scholarly journals Caseinolytic Proteins (Clp) in the Genus Klebsiella: Special Focus on ClpK

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 200
Author(s):  
Tehrim Motiwala ◽  
Blessing Oluebube Akumadu ◽  
Sbahle Zuma ◽  
Mbalenhle Sizamile Mfeka ◽  
Wanping Chen ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
In Silico ◽  
Protein Quality ◽  
Exchange Chromatography ◽  
Biologically Active ◽  
Cell Protein ◽  
Special Focus ◽  
Dependent Manner ◽  
Dynamic Simulations ◽  
Concentration Dependent Manner

Caseinolytic proteins (Clp), which are present in both prokaryotes and eukaryotes, play a major role in cell protein quality control and survival of bacteria in harsh environmental conditions. Recently, a member of this protein family, ClpK was identified in a pathogenic strain of Klebsiella pneumoniae which was responsible for nosocomial infections. ClpK is linked to the thermal stress survival of this pathogen. The genome wide analysis of Clp proteins in Klebsiella spp. indicates that ClpK is present in only 34% of the investigated strains. This suggests that the uptake of the clpk gene is selective and may only be taken up by a pathogen that needs to survive harsh environmental conditions. In silico analyses and molecular dynamic simulations show that ClpK is mainly α-helical and is highly dynamic. ClpK was successfully expressed and purified to homogeneity using affinity and anion exchange chromatography. Biophysical characterization of ClpK showed that it is predominantly alpha-helical, and this is in agreement with in silico analysis of the protein structure. Furthermore, the purified protein is biologically active and hydrolyses ATP in a concentration- dependent manner.

Chickpea (Cicer arietinum L.) Lectin Exhibit Inhibition of ACE-I, α-amylase and α-glucosidase Activity

2019 ◽  
Vol 26 (7) ◽  
pp. 494-501 ◽  
Author(s):  
Sameer Suresh Bhagyawant ◽  
Dakshita Tanaji Narvekar ◽  
Neha Gupta ◽  
Amita Bhadkaria ◽  
Ajay Kumar Gautam ◽  
...  
Keyword(s):  
Biological Effects ◽  
Exchange Chromatography ◽  
Health Concern ◽  
Carbohydrate Binding ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ic50 Values ◽  
Chickpea Lectin

Background: Diabetes and hypertension are the major health concern and alleged to be of epidemic proportions. This has made it a numero uno subject at various levels of investigation. Glucosidase inhibitor provides the reasonable option in treatment of Diabetes Mellitus (DM) as it specifically targets post prandial hyperglycemia. The Angiotensin Converting Enzyme (ACE) plays an important role in hypertension. Therefore, inhibition of ACE in treatment of elevated blood pressure attracts special interest of the scientific community. Chickpea is a food legume and seeds contain carbohydrate binding protein- a lectin. Some of the biological properties of this lectin hitherto been elucidated. Methods: Purified by ion exchange chromatography, chickpea lectin was tested for its in vitro antioxidant, ACE-I inhibitory and anti-diabetic characteristic. Results: Lectin shows a characteristic improvement over the synthetic drugs like acarbose (oral anti-diabetic drug) and captopril (standard antihypertensive drug) when, their IC50 values are compared. Lectin significantly inhibited α-glucosidase and α-amylase in a concentration dependent manner with IC50 values of 85.41 ± 1.21 ҝg/ml and 65.05 ± 1.2 µg/ml compared to acarbose having IC50 70.20 ± 0.47 value of µg/ml and 50.52 ± 1.01 µg/ml respectively. β-Carotene bleaching assay showed antioxidant activity of lectin (72.3%) to be as active as Butylated Hydroxylanisole (BHA). In addition, lectin demonstrated inhibition against ACE-I with IC50 value of 57.43 ± 1.20 µg/ml compared to captopril. Conclusion: Lectin demonstrated its antioxidant character, ACE-I inhibition and significantly inhibitory for α-glucosidase and α-amylase seems to qualify as an anti-hyperglycemic therapeutic molecule. The biological effects of chickpea lectin display potential for reducing the parameters of medically debilitating conditions. These characteristics however needs to be established under in vivo systems too viz. animals through to humans.

scholarly journals 5-bromo-2'-deoxyuridine-stimulated calcium ion- or magnesium ion-dependent ecto-(adenosine triphosphatase) activity of cultured hamster cardiac cells

1977 ◽  
Vol 164 (3) ◽  
pp. 645-652 ◽  
Author(s):  
G A Coetzee ◽  
W Gevers
Keyword(s):  
Adenosine Triphosphatase ◽  
Primary Cultures ◽  
Cardiac Cells ◽  
Cell Protein ◽  
Heart Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Active Centre ◽  
Cellular Dna ◽  
Hamster Heart

1. Treatment of hamster heart cells in primary culture with 5-bromo-2'-deoxyuridine resulted in the greatly increased activity of a particulate Ca2+- or Mg2+-dependent ATPase (adenosine triphosphatase). 2. 5-Bromo-2'-deoxyuridine exerted these effects only when it was incorporated into cellular DNA, and then in a concentration-dependent manner. 3. Serially replated cells contained less of the activity (expressed as a function of total cell protein) than did the primary cultures, but the stimulation caused by 5-bromo-2'-deoxyuridine addition was much greater. 4. The affected enzyme was apparently localized in the plasma membrane of the cells with its active centre exposed to the outer environment [ecto-(ATPase) dependent on Ca2+ or Mg2+].5. The activity was unaffected by treatment with p-chloromercuriphenylsulphonate, ouabain andverapamil. 6. Ecto (5'-nucleotidase) activity was not increased by 5-bromo-2'-deoxyuridine treatment of cells, and ecto-(p-nitrophenyl phosphatase) activity was only slightly enhanced.

Beta-adrenergic agonists attenuate fibroblast-mediated contraction of released collagen gels

1996 ◽  
Vol 270 (5) ◽  
pp. L829-L835 ◽  
Author(s):  
T. Mio ◽  
Y. Adachi ◽  
S. Carnevali ◽  
D. J. Romberger ◽  
J. R. Spurzem ◽  
...  
Keyword(s):  
Collagen Gel ◽  
Biologically Active ◽  
Dependent Manner ◽  
Collagen Gels ◽  
Adrenergic Agonists ◽  
Concentration Dependent Manner ◽  
Beta Adrenergic ◽  
Cyclic Monophosphate ◽  
Beta Adrenergic Agonists ◽  
Collagen Gel Contraction

The effects of beta-adrenergic agonists on fibroblast-mediated collagen gel contraction were investigated. beta-Agonists isoproterenol and epinephrine significantly attenuated fibroblast-mediated gel contraction in a concentration-dependent manner, whereas alpha-agonist norepinephrine had no effect. The biologically active form of isoproterenol, (-)-isoproterenol, was 10-fold more effective than the optical isoform, (+)-isoproterenol. beta-Antagonists sotalol and propranolol reversed the attenuation caused by 10(-7) M isoproterenol or epinephrine at the concentration of 10(-7) M or 10(-6) M, but the alpha-antagonist phentolamine did not. However, beta1- or beta2-specificity of these effects is not clear. Isobutyl methylxanthine augmented the effect of isoproterenol and also prolonged the duration. Two reagents which are known to increase intracellular adenosine 3',5'-cyclic monophosphate (cAMP), prostaglandin E2 and dibutyryl adenosine 3',5'-cyclic monophosphate, attenuated gel contraction in a concentration-dependent manner. These data suggest that the fibroblast-mediated collagen gel contraction can be modulated by beta-adrenergic agonists and that the effect depends on cAMP.

scholarly journals Isolation, Chemical Characterization and Antioxidant Activity of Pectic Polysaccharides of Fireweed (Epilobium angustifolium L.)

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7290
Author(s):  
Sergey Popov ◽  
Vasily Smirnov ◽  
Elizaveta Kvashninova ◽  
Victor Khlopin ◽  
Fedor Vityazev ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Exchange Chromatography ◽  
Enzyme Hydrolysis ◽  
Dependent Manner ◽  
Apple Pectin ◽  
Pectic Polysaccharides ◽  
Concentration Dependent Manner ◽  
Epilobium Angustifolium

The aim of this study was to isolate pectins with antioxidant activity from the leaves of Epilobium angustifolium L. Two pectins, EA-4.0 and EA-0.8, with galacturonic acid contents of 88 and 91% were isolated from the leaves of E. angustifolium L. by the treatment of plant raw materials with aqueous hydrochloric acid at pH 4.0 and 0.8, respectively. EA-4.0 and EA-0.8 were found to scavenge the DPPH radical in a concentration-dependent manner at 17–133 μg/mL, whereas commercial apple pectin scavenged at 0.5–2 mg/mL. The antioxidant activity of EA-4.0 was the highest and exceeded the activity of EA-0.8 and a commercial apple pectin by 2 and 39 times (IC50—0.050, 0.109 and 1.961 mg/mL), respectively. Pectins EA-4.0 and EA-0.8 were found to possess superoxide radical scavenging activity, with IC50s equal to 0.27 and 0.97 mg/mL, respectively. Correlation analysis of the composition and activity of 32 polysaccharide fractions obtained by enzyme hydrolysis and anionic exchange chromatography revealed that the antioxidant capacity of fireweed pectins is mainly due to phenolics and is partially associated with xylogalacturonan chains. The data obtained demonstrate that pectic polysaccharides appeared to be bioactive components of fireweed leaves with high antioxidant activity, which depend on pH at their extraction.

scholarly journals Design, Molecular Docking And In Silico Analysis Of Analogues Of Chloroquine And Hydroxychloroquine Against SARs-COV-2 Target (6w63.pdb)

2020 ◽  
Author(s):  
Naruka Solomon Yakubu ◽  
Olanike Catherine Poyi ◽  
Ezikiel Olabisi Afolabi
Keyword(s):  
Binding Affinity ◽  
In Silico ◽  
Target Prediction ◽  
In Silico Analysis ◽  
Docking Studies ◽  
Biologically Active ◽  
Dynamic Simulations ◽  
Comparable Activity ◽  
Silico Analysis

Abstract Computer-aided drug design has been an effective strategy and approach to discover, develop, analyze, accelerate and economize design and development of drugs and biologically active molecules. A total of twelve analogues of chloroquine (CQ) and hydroxychloroquine (HCQ) were designed and virtually analyzed using PyRx software, Molinspiration, Swiss ADME, Swiss-Target Prediction software and ProTox-II-Prediction of toxicity platform. Based on the docking studies carried out using Autodock vina, five analogues; H-368 (-6.0 Kcal/mol), H-372 (--6.0 Kcal/mol), H-156 (-5.9 Kcal/mol), H-139 (-5.7 Kcal/mol), C-136 (-5.7 Kcal/mol) exhibited higher binding affinity compared to HCQ(-5.5 Kcal/mol), while all twelve analogues exhibited higher binding affinity compared to CQ (-4.5Kcal/mol). In silico analysis of toxicity profile of this analogues shows a lower potential to toxicity and a comparable activity on some major isoforms of cytochrome P450. But unlike the parent molecules, both H-139 and H-156 are substrates of P-glycoproteins (P-gp) which implies that these analogues possess high clearance and less pharmacokinetic-related drug-drug interactions compared to the parent molecules. Herein we propose these analogues as potential inhibitors or lead compounds against the coronavirus with a view of conducting more molecular dynamic simulations, synthesizing and conducting in vitro studies on them.

scholarly journals Panax quinquefolium L. Ginsenosides from Hairy Root Cultures and Their Clones Exert Cytotoxic, Genotoxic and Pro-Apoptotic Activity towards Human Colon Adenocarcinoma Cell Line Caco-2

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2262 ◽  
Author(s):  
Ewa Kochan ◽  
Adriana Nowak ◽  
Małgorzata Zakłos-Szyda ◽  
Daria Szczuka ◽  
Grażyna Szymańska ◽  
...  
Keyword(s):  
Cell Line ◽  
Hairy Root ◽  
Biologically Active ◽  
Hairy Root Cultures ◽  
Dependent Manner ◽  
Root Cultures ◽  
Panax Quinquefolium ◽  
Adenocarcinoma Cell Line ◽  
Concentration Dependent Manner ◽  
Adenocarcinoma Cell

American ginseng, Panax quinquefolium (L.), is traditionally used in folk medicine. It exhibits a range of anti-inflammatory, hepatoprotective, anti-diabetic, anti-obesity, anti-hyperlipidemic and anti-carcinogenic effects. Its main components are ginsenosides, also known as panaxosides or triterpene saponins. In order to obtain high yields of ginsenosides, different methods of controlled production are involved, i.e., with hairy root cultures. However, they are still employed under in vitro conditions. Our studies revealed that hairy root cultures subjected to an elicitation process can be considered as a potent source of ginsenosides. The present study examines the biological activity of ginseng hairy root cultures against the Caco-2 human adenocarcinoma cell line. Among our six different clones of P. quinquefolium hairy roots, extracts B and Be (treated with elicitor) were the strongest inhibitors of the cellular metabolic activity. While all extracts induced DNA damage, B and Be also generated reactive oxygen species (ROS) in a concentration-dependent manner, which was correlated with the depletion of the mitochondrial membrane potential and induction of apoptosis. These findings indicate that further research concerning P. quinquefolium hairy root cultures should focus on the activity of rare ginsenosides and other biologically active compound profiles (i.e., phenolic compounds).

scholarly journals The Anti-Inflammatory Role of Mannich Curcuminoids; Special Focus on Colitis

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1546 ◽  
Author(s):  
Gábor J. Szebeni ◽  
Lajos I. Nagy ◽  
Anikó Berkó ◽  
Alexandra Hoffmann ◽  
Liliána Z. Fehér ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Neutrophil Infiltration ◽  
Therapeutic Interventions ◽  
Inflammatory Activity ◽  
Interleukin 4 ◽  
Special Focus ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Peripheral Blood Mononuclear ◽  
Anti Inflammatory

The incidence of inflammatory bowel disease (IBD) increases gradually in Western countries with high need for novel therapeutic interventions. Mannich curcuminoids, C142 or C150 synthetized in our laboratory, have been tested for anti-inflammatory activity in a rat model of TNBS (2,4,6-trinitrobenzenesulphonic acid) induced colitis. Treatment with C142 or C150 reduced leukocyte infiltration to the submucosa and muscular propria of the inflamed gut. C142 or C150 rescued the loss of body weight and C150 decreased the weight of standard colon preparations proportional with 20% less tissue oedema. Both C142 and C150 curcumin analogues caused 25% decrease in the severity of colonic inflammation and haemorrhagic lesion size. Colonic MPO (myeloperoxidase) enzyme activity as an indicator of intense neutrophil infiltration was 50% decreased either by C142 or C150 Mannich curcuminoids. Lipopolysaccharide (LPS) co-treatment with Mannich curcuminoids inhibited NF-κB (nuclear factor kappa B) activity on a concentration-dependent manner in an NF-κB-driven luciferase expressing reporter cell line. Co-treatment with LPS and curcuminoids, C142 or C150, resulted in NF-κB inhibition with 3.57 μM or 1.6 μM half maximal effective concentration (EC50) values, respectively. C150 exerted a profound inhibition of the expression of inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-4 (IL-4) in human PBMCs (peripheral blood mononuclear cells) upon LPS stimulus. Mannich curcuminoids reported herein possess a powerful anti-inflammatory activity.

scholarly journals Peptidoglycan O Acetylation and Autolysin Profile of Enterococcus faecalis in the Viable but Nonculturable State

2006 ◽  
Vol 188 (3) ◽  
pp. 902-908 ◽  
Author(s):  
John M. Pfeffer ◽  
Hendrik Strating ◽  
Joel T. Weadge ◽  
Anthony J. Clarke
Keyword(s):  
High Performance ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Hydroxyl Group ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Viable But Nonculturable ◽  
Egg White Lysozyme

ABSTRACT The O acetylation of peptidoglycan occurs specifically at the C-6 hydroxyl group of muramoyl residues. Using a combination of high-performance liquid chromatography-based organic acid analysis and carbohydrate analysis by high-pH anion-exchange chromatography, we determined that strains of Entercoccus durans, E. faecalis, E. faecium, and E. hirae produce O-acetylated peptidoglycan. The levels of O acetylation ranged from 19% to 72% relative to the muramic acid content, and they were found to vary with the growth phase of the culture. Increases of 10 to 40% in O acetylation were observed with cultures entering the stationary phase. Cells of E. faecalis in the viable but nonculturable (VBNC) state had the highest levels of peptidoglycan O acetylation. The presence of this modification to peptidoglycan was shown to inhibit the action of hen egg white lysozyme in a concentration-dependent manner. Zymography using sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels containing either O-acetylated or chemically de-O-acetylated peptidoglycan was used to monitor the production of specific autolysins in E. faecalis. Differences in the expression of specific autolysins were observed with the age of the culture, and VBNC E. faecalis produced the highest levels of these enzymes. This technique also permitted classification of the enterococcal autolysins into enzymes that preferentially hydrolyze either O-acetylated or non-O-acetylated peptidoglycan and enzymes that show no apparent preference for either substrate type.

scholarly journals Targeted Delivery of Gene Silencing in Fungi Using Genetically Engineered Bacteria

2021 ◽  
Vol 7 (2) ◽  
pp. 125
Author(s):  
Jonatan Niño-Sánchez ◽  
Li-Hung Chen ◽  
Jorge Teodoro De Souza ◽  
Sandra Mosquera ◽  
Ioannis Stergiopoulos
Keyword(s):  
Targeted Delivery ◽  
Pathogenic Bacteria ◽  
Target Genes ◽  
Genetically Engineered ◽  
Biologically Active ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Whole Cell ◽  
Thaw Cycle ◽  
Living Bacteria

Exploiting RNA interference (RNAi) in disease control through non-transformative methods that overcome the hurdle of producing transgenic plants has attracted much attention over the last years. Here, we explored such a method and used non-pathogenic bacteria as a versatile system for delivering RNAi to fungi. Specifically, the RNaseIII-null mutant strain of Escherichia coli HT115(DE3) was transformed with two plasmid vectors that enabled the constitutive or IPTG-inducible production of double-stranded RNAs (dsRNAs) against genes involved in aflatoxins production in Aspergillus flavus (AflC) or virulence of Botrytis cinerea (BcSAS1). To facilitate the release of the dsRNAs, the bacterial cells were further genetically engineered to undergo a bacteriophage endolysin R-mediated autolysis, following a freeze-thaw cycle. Exposure under in vitro conditions of A. flavus or B. cinerea to living bacteria or their whole-cell autolysates induced silencing of AflC and BcSAS1 in a bacteria concentration-dependent manner, and instigated a reduction in aflatoxins production and mycelial growth, respectively. In planta applications of the living bacteria or their crude whole-cell autolysates produced similar results, thus creating a basis for translational research. These results demonstrate that bacteria can produce biologically active dsRNA against target genes in fungi and that bacteria-mediated RNAi can be used to control fungal pathogens.

scholarly journals Brevinin-1 and multiple insulin-releasing peptides in the skin of the frog Rana palustris

2004 ◽  
Vol 181 (2) ◽  
pp. 347-354 ◽  
Author(s):  
L Marenah ◽  
PR Flatt ◽  
DF Orr ◽  
S McClean ◽  
C Shaw ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Insulin Release ◽  
Biologically Active ◽  
Mass Spectrometry Analysis ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Bicarbonate Buffer ◽  
Skin Secretions

Few studies have comprehensively examined amphibian granular gland secretions for novel insulinotropic peptides. This study involved isolation and characterisation of biologically active peptides from the skin secretions of Rana palustris frogs. Crude secretions obtained by mild electrical stimulation from the dorsal skin surface were purified by reversed-phase HPLC on a semipreparative Vydac C18 column, yielding 80 fractions. These fractions were assayed for insulin-releasing activity using glucose-responsive BRIN-BD11 cells. Acute 20 min incubations were performed in Krebs Ringer bicarbonate buffer supplemented with 5.6 mmol/l glucose in the absence (control) and presence of various fractions. Fractions 29-54 and fractions 68-75 showed significant 2.0-6.5-fold increases in insulin-releasing activity (P<0.001). The fractions showing most prominent insulinotropic activity were further purified to single homogeneous peaks, which, on testing, evoked 1.5-2.8-fold increases in insulin release (P<0.001). The structures of the purified peptides were determined by mass spectrometry and N-terminal amino acid sequencing. Electrospray ionisation ion-trap mass spectrometry analysis revealed molecular masses of 2873.5-8560.4 Da. Sufficient material was isolated to determine the primary amino acid sequence of the 2873.5 Da peptide, revealing a 27 amino acid sequence, ALSILRGLEKLAKMGIALTNCKATKKC, repressing palustrin-1c. The database search for this peptide showed a 48% homology with brevinin-1, an antimicrobial peptide isolated from various Rana species, which itself stimulated insulin release from BRIN-BD11 cells in a concentration-dependent manner. In conclusion, the skin secretions of R. palustris frogs contain a novel class of peptides with insulin-releasing activity that merit further investigation.

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