PAK: an essential motif for forming β-turn structures and exhibiting the thrombolytic effect of P6A and its analogs

2007 ◽  
Vol 85 (6) ◽  
pp. 730-740 ◽  
Author(s):  
Ming Zhao ◽  
Xin Jia ◽  
Chao Wang ◽  
Qin Li ◽  
Kexiang Zhou ◽  
...  
Keyword(s):  
Side Chain ◽  
Conformational Structure ◽  
Thrombolytic Activity ◽  
Solution Structures ◽  
Structure Relationship ◽  
Thrombolytic Effect ◽  
Dependent Pathway ◽  
Positively Charged

Ala-Arg-Pro-Ala-Lys (ARPAK; also known as P6A) and 19 of its analogs were synthesized, and their thrombolytic activities were assessed in vitro and in vivo. The solution structures of 12 of the P6A analogs were determined using nuclear magnetic resonance (NMR) spectroscopy. The thrombolytic activity and conformational structure relationship was analyzed. We found that the Pro-Ala-Lys (PAK) sequence was essential for thrombolytic activity and was also responsible for the β-turn structure found in the P6A analogs studied. The well defined β turn may act as a binding head with the protruding lysine side-chain (positively charged) found at the target site for target recognition. Additionally, the N-terminal residue may be critical for thrombolytic activity, which for PAK-containing peptides, is likely achieved via a plasminogen-dependent pathway.

scholarly journals Ascertainment of In vivo Antidiarrheal and In vitro Thrombolytic Effect of Ethanolic Extract of Leaves of Amomum dealbatum

2019 ◽  
Author(s):  
Md. Azimul Islam ◽  
Mohammed Aktar Sayeed ◽  
Md. Abdul Barek ◽  
Enama Nabi Shetu ◽  
Md. Nurul Faisal
Keyword(s):  
Castor Oil ◽  
Venous Blood ◽  
Ethanolic Extract ◽  
Positive Control ◽  
Negative Control ◽  
Clot Lysis ◽  
Thrombolytic Activity ◽  
Thrombolytic Effect

Aims: The present study aimed to investigate antidiarrheal and thrombolytic effect of ethanolic extract of leaves of A. dealbatum in mice. Study design: Antidiarrheal effect was evaluated by castor oil-induced diarrhea method at two different concentrations in mice and in vitro thrombolytic activity was analyzed with clot lysis assay of human blood. Place and duration of study: Department of Pharmacy, International Islamic University Chittagong, Kumira, Chittagong-4318, Bangladesh, between December 2018 and February 2019. Methodology: The male Swiss mice’s were divided into four groups (n = 5). First group was orally treated with 1% Tween-80 (10 ml/kg) and second group was orally treated with loperamide (5 mg/kg). Third and fourth group were orally treated with ethanolic extract of leaves of A. dealbatum at 200 and 400 mg/kg accordingly. Human RBCs were collected for conducting thrombolytic assay. During this study, 1.5 ml of venous blood was drawn from healthy volunteers (n = 10) and Streptokinase was employed as positive control and distilled water was employed as negative control. Results: In castor oil induced diarrhea model, ethanolic extract of leaves of A. dealbatum at 200, 400 mg/kg and loperamide (5 mg/kg) significantly reduced the number of feces and increase percent of inhibition of defecations compared to negative control. The extract showed percent of inhibition of defecation of 16.67 and 37.50 for 200 and 400 mg/ml respectively where the positive control loperamide showed 66.67%. Percentage of clot disruptions were 4.51 (p<.001), 75.69 (p<.001) and 26.07 (p<.001) for water, streptokinase and 10 mg/ml extract respectively. Conclusion: Based on the results from in vivo and in vitro activities, the leaves of A. dealbatum were found to be a potential source of new antidiarrheal and thrombolytic agents.

scholarly journals Accounting for biases in riboprofiling data indicates a major role for proline and not positive amino acids in stalling translation

2014 ◽  
Author(s):  
Carlo G. Artieri ◽  
Hunter B. Fraser
Keyword(s):  
Amino Acids ◽  
Ribosome Profiling ◽  
Side Chain ◽  
Data Sets ◽  
Charged Amino Acids ◽  
Recent Method ◽  
Low Coverage ◽  
Positively Charged

The recent advent of ribosome profiling ? sequencing of short ribosome-bound fragments of mRNA ? has offered an unprecedented opportunity to interrogate the sequence features responsible for modulating translational rates. Nevertheless, numerous analyses of the first riboprofiling dataset have produced equivocal and often incompatible results. Here we analyze three independent yeast riboprofiling data sets, including two with much higher coverage than previously available, and find that all three show substantial technical sequence biases that confound interpretations of ribosomal occupancy. After accounting for these biases, we find no effect of previously implicated factors on ribosomal pausing. Rather, we find that incorporation of proline, whose unique side-chain stalls peptide synthesis in vitro, also slows the ribosome in vivo. We also reanalyze a recent method that reported positively charged amino acids as the major determinant of ribosomal stalling and demonstrate that its assumptions lead to false signals of stalling in low-coverage data. Our results suggest that any analysis of riboprofiling data should account for sequencing biases and sparse coverage. To this end, we establish a robust methodology that enables analysis of ribosome profiling data without prior assumptions regarding which positions spanned by the ribosome cause stalling.

scholarly journals Effects of Size and Surface Properties of Nanodiamonds on the Immunogenicity of Plant-Based H5 Protein of A/H5N1 Virus in Mice

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1597
Author(s):  
Thuong Thi Ho ◽  
Van Thi Pham ◽  
Tra Thi Nguyen ◽  
Vy Thai Trinh ◽  
Tram Vi ◽  
...  
Keyword(s):  
High Pressure ◽  
Neutralizing Antibodies ◽  
H5n1 Virus ◽  
Vaccine Development ◽  
Particle Characterization ◽  
Innovative Strategy ◽  
Specific Igg ◽  
Positively Charged

Nanodiamond (ND) has recently emerged as a potential nanomaterial for nanovaccine development. Here, a plant-based haemagglutinin protein (H5.c2) of A/H5N1 virus was conjugated with detonation NDs (DND) of 3.7 nm in diameter (ND4), and high-pressure and high-temperature (HPHT) oxidative NDs of ~40–70 nm (ND40) and ~100–250 nm (ND100) in diameter. Our results revealed that the surface charge, but not the size of NDs, is crucial to the protein conjugation, as well as the in vitro and in vivo behaviors of H5.c2:ND conjugates. Positively charged ND4 does not effectively form stable conjugates with H5.c2, and has no impact on the immunogenicity of the protein both in vitro and in vivo. In contrast, the negatively oxidized NDs (ND40 and ND100) are excellent protein antigen carriers. When compared to free H5.c2, H5.c2:ND40, and H5.c2:ND100 conjugates are highly immunogenic with hemagglutination titers that are both 16 times higher than that of the free H5.c2 protein. Notably, H5.c2:ND40 and H5.c2:ND100 conjugates induce over 3-folds stronger production of both H5.c2-specific-IgG and neutralizing antibodies against A/H5N1 than free H5.c2 in mice. These findings support the innovative strategy of using negatively oxidized ND particles as novel antigen carriers for vaccine development, while also highlighting the importance of particle characterization before use.

scholarly journals Effects of Ubiquinol-10 on MicroRNA-146a Expression In Vitro and In Vivo

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Constance Schmelzer ◽  
Mitsuaki Kitano ◽  
Gerald Rimbach ◽  
Petra Niklowitz ◽  
Thomas Menke ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reactive Oxygen Species ◽  
Biological Processes ◽  
Oxygen Species ◽  
Moderate Reduction ◽  
Suppression Of Gene Expression ◽  
Fine Tune ◽  
Dependent Pathway

MicroRNAs (miRs) are involved in key biological processes via suppression of gene expression at posttranscriptional levels. According to their superior functions, subtle modulation of miR expression by certain compounds or nutrients is desirable under particular conditions. Bacterial lipopolysaccharide (LPS) induces a reactive oxygen species-/NF-κB-dependent pathway which increases the expression of the anti-inflammatory miR-146a. We hypothesized that this induction could be modulated by the antioxidant ubiquinol-10. Preincubation of human monocytic THP-1 cells with ubiquinol-10 reduced the LPS-induced expression level of miR-146a to 78.9±13.22%. In liver samples of mice injected with LPS, supplementation with ubiquinol-10 leads to a reduction of LPS-induced miR-146a expression to 78.12±21.25%. From these consistent in vitro and in vivo data, we conclude that ubiquinol-10 may fine-tune the inflammatory response via moderate reduction of miR-146a expression.

scholarly journals Effect of the cholesterol content of small unilamellar liposomes on their stability in vivo and in vitro

1980 ◽  
Vol 186 (2) ◽  
pp. 591-598 ◽  
Author(s):  
Christopher Kirby ◽  
Jacqui Clarke ◽  
Gregory Gregoriadis
Keyword(s):  
Blood Plasma ◽  
Intravenous Injection ◽  
Whole Blood ◽  
Cholesterol Content ◽  
Molar Ratio ◽  
Phosphatidylcholine Liposomes ◽  
Effective Use ◽  
Positively Charged

Small unilamellar neutral, negatively and positively charged liposomes composed of egg phosphatidylcholine, various amounts of cholesterol and, when appropriate, phosphatidic acid or stearylamine and containing 6-carboxyfluorescein were injected into mice, incubated with mouse whole blood, plasma or serum or stored at 4°C. Liposomal stability, i.e. the extent to which 6-carboxyfluorescein is retained by liposomes, was dependent on their cholesterol content. (1) Cholesterol-rich (egg phosphatidylcholine/cholesterol, 7:7 molar ratio) liposomes, regardless of surface charge, remained stable in the blood of intravenously injected animals for up to at least 400min. In addition, stability of cholesterol-rich liposomes was largely maintained in vitro in the presence of whole blood, plasma or serum for at least 90min. (2) Cholesterol-poor (egg phosphatidylcholine/cholesterol, 7:2 molar ratio) or cholesterol-free (egg phosphatidylcholine) liposomes lost very rapidly (at most within 2min) much of their stability after intravenous injection or upon contact with whole blood, plasma or serum. Whole blood and to some extent plasma were less detrimental to stability than was serum. (3) After intraperitoneal injection, neutral cholesterol-rich liposomes survived in the peritoneal cavity to enter the blood circulation in their intact form. Liposomes injected intramuscularly also entered the circulation, although with somewhat diminished stability. (4) Stability of neutral and negatively charged cholesterol-rich liposomes stored at 4°C was maintained for several days, and by 53 days it had declined only moderately. Stored liposomes retained their unilamellar structure and their ability to remain stable in the blood after intravenous injection. (5) Control of liposomal stability by adjusting their cholesterol content may help in the design of liposomes for effective use in biological systems in vivo and in vitro.

scholarly journals d-Sedoheptulose-7-phosphate is a common precursor for the heptoses of septacidin and hygromycin B

2018 ◽  
Vol 115 (11) ◽  
pp. 2818-2823 ◽  
Author(s):  
Wei Tang ◽  
Zhengyan Guo ◽  
Zhenju Cao ◽  
Min Wang ◽  
Pengwei Li ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Carbon Chain ◽  
Side Chain ◽  
Hygromycin B ◽  
Nucleoside Antibiotics ◽  
Common Precursor ◽  
Encoding Genes ◽  
Poultry Farming

Seven-carbon-chain–containing sugars exist in several groups of important bacterial natural products. Septacidin represents a group of l-heptopyranoses containing nucleoside antibiotics with antitumor, antifungal, and pain-relief activities. Hygromycin B, an aminoglycoside anthelmintic agent used in swine and poultry farming, represents a group of d-heptopyranoses–containing antibiotics. To date, very little is known about the biosynthesis of these compounds. Here we sequenced the genome of the septacidin producer and identified the septacidin gene cluster by heterologous expression. After determining the boundaries of the septacidin gene cluster, we studied septacidin biosynthesis by in vivo and in vitro experiments and discovered that SepB, SepL, and SepC can convert d-sedoheptulose-7-phosphate (S-7-P) to ADP-l-glycero-β-d-manno-heptose, exemplifying the involvement of ADP-sugar in microbial natural product biosynthesis. Interestingly, septacidin, a secondary metabolite from a gram-positive bacterium, shares the same ADP-heptose biosynthesis pathway with the gram-negative bacterium LPS. In addition, two acyltransferase-encoding genes sepD and sepH, were proposed to be involved in septacidin side-chain formation according to the intermediates accumulated in their mutants. In hygromycin B biosynthesis, an isomerase HygP can recognize S-7-P and convert it to ADP-d-glycero-β-d-altro-heptose together with GmhA and HldE, two enzymes from the Escherichia coli LPS heptose biosynthetic pathway, suggesting that the d-heptopyranose moiety of hygromycin B is also derived from S-7-P. Unlike the other S-7-P isomerases, HygP catalyzes consecutive isomerizations and controls the stereochemistry of both C2 and C3 positions.

Abstract 230: Lipoprotein X Causes Renal Disease in LCAT Deficiency

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Edward B Neufeld ◽  
Alice Ossoli ◽  
Seth G Thacker ◽  
Boris Vaisman ◽  
Milton Pryor ◽  
...  
Keyword(s):  
Renal Disease ◽  
Plasma Clearance ◽  
Mesangial Cells ◽  
Chemical Properties ◽  
Low Hdl ◽  
Lcat Deficiency ◽  
Physical And Chemical ◽  
Dependent Pathway

Familial lecithin:cholesterol acyltransferase (LCAT) deficiency (FLD) is characterized by low HDL, accumulation of an abnormal cholesterol-rich multilamellar particle called lipoprotein-X (LpX) in plasma, and renal disease. The aim of our study was to determine if LpX is nephrotoxic and to gain insight into the pathogenesis of FLD renal disease. We administered a synthetic LpX, nearly identical to endogenous LpX in its physical, and chemical properties, to wild-type and Lcat -/- mice. Our in vitro and in vivo studies demonstrated an apoA-I and LCAT-dependent pathway for LpX conversion to HDL-like particles, which likely mediates normal plasma clearance of LpX. Plasma clearance of exogenous LpX was markedly delayed in Lcat -/- mice, which have low HDL but only minimal amounts of endogenous LpX and do not spontaneously develop renal disease. Chronically administered exogenous LpX deposited in all renal glomerular cellular and matrical compartments of Lcat -/- mice, and induced proteinuria and nephrotoxic gene changes, as well as all of the hallmarks of FLD renal disease as assessed by histological, TEM, and SEM analyses. Extensive in vivo EM studies revealed LpX uptake by macropinocytosis into mouse glomerular endothelial cells, podocytes, and mesangial cells and delivery to lysosomes, where it was degraded. Endocytosed LpX appeared to be degraded by both human podocyte and mesangial cell lysosomal PLA 2 and induced podocyte secretion of pro-inflammatory IL-6 in vitro and renal Cxl10 expression in Lcat -/- mice. In conclusion, LpX is a nephrotoxic particle that in the absence of LCAT induces all of the histological and functional hallmarks of FLD and hence may serve as a biomarker for monitoring recombinant LCAT therapy. In addition, our studies suggest that LpX-induced loss of endothelial barrier function and release of cytokines by renal glomerular cells likely plays a role in the initiation and progression of FLD nephrosis.

scholarly journals Difference in Thrombolytic Effect between Higher and Lower Molecular Weight Forms of Urokinase

1977 ◽  
Author(s):  
T. Suyama ◽  
M. Nishida ◽  
Y. Iga ◽  
R. Naito
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Lower Molecular Weight ◽  
Dissolution Time ◽  
Thrombolytic Activity ◽  
Lysis Time ◽  
Thrombolytic Effect ◽  
Approximate Molecular Weight ◽  
Made In

Urokinase (UK) from human urine has been widely used for thrombolytic therapy in Japan. However, commercially available preparations are not identical but consist of mainly two forms of UK with higher and lower molecular weight (H-UK and L-UK) . An attempt was made in this report to compare thrombolytic activity of H-UK with that of L-UK on artificial thrombi produced from human blood by a modification of Chandler’s loop method, which was somehow comparable to the situation in vivo. Two active forms of UK were purified from crude preparation by gel filtration. The approximate molecular weight of the H-UK was 54,000 and of the L-UK 34,000. The potency of UK was determined by “two-stage lysis time method” and expressed by International unit(lU). Thrombolytic activity measured by Chandler’s method was calculated as % lysis of the control thrombus that was formed in the abscence of UK.As a result, thrombus-dissolution time of H-UK was much shorter than that of L-UK. Furthermore, concentration of H-UK (IU/ml blood) necessary to induce 50% lysis was approximately one half lower than that of L-UK. The similiar results were obtained on artificial thrombi from the blood of dog, rat and rabbit. The data suggest that H-UK seems to be more effective on treatment of thromboembolicdisorders as compared to L-UK in terms of the same IU basis.

scholarly journals Solid lipid nanoparticle induced apoptosis of macrophages via a mitochondrial-dependent pathway in vitro and in vivo

2019 ◽  
Vol Volume 14 ◽  
pp. 3283-3295 ◽  
Author(s):  
Wan-Li Liang ◽  
Lan Xiao ◽  
Hong-Wei Gu ◽  
Xiao-Jun Li ◽  
Yu-Sang Li ◽  
...  
Keyword(s):  
Solid Lipid Nanoparticle ◽  
Solid Lipid ◽  
Lipid Nanoparticle ◽  
Induced Apoptosis ◽  
Dependent Pathway
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