a reticuloendothelial cell, lymphoblast, leukemic cell or fibroblastic cell of a warm-blooded animal to a salting out treatment, ion exchange chromatography, gel filtration, affinity chromatography or dialysis, etc. A remedy for tumor is obtd. using said CB x as a main constituent. COPYRIGHT: (C)1983,JPO&Japio

Process for measuring calcium

Abstract: A process for measuring the amount of calcium in a sample using as a color reagent ortho-cresolphthalein com- plexone and a buffer solution by a colorimetric method, characterized by using a carbonate and/or bicarbonate solution as buffer solution can give precise measured values without causing a problem of environmental pollution.

Buffer solution for calibration and control purposes for analytical apparatus for single or combined potentiometric measurement of the pH and of the electrolytes K and Na and Ca of aqueous solutions, in particular of blood samples

Abstract: The buffer solution according to the invention consists of sodium chloride, potassium chloride, lithium chloride and [bis(2-hydroxyethyl)imino]tris[(hydroxymethyl)methane] or sodium chloride, potassium chloride and tris(hydroxymethyl)aminomethane, where appropriate calcium carbonate, dissolved in an aqueous solution to which hydrochloric acid is added.

Method and apparatus for quantitative determination of cyanogen ion, thiocyanate ion or salts thereof by liquid chromatography

Abstract: PURPOSE:To make the pretreatment unnecessary, by separating a cyanide ion, a thiocyanate ion or these salts by a separation column for a liquid chromatography and bringing out the color development by adding a coloring reagent continuously and then, carrying out a colorimetric determination. CONSTITUTION:Anion exchange resin is packed in column 4 circulating 30 deg.C warm water through a jacket. An acetic acid buffer solution controlled at 5.0pH and containing 0.1M sodium perchlorate, is sent out from an eluate storage vessel 1 by a pump 2 and a chloramine T solution is sent out from a chlorination solution storage vessel 22 by a pump 20 and then, a barbituric acid-pyridine reagent is sent out from a coloring reagent solution storage vessel 27 by a pump 25. Colorimetry of sample reached a transparent cell 35 through a coloring reaction tube 7 is carried out by a detector 8 consisting of a light source 33, a spectral material 34, a photodetecting element 36, an amplifier 37 and a recorder 38. In such constitution, a cyanide ion and a thiocyanate ion, are determined by one operation only and the apparatus is simplified because pretreatment such as distillation is unnecessary.

Purification of heparan sulfate

Abstract: PURPOSE: A mixture of acidic mucopolysaccharides is subjected to chromatography by means of poly-L-lysine-cephalose as a support and eluted for separation by gradient concentration of a buffer solution to produce heparan sulfate with high potency through easy and simple operations. CONSTITUTION: Internal organs of mammarians are minced, treated with acetone into powder. The powder is digested with pronase to remove protein therefrom, dialyzed and precipitated with ethanol. The precipitate is subjected to chromatography and the resultant solution of acidic mucopolysaccharide mixture is eluted by means of a poly-L-lysine-cephalose column using a 0.05M-tris-hydrochloric acid buffer solution of pH 7.3W7.7, containing sodium chloride, to buffer the column with gradient concentration of sodium chloride from 0 to 2.0M, then collecting heparan sulfate from the fractions of 1.0W1.3M sodium chloride concentration. COPYRIGHT: (C)1983,JPO&Japio

Immobilized composite enzyme composition

Abstract: PURPOSE: To prepare the titled composition having excellent long-term stability, by combining an immobilized composite enzyme with a buffer solution containing a metal-chelating agent and a reducing agent. CONSTITUTION: (A) A buffer solution (e.g. phosphate buffer solution) containing 0.010mM of a metal-chelating agent (e.g. ethylenediaminetetraacetic acid sodium salt) and 0.1W20mM of a reducing agent (e.g. phosphorous acid) is combined with (B) a composite enzyme (creatinine amide hydrolase, creatinamidino hydrolase and sarcosine oxidase) imobilized with a carrier (e.g. cellulose acetate) in the form of powder, solution, bead, fiber, tube, film, etc. COPYRIGHT: (C)1983,JPO&Japio

Detergent effects on an albumin-chlorophyll complex model of photosynthetic protein-pigment complexes

Abstract: The absorption, fluorescence, fluorescence polarization and circular dichroism spectra of an artificial complex human serum albumin-chlorophyll-a were measured at 20°C in buffer solution (pH 7.2) and the effect of detergents (digitonin, sodium lauryl sulfate, above critical micelle concentration) was studied. A strong chlorophyll-chlorophyll interaction found in the complex is removed by detergent treatment. The ionic detergent sodium lauryl sulphate induces pheophytinization and conformational changes in the protein part of the complex leading to changes in the absolute configuration of the transition moments of the pigment. Profound changes in the fluorescence polarization spectra are caused by both detergents. The effects of detergents suggest that the possibility of similar phenomena in treating plant material should be rigorously considered.