scholarly journals HEMICELLULOSE APPARENT MOLECULAR SIZE CHANGES DURING SOFTENING OF PEACH FRUIT

HortScience ◽  
1994 ◽  
Vol 29 (7) ◽  
pp. 737d-737
Author(s):  
Supreetha Hegde ◽  
Niels Maness
Keyword(s):  
Molecular Weight ◽  
Cell Wall ◽  
Apparent Molecular Weight ◽  
Weight Fraction ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Neutral Sugar ◽  
Fruit Softening ◽  
Peach Fruit ◽  
Cell Wall Polymers

Peach fruit softening appears to be associated with changes in cell wall polymers, particularly pectins and hemicelluloses. To determine changes of cell wall polymers associated with peach fruit softening, we conducted sequential extractions of pectin and hemicellulose from softening fruit. A more tightly bound hemicellulose fraction contained considerable amounts of pectin associated sugars. This fraction was separated into charged and neutral fractions, using anion exchange chromatography, and then fractionated into two apparent molecular weight classes by size exclusion chromatography. Virtually all of the charged fraction eluted in the higher apparent molecular weight fraction. The neutral sugar fraction segregated into both apparent molecular weight size classes, with a redistribution from the large to the small size class during softening. This redistribution was accompanied by changes in neutral sugar composition. A possible relationship between changes in this fraction and fruit softening will be discussed. Supported by USDA grant 92-34150-7190 and the Oklahoma Agricultural Experiment Station.

Changes in Hemicellulose-associated Pectin during Softening of Peach Fruit

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 640c-640
Author(s):  
Supreetha Hegde ◽  
Niels O. Maness
Keyword(s):  
Molecular Weight ◽  
Cell Wall ◽  
Sodium Carbonate ◽  
Middle Lamella ◽  
Apparent Molecular Weight ◽  
Primary Cell ◽  
Size Exclusion ◽  
Primary Cell Wall ◽  
Cell Wall Polysaccharide ◽  
Peach Fruit

Softening to a normal melting flesh texture in peaches involves a combined participation between polymers located in the middle lamella and primary cell wall. Pectins located in the primary cell wall polysaccharide matrix which cosolubilize when hemicellulose is extracted with KOH have received less attention than the chelator or sodium carbonate soluble pectin likely to be associated with the middle lamella. We conducted a series of extractions for cell walls prepared from softening peach fruit (47, 30, and 15 N firmness) using 0.5 m imidazole, sodium carbonate and a graded series of KOH. Hemicellulose-associated pectin was a substantial proportion of most KOH extracts (30 to 50 mole percent) and fractionated on size exclusion chromatography as a high apparent molecular weight peak which became more prominent as fruit softened and could be separated from two lower apparent molecular weight peaks by anion exchange chromatography. The nature of a hemicellulose-pectin interaction in peach was apparently by physical entrapment, versus covalent cross-linking. Softening related changes in hemicellulose-associated pectin will be addressed.

Purification and partial characterization of a rat kidney aldehyde dehydrogenase that oxidizes retinal to retinoic acid

1993 ◽  
Vol 71 (1-2) ◽  
pp. 85-89 ◽  
Author(s):  
Jean Labrecque ◽  
Pangala V. Bhat ◽  
André Lacroix
Keyword(s):  
Molecular Weight ◽  
Retinoic Acid ◽  
Vitamin A ◽  
Aldehyde Dehydrogenase ◽  
Rat Kidney ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Apparent Molecular Weight ◽  
Exchange Chromatography ◽  
Size Exclusion

A NAD-dependent aldehyde dehydrogenase (EC 1.2.1.3) which catalyzes the oxidation of retinal to retinoic acid was purified to homogeneity from rat kidney by using Affi-Gel blue affinity chromatography and chromatofocusing, followed by Mono-Q anion-exchange chromatography. The apparent molecular weight of the native enzyme determined by size-exclusion fast protein liquid chromatography was 140 000. Sodium dodecyl sulfate - polyacrylamide gel electrophoresis gave a subunit molecular weight of 53 000. The isoelectric point as measured by chromatofocusing was 8.5. The enzyme also catalyzed the oxidation of acetaldehyde, but showed much lower Km value for the retinal substrate. We suggest that aldehyde dehydrogenase found in the kidney may be a specific retinal dehydrogenase, involved in vitamin A metabolism.Key words: aldehyde dehydrogenase, vitamin A, retinal, retinoic acid, kidney.

Comparison of exopolysaccharides from mucoid and nonmucoid strains of Clavibacter michiganensis subspecies sepedonicus

1993 ◽  
Vol 39 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Paul J. Henningson ◽  
Neil C. Gudmestad
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Size Exclusion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Low Molecular Weight ◽  
Neutral Sugar ◽  
Clavibacter Michiganensis ◽  
Serological Reaction ◽  
Molecular Weights ◽  
Exclusion Chromatography

The exopolysaccharides produced by six strains of Clavibacter michiganensis ssp. sepedonicus were isolated and purified by liquid chromatography. Neutral sugar composition and molecular weights were determined for each polysaccharide fraction, using gas chromatography and high-performance size-exclusion chromatography. The serological reaction of each fraction was tested using enzyme-linked immunosorbent assay. Exopolysaccharide from nonmucoid strains contained only low molecular weight polysaccharides (1.5 × 103 to 1.1 × 104). Exopolysaccharide from mucoid and intermediate strains could be separated into low (4.0 × 103 to 1.1 × 104) molecular weight and high (5.0 × 105 to 1.6 × 106) molecular weight fractions. High molecular weight polysaccharides were composed almost exclusively of galactose, glucose, and fucose. The ratios of these sugars were highly variable among strains. Low molecular weight polysaccharides were primarily composed of galactose with significant and varying amounts of glucose, rhamnose, mannose, and ribose. All polysaccharide fractions except one, produced by a nonmucoid strain, reacted in the immunoassay test.Key words: exopolysaccharide, polysaccharide, Clavibacter, michiganensis, sepedonicus.

Multiple forms of ribonuclease II in mouse liver: relative sizes, subcellular distributions, and pH–activity profiles

1987 ◽  
Vol 65 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Scot R. Kimball ◽  
William L. Meyer
Keyword(s):  
Molecular Weight ◽  
Mouse Liver ◽  
Heavy Particle ◽  
Gel Permeation Chromatography ◽  
Apparent Molecular Weight ◽  
Total Activity ◽  
Exchange Chromatography ◽  
The Other ◽  
Multiple Forms ◽  
Small Series

Multiple forms of ribonuclease II (EC 3.1.27.5) have been resolved from extracts of crude fractions of mouse liver by ion-exchange chromatography on phosphocellulose and gel permeation chromatography. The forms are designated 6S, 6L, 5S, 5L, 4S, 4L, 3S, 3L, 2, and 1 in increasing order of apparent cationic character. The forms fall into two series of apparent molecular weight. The small series increases from molecular weight equal to 9000 for form 1 to 14 000 for form 6S. The large series increases from molecular weight equal to 22 000 for form 2 to 44 000 for form 6L. All forms have pH–activity profiles with maxima near pH 7. Activity falls to no less than 30% of this maximum at pHs 5 and 8.5. Relative to the other forms, form 1 has a higher ratio of activity in the alkaline compared with acid pH range. Form 1 is found in the cytosolic, "light" particle, and "heavy" particle fractions. The other forms are largely restricted to the heavy particle fraction. In this fraction the proportion of total activity attributable to each form generally decreases in order from form 1 down to form 6. The results are accommodated by models in which one or more gene products give rise to multiple forms of ribonuclease II by processes involving dimerization and glycosylation.

scholarly journals A Polysaccharide Produced by Lactococcus lactis subsp. lactis YZ1 Isolated from Traditional Indonesian Fermented Milk, "Dadih"

2000 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Yusdar Zakaria
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Lactococcus Lactis ◽  
Monosaccharide Composition ◽  
Fermented Milk ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Molar Ratio ◽  
Neutral Sugar ◽  
Glycoside Linkage

ABSTRACT.Lactococcus lactis subsp. Lactis YZI was isolated from M17 agar in which diluted Dadih was poured and incubated at 30 0C for 48 h. Taxonomix properties of the isolate were examined according to Bergey’s Manual of Systematic Bacteriologi and Manual for  Identification of Medical Bacteria. The isolation of polysaccharide from the precipitant was performed on an ion-exchange chromatography. The result showed that the polysaccharides produced by Lactococus lactis subsp. lactis YZI were neutral sugar (unadsorbrd fraction) and glycoconjugated (absorbed fraction). The neutral sugar had molecular weight of 10,000 and 20,000 with and α-glycoside linkage. The monosaccharide composition was mannose, glucose and galactose with a molar ratio of 1 :1,5 : 4,9.

scholarly journals Changes in the Physico-chemical Properties of Peach Fruit Pectin during On-tree Ripening and Storage

1993 ◽  
Vol 118 (3) ◽  
pp. 343-349 ◽  
Author(s):  
M.L. Fishman ◽  
B. Levaj ◽  
D. Gillespie ◽  
R. Scorza
Keyword(s):  
Molecular Weight ◽  
Cell Wall ◽  
Intrinsic Viscosity ◽  
Cell Walls ◽  
Prunus Persica ◽  
Chemical Properties ◽  
Radius Of Gyration ◽  
Weight Percentage ◽  
Pectin Content ◽  
Cell Wall Polymers

Radius of gyration (size), intrinsic viscosity, molecular weight, percentage of galacturonate, and percentage of neutral sugars were measured for chelate-soluble (CSP) and alkaline-soluble (ASP) pectins extracted from the cell walls of melting flesh (MF) and nonmelting flesh (NMF) peach [Prunus persica (L.) Batsch]. Weight percentage of cell walls, pectin content, and firmness were measured also. Peaches were extracted at 20, 21, and 22 weeks after flowering (WAF) and after various lengths of shelf storage at 25 ± 2C for the peaches picked at 21 WAF. Weight percentage of cell walls and firmness decreased markedly between the 21st and 22nd WAF; and between the 3rd and 6th day of storage for MF peaches as compared to NMF peaches. During these same periods, there were marked drops in the pectin content and the uronide content for MF as compared to NMF peaches. Size and intrinsic viscosity dropped markedly for CSP of MF peaches in comparison with NMF peaches during these same periods, whereas the molecular weight of CSP and ASP increased in MF peaches over that measured for NMF peaches. These results suggested that α -D-galacturonase (E.C. 3.2.1.15) was involved in softening only in the latter stages of ripening MF peaches. Further, cell wall polymers containing long thin pectin aggregates were destroyed, whereas cell wall polymers containing short thick pectin aggregates remained.

scholarly journals Physicochemical and Biological Examination of Two Glatiramer Acetate Products

Biomedicines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 49 ◽  
Author(s):  
Komlosh ◽  
Weinstein ◽  
Loupe ◽  
Hasson ◽  
Timan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Glatiramer Acetate ◽  
Active Ingredient ◽  
In Vitro Cytotoxicity ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Potency Assay ◽  
Scientific Discussion

Herein we compared 40 mg/mL lots of the active ingredient, glatiramer acetate, manufactured by Mylan/Natco to the active ingredient, glatiramer acetate in Copaxone (Teva Pharmaceuticals, Ltd., Netanya Israel) using physicochemical (PCC) methods and biological assays. No differences were seen between the Mylan/Natco and Teva lots with some low resolution release PCC assays (amino acid analysis, molecular weight distribution, interaction with Coomassie Brilliant Blue G-250). Changes in polydispersity between Mylan/Natco and Copaxone lots were found using size exclusion chromatography and the high resolution PCC method, known as Viscotek, and suggestive of a disparity in the homogeneity of mixture, with a shift towards high molecular weight polypeptides. Using RPLC-2D MALLS, 5 out of 8 Mylan/Natco lots fell outside the Copaxone range, containing a high molecular weight and high hydrophobicity subpopulation of polypeptides not found in Copaxone lots. Cation exchange chromatography showed differences in the surface charge distribution between the Copaxone and Mylan/Natco lots. The Mylan/Natco lots were found to be within Copaxone specifications for the EAE model, monoclonal and polyclonal binding assays and the in vitro cytotoxicity assay, however higher IL-2 secretion was shown for three Mylan/Natco lots in a potency assay. These observations provide data to inform the ongoing scientific discussion about the comparability of glatiramer acetate in Copaxone and follow-on products.

Characterisation of a Neutral Protease Produced by Micrococcus luteus

1996 ◽  
Vol 51 (5-6) ◽  
pp. 429-431 ◽  
Author(s):  
M.O. Ilori ◽  
O.O. Amund ◽  
O. Omidiji
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Proteolytic Enzyme ◽  
Micrococcus Luteus ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Optimum Temperature ◽  
Optimum Ph

Abstract A proteolytic enzyme produced by a cassava-ferment­ing strain of Micrococcus luteus was extracted and puri­fied 50-fold by gel filtration and ion exchange chromatography. The optimum pH for the enzyme was 7.0, the optimum temperature 25 °C, the apparent molecular weight 42 kDa and the Km value, 0.45 mg ml-1 with casein as substrate. The enzyme was stimulated by Ca2+ and Mg2+ but inhibited by Zn2+ and Co2+ ions. Other inhibitors were EDTA, KCN, citric acid and L-cysteine indicating the enzyme to be a metalloprotease.

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