scholarly journals A Midgut Digestive Phospholipase A2 in Larval Mosquitoes, Aedes albopictus and Culex quinquefasciatus

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Nor Aliza Abdul Rahim ◽  
Marlini Othman ◽  
Muna Sabri ◽  
David W. Stanley
Keyword(s):  
Aedes Albopictus ◽  
Culex Quinquefasciatus ◽  
Protein Concentration ◽  
Control Strategies ◽  
Digestive Enzyme ◽  
Site Specific ◽  
Enzyme Active Site ◽  
Protein Mass ◽  
Optimal Activity ◽  
Sds Page

Phospholipase A2 (PLA2) is a secretory digestive enzyme that hydrolyzes ester bond at sn-2 position of dietary phospholipids, creating free fatty acid and lysophospholipid. The free fatty acids (arachidonic acid) are absorbed into midgut cells. Aedes albopictus and Culex quinquefasciatus digestive PLA2 was characterized using a microplate PLA2 assay. The enzyme showed substantial activities at 6 and 8 μg/μl of protein concentration with optimal activity at 20 and 25 μg/μl of substrate concentration in Aedes albopictus and Culex quinquefasciatus, respectively. PLA2 activity from both mosquitoes increased in a linear function up to 1 hour of the reaction time. Both enzymes were sensitive to pH and temperature. PLA2 showed higher enzyme activities in pH 8.0 and pH 9.0 from Aedes albopictus and Culex quinquefasciatus, respectively, at 40°C of incubation. The PLA2 activity decreased in the presence of 5 mM (Aedes albopictus) and 0.5 mM (Culex quinquefasciatus) site specific PLA2 inhibitor, oleyloxyethylphosphorylcholine. Based on the migration pattern of the partially purified PLA2 on SDS-PAGE, the protein mass of PLA2 is approximately 20–25 kDa for both mosquitoes. The information on PLA2 properties derived from this study may facilitate in devising mosquitoes control strategies especially in the development of inhibitors targeting the enzyme active site.

scholarly journals Quality Attributes of Ultra-High Temperature-Treated Model Beverages Prepared with Faba Bean Protein Concentrates

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1244
Author(s):  
Malik Adil Nawaz ◽  
Tanoj Kumar Singh ◽  
Regine Stockmann ◽  
Hema Jegasothy ◽  
Roman Buckow
Keyword(s):  
Physicochemical Properties ◽  
Faba Bean ◽  
Protein Concentration ◽  
High Concentration ◽  
Molecular Weights ◽  
Oil In Water ◽  
Sds Page ◽  
Lower Protein ◽  
7S Globulin ◽  
Bean Protein

The objective of this research was to develop a model faba bean drink with a high concentration of protein (>4% w/w). The protein molecular weights and frequency for both faba and soy were assessed using SDS-PAGE. Results showed similarities in the protein molecular weight of both faba and soy (mainly 11S globulin ~Glycinin and 7S globulin ~β-conglycinin). Thus, faba can be considered as a potential soy replica in plant-based milk beverages. Oil-in-water emulsions (5–8% w/w available protein) were prepared using faba bean protein concentrate (FPC), 1% sunflower oil, and 0.2% sunflower lecithin. These emulsions were used as model beverages and were further investigated for UHT processibility, stability, and physicochemical properties. The physicochemical properties of emulsions at various processing stages viz., coarse emulsification, homogenisation, and UHT, were measured. An increase in the protein concentration and thermal treatment resulted in an increased oil droplet size, coalescence and flocculation, and protein aggregation. Lower protein concentrations viz., 5–6%, showed greater negative ζ-potential, and thereby, high dispersibility through enhanced electrostatic repulsions than those of higher concentrations (7–8%). Furthermore, an increase in protein concentration and UHT treatment resulted in an increased creaming index. In total, 21 different volatile compounds were detected and quantified, representing different chemical classes, namely alcohols, aldehydes, ketones, esters, furan, and acids. These volatiles have major consequences for the overall flavour chemistry of the model beverage product. Overall, this study showed the potential for application of faba bean as a protein source in UHT-treated legume-based beverages and identified areas for further development.

scholarly journals High insecticide resistance mediated by different mechanisms in Culex quinquefasciatus populations from the city of Yaoundé, Cameroon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdou Talipouo ◽  
Konstantinos Mavridis ◽  
Elysée Nchoutpouen ◽  
Borel Djiappi-Tchamen ◽  
Emmanouil Alexandros Fotakis ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
High Resistance ◽  
Culex Quinquefasciatus ◽  
Control Strategies ◽  
Cuticular Hydrocarbon ◽  
Control Measures ◽  
High Frequencies ◽  
The City ◽  
Integrated Vector Control

AbstractCulex mosquitoes particularly Culex quinquefasciatus are important arboviral and filariasis vectors, however despite this important epidemiological role, there is still a paucity of data on their bionomics. The present study was undertaken to assess the insecticide resistance status of Cx. quinquefasciatus populations from four districts of Yaoundé (Cameroon). All Culex quinquefasciatus populations except one displayed high resistance to bendiocarb and malathion with mortalities ranging from 0 to 89% while high resistance intensity against both permethrin and deltamethrin was recorded. Molecular analyses revealed high frequencies of the ACE-1 G119S mutation (ranging from 0 to 33%) and kdr L1014F allele (ranging from 55 to 74%) in all Cx. quinquefasciatus populations. Significant overexpression was detected for cytochrome P450s genes CYP6AA7 and CYP6Z10, as well as for Esterase A and Esterase B genes. The total cuticular hydrocarbon content, a proxy of cuticular resistance, was significantly increased (compared to the S-lab strain) in one population. The study confirms strong insecticide resistance mediated by different mechanisms in Cx. quinquefasciatus populations from the city of Yaoundé. The expansion of insecticide resistance in Culex populations could affect the effectiveness of current vector control measures and stress the need for the implementation of integrated vector control strategies in urban settings.

Changes in casein composition of goats' milk during the course of lactation: physiological inferences and technological implications

1995 ◽  
Vol 62 (3) ◽  
pp. 431-439 ◽  
Author(s):  
Joanna R. Brown ◽  
Andrew J. R. Law ◽  
Christopher H. Knight
Keyword(s):  
Cation Exchange ◽  
Protein Concentration ◽  
Stage Of Lactation ◽  
Sds Page ◽  
Lower Protein ◽  
Kjeldahl Method ◽  
Compositional Changes ◽  
The Individual ◽  
Cheese Production ◽  
Peak Lactation

SummaryFive British Saanen goats were milk sampled during the first 39 weeks of lactation to determine changes in casein composition. Caseins were separated by anion- and cation-exchange FPLC to determine the relative amounts of the individual caseins. Acid, alkaline and SDS-PAGE were used to determine possible genetic polymorphisms and observe any lactational changes. Total casein nitrogen was determined using a micro-Kjeldahl method and this allowed the concentrations of individual caseins to be calculated. The milk of one animal, which had the deduced genotype αs1-CnAB, showed higher concentrations of both total and αs1-casein. The remainder of the group were either heterozygous αs1-CnBE or, more probably, homozygous αs1-CnE and produced milk of a generally lower protein concentration. Both FPLC and PAGE results showed that the relative amounts and concentrations of αs2-casein decreased with stage of lactation, consistent with its susceptibility to proteolysis. The relative amounts of the breakdown products of plasmin attack on β-casein, γ-caseins, were highly negatively correlated with milk yield (r = –0·942, P < 0·001) in the declining phase of lactation, reflecting the gradual involution of the gland at this time. The relative amount of κ-casein increased by ∼ 50% after peak lactation and its concentration almost doubled near the end of lactation. These compositional changes may alter the processing qualities of goats' milk in relation to cheese production.

scholarly journals Transcriptome-Based Identification of a Functional Fasciola hepatica Carboxylesterase B

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1454
Author(s):  
Yaretzi J. Pedroza-Gómez ◽  
Raquel Cossio-Bayugar ◽  
Hugo Aguilar-Díaz ◽  
Silvana Scarcella ◽  
Enrique Reynaud ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Dna Sequences ◽  
Bioinformatics Analysis ◽  
Fasciola Hepatica ◽  
Polyacrylamide Gel Electrophoresis ◽  
Cellular Membrane ◽  
Reading Frame ◽  
Protein Mass ◽  
Gene Coding ◽  
Sds Page

Bioinformatics analysis of the complete transcriptome of Fasciola hepatica, identified a total of ten putative carboxylesterase transcripts, including a 3146 bp mRNA transcript coding a 2205 bp open reading frame that translates into a protein of 735 amino acids, resulting in a predicted protein mass of 83.5 kDa and a putative carboxylesterase B enzyme. The gene coding for this enzyme was found in two reported F. hepatica complete genomes stretching 23,230 bp, containing two exons of 1282 and 1864 bp, respectively, as well as a 20,084 bp intron between the exons. The enzymatic activity was experimentally assayed on F. hepatica protein extracts by SDS-PAGE zymograms using synthetic chromogenic substrates, confirming both the theoretical molecular weight and carboxylesterase enzymatic activity. Further bioinformatics predicted that this enzyme is an integral component of the cellular membrane that should be active as a 167 kDa homodimer complex and polyacrylamide gel electrophoresis (PAGE) zymograms experiments confirmed the analysis. Additional bioinformatics analysis showed that DNA sequences that code for this particular enzyme are highly conserved in other parasitic trematodes, although they are labeled hypothetical proteins.

scholarly journals Site-Specific and Trigger-Activated Modification of Proteins by Means of Catalytic Hemin/G-quadruplex (hGQ) DNAzyme Nanostructures

2020 ◽  
Author(s):  
Jordi Keijzer ◽  
Bauke Albada
Keyword(s):  
Heavy Chain ◽  
Protein Modification ◽  
Site Specificity ◽  
Site Specific ◽  
Antibody Drug Conjugates ◽  
Synthetic Dna ◽  
Drug Conjugates ◽  
Sds Page ◽  
G Quadruplex ◽  
Antibody Drug

<div>Synthetic DNA that forms various G-quadruplex nanostructures, in combination with hemin, <i>N</i>-methyl luminol derivatives, and H2O2 can site-specifically modify proteins (i.e. evidence is provided for lysozyme and human alpha-thrombin). The catalytic modification is completed in 15-30 mins, and the site-specificity is influenced by the G-quadruplex topology (a total of 22 G-quadruplex forming sequences was tested). We also show that the heavy chain of the therapeutic antibody trastuzumab is modified, which facilitates the preparation of antibody-drug conjugates. Furthermore, a trigger can be programmed into this synthetic DNA so that the protein modification chemistry is made dependent on an external trigger.</div><div><br></div>Techniques used: HPLC, SDS-PAGE, LC-MS/MS, NMR.

Effects of hypoproteinemia on blood volume and arterial pressure of volume-loaded dogs

1990 ◽  
Vol 259 (5) ◽  
pp. H1317-H1324
Author(s):  
R. D. Manning
Keyword(s):  
Body Weight ◽  
Arterial Pressure ◽  
Blood Volume ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Control Period ◽  
Plasma Protein Concentration ◽  
Autologous Plasma ◽  
Protein Mass

Studies were performed in 14 conscious, anephric dogs to clarify the role of blood volume in the genesis of hypertension. The dogs were splenectomized and had plasma protein concentration (PPC) reduced to 2.7 g/dl by daily plasmapheresis for 9 days. This hypoproteinemia resulted in a 20% decrease in both blood volume and mean arterial pressure. On the 10th day the dogs were nephrectomized. On the 11th day after a 3-h control period with plasmapheresis, lactated Ringer equivalent to 10 or 20% of body weight was intravenously infused. By 25 h postinfusion blood volume had not increased, and the dogs were still hypotensive. At 25 h plasma protein mass was returned to normal by intravenous infusion of autologous plasma, the average blood volume of the three low PPC groups increased approximately 50%, and the arterial pressure increased greater than 60%. The decrease in PPC shifted the regression of blood volume on sodium space down the blood volume axis. In conclusion, the dependence of arterial pressure on blood volume was demonstrated by the decrease in both blood volume and arterial pressure after PPC reduction, the constancy of blood volume and pressure during Ringer infusion, and the increase in both volume and pressure after plasma infusion.

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