δ-Toxin, unlike melittin, has only hemolytic activity and no antimicrobial activity: Rationalization of this specific biological activity

1993 ◽  
Vol 13 (4) ◽  
pp. 245-250 ◽  
Author(s):  
Vishnu Mukund Dhople ◽  
Ramakrishnan Nagaraj
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activity ◽  
Cell Surface ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Synthetic Peptide ◽  
Lipid Membrane ◽  
Cell Surfaces ◽  
Gram Negative ◽  
Micro Organisms

The antimicrobial activity of a synthetic peptide corresponding to δ-hemolysin had been examined. The peptide did not exhibit antimicrobial activity against gram negative and gram positive micro-organisms unlike other hemolytic peptides like melittin. This lack of antibacterial activity arises due to the inability of δ-hemolysin to perturb the negatively charged bacterial cell surface and permeabilize the bacterial plasma membrane. However, the red blood cell surface has a structure considerably different from bacteria, and does not act as a barrier to molecules reaching the lipid membrane. Hence δ-toxin can lyse erythrocytes. Thus, the specificity in biological activity has been rationalized in terms of differences, in the interaction of the toxin with the bacterial and red blood cell surfaces.

Biosynthesis of Silver Nanoparticles by Punica Granatum Peel Extract and their Biological Activity on different Pathogenic Bacteria

2021 ◽  
Vol 19 (9) ◽  
pp. 38-45
Author(s):  
Hussein H. Al-Turnachy ◽  
Fadhilk. alibraheemi ◽  
Ahmed Abd Alreda Madhloom ◽  
Zahraa Yosif Motaweq ◽  
Nibras Yahya Abdulla
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Biological Activity ◽  
Pathogenic Bacteria ◽  
Punica Granatum ◽  
Gram Positive ◽  
Gram Negative ◽  
Inhibition Zones ◽  
Peel Extract

The present study was included the assessment of the antimicrobial activity of AgNPs synthesized by Punica granatum peel extract against pathogenic bacteria by testing warm aqueous P. granatum peel extract and silver nanoparticles. Punica granatum indicated potency for AgNP extracellular nanobiosynthesis after addition of silver nitrate (AgNO3) 4mM to the extract supernatant, in both concentrations (100mg and 50mg). The biogenic AgNPs showed potency to inhibit both gram-negative and gram-positive bacterial growth. Zons of inhibition in (mm) was lesser in gram-positive than gram-negative bacteria. The resulted phytogenic AgNPs gave higher biological activity than warm aqueous Punica granatum peel extract. The inhibition zone of the phytogenic AgNPs on E. coli reached 17.53, 22.35, and 26.06 mm at (0.1, 0.5, and 1) mg/ml respectively. While inhibition zones of Punica warm aqueous extract reached 5.33, 10.63, and 16.08 mm at the same concentrations. phytogenic AgNPs gave smaller inhibition zones in gram-positive than gram- negative. Cytotoxic activity of the phytogenic AgNPs was assayed in vitro agaist human blood erythrocytes (RBCs), spectroscopic results showed absorbance at 540 nm hemolysis was observed. In general, AgNPs showed least RBCs hemolysis percentage, at 1 mg/ml concentration, hemolysis percentage was (4.50%). This study, concluded that the Punica granatum peel extract has the power of synthses of AgNPs characterized by broad spectrum antimicrobial activity with cyto-toxicity proportional to AgNPs concentration.

scholarly journals Antibodies in children with malaria to PfEMP1, RIFIN and SURFIN expressed at the Plasmodium falciparum parasitized red blood cell surface

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Maria del Pilar Quintana ◽  
Jun-Hong Ch’ng ◽  
Kirsten Moll ◽  
Arash Zandian ◽  
Peter Nilsson ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Cell Surface ◽  
Blood Cell ◽  
Red Blood Cell

scholarly journals Synthesis and Antimicrobial Activity of Piperine Analogues Containing 1,2,4-Triazole Ring

2019 ◽  
Vol 31 (5) ◽  
pp. 1077-1080
Author(s):  
Kottakki Naveen Kumar ◽  
Karteek Rao Amperayani ◽  
V. Ravi Sankar Ummdi ◽  
Uma Devi Parimi
Keyword(s):  
Antimicrobial Activity ◽  
Triazole Ring ◽  
Diffusion Method ◽  
Moderate Activity ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
Antibacterial Study ◽  
Gram Negative ◽  
E Coli ◽  
Micro Organisms

A series 1,2,4-triazole piperine analogues (TP1-TP6) were designed and synthesized. The structures were confirmed using 1H NMR and 13C NMR. Antibacterial study was done using Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative micro-organisms (E. coli and Pseudomonas aeruginosa) by disc diffusion method. Compound containing chloro substitution (TP6) showed the highest effect, while compound TP1, TP3, TP4, TP5 showed the moderate activity.

scholarly journals EFFECT OF ARABICA AND CANEPHORA COFFEE BEAN EXTRACTS TOWARDS MODIFICATION OF RED BLOOD CELL SURFACE ANTIGENS

2018 ◽  
Vol 9 (5) ◽  
pp. 91-95 ◽  
Author(s):  
Praveen Kumar Vemuri ◽  
Sanjay Madala ◽  
Vijaya Lakshmi Bodiga ◽  
Suryanarayana Veeravalli ◽  
Nithin Chand Kurra
Keyword(s):  
Cell Surface ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Surface Antigens ◽  
Coffee Bean ◽  
Cell Surface Antigens

The Presence of Novel Amino Acids in the Cytoplasmic Domain of Stem Cell Factor Results in Hematopoietic Defects inSteel17H Mice

Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 1915-1925 ◽  
Author(s):  
Reuben Kapur ◽  
Ryan Cooper ◽  
Xingli Xiao ◽  
Mitchell J. Weiss ◽  
Peter Donovan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bone Marrow ◽  
Biological Activity ◽  
Stem Cell ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Stem Cell Factor ◽  
Cytoplasmic Domain

Abstract Stem cell factor (SCF) is expressed as an integral membrane growth factor that may be differentially processed to produce predominantly soluble (S) (SCF248) or membrane-associated (MA) (SCF220) protein. A critical role for membrane presentation of SCF in the hematopoietic microenvironment (HM) has been suggested from the phenotype of the Steel-dickie(Sld) mice, which lack MA SCF, and by studies performed in our laboratory (and by others) using long-term bone marrow cultures and transgenic mice expressing different SCF isoforms.Steel17H (Sl17H) is an SCF mutant that demonstrates melanocyte defects and sterility in males but not in females. The Sl17H allele contains a intronic mutation resulting in the substitution of 36 amino acids (aa’s) in the SCF cytoplasmic domain with 28 novel aa’s. This mutation, which affects virtually the entire cytoplasmic domain of SCF, could be expected to alter membrane SCF presentation. To investigate this possibility, we examined the biochemical and biologic properties of the Sl17H-encoded protein and its impact in vivo and in vitro on hematopoiesis and on c-Kit signaling. We demonstrate that compound heterozygous Sl/Sl17H mice manifest multiple hematopoietic abnormalities in vivo, including red blood cell deficiency, bone marrow hypoplasia, and defective thymopoiesis. In vitro, both S and MA Sl17H isoforms of SCF exhibit reduced cell surface expression on stromal cells and diminished biological activity in comparison to wild-type (wt) SCF isoforms. These alterations in presentation and biological activity are associated with a significant reduction in the proliferation of an SCF-responsive erythroid progenitor cell line and in the activation of phosphatidylinositol 3-Kinase/Akt and mitogen-activated protein-Kinase signaling pathways. In vivo, transgene expression of the membrane-restricted (MR) (SCFX9/D3) SCF in Sl/Sl17H mutants results in a significant improvement in peripheral red blood cell counts in comparison toSl/Sl17H mice.

scholarly journals The Cytoplasmic Region of Plasmodium falciparum SURFIN4.2 Is Required for Transport from Maurer’s Clefts to the Red Blood Cell Surface

2015 ◽  
Vol 43 (4) ◽  
pp. 265-272 ◽  
Author(s):  
Wataru Kagaya ◽  
Shinya Miyazaki ◽  
Kazuhide Yahata ◽  
Nobuo Ohta ◽  
Osamu Kaneko
Keyword(s):  
Plasmodium Falciparum ◽  
Cell Surface ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Cytoplasmic Region ◽  
Maurer's Clefts

scholarly journals Plasmodium falciparum erythrocyte-binding antigen 175 triggers a biophysical change in the red blood cell that facilitates invasion

2017 ◽  
Vol 114 (16) ◽  
pp. 4225-4230 ◽  
Author(s):  
Marion Koch ◽  
Katherine E. Wright ◽  
Oliver Otto ◽  
Maik Herbig ◽  
Nichole D. Salinas ◽  
...  
Keyword(s):  
Cell Surface ◽  
Blood Cell ◽  
Signaling Pathways ◽  
Red Blood Cell ◽  
Malaria Parasite ◽  
Red Cell ◽  
Biophysical Properties ◽  
Parasite Invasion ◽  
Bending Modulus ◽  
Erythrocyte Binding

Invasion of the red blood cell (RBC) by the Plasmodium parasite defines the start of malaria disease pathogenesis. To date, experimental investigations into invasion have focused predominantly on the role of parasite adhesins or signaling pathways and the identity of binding receptors on the red cell surface. A potential role for signaling pathways within the erythrocyte, which might alter red cell biophysical properties to facilitate invasion, has largely been ignored. The parasite erythrocyte-binding antigen 175 (EBA175), a protein required for entry in most parasite strains, plays a key role by binding to glycophorin A (GPA) on the red cell surface, although the function of this binding interaction is unknown. Here, using real-time deformability cytometry and flicker spectroscopy to define biophysical properties of the erythrocyte, we show that EBA175 binding to GPA leads to an increase in the cytoskeletal tension of the red cell and a reduction in the bending modulus of the cell’s membrane. We isolate the changes in the cytoskeleton and membrane and show that reduction in the bending modulus is directly correlated with parasite invasion efficiency. These data strongly imply that the malaria parasite primes the erythrocyte surface through its binding antigens, altering the biophysical nature of the target cell and thus reducing a critical energy barrier to invasion. This finding would constitute a major change in our concept of malaria parasite invasion, suggesting it is, in fact, a balance between parasite and host cell physical forces working together to facilitate entry.

Simultaneous Camouflage of Major and Minor Antigens on Red Blood Cell Surface With Activated mPEGs

2014 ◽  
Vol 12 (2) ◽  
Author(s):  
Zahra Gholami ◽  
Sameereh Hashemi Najafabadi ◽  
Masoud Soleimani
Keyword(s):  
Cell Surface ◽  
Blood Cell ◽  
Red Blood Cell
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