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P K Kindel

Publications and source records attributed to P K Kindel.

11 recordsLinked to original sources
PubMed1995

Effect of cations on the elution of pectic polysaccharides from anion-exchange resins.

Conditions for quantitatively eluting six plant pectic polysaccharides from diethylaminoethyl (DEAE)-columns were established. Cations, surprisingly, greatly affected the elution of pectic polysaccharides from these anion-exchange columns. Quantitative elution of apple pectic acid was achieved when columns of DEAE-Sephadex A-25 and DEAE-Trisacryl Plus-M were developed with 0.5 M NH4Cl, 0.5 M LiCl, or 0.5 M CsCl in buffer. In contrast, up to 1 M NaCl and KCl in buffer only eluted 6.3 to 54% of the apple pectic acid from the two types of columns. In each case the retained apple pectic acid was eluted basically quantitatively by 0.5 M NH4Cl in buffer. The elution of a pectic polysaccharide fraction from Apium graveolens (celery), commercial citrus polygalacturonic acid, and two polysaccharides isolated from purified cell walls of Lemna minor (duckweed) from columns of DEAE-Trisacryl was incomplete when the columns were developed wit 0.5 M NaCl or 0.5 M KCl in buffer, ranging from 0 to 89%; however, again, the retained portion of each sample was eluted quantitatively or almost so from the columns with 0.5 M NH4Cl in buffer. One pectic polysaccharide, commercial citrus pectin, was eluted equally well and almost quantitatively by 0.5 M NaCl, KCl and NH4Cl in buffer. When a pectic polysaccharide fraction from purified cell walls of L. minor was applied to a preparative column of DEAE-Trisacryl Plus-M, 99% of the sample was eluted by a gradient of 0 to 0.5 M NH4Cl in buffer.(ABSTRACT TRUNCATED AT 250 WORDS)

Anions↗
PubMed1990

The acetylation of apiitol in the determination of apiose.

The complete acetylation of apiitol required 9 h when acetic anhydride at 120 degrees was used and sodium acetate was the catalyst. Both apiitol pentaacetate and apiitol tetraacetate were detected before acetylation was complete. When the reaction was done in dimethyl sulfoxide, with 1-methylimidazole as the catalyst, a third compound was observed, and identified as 1,2,4-tri-O-acetyl-3-C-(acetoxymethyl)-3-O-(methylthiomethyl)-D-glycero- tetrito l [3-O-(methylthiomethyl)apiitol tetraacetate] by gas-liquid chromatography and mass spectrometry. In N,N-dimethylformamide, with 1-methylimidazole as catalyst, the acetylation of apiitol was essentially complete in 4 h at 85 degrees, and the formation of methylthiomethyl ether was avoided. A method for preparing alditol acetates using 1-methylimidazole as the catalyst, and suitable for samples containing apiose as well as ordinary sugars, is described. The separation of apiitol pentaacetate from xylitol pentaacetate by gas-liquid chromatography proved difficult. However, a virtually complete separation of the peracetates of apiitol and xylitol as well as complete separation of those of rhamnitol, fucitol, arabinitol, mannitol, galactitol, glucitol, and myo-inositol, plus apiitol tetraacetate and 3-O-(methylthiomethyl)apiitol tetraacetate, was accomplished with a 30 m x 0.53 mm (i.d.) SP-2380 column in 49 min, and on a 30 m x 0.75 mm (i.d.) SP-2330 column in 82 min. A complete separation of apiitol and xylitol pentaacetates as well as four other alditol peracetates was obtained with a 60 m DB-1 column in 15.2 min, however this column did not resolve the acetates of fucitol and arabinitol. A variety of other columns and column conditions were ineffective.

4-Aminopyridine↗
PubMed1989

Arabinoxylans from rye and wheat seed that interact with ice.

Arabinoxylans that interfere with growth of ice crystals have been purified from rye (Secale cereale L., Rosen) and two varieties of wheat (Triticum aestivum L., Genesee and Hillsdale) seed. The most active polysaccharide from each seed type was homogeneous in the sense that all the molecules were in the same size range, they contained the same sugar residues, and they reacted similarly in chemical characterization experiments. Structural studies showed that the polysaccharides consist of a xylan chain to which are attached side-chains that contain a single, terminal arabinose residue. The polysaccharides differ with respect to the number of arabinose residues. The xylose:arabinose ratios in the most active fractions from rye, Genesee wheat, and Hillsdale wheat are 1.26, 1.54, and 2.08, respectively. Gel-permeation column chromatography showed that the most active polysaccharide from each seed type has a molecular weight greater than 2 x 10(6) and that the rye polysaccharide is slightly larger than the Hillsdale wheat polysaccharide. The rye polysaccharide is a better inhibitor of ice-crystal growth than is the Hillsdale wheat polysaccharide.

Arabinose↗
PubMed1973

Synthesis, characterization and properties of uridine 5'-( -D-apio-D-furanosyl pyrophosphate).

1. A method was developed for synthesizing UDP-apiose [uridine 5'-(alpha-d-apio-d-furanosyl pyrophosphate)] from UDP-glucuronic acid [uridine 5'-(alpha-d-glucopyranosyluronic acid pyrophosphate)] in 62% yield with the enzyme UDP-glucuronic acid cyclase. 2. UDP-apiose had the same mobility as uridine 5'-(alpha-d-xylopyranosyl pyrophosphate) when chromatographed on paper and when subjected to paper electrophoresis at pH5.8. When [(3)H]UDP-[U-(14)C]glucuronic acid was used as the substrate for UDP-glucuronic acid cyclase, the (3)H/(14)C ratio in the reaction product was that expected if d-apiose remained attached to the uridine. In separate experiments doubly labelled reaction product was: (a) hydrolysed at pH2 and 100 degrees C for 15min; (b) degraded at pH8.0 and 100 degrees C for 3min; (c) used as a substrate in the enzymic synthesis of [(14)C]apiin. In each type of experiment the reaction products were isolated and identified and were found to be those expected if [(3)H]UDP-[U-(14)C]apiose was the starting compound. 3. Chemical characterization established that the product containing d-[U-(14)C]apiose and phosphate formed on alkaline degradation of UDP-[U-(14)C]apiose was alpha-d-[U-(14)C]apio-d-furanosyl 1:2-cyclic phosphate. 4. Chemical characterization also established that the product containing d-[U-(14)C]apiose and phosphate formed on acid hydrolysis of alpha-d-[U-(14)C]apio-d-furanosyl 1:2-cyclic phosphate was d-[U-(14)C]apiose 2-phosphate. 5. The half-life periods for the degradation of UDP-[U-(14)C]apiose to alpha-d-[U-(14)C]apio-d-furanosyl 1:2-cyclic phosphate and UMP at pH8.0 and 80 degrees C, at pH8.0 and 25 degrees C and at pH8.0 and 4 degrees C were 31.6s, 97.2min and 16.5h respectively. The half-life period for the hydrolysis of UDP-[U-(14)C]-apiose to d-[U-(14)C]apiose and UDP at pH3.0 and 40 degrees C was 4.67min. After 20 days at pH6.2-6.6 and 4 degrees C, 17% of the starting UDP-[U-(14)C]apiose was degraded to alpha-d-[U-(14)C]apio-d-furanosyl 1:2-cyclic phosphate and UMP and 23% was hydrolysed to d-[U-(14)C]apiose and UDP. After 120 days at pH6.4 and -20 degrees C 2% of the starting UDP-[U-(14)C]apiose was degraded and 4% was hydrolysed.

Carbon Isotopes↗
PubMed1970

Isolation and partial characterization of apiogalacturonans from the cell wall of Lemna minor.

1. A mild, reproducible extraction procedure, using 0.5% ammonium oxalate, was developed for the isolation of polysaccharides containing d-apiose from the cell wall of Lemna minor. On a dry-weight basis the polysaccharide fractions extracted with ammonium oxalate made up 14% of the material designated cell walls and contained 20% of the d-apiose originally present in the cell walls. The cell walls, as isolated, contained 83% of the d-apiose present in L. minor. 2. After extraction with ammonium oxalate, purified polysaccharides were obtained by DEAE-Sephadex column chromatography and by fractional precipitation with sodium chloride. With these procedures the material extracted at 22 degrees C could be separated into at least five polysaccharides. On a dry-weight basis two of these polysaccharides made up more than 50% of the material extracted at 22 degrees C. There was a direct relationship between the d-apiose content of the polysaccharides and their solubility in sodium chloride solutions; those of highest d-apiose content were most soluble. 3. All the polysaccharides isolated appeared to be of one general type, namely galacturonans to which were attached side chains containing d-apiose. The d-apiose content of the apiogalacturonans varied from 7.9 to 38.1%. The content of esterified d-galacturonic acid residues in all apiogalacturonans was low, being in the range 1.0-3.5%. Hydrolysis of a representative apiogalacturonan with dilute acid resulted in the complete removal of the d-apiose with little or no degradation of the galacturonan portion. 4. Treatment of polysaccharide fractions with pectinase established that those of high d-apiose content and soluble in m-sodium chloride were not degraded, whereas those of low d-apiose content and insoluble in m-sodium chloride were extensively degraded. When the d-apiose was removed from a typical pectinase-resistant polysaccharide, the remainder of the polysaccharide was readily degraded by this enzyme. 5. Periodate oxidation of representative polysaccharide fractions and apiogalacturonans and determination of the formaldehyde released showed that about 50% of the d-apiose molecules were substituted at either the 3- or the 3'-position.

Cell Wall↗
PubMed1970

D-apiose reductase from Aerobacter aerogenes.

A strain of Aerobacter aerogenes PRL-R3 has been isolated which utilizes d-apiose as its sole source of carbon. A new enzyme, d-apiose reductase, was discovered in this strain. The enzyme was not present when the strain was grown on d-glucose. d-Apiose reductase catalyzes the nicotinamide adenine dinucleotide-dependent interconversion of d-apiose and d-apiitol. The enzyme is specific for d-apiose and d-apiitol, with a few possible exceptions. The K(m) for d-apiose is 0.02 m. The K(m) for d-apiitol is 0.01 m. The enzyme is almost completely specific for the reduced and oxidized forms of nicotinamide adenine dinucleotide. When cell-free extracts were centrifuged at 100,000 x g for 1 hr, the enzyme remained in solution. Optimal activity for the reduction of d-apiose was obtained at pH 7.5 in glycylglycine buffer, whereas for the oxidation of d-apiitol it was obtained at pH 10.5 in glycine buffer. Enzymatic reduction of d-apiose was not appreciably affected by the presence of 0.02 m ethylenediaminetetraacetate. Paper chromatography and specific spray reagents were used to identify d-apiitol and d-apiose as the products of this reversible reaction. d-Apiose and d-apiitol did not serve as substrates for ribitol dehydrogenase and d-arabitol dehydrogenase from A. aerogenes PRL-R3.

Alcohol Oxidoreductases↗