scholarly journals Characterization of SNP1, a Cell Wall-Degrading Trypsin, Produced During Infection by Stagonospora nodorum

2000 ◽  
Vol 13 (5) ◽  
pp. 538-550 ◽  
Author(s):  
A. J. Carlile ◽  
L. V. Bindschedler ◽  
A. M. Bailey ◽  
P. Bowyer ◽  
J. M. Clarkson ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Cell Walls ◽  
Fluorescent Protein ◽  
Sodium Dodecyl ◽  
Leaf Tissue ◽  
Pcr Primers ◽  
Exchange Chromatography ◽  
Infected Leaf ◽  
In Planta ◽  
Ph Optimum

Stagonospora (= Septoria) nodorum when grown in liquid culture with wheat cell walls as the sole carbon and nitrogen source secretes numerous extracellular depoly-merases, including a rapidly produced, alkaline, trypsin-like protease (SNP1). The enzyme was purified 417-fold by cation exchange chromatography and has a molecular mass of 25 kDa on sodium dodecyl sulfate gels, pI 8.7, and pH optimum of 8.5. It cleaved peptide bonds on the carboxyl side of lysine or arginine, was strongly inhibited by the trypsin inhibitors aprotinin and leupeptin and weakly by phenylmethylsulfonyl fluoride, and its activity was stimulated by calcium. SNP1 has the characteristic, conserved, fungal, trypsin N terminus. Polymerase chain reaction (PCR) primers based on this sequence and the conserved trypsin active site were used to amplify a DNA fragment that facilitated isolation of the corresponding genomic clone from a lambda library of S. nodorum. The full-length sequence confirmed its identity as a trypsin-like protease containing the N-terminal sequence of the previously purified enzyme. Infected leaf tissue contained a protease, not present in controls, that coeluted with the fungal trypsin from cation exchange, and had properties (pI and inhibitor characteristics) similar to those of the fungal trypsin. SNP1 expression in planta was detected by Northern (RNA) blotting, reverse transcription PCR, and green fluorescent protein confocal microscopy. SNP1 released hydroxyproline from wheat cell walls. The release of hydroxyproline, together with its early expression in planta, suggests that SNP1 participates in the degradation of host cell walls during infection.

Purification and characterization of the extracellular α-amylase activity of the yeast Schwanniomyces alluvius

1987 ◽  
Vol 65 (10) ◽  
pp. 899-908 ◽  
Author(s):  
F. Moranelli ◽  
M. Yaguchi ◽  
G. B. Calleja ◽  
A. Nasim
Keyword(s):  
Amino Acid ◽  
Amylase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Exchange Chromatography ◽  
Proteinase K ◽  
Ph Optimum ◽  
Sds Page

The extracellular α-amylase activity of the yeast Schwanniomyces alluvius has been purified by anion-exchange chromatography on DEAE-cellulose and gel-filtration chromatography on Sephadex G-100. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS–PAGE) and N-terminal amino acid analysis of the purified sample indicated that the enzyme preparation was homogeneous. The enzyme is a glycoprotein having a molecular mass of 52 kilodaltons (kDa) estimated by SDS–PAGE and 39 kDa by gel filtration on Sephadex G-100. Chromatofocusing shows that it is an acidic protein. It is resistant to trypsin but sensitive to proteinase K. Its activity is inhibited by the divalent cation chelators EDTA and EGTA and it is insensitive to sulfhydryl-blocking agents. Exogenous divalent cations are inhibitory as are high concentrations of monovalent salts. The enzyme has a pH optimum between 3.75 and 5.5 and displays maximum stability in the pH range of 4.0–7.0. Under the conditions tested, the activity is maximal between 45 and 50 °C and is very thermolabile. Analysis of its amino acid composition supports its acidic nature.

Isolation and characterization of cathepsin D from human gastric mucosa

1981 ◽  
Vol 46 (13) ◽  
pp. 3302-3313 ◽  
Author(s):  
Jan Pohl ◽  
Ladislav Bureš ◽  
Karel Slavík
Keyword(s):  
Gastric Mucosa ◽  
Cathepsin D ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Polyacrylamide Gel ◽  
Human Gastric Mucosa ◽  
Ph Optimum ◽  
Isolation And Characterization

The molecular weight of the enzyme, purified by ion-exchange chromatography and affinity chromatography, was determined by gel filtration on Sephadex G-100 as 49 000. After treatment with 2-mercaptoethanol, polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate resolved the enzyme into two chains, of molecular weights 33 000 and 18 000. This shows that in the native state the enzyme is composed of one light and one heavy chain. Isoelectric focusing in polyacrylamide gel gave four bands, the isoelectric points being 5.5, 6.1, 6.5 and 7.1. The optimum protein substrate (pH optimum 3.2-3.6) was haemoglobin. The best synthetic substrate was methyl ester of pyroglutamyl-histidyl-phenylalanyl-phenylalanyl-alanyl-leucine. The protease was inhibited by the inhibitor of cathepsin D from the potato tubers. It is concluded that the enzyme is cathepsin D from gastric mucosa.

scholarly journals Isolation, Purification, and Characterization of a Polygalacturonase Produced in Penicillium solitum-Decayed ‘Golden Delicious’ Apple Fruit

2009 ◽  
Vol 99 (6) ◽  
pp. 636-641 ◽  
Author(s):  
Wayne M. Jurick ◽  
Ivana Vico ◽  
James L. McEvoy ◽  
Bruce D. Whitaker ◽  
Wojciech Janisiewicz ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Divalent Cations ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Apple Fruit ◽  
Ruthenium Red ◽  
Exchange Chromatography ◽  
Golden Delicious ◽  
Penicillium Solitum

Polygalacturonase (PG) was extracted and purified from decayed ‘Golden Delicious’ apple fruit inoculated with Penicillium solitum. Ammonium sulfate, gel filtration, and cation exchange chromatography were used to purify the enzyme. Both chromatographic methods revealed a single peak corresponding to PG activity. The purified PG most likely originates from the fungus because PG activity from healthy and wounded apple tissue was undetectable. Analysis of cation exchange-purified material using sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed a single 50-kDa band. The enzyme was active over a broad pH range (3 to 7), with optimal activity between pH 4 and 5. PG was highly active at 20 and 37°C but was also detectable at 2, 50, and 75°C. Divalent cations affected PG enzyme activity; Mg and Fe increased, whereas Ca and Mn reduced activity in vitro. Thin-layer chromatographic separation of hydrolysis products and data from a PG plate activity assay based on staining with ruthenium red showed that the enzyme exhibits both exo and endo activity. Purified PG incubated with intact apple fruit tissue in vitro caused a 30% reduction in mass after 48 h, suggesting a role in P. solitum-mediated decay of apple fruit.

scholarly journals Antibacterial Peptides from Tryptic Hydrolysate of Ricinus communis Seed Protein Fractionated Using Cation Exchange Chromatography

2021 ◽  
pp. 74-85
Author(s):  
Tri Raharjo ◽  
Woro Utami ◽  
Atdrian Fajr ◽  
Respati Swasono ◽  
Winarto Haryadi
Keyword(s):  
Antibacterial Activity ◽  
Cation Exchange ◽  
Seed Protein ◽  
High Resolution Mass Spectrometry ◽  
Protein Hydrolysate ◽  
Ricinus Communis ◽  
Sodium Dodecyl ◽  
Exchange Chromatography ◽  
Antibacterial Peptides ◽  
Cation Exchange Chromatography

Antimicrobial peptide (AMP) peptide-based lead compound has become interesting target in developing new antibiotics. AMP is possibly generated through the digestion of protein. The protein of castor (Ricinus communis) seed is characterized as a ribosome-inactivating protein (RIP) that can be a source of AMP. The objectives of this research are to identify antibacterial peptides from Ricinus communis seed protein hydrolysate.   The seed protein was isolated using sodium dodecyl sulfate and subsequently digested using trypsin. The hydrolysate was fractionated using a strong cation exchange chromatography system, and the resulting fractions were tested for antibacterial activity. The peptides present in the active fraction were identified using high-resolution mass spectrometry. As the result, the pH 4 and pH 5 fractions of the elution buffer indicated antibacterial activity, with the pH 4 fraction of the hydrolysate having high activity against both gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus) bacteria. Three peptides that have the sequences EESETVGQR, GQSTGTGQQER, and LDALEPDNR could be responsible for the activity of the pH 4 fraction. The antibacterial activity of these peptides, which is due to their ionic properties and secondary structure, supports the disruption of the bacterial cell membrane. It can be concluded that Ricinus communis seed protein hydrolysate contains peptides with sequence EESETVGQR, GQSTGTGQQER, and LDALEPDNR that potent to be used as AMP lead compounds

Amylase from human serous ovarian tumors: purification and characterization.

1984 ◽  
Vol 30 (1) ◽  
pp. 62-68 ◽  
Author(s):  
J J Zakowski ◽  
M R Gregory ◽  
D E Bruns
Keyword(s):  
Ovarian Tumor ◽  
Specific Activity ◽  
Sodium Dodecyl ◽  
Pancreatic Enzyme ◽  
Exchange Chromatography ◽  
Ovarian Tumors ◽  
Electrical Charge ◽  
Alpha Amylase ◽  
Heat Inactivation ◽  
Ph Optimum

Abstract Human serous-type ovarian tumors contain an acidic isoenzyme of amylase. Previous attempts at purification of tumor amylases have yielded preparations contaminated with other proteins. The purification scheme presented here incorporates an affinity-chromatography procedure, with use of cycloheptaamylose linked to epoxy-activated Sepharose, that is specific for alpha-amylase (EC 3.2.1.1). Purified amylase isoenzyme from a human serous ovarian tumor was characterized and compared with the purified salivary and pancreatic isoenzymes. All three were similar in amino acid composition, pH optimum, substrate specificity, calcium requirement, heat inactivation, and Km for maltotetraose substrate. The ovarian tumor amylase was similar to the salivary and distinct from the pancreatic enzyme by apparent molecular mass and doublet formation on sodium dodecyl sulfate--polyacrylamide electrophoresis, specific activity of pure enzyme, and sensitivity to specific alpha-amylase inhibitors. All three isoenzymes differed in net electrical charge as evidenced by diethylaminoethyl-Sephadex ion-exchange chromatography and isoelectric focusing. The tumor amylase is clearly distinct from the pancreatic and differs from the salivary enzyme in net electrical charge. Evidence is presented that this charge difference may reflect, at least in part, deamidation of an amylase that is similar to or identical with salivary amylase.

Purification and characterization of a chymosinlike protease from the gastric mucosa of harp seal (Pagophilus groenlandicus)

1984 ◽  
Vol 62 (8) ◽  
pp. 699-708 ◽  
Author(s):  
K. Shamsuzzaman ◽  
N. F. Haard
Keyword(s):  
Gastric Mucosa ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Polyacrylamide Gel ◽  
Ph Optimum ◽  
Porcine Pepsin ◽  
Milk Clotting

Four zymogens of acidic proteases A, B, C, and D were isolated from the gastric mucosa of harp seals by ion-exchange chromatography on a diethylaminoethyl-Sephadex A-50 column. The major zymogens were A and C, and the ratio of zymogen A to zymogen C was greater in extracts from 1-week-old animals than in extracts from adult animals. Zymogens A and C were further purified by affinity chromatography using carbobenzoxy-D-phenylalaninetriethylene tetramine Sepharose and gel filtration on a Sephadex G-100 column. Certain physical and catalytic properties of proteases A and C were compared with those of calf chymosin (EC 3.4.23.4) and porcine pepsin (EC 3.4.23.1). Zymogen C and the corresponding enzyme were homogeneous on analytical polyacrylamide gel electrophoresis. Zymogen A was homogeneous as judged by sodium dodecyl sulphate (SDS) – polyacrylamide gel electrophoresis and high performance liquid chromatography, but was heterogenous by polyacrylamide gel electrophoresis at pH 8.3. Zymogens A and C had molecular weights of 33 800 and 44 000, respectively, as estimated by SDS–polyacrylamide gel electrophoresis. Protease A had an isoelectric point of 4.90. Protease A was similar to calf chymosin with respect to several criteria. It had a higher ratio of milk-clotting to proteolytic activity than those of seal protease C and porcine pepsin and had a pH optimum of 2.2–3.5 for hemoglobin hydrolysis. It did not inactivate ribonuclease, had very low activity on N-acetyl-L-phenylalanyl-3,5-diiodo-L-tyrosine and lost activity in 6 M urea. These results indicate protease A is chymosinlike.

scholarly journals Biosensors Used for Epifluorescence and Confocal Laser Scanning Microscopies to Study Dickeya and Pectobacterium Virulence and Biocontrol

2021 ◽  
Vol 9 (2) ◽  
pp. 295
Author(s):  
Yvann Bourigault ◽  
Andrea Chane ◽  
Corinne Barbey ◽  
Sylwia Jafra ◽  
Robert Czajkowski ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Fluorescent Protein ◽  
Infected Plant ◽  
Soft Rot ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Cell Physiology ◽  
In Planta ◽  
Reporter System ◽  
Cell Wall Lysis

Promoter-probe vectors carrying fluorescent protein-reporter genes are powerful tools used to study microbial ecology, epidemiology, and etiology. In addition, they provide direct visual evidence of molecular interactions related to cell physiology and metabolism. Knowledge and advances carried out thanks to the construction of soft-rot Pectobacteriaceae biosensors, often inoculated in potato Solanum tuberosum, are discussed in this review. Under epifluorescence and confocal laser scanning microscopies, Dickeya and Pectobacterium-tagged strains managed to monitor in situ bacterial viability, microcolony and biofilm formation, and colonization of infected plant organs, as well as disease symptoms, such as cell-wall lysis and their suppression by biocontrol antagonists. The use of dual-colored reporters encoding the first fluorophore expressed from a constitutive promoter as a cell tag, while a second was used as a regulator-based reporter system, was also used to simultaneously visualize bacterial spread and activity. This revealed the chronology of events leading to tuber maceration and quorum-sensing communication, in addition to the disruption of the latter by biocontrol agents. The promising potential of these fluorescent biosensors should make it possible to apprehend other activities, such as subcellular localization of key proteins involved in bacterial virulence in planta, in the near future.

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