Read by QxMD icon Read


Kaveh Matinkhoo, Alla Pryyma, Mihajlo Todorovic, Brian O Patrick, David M Perrin
α-Amanitin is an extremely toxic bicyclic octapeptide isolated from the death-cap mushroom, Amanita phalloides. As a potent inhibitor of RNA polymerase II, α-amanitin is toxic to eukaryotic cells. Recent interest in α-amanitin arises from its promise as a payload for antibody-drug conjugates. For over 60 years, A. phalloides has been the only source of α-amanitin. Here we report a synthesis of α-amanitin, which surmounts the key challenges for installing the 6-hydroxy-tryptathionine sulfoxide bridge, enantioselective synthesis of (2 S,3 R,4 R)-4,5-dihydroxy-isoleucine, and diastereoselective sulfoxidation...
March 21, 2018: Journal of the American Chemical Society
Siew Mei Samantha Ng, Jia Mao Yap, Qiu Ying Lau, Fui Mee Ng, Esther Hong Qian Ong, Timothy Barkham, Jeanette Woon Pei Teo, Mohammad Alfatah, Kiat Whye Kong, Shawn Hoon, Prakash Arumugam, Jeffrey Hill, Cheng San Brian Chia
Vulvovaginal candidiasis (VVC) is a genital fungal infection afflicting approximately 75% of women globally and is primarily caused by the yeast Candida albicans. The extensive use of fluconazole, the first-line antifungal drug of choice, has led to the emergence of fluconazole-resistant C. albicans, creating a global clinical concern. This, coupled to the lack of new antifungal drugs entering the market over the past decade, has made it imperative for the introduction of new antifungal drug classes. Peptides with antifungal properties are deemed potential drug candidates due to their rapid membrane-disrupting mechanism of action...
March 9, 2018: European Journal of Medicinal Chemistry
Irina Velikyan, Örjan Lindhe
Monitoring general disease marker such as angiogenesis may contribute to the development of personalized medicine and improve therapy outcome. Readily availability of positron emitter based imaging agents providing quantification would expand clinical positron emission tomography (PET) applications. Generator produced68 Ga provides PET images of high resolution and the half-life time frame is compatible with the pharmacokinetics of small peptides comprising arginine-glycine-aspartic acid (RGD) sequence specific to αv β3 integrin receptors...
2018: American Journal of Nuclear Medicine and Molecular Imaging
Chang Seon Lee, Moon-Ki Choi, Ye Young Hwang, Hyunki Kim, Moon Ki Kim, Yun Jung Lee
Water purification by membranes is widely investigated to address concerns related to the scarcity of clean water. Achieving high flux and rejection simultaneously is a difficult challenge using such membranes because these properties are mutually exclusive in common artificial membranes. Nature has developed a method for this task involving water-channel membrane proteins known as aquaporins. Here, the design and fabrication of graphene oxide (GO)-based membranes with a surface-tethered peptide motif designed to mimic the water-selective filter of natural aquaporins is reported...
February 27, 2018: Advanced Materials
Leonel T Takada, Mee-Ohk Kim, Stacy Metcalf, Ignacio Illán Gala, Michael D Geschwind
Genetic prion diseases (gPrDs) are caused by autosomal-dominant mutations in the prion protein gene (PRNP). Although the first PRNP mutations identified, and most since, are PRNP missense, octapeptide repeat insertions, deletion and nonsense mutations have now also been shown to cause gPrD. Based on clinicopathologic features of familial disease, gPrDs historically have been classified into three forms: familial Jakob-Creutzfeldt disease, Gerstmann-Sträussler-Scheinker disease, and fatal familial insomnia...
2018: Handbook of Clinical Neurology
Sen Ye, Kejia Shi, Jiefeng Xu, Moli Wang, Chun-Jian Li
Previous studies have demonstrated that cholecystokinin octapeptide (CCK8) induces hypothermia and inhibits the systemic inflammatory response in septic shock in rat and murine models. The present study aimed to ascertain whether CCK8 induced hypothermia and improved the neurological outcomes in a porcine model of cardiopulmonary resuscitation (CPR). Ventricular fibrillation was induced and left untreated for 10 min in 12 male Bama miniature pigs. Defibrillation was attempted after 5 min of CPR. At 5 min following resuscitation, the pigs were randomized and equally assigned into the CCK8 or the control group...
March 2018: Experimental and Therapeutic Medicine
Kota Kasahara, Shun Sakuraba, Ikuo Fukuda
We investigate the problem of artifacts caused by the periodic boundary conditions (PBC) used in molecular simulation studies. Despite the long history of simulations with PBCs, the existence of measurable artifacts originating from PBCs applied to inherently non-periodic physical systems remains controversial. Specifically, these artifacts appear as differences between simulations of the same system but with different simulation-cell sizes. Earlier studies have implied that, even in the simple case of a small model peptide in water, sampling inefficiency is a major obstacle to understanding these artifacts...
February 13, 2018: Journal of Physical Chemistry. B
Jens J Holst, Nicolai J Wewer Albrechtsen, Maria Buur Nordskov Gabe, Mette Marie Rosenkilde
Oxyntomodulin is a product of the glucagon precursor, proglucagon, produced and released from the endocrine L-cells of the gut after enzymatic processing by the precursor prohormone convertase 1/3. It corresponds to the proglucagon sequence 33-69 and thus contains the entire glucagon sequence plus a C-terminal octapeptide, comprising in total 37 amino acids. As might have been expected, it has glucagon-like bioactivity, but also and more surprisingly also activates the receptor for GLP-1. This has given the molecule an interesting status as a glucagon-GLP-1 co-agonist, which is currently attracting considerable interest for its potential in the treatment of diabetes and obesity...
February 2018: Peptides
Wioleta Kowalczyk, Julie Sanchez, Phillipe Kraaz, Oliver E Hutt, David N Haylock, Peter J Duggan
A 54-member library of boronated octapeptides, with all but the boronated residue being proteinogenic, was tested for affinity to a set of saccharides commonly found on the terminus of mammalian glycans. After experimentation with a high-throughput dye-displacement assay, attention was focused on isothermal titration calorimetry as a tool to provide reliable affinity data, including enthalpy and entropy of binding. A small number of boronated peptides showed higher affinity and significant selectivity for N-acetylneuraminic acid over methyl-α-d-galactopyranoside, methyl-α/β-l-fucopyranoside and N-acetyl-d-glucosamine...
January 30, 2018: Biopolymers
Haijiao Zheng, Xiqian Li, Qiong Jia
β-cyclodextrin vesicles (CDVs) were firstly introduced into polymer monolith to prepare pH-responsive adsorption material and used for selective capture-release of a cardiac biomarker, myoglobin (Myo). SH-CDV was decorated with adamantane modified SH-octapeptide to enhance the encapsulation and release rates of Myo. Afterwards, SH-CDV was introduced into polymer monolith via click reaction to produce a pH-responsive monolith. Combining with mass spectrometry detection, the CDV-based pH-responsive monolith was used for selectively enrichment of Myo glycopeptides from mixture of Myo and nonglycoprotein (BSA) tryptsin digests reach up to 1:10000...
January 24, 2018: ACS Applied Materials & Interfaces
Katlyn A Fleming, Mark D Ericson, Katie T Freeman, Danielle N Adank, Mary M Lunzer, Stacey L Wilber, Carrie Haskell-Luevano
The melanocortin system has five receptors and antagonists of the central melanocortin receptors (MC3R, MC4R) are postulated to be viable therapeutics for disorders of negative energy balance such as anorexia, cachexia, and failure to thrive. Agouti-related protein (AGRP) is an antagonist of the MC3R and an antagonist/inverse agonist of the MC4R. Biophysical NMR based structural studies have demonstrated that the active sequence of this hormone, Arg-Phe-Phe, is located on an exposed β-hairpin loop. It has previously been demonstrated that the macrocyclic octapeptide scaffold c[Pro1-Arg2-Phe3-Phe4-Asn5-Ala6-Phe7-DPro8] is 16-fold less potent than AGRP at the mMC4R...
January 24, 2018: ACS Chemical Neuroscience
Subhankar Dolai, Tao Liang, Abrahim I Orabi, Douglas Holmyard, Li Xie, Dafna Greitzer-Antes, Youhou Kang, Huanli Xie, Tanveer A Javed, Patrick P Lam, Deborah C Rubin, Peter Thorn, Herbert Y Gaisano
BACKGROUND & AIMS: Pancreatic acinar cells are polarized epithelial cells that store enzymes required for digestion as inactive zymogens, tightly packed at the cell apex. Stimulation of acinar cells causes the zymogen granules to fuse with the apical membrane, and the cells undergo exocytosis to release proteases into the intestinal lumen. Autophagy maintains homeostasis of pancreatic acini. Syntaxin 2 (STX2), an abundant SNARE protein in pancreatic acini, has been reported to mediate apical exocytosis...
January 19, 2018: Gastroenterology
Robson Augusto Souza Santos, Walkyria Oliveira Sampaio, Andreia C Alzamora, Daisy Motta-Santos, Natalia Alenina, Michael Bader, Maria Jose Campagnole-Santos
The renin-angiotensin system (RAS) is a key player in the control of the cardiovascular system and hydroelectrolyte balance, with an influence on organs and functions throughout the body. The classical view of this system saw it as a sequence of many enzymatic steps that culminate in the production of a single biologically active metabolite, the octapeptide angiotensin (ANG) II, by the angiotensin converting enzyme (ACE). The past two decades have revealed new functions for some of the intermediate products, beyond their roles as substrates along the classical route...
January 1, 2018: Physiological Reviews
Jiqing Xuan, Yuli Chen, Leilei Zhu, Yuan Guo, Liming Deng, Yuanyi Zheng, Zhaoxia Wang, Zhigang Wang, Meng Ao
Hepatic fibrosis is the only chronic liver disease process that can be reversed. Developing non-invasive and effective methods to quantitatively assess the degree of liver fibrosis is of great clinical significance and remains a major challenge. The key factors in hepatic fibrosis pathogenesis are the activation and proliferation of hepatic stellate cells that subsequently express integrin αvβ3. An ultrasound (US) agent combined with a targeting peptide may be used for the early and non-invasive diagnosis of hepatic fibrosis...
December 12, 2017: Oncotarget
Markus M Heimesaat, Eliezer Giladi, Anja A Kühl, Stefan Bereswill, Illana Gozes
The octapeptide NAP has been shown to exert neuroprotective properties and reduce neuro-inflammatory responses. The aim of the present study was to investigate if NAP provides anti-inflammatory effects in acute murine colitis. To address this, C57BL/6 j mice were challenged with 3.5% dextran sulfate sodium from day 0 until day 6 to induce colitis, either treated intraperitoneally with NAP or placebo (NaCl 0.9%) from day 1 until day 6 post-induction (p.i.) and subjected to in depth macroscopic, microscopic and immunological evaluations...
December 27, 2017: Peptides
Malihe Sadeghi, Parham Reisi, Maryam Radahmadi
Objectives: Cholecystokinin (CCK) has been proposed as a mediator in stress. However, it is still not fully documented what are its effects. We aimed to evaluate the effects of systemic administration of CCK exactly before induction of stress on spatial memory and synaptic plasticity at CA1 in rats. Materials and Methods: Male Wistar rats were divided into 4 groups: the control, the control-CCK, the stress and the stress-CCK. Restraint stress was induced 6 hr per day, for 24 days...
December 2017: Iranian Journal of Basic Medical Sciences
Sabina Eigenbrod, Petra Frick, Uwe Bertsch, Gerda Mitteregger-Kretzschmar, Janina Mielke, Marko Maringer, Niklas Piening, Alexander Hepp, Nathalie Daude, Otto Windl, Johannes Levin, Armin Giese, Vignesh Sakthivelu, Jörg Tatzelt, Hans Kretzschmar, David Westaway
Prion diseases have been linked to impaired copper homeostasis and copper induced-oxidative damage to the brain. Divalent metal ions, such as Cu2+ and Zn2+, bind to cellular prion protein (PrPC) at octapeptide repeat (OR) and non-OR sites within the N-terminal half of the protein but information on the impact of such binding on conversion to the misfolded isoform often derives from studies using either OR and non-OR peptides or bacterially-expressed recombinant PrP. Here we created new transgenic mouse lines expressing PrP with disrupted copper binding sites within all four histidine-containing OR's (sites 1-4, H60G, H68G, H76G, H84G, "TetraH>G" allele) or at site 5 (composed of residues His-95 and His-110; "H95G" allele) and monitored the formation of misfolded PrP in vivo...
2017: PloS One
Anthony Fatino, Giovanna Baca, Chamitha Weeramange, Ryan J Rafferty
Reniochalistatin E (1) is one of the five related cyclic peptides isolated from the marine sponge Reniochalina stalagmitis. The discovery of these compounds resulted from a screening program directed toward the identification of proline-rich bioactive compounds. Reniochalistatin E is the only member of the family to possess a tryptophan amino acid residue. Given the cytotoxicity observed for 1, efforts were directed toward developing a synthetic route to 1. The first total synthesis of 1 has been accomplished in a 15-step route in an overall 5...
December 22, 2017: Journal of Natural Products
A Hernandez-Garcia, M A Cohen Stuart, R de Vries
Recombinant triblock polypeptides C-Sn -B, where C is a 400 amino acid long hydrophilic random coil block, Sn is a multimer of the silk-like octapeptide S = (GAGAGAGQ), and B = K12 is an oligolysine, have previously been shown to encapsulate double stranded DNA into rod-shaped, virus-like particles. In order to gain insight of the co-assembly process, and in order to be able to use these proteins for templating other types of nanorods, we here explore their co-assembly with a range of polyanionic templates: poly(acrylic acids) (PAA) of a wide range of lengths, poly(styrene sulphonate) (PSS) and the stiff anionic polysaccharide xanthan...
December 20, 2017: Soft Matter
K A Ayub Nawaz, Swapna Merlin David, Easwaran Murugesh, Murugesan Thandeeswaran, Kalarikkal Gopikrishnan Kiran, Ramasamy Mahendran, Muthusamy Palaniswamy, Jayaraman Angayarkanni
BACKGROUND: Plants are important sources of bioactive peptides. Among these, angiotensin converting enzyme (ACE) inhibitory peptides have a major focus on their ability to prevent hypertension. Inhibition of ACE has been established as an effective approach for the treatment of ACE associated diseases. HYPOTHESIS/PURPOSE: Some synthetic ACE inhibitory drugs cause side effects and hence there is a constant interest in natural compounds as alternatives. STUDY DESIGN: The study was designed to identify and characterize a peptide molecule from pigeon pea which has the biological property to inhibit ACE and can be developed as a therapeutic approach towards hypertension...
December 1, 2017: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"