scholarly journals Citrate Inhibition-Resistant Form of 6-Phosphofructo-1-Kinase from Aspergillus niger

2006 ◽  
Vol 72 (7) ◽  
pp. 4515-4521 ◽  
Author(s):  
Tina Mlakar ◽  
Matic Legiša

ABSTRACT Two forms of Aspergillus niger 6-phosphofructo-1-kinase (PFK1) have been described recently, the 85-kDa native enzyme and 49-kDa shorter fragment that is formed from the former by posttranslational modification. So far, kinetic characteristics have never been determined on the enzyme purified to near homogeneity. For the first time, kinetic parameters were determined for individual enzymes with respect to citrate inhibition. The native 85-kDa enzyme was found to be moderately inhibited by citrate, with the Ki value determined to be 1.5 mM, in the system with 5 mM Mg2+ ions, while increasing magnesium concentrations relieved the negative effect of citrate. An identical inhibition coefficient was determined also in the presence of ammonium ions, although ammonium acted as a strong activator of enzyme activity. On the other hand, the shorter fragment of PFK1 proved to be completely resistant to inhibition by citrate. Allosteric citrate binding sites were most probably lost after the truncation of the C-terminal part of the native protein, in which region some binding sites for inhibitor are known to be located. At near physiological conditions, characterized by low fructose-6-phosphate concentrations, a much higher efficiency of the shorter fragment was observed during an in vitro experiment. Since the enzyme became more susceptible to the positive control by specific ligands, while the negative control was lost after posttranslational modification, the shorter PFK1 fragment seems to be the enzyme most responsible for generating undisturbed metabolic flow through glycolysis in A. niger cells.

2017 ◽  
Vol 9 (2) ◽  
pp. 71
Author(s):  
Nurhasanah Nurhasanah ◽  
Fauzia Andrini ◽  
Yulis Hamidy

Shallot (Allium ascalonicum L.) has been known as traditional medicine. Shallot which has same genus with garlic(Allium sativum L.) contains allicin that is also found in garlic and has been suspected has fungicidal activity toCandida albicans. It is supported by several researches. Therefore, shallot is suspected has antifungal activity too.The aim of this research was to know antifungal activity of shallot’s water extortion againsts Candida albicans invitro. This was a laboratory experimental research which used completely randomized design, with diffusion method.Shallot’s water extortion was devided into three concentrations, there were 50%, 100% and 200%. Ketoconazole 2%was positive control and aquadest was negative control. The result of this research based on analysis of varians(Anova), there was significant difference between several treatments and was confirmed with Duncan New MultipleRange Test (DNMRT) p<0,05, there was significant difference between 100% shallot’s water extortion with othertreatments, but there was no significant difference between 50% shallot’s water extortion with 200% shallot’s. Theconclusion was shallot’s water extortion had antifungal activity againsts Candida albicans with the best concentration100%, but it was lower than ketoconazole 2%.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Mazni Abu Zarin ◽  
Joo Shun Tan ◽  
Paramasivam Murugan ◽  
Rosma Ahmad

Abstract Background The banana or scientifically referred to as Musa sp., is one of the most popular fruits all over the world. Almost all parts of a banana tree, including the fruits, stem juice, and flowers are commonly used as traditional medicine for treating diarrhoea (unripe), menorrhagia, diabetes, dysentery, and antiulcerogenic, hypoglycemic, antilithic, hypolipidemic conditions, plus antioxidant actions, inflammation, pains and even snakebites. The study carried out was to evaluate in vitro anti-urolithiatic activity from different types of Musa pseudo-stems. Methods Observing anti-urolithiathic activity via in vitro nucleation and aggregation assay using a spectrophotometer followed by microscopic observation. A total of 12 methanolic extracts were tested to determine the potential extracts in anti-urolithiasis activities. Cystone was used as a positive control. Results The results manifested an inhibition of nucleation activity (0.11 ± 2.32% to 55.39 ± 1.01%) and an aggregation activity (4.34 ± 0.68% to 58.78 ± 1.81%) at 360 min of incubation time. The highest inhibition percentage in nucleation assay was obtained by the Musa acuminate x balbiciana Colla cv “Awak Legor” methanolic pseudo-stem extract (2D) which was 55.39 ± 1.01%at 60 min of incubation time compared to the cystone at 30.87 ± 0.74%. On the other hand,the Musa acuminate x balbiciana Colla cv “Awak Legor” methanolic bagasse extract (3D) had the highest inhibition percentage in the aggregation assay incubated at 360 min which was obtained at 58.78 ± 1.8%; 5.53% higher than the cystone (53.25%).The microscopic image showed a great reduction in the calcium oxalate (CaOx) crystals formation and the size of crystals in 2D and 3D extracts, respectively, as compared to negative control. Conclusions The results obtained from this study suggest that the extracts are potential sources of alternative medicine for kidney stones disease.


2013 ◽  
Vol 18 (1) ◽  
pp. 86-93
Author(s):  
Gustavo Antônio Martins Brandão ◽  
Rafael Menezes Simas ◽  
Leandro Moreira de Almeida ◽  
Juliana Melo da Silva ◽  
Marcelo de Castro Meneghim ◽  
...  

OBJECTIVE: To evaluate the in vitro ionic degradation and slot base corrosion of metallic brackets subjected to brushing with dentifrices, through analysis of chemical composition by Energy Dispersive Spectroscopy (EDS) and qualitative analysis by Scanning Electron Microscopy (SEM). METHODS: Thirty eight brackets were selected and randomly divided into four experimental groups (n = 7). Two groups (n = 5) worked as positive and negative controls. Simulated orthodontic braces were assembled using 0.019 x 0.025-in stainless steel wires and elastomeric rings. The groups were divided according to surface treatment: G1 (Máxima Proteção Anticáries®); G2 (Total 12®); G3 (Sensitive®); G4 (Branqueador®); Positive control (artificial saliva) and Negative control (no treatment). Twenty eight brushing cycles were performed and evaluations were made before (T0) and after (T1) experiment. RESULTS: The Wilcoxon test showed no difference in ionic concentrations of titanium (Ti), chromium (Cr), iron (Fe) and nickel (Ni) between groups. G2 presented significant reduction (p < 0.05) in the concentration of aluminium ion (Al). Groups G3 and G4 presented significant increase (p < 0.05) in the concentration of aluminium ion. The SEM analysis showed increased characteristics indicative of corrosion on groups G2, G3 and G4. CONCLUSION: The EDS analysis revealed that control groups and G1 did not suffer alterations on the chemical composition. G2 presented degradation in the amount of Al ion. G3 and G4 suffered increase in the concentration of Al. The immersion in artificial saliva and the dentifrice Máxima Proteção Anticáries® did not alter the surface polishing. The dentifrices Total 12®, Sensitive® and Branqueador® altered the surface polishing.


Author(s):  
Liliana Aguilar Marcelino ◽  
Jesús Antonio Pineda Alegría ◽  
David Osvaldo Salinas-Sánchez ◽  
Víctor Manuel Hernández Velázquez ◽  
Gonzalo Iván Silva Aguayo ◽  
...  

The sugarcane aphid, Melanaphis sacchari Zehntner (Hemiptera: Aphididae), is the main pest of sorghum, Sorghum bicolor L. Moench (Poaceae), in Mexico. To control this insect, farmers currently use synthetic chemical insecticides, which are toxic to humans and biodiversity. However, natural products are a promising potential source of safer alternative means to control different agricultural pests. The main objective of this study was to evaluate the insecticidal effect of contact by fumigation of pure molecules of four commercial fatty acids (palmitic, stearic, pentadecanoic and linoleic acids), the phytosterol ß -sitosterol, and the flavonoid rutin. The results showed that fatty acids were the most effective against M. sacchari ; the highest mortality rate (85%) was produced by linoleic acid and the LC 50 was 1,181 ppm, followed by stearic and palmitic acids with mortality percentages of 74 and 63%, respectively, at a concentration of 2,500 ppm at 72 h. The positive control, imidacloprid, had 100% mortality in 24 h and the tween 20 negative control exhibited 4% mortality in 72 h. Our results show that commercial fatty acids are effective against adults of M. sacchari , and can be considered an environmentally friendly alternative to the frequent use of synthetic chemical insecticides.


2016 ◽  
Vol 45 (4) ◽  
pp. 234-239 ◽  
Author(s):  
Priscilla Barbosa Ferreira SOARES ◽  
Aletheia Moraes ROCHA ◽  
Manuella Verdinelli de Paula REIS ◽  
Camilla Christian Gomes MOURA ◽  
Carlos José SOARES

Abstract Objective This study evaluated four types of pH adjustment of the coconut water (CW) on viability of human fibroblasts (HFF). Material and method Natural and industrialized CW were adjusted to pH 7.0 using: (1) Sodium Hidroxide (NaOH), (2) Sodium bicarbonate (NaHCO3), (3) Triethanolamine (C6H15NO3), (4) 2-Amino-2-Methil-1-Propanol (C4H11NO). Fibroblasts were plated at 2×104/ well in 96 well plates and maintained in the CW solutions for 2 h and 4 h. Positive control was represented by HFF maintained in DMEM and the negative control by tap water. Cell viability was analyzed by MTT formazan method. Data were analyzed by 3-way ANOVA followed by Tukey’s and Dunnet’s test. Result There are no significant effect on the cell viability regarding type of CW, period of evaluation, and the interactions between CW and period of evaluation, CW and pH adjustment method, pH adjustment method and period of evaluation (p>0.05). Conclusion The product used for CW pH adjustment did not influenced HFF viability, thought there are a tendency of better performance in natural CW.


2020 ◽  
Vol 18 (1) ◽  
pp. 47
Author(s):  
FERIZAL NEGERI SAMUDRA ◽  
RETNO BUDIARTI ◽  
IRMAWATI IRMAWATI

<p><strong>ABSTRACT</strong></p><p><strong>Background</strong>; In Indonesia, most diarrhea disease in 1995 to 2001 are caused by Shigella spp. Shigella spp infection can cause various symptom dan complication. Generally, the treatment by using antibiotic can cause antibiotic resistance. Sea cucumber (Holoturia scabra) is an herb that known, available, and easy to consume by society and has an antibacterial effect. Therefore, further research to study the effect of Holoturia Scabra on <em>Shigella Dysentriae</em> growth in vitro is needed.</p><p><strong>Objectives</strong>: The goal of this research is demonstrate the effect of sea cucumber (Holoturia scabra) to the growth of the <em>Shigella dysentriae</em> bacteria in vitro.</p><p><strong>Method</strong>: The method in this research is Posttest Only Control Group. There are 6 groups, 4 types of and 2 control groups. The concentration of the treatment group is 100%,50%, 25%, and, 12.5% while for positive control tests using chloramphenicol and aquadest as a negative control.</p><p><strong>Result</strong>: The result showed there is an influence on the intake of sand cucumber to the growth of the Shigella dysenteriae.</p><p><strong>Conclusion</strong>: Sea cucumber (<em>Holoturia scabra</em>) inhibit the growth of <em>Shigella dysenteriae</em>.</p><p><strong>Key words</strong>: <em>Shigella dysenteriae</em>, sea cucumber (<em>Holoturia scabra</em>), antibacterial</p>


2020 ◽  
Vol 1 (2) ◽  
pp. 8-15
Author(s):  
Gislanne Stéphanne Estevam da Silva ◽  
Rivaldo Leon Bezerra Cabral ◽  
Nathalie de Sena Pereira ◽  
José Heriberto Oliveira do Nascimento ◽  
Dany G kramer

Silver nanoparticles (AgNP) can be incorporated into medical devices, such as tissues, to circumvent bacterial resistance such as Klebsiella spp, which can lead to skin and mucosal infections. Thus, the aim of the present study was to synthesize silver nanoparticles for later incorporation into cotton fabrics and in vitro tests against Klebsiella spp. The AgNP colloidal solution was synthesized (AgNO3 - 0.1 mM, 100 mM trisodium citrate, polyvinylpyrrolidone - 0.24 g, H2OH2) and then impregnated into the cotton fabric pretreated with poly diallyl dimethylammonium chloride (PDDA) of 100/500 tissue, shaken for 30 minutes). The material produced was analyzed by the FTIR; DLS and reflectance spectroscopy. The tests of the antimicrobial activities were by the microdilution technique against Klebsiella spp, in tubes containing Brain Heart Infusion (BHI), with the solution of silver (1); Tissue containing AgNP - 4 mm (2); Negative control (3) and positive control - ceftriaxone (4). Regarding MIC, the inhibitory activity occurred of the dilutions between 1/2 and 1/16. The AgNP particles had an average size of 24.75 nm. As synthesized AgNPs demonstrate the excellent antimicrobial activity against Klebsiella spp, with special emphasis on applications in nanotechnology and nanomedicine, targeting multiresistant antibiotic bacteria.


2017 ◽  
Vol 44 (3) ◽  
pp. 535-545
Author(s):  
Luis R. Martínez-Córdova ◽  
Teresa Gollas-Galván ◽  
Estefanía Garibay-Valdez ◽  
Rocío Valenzuela-Gutiérrez ◽  
Marcel Martínez Porchas ◽  
...  

The physiological and immune responses of adult shrimp (Litopenaeus vannamei) undergoing the acute phase of the necrotizing hepatopancreatitis (NHP) disease and the efficiency of oxytetracycline (OXI) and florfenicol (FF) to eliminate the pathogen were evaluated. Four shrimp groups were considered: three groups infected with necrotizing hepatopancreatitis bacteria (NHP-B) (two treated with antibiotics and a positive control) and one group non-infected (negative control). Hemolymph concentration of glucose, lactate, acylglycerides, cholesterol, total protein, aminotransferases, superoxide dismutase, and the transcriptional expression of several immune related genes were monitored at the acute phase of the disease, and at 15 and 20 days after administration of antibiotics (daa). Shrimp from the positive control registered a mortality of 100%. NHP-B infection affected the immu-nophysiological response of shrimp; herein, most of the parameters were significantly up regulated in infected shrimp before the use of antibiotics, compared to the negative control. Increased transcriptional levels of clotting protein, lipopolysaccharide and β-1-3-glucan binding protein (LGBP), serine protease, peroxinectin, lysozyme, heat shock proteins (HSP) 60 and 70 were detected in shrimp treated with OXI. At 20 daa NHP-B was still detected in FF-treated shrimp, but not in OXI-treated shrimp. It is hypothesized that despite none of the antibiotics per se eliminated the bacterium, both had a negative effect on its virulence. OXI seems to have a greater effect, allowing shrimp to integrate a better immune response at 15 daa.


2020 ◽  
Vol 2 (1) ◽  
pp. 26-34
Author(s):  
Margareta Retno Priamsari ◽  
Agastia Cicilia Wibowo

Noni juice can inhibit the growth of Escherichia coli bacteria. Noni juice extraction needs concentration to extract so that the preparation is more stable in the storage process. The purpose of this study was to determine the antibacterial activity and the amount of the minimum inhibitory concentration of noni juice extract from E. coli bacteria in vitro. This type of experimental research with a completely randomized one-way design. The extract was obtained by concentrating the Noni leaf extract. Extract quality control parameters include organoleptic, yield, drying shrinkage, and qualitative tests of flavonoid and anthraquinone compounds. Antibacterial activity test using the disc diffusion method with an extract concentration of 1.56%; 3.12%; 6.25%; 12.5%; and 25% with 3 replications. Positive control of amoxicillin and negative control of distilled water. Inhibition is known from the zone formed around the paper disc. The data obtained were statistically analyzed using Kruskall Wallis followed by Mann Whitney with a 95% confidence level. The results showed that the variation in the concentration of the noni juice extract had a significant effect (p <0.05). The biggest inhibitory zone was seen at 25% concentration of 10.16 mm and included in the strong category. The minimum inhibitory power was produced at a concentration of 3.12% at 2.50 mm with a weak treatment category.


2019 ◽  
Vol 2 (1) ◽  
pp. 82-87
Author(s):  
O. S Salami

Ascariasis is a neglected tropical disease prevalent in areas with poor hygiene and low standard of living in tropical countries. Hyptis suaveolens is been used traditionally around the world for various ailments. The aim of the study was to evaluate the anthelminthic activity of the methanolic leaf extract of the plant on the three life cycle stages of Ascaris suum synonymous to Ascaris lumbricoides. The phytochemical analysis of the extract was evaluated. The in-vitro anthelminthic activity of the methanolic leaf extract of Hyptis suaveolens on the egg hatchability and larva inhibition of Ascaris suum were assessed using Bizimenyara inhibition method, where 100 eggs were counted and incubated in 5 different plate-wells containing positive control, negative control and 3 concentrations (50, 70 and 100 mg/ml) of extract. The plate wells were brought out after incubation and content examined under the microscope. The effect of the methanolic leaf extract and pyrantel pamoate on cuticle peeling, motility and mortality were evaluated using adult worms. The egg hatchability and larval development after incubation for 48 h and 21 days significantly (p<0.05 for both) inhibited with 98% unhatched eggs and 95% undeveloped larva of A. suum respectively. There was significant (p<0.05) visible peeling of cuticles, reduced motility and mortality of the adult worms after 30, 12 and 80 minutes respectively. It can be concluded that H. suaveolens has anthelminthic activity on A. suum which may be attributed to some of the phytochemical constituents.


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