Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:4.2.2.10 (PNL)
341 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study characterized the ability of a bacterial cutinase to improve the wettability of raw cotton fabrics by specific hydrolysis of the cutin structure of the cuticle. The effect of cutinase was studied alone and in coreaction with pectin lyase. The changes in both the fabric and the reaction fluid were measured and compared to enzymatic hydrolysis with polygalacturonase, and to chemical hydrolysis with boiling NaOH. Water absorbancy, specific staining, fabric weight loss, and evaporative light-scattering reverse-phase high-performance liquid chromatography analysis of chloroform extract of the reaction fluid were measured to assess the enzymatic hydrolysis of the cuticle waxy layer. The pattern and extent of hydrolysis of the major cuticle constituents depended on the enzyme type and titers employed and paralleled the degree of wettability obtained. The combination of cutinase and pectin lyase resulted in a synergistic effect. The use of detergents improved enzymatic scouring. The major products released to the reaction medium by the cutinase treatment were identified by gas chromatography/mass spectrometry analysis as C:16 and C:18 saturated fatty acid chains.
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PMID:Potential use of cutinase in enzymatic scouring of cotton fiber cuticle. 1239 30

The gelling properties of pectins are known to be closely related to the degree of methylation (DM) and the distribution of the ester groups. In order to investigate this dependency, a natural citrus pectin (DM 64%) has been methylated to pectins with higher DM or saponified to achieve pectins with lower DM. A simple method for determination of DM by 1H NMR spectroscopy is presented. New modified pectins have been prepared by treatment of pectins having different DM with NaBH(4) to reduce selectively the methyl esters to primary alcohols in the presence of free acids. The degree of reduction (DR) and the DM of the remaining carboxylic acids could likewise be determined by 1H NMR spectroscopy. The new reduced pectins are recognized by the pectin degrading enzymes polygalacturonase PGI and PGII as well as by pectin lyase, all from Aspergillus niger, but the enzymes exhibit lower specific activities as compared with unmodified pectin. The new reduced pectins exhibit high gelling properties.
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PMID:Chemically methylated and reduced pectins: preparation, characterisation by 1H NMR spectroscopy, enzymatic degradation, and gelling properties. 1264 77

Eight cold-adapted, polygalacturonase-producing yeasts belonging to four species were isolated from frozen environmental samples in Iceland. They were identified as Cystofilobasidium lari-marini, Cystofilobasidium capitatum, Cryptococcus macerans and Cryptococcus aquaticus species by sequence analysis of rDNA regions. Growth behavior of the isolates was investigated. All strains could grow at 2 degrees C. Addition of glucose to pectin-containing culture medium had a repressive effect on enzyme production except for C. aquaticus, which showed increased polygalacturonase activity. Optimal temperature for enzyme production for the Cystofilobasidium strains was 14 degrees C, while that for the Cryptococcus strains was lower. Among the isolates, C. lari-marini S3B produced highest levels of enzyme activity at pH 3.2. Preliminary characterization of the polygalacturonases in the culture supernatant showed the enzyme from Cystofilobasidium strains to be optimally active at 40 degrees C and pH 5, and that from the Cryptococcus strains at 50 degrees C and pH 4. The polygalacturonase from C. macerans started to lose activity after 1 h of incubation at 40 degrees C, while that from the other strains had already lost activity at 30 degrees C. All the strains except C. aquaticus produced isoenzymes of polyglacturonase. In addition to polygalacturonase, the Cystofilobasidium strains produced pectin lyase, C. aquaticus pectin esterase, and C. macerans pectin lyase, pectate lyase and pectin esterase.
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PMID:Cold-adapted yeasts as producers of cold-active polygalacturonases. 1276 49

This present study was undertaken to find optimum conditions of pH, temperature and, period of incubation for the pectinolytic activity of Kluyveromyces wickerhamii isolated from rotting fruits and to assess the effect of these factors by use of response surface methodology (RSM). A central composite rotatable design was used as an experimental design for the analysis of the allocation of treatment combinations. A second order polynomial regression model was fitted and was found adequate, with an R(2) of 0.94469 (P<0.001). The effects of temperature and pH were the most significant factors in influencing enzyme production. Estimated optimum conditions were as follows: pH 5.0, temperature, 32 degrees C and an incubation period of 91 h. Pectinesterase (PE), pectin lyase (PL), and cellulase activities were not detected. Pectinase production was partially constitutive. Pectin was degraded by the isolated strain of K. wickerhamii in the current study, and the pectinolytic activity is referred to as polygalacturonase (PG) activity. Crude enzyme extract was thermostable at various temperatures and, stimulated by the presence of Ca(2+) ions but inhibited by other ions like Mg(2+), Zn(2+), Co(2+), Mn(2+) and Na(+).
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PMID:Optimising growth conditions for the pectinolytic activity of Kluyveromyces wickerhamii by using response surface methodology. 1281 Feb 74

Using anion-exchange chromatography on different carriers and phenyl-Sepharose hydrophobic chromatography, five pectolytic enzymes were isolated from the culture liquid of a mutant strain of Aspergillus japonicus: two endo-polygalacturonases (I and II, 38 and 65 kD, pI 5.6 and 3.3), pectin lyase (50 kD, pI 3.8), and two pectinesterases (I and II) with similar molecular weights (46 and 47 kD) and the same pI (3.8). The pectinesterases apparently represent two isoforms of the same enzyme. All purified enzymes were homogenous according to SDS-PAGE and polyacrylamide gel-IEF, except for endo-polygalacturonase II that gave two bands on isoelectric focusing, but one band on electrophoresis. All enzymes had maximal activity in an acid medium (at pH 4.0-5.5). The pectin lyase and pectinesterase were stable at 40-50 degrees C. The thermal stability of both endo-polygalacturonases was much lower (after 3 h of incubation at 30 degrees C, endo-polygalacturonases I and II lost 40 and 10% of the activity, respectively). The activity of endo-polygalacturonases I and II towards polygalacturonic acid strongly depended on NaCl concentration (optimal concentration of the salt was 0.1-0.2 M); the enzymes were also capable of reducing the viscosity of pectin solution, but rather slowly. The pectin lyase had no activity towards polygalacturonic acid. The activity of the pectin lyase increased with increasing degree of methylation of pectins. Both endo-polygalacturonases demonstrated synergism with the pectinesterase during the hydrolysis of highly methylated pectin. On the contrary, in the mixture of pectin lyase and pectinesterase an antagonism between the two enzymes was observed.
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PMID:Isolation and properties of pectinases from the fungus Aspergillus japonicus. 1288 38

Tissue maceration was generally elucidated by the action of endo-polygalacturonase and endo-pectate or -pectin lyase (endo-PAL or -PNL). In a process of screening of Erwinia and Pseudomonas strains for enzymatic pulping of pectocellulosic bast fibers, it was found that their PAL productivity was not completely related with defibration activity, i.e., the fact that an E.chrysanthemi strain showed high PAL productivity but possessed rather low defibration activity. Moreover, defibration activity was parallel to the amount of neutral sugars released during pulping. Based on these fact, the maceration or enzymatic pulping of basts was estimated to proceed not only by cleavage of interfiber bonding cause by PAL action but also another factors. Among three possibilities proposed on the maceration mechanism of basts, it was elucidated by a concerted action of PAL and PNL with an aid of xylanase. In addition, a quantitative determinative method of maceration activity toward basts was also presented.
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PMID:Approach to maceration mechanism in enzymatic pulping of bast fibers by alkalophilic pectinolytic enzymes produced by Erwinia species. 1454 40

Thanatephorus cucumeris is a ubiquitous fungus responsible for many types of plant diseases worldwide. All isolates from infected Hevea brasiliensis trees secreted pectolytic enzymes; polygalacturonase (PG), pectin lyase (PL) and cellulolytic enzymes; beta-glucosidase and cellobiase in culture. The extracts of the rubber tree leaf tissues, inoculated with T. cucumeris did not show any PG activity. However, PL activity was detected in tissue with the establishment of the infection. The levels of beta-glucosidase, an inherent enzyme in Hevea spp. increased rapidly following infection. However, cellobiase was detected only with the initiation of infection. Molecular weights of PG in all isolates were similar and in the range of 53,000 to 58,000. PL also followed the same pattern showing a molecular weight around 39,000.
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PMID:Characterization of cell wall degrading enzymes of Thanatephorus cucumeris. 1500 48

A method for the isolation of single plant cells from Taxus suspension cultures has been developed for the analysis of single cells via rapid throughput techniques such as flow cytometry. Several cell wall specific enzymes, such as pectinase, pectolyase Y-23, macerozyme, Driselase(R), and cellulase were tested for efficacy in producing single cell suspensions. The method was optimized for single cell yield, viability, time, and representivity of aggregated cell cultures. The best combination for single cell isolation was found to be 0.5% (w/v) pectolyase Y-23 and 0.04% (w/v) cellulase. High viability (>95%) and high yields of single cell aggregates (>90%) were obtained following 4 hours of digestion for four separate Taxus cell lines. In addition, methyl jasmonate elicitation (200 microM) was found to have no effect on three of the four tested Taxus lines. Isolated single cells were statistically similar to untreated cell cultures for peroxidase activity (model cell wall protein) and paclitaxel content (secondary metabolite produced in Taxus cell cultures). In comparison, protoplasts showed marked changes in both peroxidase activity and paclitaxel content as compared to untreated cultures. The use of flow cytometry was demonstrated with isolated cells that were found to have > 99% viability upon staining with fluorescein diacetate. The development of a method for the isolation of single plant cells will allow the study of population dynamics and culture variability on a single cell level for the development of population models of plant cell cultures and secondary metabolism.
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PMID:Preparation of single cells from aggregated Taxus suspension cultures for population analysis. 1516 58

Three hundred yeasts isolated from tropical fruits were screened in relation to secretion of pectinases. Twenty-one isolates were able to produce polygalacturonase and among them seven isolates could secrete pectin lyase. None of the isolates was able to secrete pectin methylesterase. The pectinolytic yeasts identified belonged to six different genera. Kluyveromyces wickerhamii isolated from the fruit mangaba (Hancornia speciosa) secreted the highest amount of polygalacturonase, followed by K. marxianus and Stephanoascus smithiae. The yeast Debaryomyces hansenii produced the greatest decrease in viscosity while only 3% of the glycosidic linkages were hydrolysed, indicating that the enzyme secreted was an endo-polygalacturonase. The hydrolysis of pectin by polygalacturonase secreted by S. smithiae suggested an exo-splitting mechanism. The other yeast species studied showed low polygalacturonase activity.
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PMID:Pectinolytic enzymes secreted by yeasts from tropical fruits. 1592 14

A pectinolytic and psychrophilic yeast was isolated from soil from Abashiri, Hokkaido, Japan. The phenotype and sequencing of the 28S rDNA of the isolated strain (PPY-1) indicated a taxonomic affiliation to the basidiomycetous yeast Cystofilobasidium capitatum. C. capitatum strain PPY-1 was able to grow on two pectic compounds, polygalacturonate and pectin, at below 5 degrees C. Moreover, the extracellular fraction of the strain exhibited pectin methylesterase, pectin lyase and polygalacturonase activities at 5 degrees C. Thus strain PPY-1 may produce novel enzymes that are able to degrade pectin at low temperature, although the strain has isozymes of these enzymes.
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PMID:Cold-active pectinolytic activity of psychrophilic-basidiomycetous yeast Cystofilobasidium capitatum strain PPY-1. 1623 89


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