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Elaheh Jamasbi, Sasidharan S Lucky, Wenyi Li, Mohammed Akhter Hossain, Ponnampalam Gopalakrishnakone, Frances Separovic
Melittin is the peptide toxin found in bee venom and is effective against cancer cells. To enhance its activity, a branched dimeric form of melittin was designed. The monomeric form of the peptide was more cytotoxic against gastric cancer cells at low concentrations (1-5 μM) than the dimer form, while the cytotoxic effect was comparable at higher concentrations (10 μM). Confocal microscopy showed that both the monomer and dimer forms of melittin with fluorescent label at the C terminus penetrated the cytoplasm and localized at the cell nucleus and disrupted the cell membrane...
May 16, 2018: Amino Acids
Yingying Li, Wanjun Han, Songsong Cao, Juncai Hou, Zhanmei Jiang, Chenggang Jiang, Haimei Wang, Shiyue Pang
The objective of the study is to analyze the biological characteristics and stability of the linear derivative Bac2a from bactenecin, compared with the control peptide melittin. The secondary structure, antibacterial activity, hemolytic activity, cell toxicity and stability of the Bac2a were determined by circular dichroism spectroscopy, broth micro-dilution method and MTT assay. The results showed that Bac2a was a nonregular curl in aqueous solution, however, it was an α-helix structure in the hydrophobic environment...
August 1, 2017: Sheng Wu Yi Xue Gong Cheng Xue za Zhi, Journal of Biomedical Engineering, Shengwu Yixue Gongchengxue Zazhi
Fábio C Carneiro, Simone S Weber, Osmar N Silva, Ana Cristina Jacobowski, Marcelo H S Ramada, Maria L R Macedo, Octávio L Franco, Nádia S Parachin
Protease inhibitors have a broad biotechnological application ranging from medical drugs to anti-microbial agents. The Inga laurina trypsin inhibitor (ILTI) previously showed a great in vitro inhibitory effect under the adherence of Staphylococcus species, being a strong candidate for use as an anti-biofilm agent. Nevertheless, this is found in small quantities in its sources, which impairs its utilization at an industrial scale. Within this context, heterologous production using recombinant microorganisms is one of the best options to scale up the recombinant protein production...
April 28, 2018: Microorganisms
Yoonmi Lee, Sung-Geun Kim, In-Su Kim, Hwa-Dong Lee
Background: Pharmacopuncture is a unique treatment in oriental medicine that combines chemical stimulation with conventional acupuncture. However, there are no standardized methods for preparing the herbal medicines used in pharmacopuncture, and it is not clear whether the active ingredients are safe and stable. Several studies have investigated nonstandardized preparation processes, but few investigations have addressed safety and preparation methods. Pharmacopuncture may provide an alternative treatment for incurable diseases...
2018: Evidence-based Complementary and Alternative Medicine: ECAM
Arnaud Marquette, Burkhard Bechinger
Biophysical and structural investigations are presented with a focus on the membrane lipid interactions of cationic linear antibiotic peptides such as magainin, PGLa, LL37, and melittin. Observations made with these peptides are distinct as seen from data obtained with the hydrophobic peptide alamethicin. The cationic amphipathic peptides predominantly adopt membrane alignments parallel to the bilayer surface; thus the distribution of polar and non-polar side chains of the amphipathic helices mirror the environmental changes at the membrane interface...
April 18, 2018: Biomolecules
Lisa Ramirez, Alexander Shekhtman, Jayanti Pande
In recent years there has been a resurgence of interest in melittin and its variants as their therapeutic potential has become increasingly evident. Melittin is a 26-residue peptide and a toxic component of honey bee venom. The versatility of melittin in interacting with various biological substrates, such as membranes, glycosaminoglycans and a variety of proteins has inspired a slew of studies to understand the structural basis of such interactions. However, these studies have largely focused on melittin solutions at high concentrations (> 1mM), even though melittin is generally effective at lower, (micromolar) concentrations...
April 18, 2018: Biochemistry
Rianne Bartelds, Mohammad Hadi Nematollahi, Tjeerd Pols, Marc C A Stuart, Abbas Pardakhty, Gholamreza Asadikaram, Bert Poolman
Niosomes are used in studies for drug delivery or gene transfer. However, their physical properties and features relative to liposomes are not well documented. To characterize and more rationally optimize niosome formulations, the properties of these vesicle systems are compared to those of liposomes composed of phosphatidylcholine and phosphatidylethanolamine lipids plus cholesterol. Niosomes are highly stable and only slightly more leaky than liposomes as assayed by calcein leakage; the permeability for ions (KCl) is higher than that of liposomes...
2018: PloS One
Joonsoo Park, Osung Kwon, Hyun-Jin An, Kwan Kyu Park
Background: Bee venom (BV) has been widely investigated for potential medical uses. Recent inadvertent uses of BV based products have shown to mitigate signs of fungal infections. However, the component mediating the antifungal effect has not been identified. Objective: This investigation compares bee venom in its whole and partial forms to evaluate the possible component responsible for the antifungal effect. Methods: Forty-eight plates inoculated with Trichophyton rubrum were allocated into four groups...
April 2018: Annals of Dermatology
Qian-Qian Li, Pu-Guang Chen, Zhi-Wen Hu, Yuan Cao, Liang-Xiao Chen, Yong-Xiang Chen, Yu-Fen Zhao, Yan-Mei Li
The selective killing of cancer cells and the avoidance of drug resistance are still difficult challenges in cancer therapy. Here, we report a new strategy that uses enzyme-induced gain of function (EIGF) to regulate the structure and function of phosphorylated melittin analogues (MelAs). Original MelAs have the capacity to disrupt plasma membranes and induce cell death without selectivity. However, phosphorylation of Thr23 on one of the MelAs (MelA2-P) efficiently ameliorated the membrane lysis potency as well as the cytotoxicity for normal mammalian cells...
November 1, 2017: Chemical Science
Honglin Jin, Chao Wan, Zhenwei Zou, Guifang Zhao, Lingling Zhang, Yuanyuan Geng, Tong Chen, Ai Huang, Fagang Jiang, Jue-Ping Feng, Jonathan F Lovell, Jing Chen, Gang Wu, Kunyu Yang
Immunosuppressive tumor microenvironments (TMEs) create tremendous obstacles for an effective cancer therapy. Herein, we developed a melittin-RADA32 hybrid peptide hydrogel loaded with doxorubicin (DOX) for a potent chemoimmunotherapy against melanoma through the active regulation of TMEs. The formed melittin-RADA32-DOX (MRD) hydrogel has an interweaving nanofiber structure and exhibits excellent biocompatibility, controlled drug release properties both in vitro and in vivo, and an enhanced killing effect to melanoma cells...
March 20, 2018: ACS Nano
Süleyman Cinar, Claus Czeslik
We compare the binding of an inhibitor with that of a natural peptide to Ca2+ saturated calmodulin (holo-CaM). As inhibitor we have chosen trifluoperazine (TFP) that is inducing a huge conformational change of holo-CaM from the open dumbbell-shaped to the closed globular conformation upon binding. On the other hand, melittin is used as model peptide, which is a well-known natural binding partner of holo-CaM. The experiments are carried out as a function of pressure to reveal the contribution of volume or packing effects to the stability of the calmodulin-ligand complexes...
March 16, 2018: Biochimica et Biophysica Acta
Svetlana S Efimova, Evgeny G Chulkov, Olga S Ostroumova
The effects of local anesthetics (LAs), namely, lidocaine (LDC), prilocaine (PLC), mepivacaine (MPV), bupivacaine (BPV), procaine (PC), and tetracaine (TTC), on the steady-state transmembrane conductance induced by the cis-side addition of the antifungal polyene macrolide antibiotic, nystatin (NYS), in planar lipid bilayers were studied. The addition of TTC to model membranes comprising DOPC and cholesterol (33 mol%) led to a nearly twenty-fold increase in the steady-state NYS-induced membrane conductance...
June 1, 2018: Colloids and Surfaces. B, Biointerfaces
Suvimol Somwongin, Panuwan Chantawannakul, Wantida Chaiyana
Pharmacological effects of bee venom has been reported, however, it has been restricted to the bee venom collected from European honey bee (Apis mellifera). The aim of the present study was to compare the antioxidant activities and irritation properties of venoms collected from four different Apis species in Thailand, which includes Apis cerena (Asian cavity nesting honeybee), Apis florea (dwarf honeybee), Apis dorsata (giant honeybee), and A. mellifera. Melittin content of each bee venom extracts was investigated by using high-performance liquid chromatography...
April 2018: Toxicon: Official Journal of the International Society on Toxinology
Daniel P Feldmann, Yilong Cheng, Rima Kandil, Yuran Xie, Mariam Mohammadi, Hartmann Harz, Akhil Sharma, David J Peeler, Anna Moszczynska, Heinrich Leonhardt, Suzie H Pun, Olivia M Merkel
The block copolymer VIPER (virus-inspired polymer for endosomal release) has been reported to be a promising novel delivery system of DNA plasmids both in vitro and in vivo. VIPER is comprised of a polycation segment for condensation of nucleic acids as well as a pH-sensitive segment that exposes the membrane lytic peptide melittin in acidic environments to facilitate endosomal escape. The objective of this study was to investigate VIPER/siRNA polyplex characteristics, and compare their in vitro and in vivo performance with commercially available transfection reagents and a control version of VIPER lacking melittin...
April 28, 2018: Journal of Controlled Release: Official Journal of the Controlled Release Society
Yijie Chen, Mengchun Chen, Yue Zhang, Joo Hee Lee, Tamara Escajadillo, Hua Gong, Ronnie H Fang, Weiwei Gao, Victor Nizet, Liangfang Zhang
Neutralization of bacterial toxins has become a compelling approach to treating bacterial infections as it may pose less selective pressure for the development of bacterial resistance. Currently, the majority of toxin neutralization platforms act by targeting the molecular structure of the toxin, which requires toxin identification and customized design for different diseases. Therefore, their development has been challenged by the enormous number and complexity of bacterial toxins. Herein, biomimetic toxin nanosponges are formulated by coating membranes of human red blood cells (hRBCs) onto polymeric nanoparticles, which act as a toxin decoy to absorb and neutralize a broad-spectrum of hemolytic toxins regardless of their molecular structure...
February 13, 2018: Advanced Healthcare Materials
Gongyu Li, Siming Yuan, Shihui Zheng, Yangzhong Liu, Guangming Huang
In situ living cell protein analysis would enable the structural identification and functional interrogation of intracellular proteins in native cellular environments. Previously, we have presented an in situ mass spectrometry (MS) strategy to identify protein and protein/metal ion complex with relatively small molecular weight ( Anal. Chem. 2016, 88, 10860-10866). However, it is still challenging to directly identify larger proteins and protein/ligand complexes in cell, due to numerous nonspecific bindings of ligands, solvents, and other cellular constituents...
March 6, 2018: Analytical Chemistry
Woon-Hae Kim, Hyun-Jin An, Jung-Yeon Kim, Mi-Gyeong Gwon, Hyemin Gu, Minji Jeon, Min-Kyung Kim, Sang-Mi Han, Kwan-Kyu Park
Periodontitis is a chronic inflammatory disease that contributes to the destruction of the gingiva. Porphyromonas gingivalis ( P. gingivalis ) can cause periodontitis via its pathogenic lipopolysaccharides (LPS). Melittin, a major component of bee venom, is known to have anti-inflammatory and antibacterial effects. However, the role of melittin in the inflammatory response has not been elucidated in periodontitis-like human keratinocytes. Therefore, we investigated the anti-inflammatory effects of melittin on a P...
February 5, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Zhilin Yang, Heejun Choi, James C Weisshaar
The permeabilization of model lipid bilayers by cationic peptides has been studied extensively over decades, with the bee-sting toxin melittin perhaps serving as the canonical example. However, the relevance of these studies to the permeabilization of real bacterial membranes by antimicrobial peptides remains uncertain. Here, we employ single-cell fluorescence microscopy in a detailed study of the interactions of melittin with the outer membrane (OM) and the cytoplasmic membrane (CM) of live Escherichia coli...
January 23, 2018: Biophysical Journal
William C Wimley
No abstract text is available yet for this article.
January 23, 2018: Biophysical Journal
Lanlan Wan, Daqi Zhang, Jinnan Zhang, Liqun Ren
Melittin is a 26 amino acid residue antimicrobial peptide with known antitumor activity. In the present study, a novel peptide TT-1, derived from melittin and contained only 11 amino acids, was designed, and its antitumor effect was investigated. The present study is aimed to elucidate the effects and relative mechanisms of TT-1 on a human thyroid cancer cell line (TT) in vitro and in vivo . Cell viability assays, Annexin V/propidium iodide assays, western blotting and quantitative reverse transcription polymerase chain reaction were performed...
January 2018: Oncology Letters
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