scholarly journals Pathway of phytate dephosphorylation by β-propeller phytases of different origins

2007 ◽  
Vol 53 (4) ◽  
pp. 488-495 ◽  
Author(s):  
Ralf Greiner ◽  
Boon L. Lim ◽  
Chiwai Cheng ◽  
Nils-Gunnar Carlsson
Keyword(s):  
High Performance ◽  
Structural Model ◽  
Shewanella Oneidensis ◽  
Kinetic Studies ◽  
Inositol Hexakisphosphate ◽  
Chromatography Analysis ◽  
Bacillus Subtilis 168 ◽  
Phytate Degradation ◽  
Degradation Models ◽  
Different Origins

Using a combination of high-performance ion chromatography analysis and kinetic studies, the pathway of myo-inositol hexakisphosphate dephosphorylation by the β-propeller phytase of Shewanella oneidensis was established, which was then compared with that of Bacillus subtilis 168, Bacillus amyloliquefaciens ATCC 15841, and B. amyloliquefaciens 45 β-propeller phytases. The data demonstrate that all of these β-propeller phytases dephosphorylate myo-inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via d-Ins(1,2,4,5,6)P5, Ins(2,4,5,6)P4 to finally Ins(2,4,6)P3. Thus, the β-propeller phytases prefer the hydrolysis of every second phosphate over that of adjacent ones. This finding does not support previous phytate degradation models proposed by J. Kerovuo, J. Rouvinen, and F. Hatzack (2000. Biochem. J. 352: 623–628) and R. Greiner, A. Farouk, M. Larsson Alminger, and N.G. Carlsson (2002. Can. J. Microbiol. 48: 986–994) , but seems to fit with the structural model given by S. Shin, N.C. Ha, B.C. Oh, T.K. Oh, and B.H. Oh (2001. Structure, 9: 851–858) .

The pathway of dephosphorylation of myo-inositol hexakisphosphate by phytate-degrading enzymes of different Bacillus spp.

2002 ◽  
Vol 48 (11) ◽  
pp. 986-994 ◽  
Author(s):  
Ralf Greiner ◽  
Adelazim Farouk ◽  
Marie Larsson Alminger ◽  
Nils-Gunnar Carlsson
Keyword(s):  
Bacillus Amyloliquefaciens ◽  
High Performance ◽  
Inositol Phosphate ◽  
Kinetic Studies ◽  
Enzyme Concentration ◽  
Inositol Hexakisphosphate ◽  
Prolonged Incubation ◽  
Chromatography Analysis ◽  
Degrading Enzymes ◽  
Bacillus Spp

The pathway of dephosphorylation of myo-inositol hexakisphosphate by the phytate-degrading enzymes of Bacillus subtilis 168, Bacillus amyloliquefaciens ATCC 15841, and Bacillus amyloliquefaciens 45 was established using a combination of high-performance ion chromatography analysis and kinetic studies. The data demonstrate that all the Bacillus phytate-degrading enzymes under investigation dephosphorylate myo-inositol hexakisphosphate by sequential removal of phosphate groups via two independent routes; the routes proceed via D-Ins(1,2,4,5,6)P5 to Ins(2,4,5,6)P4 to finally Ins(2,4,6)P3 or D-Ins(2,5,6)P3 and via D-Ins(1,2,4,5,6)P5 to D-Ins(1,2,5,6)P4 to finally D-Ins(1,2,6)P3. The resulting myo-inositol trisphosphate D-Ins(1,2,6)P3 was degraded via D-Ins(2,6)P2 to finally Ins(2)P after prolonged incubation times in combination with increased enzyme concentration. Key words: Bacillus spp., myo-inositol phosphate isomers, phytase, phytate degradation.

scholarly journals In Vitro Propagation, Huperzine A Content and Antioxidant Activity of Three Genotypic Huperzia serrata

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1112
Author(s):  
Yan Yang ◽  
Liangfang Dai ◽  
Decai Wu ◽  
Limin Dong ◽  
Yisheng Tu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
High Performance ◽  
In Vitro Propagation ◽  
Huperzine A ◽  
Induction Medium ◽  
Naphthalene Acetic Acid ◽  
Regeneration Rate ◽  
Huperzia Serrata ◽  
Chromatography Analysis

Huperzia serrata is a traditional herb and endangered Chinese medicinal material, which has attracted much attention due to its production of Huperzine A (HupA). In vitro propagation of H. serrata is considered a new way to relieve the resource pressure of H. serrata. In this study, three different genotypic wild H. serrata were used for in vitro propagation. Then, the antioxidant activity and the content of HupA in the regenerated H. serrata were investigated. The results showed the survival rate of the explant was increased to 25.37% when using multiple sterilization processes. The best induction medium for H. serrata was the Schenk and Hildebrandt (SH) medium supplemented with 0.5 mg·L−1 Naphthalene acetic acid (NAA) and 0.1 mg·L−1 2,4-Dichlorophenoxyacetic acid (2,4-D), where the regeneration rate of the explant was to 57.04%. The best proliferation medium was the SH medium with NAA (1.0 mg·L−1), as the biomass of in vitro tissue increased 164.17 ± 0.41 times. High-performance liquid chromatography analysis showed that the in vitro culture of three genotypes could produce HupA and the content of HupA was 53.90–87.17 µg·g−1. The antioxidant experiment showed that the methanol extract of in vitro H. serrata had higher antioxidant activity than that of wild H. serrata. This study provides a reliable in vitro H. serrata culture protocol and laid an important foundation for the antioxidant capacity of the thallus and the content of HupA.

scholarly journals Abnormal physiological properties and altered cell wall composition in Streptococcus pneumoniae grown in the presence of clavulanic acid.

1997 ◽  
Vol 41 (3) ◽  
pp. 504-510 ◽  
Author(s):  
A Severin ◽  
E Severina ◽  
A Tomasz
Keyword(s):  
Streptococcus Pneumoniae ◽  
High Performance ◽  
Biochemical Properties ◽  
Beta Lactam ◽  
Chromatography Analysis ◽  
Peptide Composition ◽  
Increased Sensitivity ◽  
Altered Cell ◽  
Quantitative Changes

Subinhibitory concentrations of clavulanate caused premature induction of stationary-phase autolysis, sensitization to lysozyme, and reductions in the MICs of deoxycholate and penicillin for Streptococcus pneumoniae. In the range of clavulanate concentrations producing these effects, this beta-lactam compound was selectively bound to PBP 3. Cell walls isolated from pneumococci grown in the presence of clavulanate showed increased sensitivity to the hydrolytic action of purified pneumococcal autolysin in vitro. High-performance liquid chromatography analysis of the peptidoglycan isolated from the clavulanate-grown cells showed major qualitative and quantitative changes in stem peptide composition, the most striking feature of which was the accumulation of peptide species carrying intact D-alanyl-D-alanine residues at the carboxy termini. The altered biological and biochemical properties of the clavulanate-grown pneumococci appear to be the consequences of suppressed D,D-carboxypeptidase activity.

scholarly journals Histological Characterization of Resistance to Different Root-Knot Nematode Species Related to Phenolics Accumulation in Capsicum annuum

2005 ◽  
Vol 95 (2) ◽  
pp. 158-165 ◽  
Author(s):  
A. Pegard ◽  
G. Brizzard ◽  
A. Fazari ◽  
O. Soucaze ◽  
P. Abad ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Capsicum Annuum ◽  
High Performance ◽  
Nematode Species ◽  
Susceptible Cultivar ◽  
Resistant Line ◽  
Root Knot Nematode ◽  
Resistance Response ◽  
Root Knot Nematodes ◽  
Chromatography Analysis

In the pepper Capsicum annuum CM334, which is used by breeders as a source of resistance to Phytophthora spp. and potyviruses, a resistance gene entirely suppresses reproduction of the root-knot nematode (Meloidogyne spp.). The current study compared the histological responses of this resistant line and a susceptible cultivar to infection with the three most damaging root-knot nematodes: M. arenaria, M. incognita, or M. javanica. Resistance of CM334 to root-knot nematodes was associated with unidentified factors that limited nematode penetration and with post-penetration biochemical responses, including the hypersensitive response, which apparently blocked nematode migration and thereby prevented juvenile development and reproduction. High-performance liquid chromatography analysis suggested that phenolic compounds, especially chlorogenic acid, may be involved in CM334 resistance. The response to infection in the resistant line varied with root-knot nematode species and was correlated with nematode behavior and pathogenicity in the susceptible cultivar: nematode species that quickly reached the vascular cylinder and initiated feeding sites in the susceptible cultivar were quickly recognized in CM334 and stopped in the epidermis or cortex. After comparing our data with those from other resistant pepper lines, we suggest that timing of the resistance response and the mechanism of resistance vary with plant genotype, resistance gene, and root-knot nematode species.

Time-Resolved Micro Liquid Desorption Mass Spectrometry: Mechanism, Features, and Kinetic Applications

2006 ◽  
Vol 59 (2) ◽  
pp. 81 ◽  
Author(s):  
Ales Charvat ◽  
Andreas Bógehold ◽  
Bernd Abel
Keyword(s):  
Mass Spectrometry ◽  
Liquid Phase ◽  
High Speed ◽  
High Performance ◽  
Kinetic Studies ◽  
Solution Concentration ◽  
Bulk Water ◽  
Laser Wavelength ◽  
Time Resolved ◽  
Desorption Mass Spectrometry

Liquid water beam desorption mass spectrometry is an intriguing technique to isolate charged molecular aggregates directly from the liquid phase and to analyze them employing sensitive mass spectrometry. The liquid phase in this approach consists of a 10 µm diameter free liquid filament in vacuum which is irradiated by a focussed infrared laser pulse resonant with the OH-stretch vibration of bulk water. Depending upon the laser wavelength, charged (e.g. protonated) macromolecules are isolated from solution through a still poorly characterized mechanism. After the gentle liquid-to-vacuum transfer the low-charge-state aggregates are analyzed using time-of-flight mass spectrometry. A recent variant of the technique uses high performance liquid chromatography valves for local liquid injections of samples in the liquid carrier beam, which enables very low sample consumption and high speed sample analysis. In this review we summarize recent work to characterize the ‘desorption’ or ion isolation mechanism in this type of experiment. A decisive and interesting feature of micro liquid beam desorption mass spectrometry is that — under certain conditions — the gas-phase mass signal for a large number of small as well as supramolecular systems displays a surprisingly linear response on the solution concentration over many orders of magnitude, even for mixtures and complex body fluids. This feature and the all-liquid state nature of the technique makes this technique a solution-type spectroscopy that enables real kinetic studies involving (bio)polymers in solution without the need for internal standards. Two applications of the technique monitoring enzyme digestion of proteins and protein aggregation of an amyloid model system are highlighted, both displaying its potential for monitoring biokinetics in solution.

scholarly journals The PKS4 Gene of Fusarium graminearum Is Essential for Zearalenone Production

2006 ◽  
Vol 72 (6) ◽  
pp. 3924-3932 ◽  
Author(s):  
Erik Lys�e ◽  
Sonja S. Klemsdal ◽  
Karen R. Bone ◽  
Rasmus J. N. Frandsen ◽  
Thomas Johansen ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
High Performance ◽  
Polyketide Synthase ◽  
Wild Type ◽  
Root Infection ◽  
Enoyl Reductase ◽  
Transformation Protocol ◽  
Chromatography Analysis ◽  
In The Wild ◽  
High Level

ABSTRACT Zearalenones are produced by several Fusarium species and can cause reproductive problems in animals. Some aurofusarin mutants of Fusarium pseudograminearum produce elevated levels of zearalenone (ZON), one of the estrogenic mycotoxins comprising the zearalenones. An analysis of transcripts from polyketide synthase genes identified in the Fusarium graminearum database was carried out for these mutants. PKS4 was the only gene with an enoyl reductase domain that had a higher level of transcription in the aurofusarin mutants than in the wild type. An Agrobacterium tumefaciens-mediated transformation protocol was used to replace the central part of the PKS4 gene with a hygB resistance gene through double homologous recombination in an F. graminearum strain producing a high level of ZON. PCR and Southern analysis of transformants were used to identify isolates with single insertional replacements of PKS4. High-performance liquid chromatography analysis showed that the PKS4 replacement mutant did not produce ZON. Thus, PKS4 encodes an enzyme required for the production of ZON in F. graminearum. Barley root infection studies revealed no alteration in the pathogenicity of the PKS4 mutant compared to the pathogenicity of the wild type. The expression of PKS13, which is located in the same cluster as PKS4, decreased dramatically in the mutant, while transcription of PKS4 was unchanged. This differential expression may indicate that ZON or its derivatives do not regulate expression of PKS4 and that the PKS4-encoded protein or its product stimulates expression of PKS13. Furthermore, both the lack of aurofusarin and ZON influenced the expression of other polyketide synthases, demonstrating that one polyketide can influence the expression of others.

Bioactive Compounds, High Performance Liquid Chromatography Screening of Phenolic Compounds, and Antioxidant Potential Activity of Saffron (Crocus sativus L.)

2021 ◽  
Vol 15 (5) ◽  
pp. 700-704
Author(s):  
Mohammed Saeed Alkaltham ◽  
Khizar Hayat ◽  
Mohammed Asif Ahmed ◽  
Ahmad Mohammad Salamatullah ◽  
Rokayya Sami ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Bioactive Compounds ◽  
High Performance ◽  
Antioxidant Activities ◽  
Reducing Power ◽  
Saudi Arabian ◽  
Crocus Sativus ◽  
Potential Activity ◽  
Different Origins ◽  
Crocus Sativus L

Saffron (Crocus sativus L) has been widely used for many therapeutic purposes such as a pain reliever, inflammation cure due to the highly bioactive compounds, and antioxidant activities. The effect of boiling time (5, 10, and 15 min) was investigated on the bioactive compounds of saffron samples from different origins (Spain, Saudi Arabia, and Afghanistan). Depending on the origin of the saffron sample, the extraction time showed a different effect on their total polyphenol content (TPC). The highest TPC was noted in saffron from Spain boiled for 10 min (45.01 mg GAE/g DW), followed by the sample from Saudi Arabia (44.03 mg GAE/g DW) and Afghanistan (43.54 mg GAE/g DW) boiled for 15 min, respectively. The Spanish saffron extracted for 10 min significantly (p < 0.05) exhibited the highest total flavonoid content (TFC) (12.26 mg CE/g DW), while the Saudi saffron extracted for 5 min (6.06 mg CE/g DW) showed the lowest range among all the samples. There were no significant differences among the reducing power of Saudi Arabian saffron extracted for 10 min, and Spanish saffron extracted for 5 and 15 min, respectively. The reducing power of saffron samples echoed the results of the TPC and TFC. 1,2-DHB (dihydroxy benzene), chlorogenic acid, caffeic acid are increased upon the increase of boiling time in Saudi Arabian saffron samples. In a word, 10 min and 15 min boiling times achieved the best extraction for Spanish saffron followed by Saudi and Afghani saffron samples, respectively.

scholarly journals Allelopathy and Allelochemicals of Eragrostis plana (Poaceae) and its Relation with Phenology and Nitrogen Fertilization

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
K. CECCHIN ◽  
A. FAVARETTO ◽  
S.M. SCHEFFER-BASSO ◽  
C.D. BERTOL ◽  
S.O. CHINI
Keyword(s):  
Nitrogen Fertilization ◽  
High Performance ◽  
Phenological Stage ◽  
Flowering Stage ◽  
Chromatography Analysis ◽  
Allelopathic Activity ◽  
Aerial Parts ◽  
Main Plot ◽  
Chemical Attributes ◽  
Plot Design

ABSTRACT This study was conducted in order to verify if the phenological stage and the nitrogen fertilization interfere in the allelopathic activity and in the concentration of potentially allelopathic phenolic compounds of tough lovegrass (Eragrostis plana). The assay consisted of a bifactor 3 (0.100 and 200 kg N ha-1) x 2 (harvested in vegetative and reproductive stages), in a split plot design. The N doses constituted the main plot and the phenological stage during the harvest the subplots, resulting in six treatments. The tough lovegrass plants derived from each of the treatments were subjected to allelopathy bioassays, in which aqueous extracts of the aerial parts were applied to lettuce cypselae (Lactuca sativa) and to phytochemicals tests when ethanolic extracts were used, with subsequent partition with ethyl acetate, followed by a high-performance liquid chromatography analysis. There was nitrogen x phenological stage interaction on biological and chemical attributes. The allelopathic extracts were, in descending order of inhibition of germination, those from plants harvested at the vegetative stage and fertilized with 100 kg N and at the flowering stage with 200 kg N, which showed the highest catechin concentrations. The caffeic, ferulic, p-coumaric and vanillic acids were in a higher concentration in flowered and fertilized plants with 0 or 200 kg N. The management of the nitrogen fertilization and the harvesting age influence the allelopathic activity and the phytochemical composition of tough lovegrass.

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