Extracellular enzymes of Phytophthora infestans: endo-cellulase, β-glucosidases, and 1,3-β-glucanases

1985 ◽  
Vol 31 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Jakob Bodenmann ◽  
Ursula Heiniger ◽  
Hans R. Hohl
Keyword(s):  
Phytophthora Infestans ◽  
Isoelectric Point ◽  
Culture Filtrate ◽  
Extracellular Enzymes ◽  
Biochemical Properties ◽  
The Other ◽  
Molecular Weights ◽  
Glucosidase Ii ◽  
Optimal Ph

An endo-cellulase, two β-glucosidases, and two 1,3-β-glucanases from Phytophthora infestans were partially purified from the culture filtrate and their biochemical properties determined. The molecular weights were estimated by chromatography on Sephacryl S-200 and were 21 000 (endo-cellulase), 160 000 – 230 000 and 32 000 (β-glucosidases I and II), 160 000 – 230 000 and 21 000 (β-glucanases I and II). The optimal pH of the endocellulase was 6.0. The other enzymes showed the following optimal pH and temperature values: β-glucosidase 1,5.5 and 48 °C; β-glucosidase II, 5.25 and 30 °C; 1,3-β-glucanase 1, 7.0and40 °C; and 1,3-β-glucanase II, 4.5 and 45 °C. The β-glucosidase II was unstable above 30 °C, while the other enzymes remained stable to 43 °C. The β-glucosidase I did not show Michaelis–Menten kinetics for p-nitrophenyl-glucopyranoside (pNPG) and gentiobiose as substrates. The extrapolated Km value for pNPG was 1.1 mmol/L and the Km value for cellobiose was 280 mmol/L. The Km values of the β-glucosidase II were 34 mmol/L for pNPG, 340 mmol/L for cellobiose, and 42 mmol/L for gentiobiose. Finally, the Km value of the 1,3-β-glucanase II for laminarin was 0.29 g/L. The isoelectric point of the enzymes were 3.2 (endo-cellulase), 3.3 (β-glucosidase I), 4.7 (β-glucosidase II), and 3.4 (the two 1,3-β-glucanases). At 10 mmol/L, Cu2+ inhibited the β-glucosidase I by 90%, and the β-glucosidase II by about 50%. The 1,3-(3-glucanase II was inhibited 75% by Mn2+ and 35% by Cu2+.

scholarly journals Purification and Substrate Specificities of Two α-l-Arabinofuranosidases from Aspergillus awamori IFO 4033

1998 ◽  
Vol 64 (10) ◽  
pp. 4021-4027 ◽  
Author(s):  
Satoshi Kaneko ◽  
Mitsue Arimoto ◽  
Misako Ohba ◽  
Hideyuki Kobayashi ◽  
Tadashi Ishii ◽  
...  
Keyword(s):  
Culture Filtrate ◽  
The Other ◽  
Hydrolysis Reaction ◽  
Aspergillus Awamori ◽  
Side Chain ◽  
Optimum Temperature ◽  
Substrate Specificities ◽  
Molecular Weights ◽  
Ph Values ◽  
Optimum Ph

ABSTRACT α-l-Arabinofuranosidases I and II were purified from the culture filtrate of Aspergillus awamori IFO 4033 and had molecular weights of 81,000 and 62,000 and pIs of 3.3 and 3.6, respectively. Both enzymes had an optimum pH of 4.0 and an optimum temperature of 60°C and exhibited stability at pH values from 3 to 7 and at temperatures up to 60°C. The enzymes released arabinose from p-nitrophenyl-α-l-arabinofuranoside,O-α-l-arabinofuranosyl-(1→3)-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose, and arabinose-containing polysaccharides but not fromO-β-d-xylopyranosyl-(1→2)-O-α-l-arabinofuranosyl-(1→3)-O-β-d-xylopyranosyl-(1→4)-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose. α-l-Arabinofuranosidase I also released arabinose fromO-β-d-xylopy-ranosyl-(1→4)-[O-α-l-arabinofuranosyl-(1→3)]-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose. However, α-l-arabinofuranosidase II did not readily catalyze this hydrolysis reaction. α-l-Arabinofuranosidase I hydrolyzed all linkages that can occur between two α-l-arabinofuranosyl residues in the following order: (1→5) linkage > (1→3) linkage > (1→2) linkage. α-l-Arabinofuranosidase II hydrolyzed the linkages in the following order: (1→5) linkage > (1→2) linkage > (1→3) linkage. α-l-Arabinofuranosidase I preferentially hydrolyzed the (1→5) linkage of branched arabinotrisaccharide. On the other hand, α-l-arabinofuranosidase II preferentially hydrolyzed the (1→3) linkage in the same substrate. α-l-Arabinofuranosidase I released arabinose from the nonreducing terminus of arabinan, whereas α-l-arabinofuranosidase II preferentially hydrolyzed the arabinosyl side chain linkage of arabinan.

A Comparison of Plasminogen Activators Derived from Rat Plasma, Primary Rat Hepatocytes and Isolated Perfused Rat Liver

1982 ◽  
Vol 47 (02) ◽  
pp. 166-172 ◽  
Author(s):  
Yoav Sharoni ◽  
Maria C Topal ◽  
Patricia R Tuttle ◽  
Henry Berger
Keyword(s):  
Rat Liver ◽  
Isoelectric Point ◽  
Rat Hepatocytes ◽  
Cell Types ◽  
Plasminogen Activators ◽  
Rat Plasma ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver ◽  
Molecular Weights ◽  
Physiological Relevance

SummaryOf the two cell types it was possible to culture from the dissociated rat liver, hepatocytes and Kupffer cells, only the former were fibrinolytically active. Rat hepatocytes during the first 24 hr in culture secreted two plasminogen activators with molecular weights identical to those found in rat plasma, an 80,000-dalton form (PA-80) and a 45,000-dalton form (PA-45). Partially purified preparations of plasminogen activators from both sources were subjected to isoelectric focusing (IEF) to compare characteristics further. There were three distinct peaks of PA-45 in each preparation with isoelectric points of 7.1, 7.2 and 7.4; all electrophoretic forms had the same low affinity to fibrin. PA-80 from both sources displayed similar IEF profiles with forms ranging from pH values of 7 to 8, all with the same high affinity to fibrin. The major form of PA-80 in the plasma preparation had an isoelectric point of 7.9 whereas that in the hepatocyte preparation had an isoelectric point of 7.6. The isolated perfused rat liver was also shown to produce both PA-80 and PA-45 emphasizing the physiological relevance of the findings with hepatocytes. It is concluded that in the rat hepatocytes contribute to the plasma profile with regard to the plasminogen activator content.

scholarly journals OSMOTIC PRESSURE STUDY OF PROTEIN FRACTIONS IN NORMAL AND IN NEPHROTIC SUBJECTS

1939 ◽  
Vol 69 (6) ◽  
pp. 819-831 ◽  
Author(s):  
Jaques Bourdillon
Keyword(s):  
Osmotic Pressure ◽  
Normal Serum ◽  
The Other ◽  
Protein Fractions ◽  
Molecular Weights ◽  
Other Hand ◽  
Normal Albumin

In serum of patients with nephrosis both albumin and globulin showed by osmotic pressure nearly double the molecular weights of normal albumin and globulin. In the urines of such patients, on the other hand, both proteins showed molecular weights lower even than in normal serum. The colloidal osmotic pressures were measured by the author's method at such dilutions that the van't Hoff law relating pressures to molecular concentrations could be directly applied. For the albumin and globulin of normal serum the molecular weights found were 72,000 and 164,000 respectively, in agreement with the weights obtained by other methods.

Immune responses of Texel sheep to excretory/secretory products of adult Haemonchus contortus

Parasitology ◽  
1994 ◽  
Vol 108 (3) ◽  
pp. 351-357 ◽  
Author(s):  
H. D. F. H. Schallig ◽  
M. A. W. van Leeuwen ◽  
W. M. L. Hendrikx
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Haemonchus Contortus ◽  
Lymphocyte Proliferation ◽  
The Other ◽  
Proliferation Index ◽  
Serum Samples ◽  
Immunoblotting Analysis ◽  
Molecular Weights ◽  
Secretory Products

SUMMARYThe excretory/secretory (E/S) products of adult Haemonchus contortus comprise of at least 15 polypeptides with molecular weights ranging from 10 to > 100 kDa. These E/S products induce an immune response in infected Texel sheep, as demonstrated by specific IgGI levels and a significant lymphocyte proliferation index. Moreover, immunoblotting analysis revealed that sera of primary H. contortus-infected sheep specifically recognize a 24 kDa E/S product. In addition, sera of challenged sheep react strongly with a 15 kDa E/S product. The other E/S products of H. contortus showed immunoreactivity with serum samples of Haemonchus-infected sheep as well as with samples of sheep harbouring other trichostrongylid infections. These cross-reacting epitopes are the main cause of the lack of specificity of an E/S material- based ELISA. This ELISA can differentiate Haemonchus infections from Nematodirus battus infections, but not from Ostertagia circumcincta or Trichostrongylus colubriformis infections.

scholarly journals Identification of Three Elicitins and a Galactan-Based Complex Polysaccharide from a Concentrated Culture Filtrate of Phytophthora infestans Efficient against Pectobacterium atrosepticum

Molecules ◽  
2014 ◽  
Vol 19 (10) ◽  
pp. 15374-15390 ◽  
Author(s):  
Guillaume Saubeau ◽  
Fanny Gaillard ◽  
Laurent Legentil ◽  
Caroline Nugier-Chauvin ◽  
Vincent Ferrières ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Culture Filtrate ◽  
Pectobacterium Atrosepticum

Toxic properties of Aeromonas proteolytica

1974 ◽  
Vol 20 (10) ◽  
pp. 1403-1409 ◽  
Author(s):  
B. G. Foster ◽  
Mary O. Hanna
Keyword(s):  
Thermal Stability ◽  
Culture Filtrate ◽  
Hemolytic Activity ◽  
Optimal Growth ◽  
Growth Conditions ◽  
The Other ◽  
Activity Peak ◽  
Endopeptidase Activity ◽  
Time Periods ◽  
Thermal Stability Of

Aeromonas proteolytica was grown for various time periods in nutrient broth, tryptic soy broth, a semisynthetic medium, and 1 and 5% peptone under different conditions involving temperature and in continuous shake and stationary flasks. The cell-free culture filtrates were tested for hemolytic, endopeptidase, and dermonecrotic activity and optimal growth conditions for their production were determined. The dermonecrotic activity and endopeptidase activity was found to be parallel in all tests, while hemolysin was independent of the other two. Studies on the thermal stability of the culture filtrate revealed that hemolysin and dermonecrotic and endopeptidase activity were destroyed at 70 °C for 30 min. Fractionation of the filtrate by Sephadex G-200 resolved three peaks at 280 nm. Peak I was inactive; peak II contained endopeptidase and dermonecrotic and hemolytic activity; peak III contained pigment and hemolysin. Evidence is presented that the endopeptidase and dermonecrotic substance found in the cell-free filtrates of A. proteolytica grown medium appear at the same time and thus may be the same entity.

scholarly journals Comparative analysis of plant isochorismate synthases reveals structural mechanisms underlying their distinct biochemical properties

2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Shohei Yokoo ◽  
Seiya Inoue ◽  
Nana Suzuki ◽  
Naho Amakawa ◽  
Hidenori Matsui ◽  
...  
Keyword(s):  
Biochemical Properties ◽  
Stress Conditions ◽  
The Other ◽  
Protein Accumulation ◽  
Transcriptional Level ◽  
Multiple Sequence ◽  
Primary And Secondary Metabolites ◽  
Transit Peptides ◽  
Alignment Analysis ◽  
Structural Mechanisms

Isochorismate synthase (ICS) converts chorismate into isochorismate, a precursor of primary and secondary metabolites including salicylic acid (SA). SA plays important roles in responses to stress conditions in plants. Many studies have suggested that the function of plant ICSs is regulated at the transcriptional level. In Arabidopsis thaliana, the expression of AtICS1 is induced by stress conditions in parallel with SA synthesis, and AtICS1 is required for SA synthesis. In contrast, the expression of NtICS is not induced when SA synthesis is activated in tobacco, and it is unlikely to be involved in SA synthesis. Studies on the biochemical properties of plant ICSs are limited, compared with those on transcriptional regulation. We analyzed the biochemical properties of four plant ICSs: AtICS1, NtICS, NbICS from Nicotiana benthamiana, and OsICS from rice. Multiple sequence alignment analysis revealed that their primary structures were well conserved, and predicted key residues for ICS activity were almost completely conserved. However, AtICS1 showed much higher activity than the other ICSs when expressed in Escherichia coli and N. benthamiana leaves. Moreover, the levels of AtICS1 protein expression in N. benthamiana leaves were higher than the other ICSs. Construction and analysis of chimeras between AtICS1 and OsICS revealed that the putative chloroplast transit peptides (TPs) significantly affected the levels of protein accumulation in N. benthamiana leaves. Chimeric and point-mutation analyses revealed that Thr531, Ser537, and Ile550 of AtICS1 are essential for its high activity. These distinct biochemical properties of plant ICSs may suggest different roles in their respective plant species.

scholarly journals Trypanosoma cruzi: identification of specific epimastigote antigens by human immune sera

1989 ◽  
Vol 84 (3) ◽  
pp. 309-314 ◽  
Author(s):  
M. G. Morgado ◽  
J. Ivo-dos-Santos ◽  
R. T. Pinho ◽  
E. Argüelles ◽  
J. M. Rezende ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Trypanosoma Cruzi ◽  
Western Blot ◽  
Chagas Disease ◽  
Cross Reactivity ◽  
Cross Reaction ◽  
The Other ◽  
Molecular Weights ◽  
Human Visceral Leishmaniasis ◽  
Human Immune

Soluble antigens from epimastigotes of Trypanosoma cruzi were analyzed by western blot in terms of their reactivity with sera from patients with Chagas' disease. In addition, sera from patients with visceral (AVL) and tegumentar leishmaniasis (ATL) were also tested in order to identify cross-reactivities with Trypanosoma cruzy antigens. Twenty eight polypeptides with molecular weights ranging from 14 kDa to 113 kDa were identified with sera from Chagas' disease patients. An extensive cross-reactivity was observed when sera from human visceral leishmaniasis were used, while only a slight cross-reaction was observed with sera from tegumentar leishmaniasis. On the other hand, 10 polypeptidesspecifically reacting with sera from Chagas' disease patients were identified. Among them, the antigens with molecular weights of 46 kDa and 25 kDa reacted with all sera teste and may be good candidates for specific immunodiagnosis of Chagas' disease.

Heterogeneity of High-molecular-weight Human Salivary Mucins

2000 ◽  
Vol 14 (1) ◽  
pp. 69-75 ◽  
Author(s):  
G.D. Offner ◽  
R.F. Troxler
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Biochemical Properties ◽  
Salivary Proteins ◽  
Molecular Weights ◽  
Structural Framework ◽  
Buccal Epithelial Cells ◽  
Membrane Bound ◽  
Membrane Spanning ◽  
Micro Organisms

The existence of high-molecular-weight glycoproteins in saliva and salivary secretions has been recognized for nearly 30 years. These proteins, called mucins, are essential for oral health and perform many diverse functions in the oral cavity. Mucins have been intensively studied, and much has been learned about their biochemical properties and their interactions with oral micro-organisms and other salivary proteins. In the past several years, the major high-molecular-weight mucin in salivary secretions has been identified as MUC5B, one of a family of 11 human mucin gene products expressed in tissue-specific patterns in the gastrointestinal, respiratory, and reproductive tracts. MUC5B is one of four gel-forming mucins which exist as multimeric proteins with molecular weights greater than 20-40 million daltons. The heavily glycosylated mucin multimers form viscous layers which protect underlying epithelial surfaces from microbial, mechanical, and chemical assault. Another class of mucin molecules, the membrane-bound mucins, is structurally and functionally distinct from the gel-forming mucins. These proteins do not form multimers and can exist as both secreted and membrane-bound forms, with the latter anchored to epithelial cell membranes through a short membrane-spanning domain. In the present work, we show that two of the membrane-bound mucins, MUC1 and MUC4, are expressed in all major human salivary glands as well as in buccal epithelial cells. While the functions of these mucins in the oral environment are not understood, it is possible that they form a structural framework on the cell surface which not only is cytoprotective, but also may serve as a scaffold upon which MUC5B, and possibly other salivary proteins, assemble.

scholarly journals Alteration of Feeding and Filtering Rates of Two Species of Marine Copepods Exposed to Different pH Levels

2019 ◽  
Vol 7 (2) ◽  
pp. 39 ◽  
Author(s):  
Yanqun Wang ◽  
Boyuan Wang ◽  
Ze Xue ◽  
Liyan Zhu
Keyword(s):  
The Other ◽  
Marine Copepod ◽  
Oithona Similis ◽  
Physiological Processes ◽  
Culturing Conditions ◽  
Filtering Rates ◽  
Shed Light ◽  
Optimal Ph ◽  
Schmackeria Poplesia ◽  
Marine Copepods

Impacts of different pH levels on different species of marine copepods, Calanoida copepod Schmackeria poplesia and Cyclopoida copepod Oithona similis were evaluated, and the alteration of key physiological processes of feeding and filtering were comparatively studies under controlled lab conditions. The optimal pH for O.similis and S.poplesia was 9.0 and 8.0 respectively, and they performed differently when exposed to different pH levels. For S. poplesia., the feeding and filtering rates increased steadily with the increment of pH at the range of 6.0~8.0, and reached the peak at pH 8.0. However, the rates decreased when pH was above 9.0. O.similis seemed more adaptive to the change of pH, and the increment was found in feeding and filtering rates at a range of 6.0~8.0. The maximus appeared at pH 9.0. compared to the other pH levels, the acidifying level of pH 6.0 presented the most obviously inhibition on feeding and filtering. Results in the present study would shed light on establishing the optimum culturing conditions for the cultivation of marine copepod.

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