SEARCH · Search PubMed

Results for “PECTINS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources

PubMed1990

Pectin Lyase Activity in a Penicillium italicum Strain.

An extracellular pectin lyase (PNL) [poly-(methoxygalacturonide)lyase; EC 4.2.2.10] produced by Penicillium italicum CECT 2294 grown on a surface bran (natural medium) or in a submerged (synthetic medium) culture was investigated. Both culture filtrates showed macerating activity at low pH on cucumber, potato, and orange tissues. The physicochemical properties of the enzyme obtained from both culture methods were identical, as well as its catalytic properties, which were assayed by different methods. The molecular mass of the PNL obtained by gel filtration chromatography was 22 kDa; the isoelectric point was 8.6, as determined by chromatofocusing; and the enzyme was able to catalyze the eliminative cleavage of pectins with low (37%) and high (from 54 to 82%) degrees of esterification. The PNL produced in liquid medium showed a K(m) for pectin (degree of esterification, 70%) of 3.2 mg/ml, and the optimum pH was 6.0 to 7.0. This enzyme was stable at 50 degrees C and at pH 8.0. The ability of this PNL to macerate plant tissues in acidic environmental conditions, its stability at low pH and temperatures up to 50 degrees C (thus preventing mesophilic microbial growth), and the absence of pectinesterase make this preparation useful for the food industry.

Journal Article↗

PubMed2002

Frequency-dependent breakdown of wave propagation into fibrillatory conduction across the pectinate muscle network in the isolated sheep right atrium.

Atrial fibrillation (AF) may result from stationary reentry in the left atrium (LA), with fibrillatory conduction toward the right atrium (RA). We hypothesize that periodic input to the RA at an exceedingly high frequency results in disorganized wave propagation, compatible with fibrillatory conduction. Simultaneous endocardial and epicardial optical mapping (di-4-ANEPPS) was performed in isolated, coronary-perfused sheep RA. Rhythmic pacing of Bachmann's bundle allowed well-controlled and realistic conditions for LA-driven RA. Pacing at increasingly higher frequencies (2.0 to 6.0 Hz) led to increasing delays in activation distal to major branching sites of the crista terminalis and pectinate bundles, culminating in spatially distributed intermittent blockade at or above approximately 6.5 Hz. At this "breakdown frequency," the direction of RA propagation became completely variable from beat to beat and thus transformed into fibrillatory conduction. Such frequency-dependent changes were independent of action potential duration. Rather, the spatial boundaries between proximal and distal frequencies correlated well with branch sites of the pectinate musculature. Thus, there exists a breakdown frequency in the sheep RA below which activity is periodic throughout the atrium and above which it is fibrillation-like. The data are consistent with the ideas that during AF, high-frequency activation initiated in the LA undergoes fibrillatory conduction toward the RA, and that sink-to-source effect at branch points of the crista terminalis and pectinate muscles is important in determining the complexity of the arrhythmia.

Action Potentials↗

PubMed2001

Sequence analysis and overexpression of a pectin lyase gene (pel1) from Aspergillus oryzae KBN616.

A gene (pel1) encoding pectin lyase (Pel1) was isolated from a shoyu koji mold, Aspergillus oryzae KBN616, and characterized. The structural gene comprised 1,196 bp with a single intron. The ORF encoded 381 amino acids with a signal peptide of 20 amino acids. The deduced amino acid sequence showed high similarity to those of Aspergillus niger pectin lyases and Glomerella cingulata PnlA. The pel1 gene was successfully overexpressed under the promoter of the A. oryzae TEF1 gene. The molecular mass of the recombinant pectin lyase substantially coincided with that calculated based on nucleotide sequence.

Amino Acid Sequence↗

PubMed1984

Aqueous outflow in the beagle. I. Postnatal morphologic development of the iridocorneal angle: pectinate ligament and uveal trabecular meshwork.

The present study examined the postnatal development of the pectinate ligaments and uveal trabecular meshwork of the normal canine chamber angle of the Beagle breed at one day, one through ten weeks, three, four and six months, and one and two years of age. Angle tissue was prepared and examined by standard techniques for light microscopy and scanning and transmission electron microscopy. Developmentally, pectinate ligaments matured by the third week although areas continued to develop through the eighth week. Each primary pectinate ligament possessed a large, posterior extracellular space at its iridal attachment. The uveal meshwork, which developed by rarefaction, was not formed at birth and did not appear adult-like until the end of the second month. Adult trabecular cells were ultrastructurally identical throughout the angle, having been characterized by having cilia and "special" rough endoplasmic reticulum.

Aging↗

PubMed1999

[Pectineal ligament of Cooper. Micromorphometric study].

The pectineal ligament is used in surgery as a support element in the treatment of groin hernias and female urinary stress incontinence. The question is to determine the anatomical characters that account for its strength. Three complementary approaches have been considered: an anatomical dissection study established the origin of the different fibers the ligament is composed of; a morphometric study determined the areas where the ligament is the thickest; and microscopic anatomy clearly showed the arrangement of the fibers. The pectineal ligament continues the near-by fibers fibrous elements, notably thanks to its ends. The latter are significantly thicker. At microscopic level, the regular layout of the pectineal ligament fibers accounts for its resistance.

Aged↗

PubMed1964

AVIAN ATHEROSCLEROSIS: RETARDATION BY PECTIN.

A highly significant retardation of spontaneous atherosclerosis was observed in 2-year-old cockerels fed on a standard diet supplemented with 5 percent pectin for 18 months. The pectin-fed birds excreted three times as much lipid extract and almost twice as much cholesterol as did the control cockerels fed the standard diet supplemented with 5 percent nonnutritive fiber.

Animals↗

PubMed1981

Influence of kaolin-pectin suspension on steady-state plasma digoxin levels.

The effect of a kaolin-pectin antidiarrheal mixture on steady-state plasma levels of orally administered digoxin in subjects receiving chronic digoxin therapy was evaluated when the antidiarrheal and the cardiac glycoside were given concomitantly and when two doses of antidiarrheal were given, one 2 hours before and the other 2 hours after digoxin. Although simultaneous administration of both products decreased peak digoxin levels by 36 per cent, 24-hour areas under the curve were reduced by only 15 per cent, indicative of a slight decrease in digoxin bioavailability. In contrast, when their times of administration were separated by 2 hours, no evidence of a drug interaction was noted. Hence, the effect of one or two doses of kaolin-pectin suspension on steady-state plasma levels of digoxin appears inconsequential in patients on chronic digoxin therapy. Saliva levels were poorly correlated with plasma levels, presumably because of complexation in the oral cavity.

Absorption↗

PubMed2002

Textural profiling and statistical optimization of crosslinked calcium-alginate-pectinate-cellulose acetophthalate gelisphere matrices.

A 2(5) factorial design was employed to statistically evaluate the textural properties of a crosslinked calcium-alginate-pectinate-cellulose acetophthalate gelisphere system. In accordance with the factorial matrix, gelispheres were formulated by titrating a combination polymeric solution comprised of sodium alginate, pectin and/or cellulose acetophthalate into an inducer solution (crosslinking agent) consisting of calcium and/or acetate ions. A Texture Analyzer was used to profile the gelisphere matrices for their resilience in the unhydrated and hydrated states, the fracture energy involved in matrix rupture, and the matrix hardness achieved with different levels of crosslinking. Significantly different textural properties were found among the crosslinked formulations. In particular, the unhydrated matrix resilience was selected as a parameter for optimization of the gelisphere formulation because of its large impact on drug release modulation, matrix integrity, and sensitivity to the crosslinking process. Resilience increased with increasing polymer concentration, irrespective of the polymer combination. Furthermore, resilience was not significantly influenced by the concentration of the crosslinking agents, but rather by the application of a higher polymer concentration in the crosslinking reaction; again irrespective of the polymer combination. In addition to the use of a factorial design, artificial neural modeling was employed to predict the textural properties based on the factorial matrix as a statistically suitable data source. Neural networks appeared to be a strong competitor of factorial regression for the prediction of textural data.

Alginates↗

PubMed1978

Pharmacokinetic evaluation of a drug interaction between kaolin--pectin and clindamycin.

The effect of a kaolin--pectin antidiarrheal suspension on the bioavailability of orally administered clindamycin was evaluated by model-dependent pharmacokinetic techniques. Each subject's serum clindamycin concentration--time data in the absence of the kaolin--pectin suspension were fitted to a one-compartment open model with first-order absorption and lag time. The resulting disposition parameters were used to construct individual Wagner-Nelson absorption profiles, expressed as the cumulative relative fraction of clindamycin absorbed versus time following combined antidiarrheal--antibiotic therapy. For each subject, absorption persisted to varying degrees through 14 hr. On the average, the half-time for absorption was prolonged 20-fold (from about 16 min to more than 300 min). In contrast, extrapolation of the individual time courses of relative absorption to infinity revealed that the antidiarrheal had no effect on the extent of clindamycin absorption.

Adult↗

PubMed1978

Influence of kaolin--pectin suspension on digoxin bioavailability.

The effect of a kaolin--pectin suspension on the bioavailability of orally administered digoxin was evaluated when both drugs were given concomitantly and when their time of administration was separated by 2 hr. Coadministration of the antidiarrheal with the cardiac glycoside delayed absorption of the latter and, at the same time, decreased by 62% the amount of drug absorbed. Intersubject variation in digoxin bioavailability also was increased more than twofold. When the kaolin--pectin suspension was given 2 hr before the cardiac glycoside, the digoxin absorption rate was not affected, although its relative extent of absorption was reduced by about 20%. In contrast, when the antidiarrheal was given 2 hr after digoxin, neither the rate nor the extent of absorption of the cardiac glycoside was perturbed. No change in the intersubject variability in digoxin bioavailability was noted whether the antidiarrheal was given 2 hr before or 2 hr after the cardiac glycoside.

Adult↗

PubMed2006

Effect of lemnan, pectin from Lemna minor L., and its fragments on inflammatory reaction.

An effect of apiogalacturonanic pectin of duckweed Lemna minor L. (lemnan LM) was studied on the inflammatory response to ovalbumin injected intradermally into the footpad of control and ovalbumin-fed mice. Lemnan LM (1-2 mg per mouse) was found to enhance by as much as 50-60% the footpad swelling in control mice. Oral administration of ovalbumin was shown to result in sensitization that increased inflammation. Ovalbumin admixed with lemnan was found to increase by two-fold footpad edema in comparison with the mice receiving ovalbumin alone. Apple pectin used as a reference compound failed to influence the inflammatory reaction. Degradation of lemnan was performed to elucidate the active region of the polysaccharide macromolecule. The apiogalacturonanic fragment (LMP) obtained using a digestion of lemnan LM with pectinase was shown to increase the footpad response in both control and ovalbumin-fed mice. Fragment LMPH deprived of some terminal apiose residues as a result of partial acidic hydrolysis failed to have an effect on the inflammatory response.Thus, the data obtained reveal an enhancement by lemnan of the inflammatory response. The ramified apiogalacturonan seemed to be the active region of the lemnan macromolecule.

Administration, Oral↗

PubMed2006

The effect of modified citrus pectin on urinary excretion of toxic elements.

This study was undertaken to evaluate the effect of modified citrus pectin (MCP) on the urinary excretion of toxic elements in healthy individuals. MCP is a reduced molecular weight pectin (weight-average molar mass = 15,400) that is mostly linear homogalacturonan with a 3.8% degree of esterification and approximately 10% rhamnogalacturonan II based on the presence of 2-keto-3-deoxy-octonic acid. Subjects ingested 15 g of MCP (PectaSol, EcoNugenics Inc., Santa Rosa, California 95407) each day for 5 days and 20 g on day 6. Twenty-four hour urine samples were collected on day 1 and day 6 for comparison with baseline. The urine samples were analysed for toxic and essential elements. In the first 24 h of MCP administration the urinary excretion of arsenic increased significantly (130%, p < 0.05). On day 6, urinary excretion was increased significantly for cadmium (150%, p < 0.05). In addition, lead showed a dramatic increase in excretion (560%, p < 0.08). This pilot trial provides the first evidence that oral administration of MCP increases significantly the urinary excretion of toxic metals in subjects with a 'normal' body load of metals. It is suggested that systemic chelation of toxic metals by MCP may in part be attributable to the presence of rhamnogalacturonan II, which has been shown previously to chelate metals.

Adult↗

PubMed1994

Effects of natural complex carbohydrate (citrus pectin) on murine melanoma cell properties related to galectin-3 functions.

Citrus pectin (CP) and pH-modified citrus pectin (MCP) are highly branched and non-branched complex polysaccharides, respectively, rich in galactoside residues, capable of combining with the carbohydrate-binding domain of galectin-3. We reported previously that intravenous injection of B16-F1 murine melanoma cells with CP or MCP into syngeneic mice resulted in a significant increase or decrease of lung colonization, respectively (Platt D, Raz A (1992) J Natl Cancer Inst 84:438-42). Here we studied the effects of these polysaccharides on cell-cell and cell-matrix interactions mediated by carbohydrate-recognition. MCP, but not CP, inhibited B16-F1 melanoma cells adhesion to laminin and asialofetuin-induced homotypic aggregation. Both polysaccharides inhibited anchorage-independent growth of B16-F1 cells in semisolid medium, i.e. agarose. These results indicate that carbohydrate-recognition by cell surface galectin-3 may be involved in cell-extracellular matrix interaction and play a role in anchorage-independent growth as well as the in vivo embolization of tumour cells.

Animals↗

PubMed2003

Quantitative determination of saturated oligogalacturonic acids in enzymatic digests of polygalacturonic acid, pectin and carrot pomace by on-line LC-ESI-MS.

A method for the quantitative determination of oligogalacturonic acids (OGAs) by on-line high-performance liquid chromatographic (HPLC) separation and mass spectrometric detection via an electrospray interface (ESI-MS) without additional desalting steps was developed. Saturated OGAs up to a degree of polymerization (dp) of 3 were quantified by comparison with reference compounds. The calibration plots showed high linearity (R(2)>0.99), and the detection limits for dp 1, 2, and 3 were 11, 28, and 6 ng per injection, respectively. Non- and partially methyl-esterified OGAs with a dp of 3 and 4 were calculated semi-quantitatively as dp 3. The analytical system was used for the quantification of OGAs of digests obtained by incubation of polygalacturonic acid, pectin, and carrot pomace with commercial enzyme preparations. Furthermore, methyl-esterified OGAs up to a dp of 12 containing up to 4 methyl esters were detected in a pectin digest.

Cellulases↗

PubMed2000

A (1-->3,6)-beta-d-galactosyl epitope containing uronic acids associated with bioactive pectins occurs in discrete cell wall domains in hypocotyl and root tissues of flax seedlings.

We have used a well-characterized antibody specific for an epitope consisting of (1-->3,6)-beta-d-galactosyl residues with terminal glucuronic or 4-O-methylglucuronic acids of a bioactive pectin and immunocytochemistry to investigate its secretion and wall distribution in the hypocotyl and root tissues of flax seedlings. Our results show that this antigenic epitope is associated with flax pectins and is expressed by all the cells of the hypocotyl and root tissues. In the hypocotyl, it is abundant in the primary wall of epidermal cells as well as in the secondary wall of fiber cells, and is relatively less abundant in parenchyma cell walls. In contrast, the epitope is not detected in the middle lamellae and cell junction regions. In the root tip cells, immunogold electron microscopy shows that the cell walls of peripheral, columella, meristematic, cortical, and epidermal cells contain significant amounts of this epitope and that the distribution patterns are distinct. Together, these findings show that the antigenic epitope occurs in discrete domains of the wall implying a strict spatial regulation of the epitope-containing molecules. The results also show that, in root cells, the epitope is present within Golgi cisternae and is predominantly assembled in the trans and the trans-Golgi network compartments.

Antibodies↗

PubMed2006

Comprehensive expression profiling of the pectin methylesterase gene family during silique development in Arabidopsis thaliana.

Pectin methylesterases (PME, EC. 3.1.1.11) are enzymes that demethylesterify plant cell wall pectins in muro. In Arabidopsis thaliana, putative PME proteins are thought to be encoded by a 66-member gene family. This study used real-time RT-PCR to gain an overview of the expression of the entire family at eight silique developmental stages, in flower buds and in vegetative tissue in the Arabidopsis. Only 15% of the PMEs were not expressed at any of the developmental stages studied. Among expressed PMEs, expression data could be clustered into five distinct groups: 19 PMEs highly or uniquely expressed in floral buds, 4 PMEs uniquely expressed at mid-silique developmental stages, 16 PMEs highly or uniquely expressed in silique at late developmental stages, 16 PMEs mostly ubiquitously expressed, and 1 PME with a specific expression pattern, i.e. not expressed during early silique development. Comparison of expression and phylogenetic profiles showed that, within phylogenetic group 2, all but one PME belong to the floral bud expression group. Similar results were shown for a subset of one of the phylogenetic group, which differed from others by containing most of the PMEs that do not possess any PRO part next to their catalytic part. Expression data were confirmed by two promoter:GUS transgenic plant analysis revealing a PME expressed in pollen and one in young seeds. Our results highlight the high diversity of PME expression profiles. They are discussed with regard to the role of PMEs in fruit development and cell growth.

Arabidopsis↗

PubMed2006

Cadmium-induced alterations of the structural features of pectins in flax hypocotyl.

In the course of our studies on the putative role of pectins in the control of cell growth, we have investigated the effect of cadmium on their composition, remodelling and distribution within the epidermis and fibre tissues of flax hypocotyl (Linum usitatissimum L.). Cadmium-stressed seedlings showed a significant inhibition of growth whereas the hypocotyl volume did not significantly change, due to the swelling of most tissues. The structural alterations consisted of significant increase of the thickness of all cell walls and the marked collapse of the sub-epidermal layer. The pectic epitopes recognized by the anti-PGA/RGI and JIM5 antibodies increased in the outer parts of the epidermis (external tangential wall and junctions) and fibres (primary wall and junctions). Concomitantly, there was a remarkable decrease of JIM7 antibody labelling and consequently an increase of the ratio JIM5/JIM7. Conversely, the ratio JIM7/JIM5 increased in the wall domains closest to the plasmalemma, which would expel the cadmium ions from the cytoplasm. The hydrolysis of cell walls revealed a cadmium-induced increase of uronic acid in the pectic matrix. Sequential extractions showed a remodelling of both homogalacturonan and rhamnogalacturonan I. In fractions enriched in primary walls, the main part of the pectins became cross-linked and could be extracted only with alkali. In fractions enriched in secondary walls, the homogalacturonan moieties were found more abundantly in the calcium-chelator extract while the rhamnogacturonan level increased in the boiling water extract.

Cadmium↗

PubMed2000

Protein- and pH-dependent binding of nascent pectin and glucuronoarabinoxylan to xyloglucan in pea.

Nascent pectin and glucuronoarabinoxylan, synthesised in vitro by membrane-bound enzymes from etiolated pea (Pisum sativum L.) epicotyls, were found to bind to pea xyloglucan in a pH-dependent manner. The binding was maximum at low pH (3-4), and decreased to almost zero at pH 6. The binding was probably non-covalent and reached saturation within 5 min. Removal of the fucose residues of xyloglucan decreased the degree of binding. Removal by protease of the proteins attached to nascent pectin and glucuronoarabinoxylan greatly reduced the maximum binding and abolished the pH-dependence. The observed binding may be of considerable significance in the process of cell-wall assembly and in the control of cell extension.

Binding Sites↗