scholarly journals Genetic and Biochemical Characterization of an Exopolysaccharide With in vitro Antitumoral Activity Produced by Lactobacillus fermentum YL-11

2019 ◽  
Vol 10 ◽  
Author(s):  
Yunlu Wei ◽  
Fei Li ◽  
Le Li ◽  
Linlin Huang ◽  
Quanhong Li
Keyword(s):  
Biochemical Characterization ◽  
Lactobacillus Fermentum ◽  
Antitumoral Activity

Functional and Biochemical Characterization of Immunologically Derived Equine Platelet-Activating Factor

1985 ◽  
Vol 22 (4) ◽  
pp. 375-386 ◽  
Author(s):  
H. C. Wimberly ◽  
D. O. Slauson ◽  
N. R. Neilsen
Keyword(s):  
Functional Activity ◽  
Biochemical Characterization ◽  
Platelet Activating Factor ◽  
Biochemical Properties ◽  
Naturally Occurring ◽  
Rabbit Platelets ◽  
Rapid Reaction ◽  
Specific Challenge

Antigen-specific challenge of equine leukocytes induced the non-lytic release of a platelet-activating factor in vitro. The equine platelet-activating factor stimulated the release of serotonin from equine platelets in a dose-responsive manner, independent of the presence of cyclo-oxygenase pathway inhibitors such as indomethacin. Rabbit platelets were also responsive to equine platelet-activating factor. The release of equine platelet-activating factor was a rapid reaction with near maximal secretion taking place in 30 seconds. Addition of equine platelet-activating factor to washed equine platelets stimulated platelet aggregation which could not be inhibited by the presence of aspirin or indomethacin. Platelets preincubated with equine platelet-activating factor became specifically desensitized to equine platelet-activating factor while remaining responsive to other platelet stimuli such as collagen and epinephrine. The following biochemical properties of equine platelet-activating factor are identical to those properties of 1-0-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (AGEPC): stability upon exposure to air and acid; loss of functional activity after basecatalyzed methanolysis with subsequent acylation that returned all functional activity; and identical relative mobilities on silica gel G plates developed with chloroform:methanol:water (65:35:6, volume/volume). The combined functional and biochemical characteristics of equine platelet-activating factor strongly suggest identity between this naturally occurring, immunologically derived equine factor and AGEPC.

scholarly journals Intermediate filaments in non-neuronal cells of invertebrates: isolation and biochemical characterization of intermediate filaments from the esophageal epithelium of the mollusc Helix pomatia.

1985 ◽  
Vol 101 (2) ◽  
pp. 427-440 ◽  
Author(s):  
E Bartnik ◽  
M Osborn ◽  
K Weber
Keyword(s):  
Positive Reaction ◽  
Intermediate Filaments ◽  
Biochemical Characterization ◽  
Helix Pomatia ◽  
Molar Ratio ◽  
Negative Stain ◽  
Epithelial Morphology ◽  
Lower Chordate

To screen invertebrate tissues for the possible expression of intermediate filaments (IFs), immunofluorescence microscopy with the monoclonal antibody anti-IFA known to detect all mammalian IF proteins was used (Pruss, R. M., R. Mirsky, M. C. Raff, R. Thorpe, A. J. Dowding, and B. H. Anderton. 1981. Cell, 27:419-428). In a limited survey, the lower chordate Branchiostoma as well as the invertebrates Arenicola, Lumbricus, Ascaris, and Helix pomatia revealed a positive reaction primarily on epithelia and on nerves, whereas certain other invertebrates appeared negative. To assess the nature of the positive reaction, Helix pomatia was used since a variety of epithelia was strongly stained by anti-IFA. Fixation-extraction procedures were developed that preserve in electron micrographs of esophagus impressive arrays of IFs as tonofilament bundles. Fractionation procedures performed on single cell preparations document large meshworks of long and curvilinear IF by negative stain. These structures can be purified. One- and two-dimensional gels show three components, all of which are recognized by anti-IFA in immunoblotting: 66 kD/pl 6.35, 53 kD/pl 6.05, and 52 kD/pl 5.95. The molar ratio between the larger and more basic polypeptide and the sum of the two more acidic forms is close to 1. After solubilization in 8.5 M urea, in vitro filament reconstitution is induced when urea is removed by dialysis against 2-50 mM Tris buffer at pH 7.8. The reconstituted filaments contain all three polypeptides. The results establish firmly the existence of invertebrate IFs outside neurones and demonstrate that the esophagus of Helix pomatia displays IFs which in line with the epithelial morphology of the tissue could be related to keratin IF of vertebrates.

In Vitro Biochemical Characterization of Cytokinesis Actin-Binding Proteins

2016 ◽  
pp. 151-179 ◽  
Author(s):  
Dennis Zimmermann ◽  
Alisha N. Morganthaler ◽  
David R. Kovar ◽  
Cristian Suarez
Keyword(s):  
Binding Proteins ◽  
Biochemical Characterization ◽  
Actin Binding ◽  
Actin Binding Proteins

Biochemical characterization of HIV-1 Rev as a potent activator of casein kinase II in vitro

FEBS Letters ◽  
1998 ◽  
Vol 428 (3) ◽  
pp. 235-240 ◽  
Author(s):  
Kenzo Ohtsuki ◽  
Toshiro Maekawa ◽  
Shigeyoshi Harada ◽  
Atsushi Karino ◽  
Yuko Morikawa ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Hiv 1

scholarly journals Identification and characterization of cytochrome P450 1232A24 and 1232F1 from Arthrobacter sp. and their role in the metabolic pathway of papaverine

2019 ◽  
Vol 166 (1) ◽  
pp. 51-66 ◽  
Author(s):  
Jan M Klenk ◽  
Max-Philipp Fischer ◽  
Paulina Dubiel ◽  
Mahima Sharma ◽  
Benjamin Rowlinson ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Metabolic Pathway ◽  
Biochemical Characterization ◽  
Gene Clusters ◽  
Cytochrome P450 Monooxygenases ◽  
Dihydroxyphenylacetic Acid ◽  
Meta Position ◽  
Redox Partners

AbstractCytochrome P450 monooxygenases (P450s) play crucial roles in the cell metabolism and provide an unsurpassed diversity of catalysed reactions. Here, we report the identification and biochemical characterization of two P450s from Arthrobacter sp., a Gram-positive organism known to degrade the opium alkaloid papaverine. Combining phylogenetic and genomic analysis suggested physiological roles for P450s in metabolism and revealed potential gene clusters with redox partners facilitating the reconstitution of the P450 activities in vitro. CYP1232F1 catalyses the para demethylation of 3,4-dimethoxyphenylacetic acid to homovanillic acid while CYP1232A24 continues demethylation to 3,4-dihydroxyphenylacetic acid. Interestingly, the latter enzyme is also able to perform both demethylation steps with preference for the meta position. The crystal structure of CYP1232A24, which shares only 29% identity to previous published structures of P450s helped to rationalize the preferred demethylation specificity for the meta position and also the broader substrate specificity profile. In addition to the detailed characterization of the two P450s using their physiological redox partners, we report the construction of a highly active whole-cell Escherichia coli biocatalyst expressing CYP1232A24, which formed up to 1.77 g l−1 3,4-dihydroxyphenylacetic acid. Our results revealed the P450s’ role in the metabolic pathway of papaverine enabling further investigation and application of these biocatalysts.

Biochemical characterization of bona fide polycystin-1 in vitro and in vivo

2001 ◽  
Vol 38 (6) ◽  
pp. 1421-1429 ◽  
Author(s):  
Alessandra Boletta ◽  
Feng Qian ◽  
Luiz F. Onuchic ◽  
Alessandra Bragonzi ◽  
Marina Cortese ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Bona Fide

scholarly journals Synthesis and biochemical characterization of silver nanoparticles grafted chitosan (Chi-Ag-NPs): in vitro studies on antioxidant and antibacterial applications

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Pavan Kumar Dara ◽  
R. Mahadevan ◽  
P. A. Digita ◽  
S. Visnuvinayagam ◽  
Lekshmi R. G. Kumar ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biochemical Characterization ◽  
In Vitro Studies ◽  
Ag Nps

scholarly journals Biochemical Characterization of the C4-Dicarboxylate Transporter DctA from Bacillus subtilis

2010 ◽  
Vol 192 (11) ◽  
pp. 2900-2907 ◽  
Author(s):  
Maarten Groeneveld ◽  
Ruud G. J. Detert Oude Weme ◽  
Ria H. Duurkens ◽  
Dirk Jan Slotboom
Keyword(s):  
Bacillus Subtilis ◽  
Biochemical Characterization ◽  
Krebs Cycle ◽  
Membrane Vesicles ◽  
Positive Bacterium ◽  
Proton Symport ◽  
Negative Membrane Potential ◽  
Isolated Membrane Vesicles

ABSTRACT Bacterial secondary transporters of the DctA family mediate ion-coupled uptake of C4-dicarboxylates. Here, we have expressed the DctA homologue from Bacillus subtilis in the Gram-positive bacterium Lactococcus lactis. Transport of dicarboxylates in vitro in isolated membrane vesicles was assayed. We determined the substrate specificity, the type of cotransported ions, the electrogenic nature of transport, and the pH and temperature dependence patterns. DctA was found to catalyze proton-coupled symport of the four C4-dicarboxylates from the Krebs cycle (succinate, fumurate, malate, and oxaloacetate) but not of other mono- and dicarboxylates. Because (i) succinate-proton symport was electrogenic (stimulated by an internal negative membrane potential) and (ii) the divalent anionic form of succinate was recognized by DctA, at least three protons must be cotransported with succinate. The results were interpreted in the light of the crystal structure of the homologous aspartate transporter GltPh from Pyrococcus horikoshii.

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