scholarly journals Resistance of Porphyromonas gingivalis ATCC 33277 to Direct Killing by Antimicrobial Peptides Is Protease Independent

2007 ◽  
Vol 52 (2) ◽  
pp. 638-642 ◽  
Author(s):  
Gilad Bachrach ◽  
Hamutal Altman ◽  
Paul E. Kolenbrander ◽  
Natalia I. Chalmers ◽  
Michal Gabai-Gutner ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Porphyromonas Gingivalis ◽  
Wide Spectrum ◽  
Periodontal Diseases ◽  
Amphipathic Peptides ◽  
Gram Negative ◽  
Protease Deficient ◽  
Direct Killing ◽  
Positively Charged

ABSTRACT Antimicrobial peptides are short, positively charged, amphipathic peptides that possess a wide spectrum of antimicrobial activity and have an important role in the host's innate immunity. Lack of, or dysfunctions in, antimicrobial peptides have been correlated with infectious diseases, including periodontitis. Porphyromonas gingivalis, a gram-negative anaerobe and a major pathogen associated with periodontal diseases, is resistant to antimicrobial peptides of human and nonhuman origin, a feature that likely contributes to its virulence. Expressing a robust proteolytic activity, P. gingivalis hydrolyzes antimicrobial peptides. In this study, P. gingivalis inactivated three antimicrobial peptides, while a d-enantiomer was resistant to degradation. P. gingivalis was resistant to the protease-resistant d-enantiomer peptide, and importantly, a protease-deficient P. gingivalis mutant was also resistant to the antimicrobial peptide. Finally, the binding of a fluorescently labeled antimicrobial peptide to protease-deficient P. gingivalis was much weaker than the binding of susceptible Escherichia coli. Our results suggest that the resistance of P. gingivalis ATCC 33277 to direct killing by antimicrobial peptides is protease independent and results (at least partially) from the low affinity of antimicrobial peptides to P. gingivalis.

scholarly journals LFB: A Novel Antimicrobial Brevinin-Like Peptide from the Skin Secretion of the Fujian Large Headed Frog, Limnonectes fujianensi

Biomolecules ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 242 ◽  
Author(s):  
Bin Li ◽  
Peng Lyu ◽  
Shuping Xie ◽  
Haixin Qin ◽  
Wenyuan Pu ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Human Cancer ◽  
Significant Activity ◽  
Negative Bacterium ◽  
Skin Secretion ◽  
Beta Turn ◽  
Gram Negative ◽  
Human Cancer Cell Lines ◽  
Ic50 Values

Amphibians are a natural source of abundant antimicrobial peptides and thus have been widely investigated for isolation of such biomolecules. Many new antimicrobial peptide families have been discovered from amphibians. In this study, a novel antimicrobial peptide named Limnonectes fujianensis Brevinvin (LFB) has been identified in the skin secretion from the Fujian large headed frog, Limnonectes fujianensis. The cDNA sequence was cloned from a skin secretion library and the predicted mature peptide was identified through MS/MS fragmentation sequencing of reverse phase HPLC fractions on the same sample. LFB was predicted to be an amphipathic, hydrophobic, alpha helical, and beta turn peptide that inserts into a lipid bilayer in order to kill the cells. In antimicrobial assays, a synthetic replicate of this novel antimicrobial peptide demonstrated significant activity against the Gram-positive bacterium Staphylococcus aureus, the Gram-negative bacterium Escherichia coli and the yeast, Candida albicans. This novel peptide was highly potent (MIC 4.88 uM) against Gram-negative bacterium, and also has the ability to inhibit the growth of human cancer cell lines with IC50 values ranging from 18.9 μM down to 2.0 μM. These findings help to enrich our understanding of Brevinin-like peptides. Moreover, the data presented here validate frog secretion as a source of potential novel antimicrobial peptides, that also exhibit anti-tumor properties, that could be useful for the treatment of cancer.

scholarly journals Triple-targeting Gram-negative selective antimicrobial peptides capable of disrupting the cell membrane and lipid A biosynthesis

RSC Advances ◽  
2016 ◽  
Vol 6 (70) ◽  
pp. 65418-65421 ◽  
Author(s):  
T. M. Postma ◽  
R. M. J. Liskamp
Keyword(s):  
Cell Membrane ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Lipid A ◽  
Gram Negative ◽  
Lipid A Biosynthesis

A potent Gram-negative selective triple-targeting antimicrobial peptide was developed that attacks the membrane and inhibits two enzymes involved in early lipid A biosynthesis.

scholarly journals Regulation of Antimicrobial Peptide Activity via Tuning Deformation Fields by Membrane-Deforming Inclusions

2021 ◽  
Vol 23 (1) ◽  
pp. 326
Author(s):  
Oleg V. Kondrashov ◽  
Sergey A. Akimov
Keyword(s):  
Antimicrobial Peptides ◽  
Statistical Model ◽  
Antimicrobial Peptide ◽  
Plasma Membranes ◽  
Eukaryotic Cell ◽  
Gramicidin A ◽  
Eukaryotic Cells ◽  
Amphipathic Peptides ◽  
Transmembrane Peptides

Antimicrobial peptides (AMPs) are considered prospective antibiotics. Some AMPs fight bacteria via cooperative formation of pores in their plasma membranes. Most AMPs at their working concentrations can induce lysis of eukaryotic cells as well. Gramicidin A (gA) is a peptide, the transmembrane dimers of which form cation-selective channels in membranes. It is highly toxic for mammalians as being majorly hydrophobic gA incorporates and induces leakage of both bacterial and eukaryotic cell membranes. Both pore-forming AMPs and gA deform the membrane. Here we suggest a possible way to reduce the working concentrations of AMPs at the expense of application of highly-selective amplifiers of AMP activity in target membranes. The amplifiers should alter the deformation fields in the membrane in a way favoring the membrane-permeabilizing states. We developed the statistical model that allows describing the effect of membrane-deforming inclusions on the equilibrium between AMP monomers and cooperative membrane-permeabilizing structures. On the example of gA monomer-dimer equilibrium, the model predicts that amphipathic peptides and short transmembrane peptides playing the role of the membrane-deforming inclusions, even in low concentration can substantially increase the lifetime and average number of gA channels.

scholarly journals Inducible Resistance of Fish Bacterial Pathogens to the Antimicrobial Peptide Cecropin B

2008 ◽  
Vol 52 (9) ◽  
pp. 3006-3012 ◽  
Author(s):  
Ulysses W. Sallum ◽  
Thomas T. Chen
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Pathogenic Bacteria ◽  
Bacterial Pathogens ◽  
Cell Monolayer ◽  
Yersinia Ruckeri ◽  
Cationic Antimicrobial Peptide ◽  
Gram Negative ◽  
Cecropin B ◽  
Inducible Resistance

ABSTRACT Cecropin B is a cationic antimicrobial peptide originally isolated from the diapausing pupae of the giant silk moth, Hylphora cecropia. Cecropin B elicits its antimicrobial effects through disruption of the anionic cell membranes of gram-negative bacteria. Previous work by our laboratory demonstrated that a constitutively expressed cecropin B transgene conferred enhanced resistance to bacterial infection in medaka. The development of antibiotic resistance by pathogenic bacteria is a growing problem. The potential for fish bacterial pathogens to develop resistance to cecropin B was addressed in this study. Four fish bacterial pathogens were selected for the study based on their importance in aquaculture. Vibrio anguillarum, Vibrio vulnificus, and Yersinia ruckeri all exhibited inducible resistance to cecropin B. The inducible resistance of these three pathogens was correlated with reversible changes in their ultrastructures, as observed by scanning electron microscopy. V. anguillarum was demonstrated to become more adhesive to a CHSE-214 cell monolayer and to cause increased cumulative mortality in medaka following exposure to cecropin B. This work demonstrates that the resistance of fish bacterial pathogens to cecropin B is inducible and suggests that resistance to other cationic antimicrobial peptides may occur through similar means. The observed changes in ultrastructure and infectivity suggest that resistance to antimicrobial peptides is an integral part of the pathogenesis of fish gram-negative bacterial pathogens.

APPLICATIONS OF CHITOSAN-SULFATHIAZOLE AS ANTIMICROBIAL AGENT

2018 ◽  
Vol 28 (2) ◽  
pp. 429-432
Author(s):  
Dilyana Zvezdova
Keyword(s):  
Wound Healing ◽  
Antibacterial Activity ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Antimicrobial Agent ◽  
Defense Mechanisms ◽  
Solvent Casting ◽  
Casting Method ◽  
Gram Negative ◽  
Positively Charged

Chitosan, a hydrophilic biopolymer industrially obtained by N-deacetylation of chitin, can be applied as an antimicrobial agent. It highlights the applications of chitosan as an antimicrobial agent against fungi, bacteria, and viruses and as an elicitor of plant defense mechanisms. A series of novel chitosan-sulfathiazole nanocomposite (CSFZ) films were prepared by using solvent casting method for wound healing application. Fourier transform infrared spectroscopy (FTIR) was employed to ascertain the interaction between negatively charged sulfathiazole and positively charged chitosan. Moreover, the antibacterial activity of the films was investigated against gram positive and gram negative microorganisms. It was found that all CSFZ films showed good inhibitory activity against all the tested bacteria as compared to control. The above analysis suggested that the CSFZ films could be used as potential candidates for wound healing application.

The potential role of tea in periodontal therapy: An updated review

2020 ◽  
Vol 17 ◽  
Author(s):  
Ali Forouzanfar ◽  
Hamideh Sadat Mohammadipour ◽  
Fatemeh Forouzanfar
Keyword(s):  
Green Tea ◽  
Potential Role ◽  
Wide Spectrum ◽  
Periodontal Diseases ◽  
Herbal Remedies ◽  
World Population ◽  
Tea Leaves ◽  
The World ◽  
Green Tea Leaves

: Periodontal diseases are highly prevalent and can affect high percentage of the world population. Oxidative stress and inflammation plays an important role in the pathogenesis of periodontal diseases. Nowadays, more attention has been focused on the herbal remedies in the field of drug discovery. Green tea is an important source of polyphenol antioxidants, it has long been used as a beverage worldwide. The most interesting polyphenol components of green tea leaves that are related with health benefits are the catechins. Taken together this review suggested that green tea with its wide spectrum of activities could be a healthy alternative for controlling the damaging reactions seen in periodontal diseases.

Antimicrobial Peptides: A Promising Avenue for Human Healthcare

2020 ◽  
Vol 21 (2) ◽  
pp. 90-96 ◽  
Author(s):  
Girish M. Bhopale
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Antimicrobial Agents ◽  
Current Status ◽  
Antimicrobial Drugs ◽  
Spectrum Activity ◽  
Low Levels ◽  
Human Healthcare ◽  
Broad Spectrum Activity ◽  
Promising Avenue

Antimicrobial drugs resistant microbes have been observed worldwide and therefore alternative development of antimicrobial peptides has gained interest in human healthcare. Enormous progress has been made in the development of antimicrobial peptide during the last decade due to major advantages of AMPs such as broad-spectrum activity and low levels of induced resistance over the current antimicrobial agents. This review briefly provides various categories of AMP, their physicochemical properties and mechanism of action which governs their penetration into microbial cell. Further, the recent information on current status of antimicrobial peptide development, their applications and perspective in human healthcare are also described.

Potential Antimicrobial Peptides Elucidation From The Marine Bacteria

2020 ◽  
Vol 18 ◽  
Author(s):  
Adyasa Barik ◽  
Pandiyan Rajesh ◽  
Manthiram Malathi ◽  
Vellaisamy Balasubramanian
Keyword(s):  
Antimicrobial Peptide ◽  
Marine Bacteria ◽  
Unnatural Amino Acids ◽  
Wide Spectrum ◽  
Drug Resistant ◽  
Medical Field ◽  
The World ◽  
Pathogenic Microbes ◽  
Antimicrobial Peptide Resistance ◽  
Significant Attention

: In recent years, over use of antibiotics has been raising its head to a serious problem all around the world as pathogens become drug resistant and create challenges to the medical field. This failure of most potent antibiotics that kill pathogens increases the thirst for research to look further way of killing pathogens. It has been led to the findings of antimicrobial peptide which is the most potent peptide to destroy pathogens. This review gives special emphasis to the usage of marine bacteria and other microorganisms for antimicrobial peptide (AMP) which are eco friendly as well as a developing class of natural and synthetic peptides with a wide spectrum of targets to pathogenic microbes. Consequently, a significant attention has been paid mainly to (i) the structure and types of anti microbial peptides and (ii) mode of action and mechanism of antimicrobial peptide resistance to pathogens. In addition to this, the designing of AMPs has been analysed thoroughly for reducing toxicity and developing better potent AMP. It has been done by the modified unnatural amino acids by amidation to target the control of biofilm and persister cell.

scholarly journals A mixed chirality α-helix in a stapled bicyclic and a linear antimicrobial peptide revealed by X-ray crystallography

2021 ◽  
Author(s):  
Stéphane Baeriswyl ◽  
Hippolyte Personne ◽  
Ivan Di Bonaventura ◽  
Thilo Köhler ◽  
Christian van Delden ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Crystal Structures ◽  
X Ray ◽  
X Ray Crystallography ◽  
Α Helix

We report the first X-ray crystal structures of mixed chirality α-helices comprising only natural residues as the example of bicyclic and linear membrane disruptive amphiphilic antimicrobial peptides containing seven l- and four d-residues.

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