5-ala nmr

For the first time a hybrid molecularly imprinted polymer (MIP) doped with 3-(trimethoxysilyl) propyl methacrylate (γ-MPS)-modified mesoporous molecular sieve SBA-15 for target peptide recognition has been developed. Zinc acrylate and methacrylic acid were used as binary functional monomers, and ethylene dimethacrylate was used as cross-linking agent to prepare an imprinted monolith against Val-Tyr-Ala-Leu-Lys(glutarylation) (VYALKglu ). The morphology of the polymers was characterized by scanning electron microscopy, FT-IR spectroscopy, energy dispersive spectroscopy, and 1 H NMR...

The concept of peptidomimetics is based on structural modifications of natural peptides that aim not only to mimic their 3D shape and biological function, but also to reduce their limitations. The peptidomimetic approach is used in medicinal chemistry to develop drug-like compounds that are more active and selective than natural peptides and have fewer side effects. One of the synthetic strategies for obtaining peptidomimetics involves mimicking peptide α-helices, β-sheets or turns. Turns are usually located on the protein surface where they interact with various receptors and are therefore involved in numerous biological events...

Fibrin (Fbn) deposits are a hallmark of staphylocoagulase (SC)-positive endocarditis. Binding of the N-terminus of S. aureus SC to host prothrombin (ProT) triggers formation of an active SC·ProT* complex that cleaves host fibrinogen (Fbg) to Fbn. In addition, the C-terminal domain of the prototypical SC contains 1 pseudo-repeat (PR) and 7 repeats (R1→R7) that bind Fbg/Fbn Fragment D (Frag D), by a mechanism that is unclear. Here, we define affinities and stoichiometries of Frag D binding to C-terminal SC constructs, using fluorescence equilibrium binding, NMR titration, Ala scanning and native PAGE...

Fungal species of genus Sepedonium are rich sources of diverse secondary metabolites (e.g., alkaloids, peptaibols), which exhibit variable biological activities. Herein, two new peptaibols, named ampullosporin F ( 1 ) and ampullosporin G ( 2 ), together with five known compounds, ampullosporin A ( 3 ), peptaibolin ( 4 ), chrysosporide ( 5 ), c(Trp-Ser) ( 6 ) and c(Trp-Ala) ( 7 ), have been isolated from the culture of Sepedonium ampullosporum Damon strain KSH534. The structures of 1 and 2 were elucidated based on ESI-HRMSn experiments and intense 1D and 2D NMR analyses...

Background Peripheral artery disease (PAD) and coronary artery disease (CAD) represent atherosclerosis in different vascular beds. We used detailed metabolic biomarker profiling to identify common and discordant biomarkers and clarify pathophysiological differences for these vascular diseases. Methods and Results We used 5 prospective cohorts from Finnish population (FINRISK 1997, 2002, 2007, and 2012, and Health 2000; n=31 657; median follow-up time of 14 years) to estimate associations between >200 metabolic biomarkers and incident PAD and CAD...

In this study, pyrralylisoleucine (Pyrr-Ile) and pyrralylalanine (Pyrr-Ala), two dipeptide-bound pyrralines with different C-termini were synthesized as the representatives of dietary advanced glycation end products (dAGEs). The structures of Pyrr-Ile and Pyrr-Ala were characterized by high-resolution mass spectrometry, nuclear magnetic resonance, and Fourier transform infrared spectroscopy. Then, the transport of Pyrr-Ile and Pyrr-Ala across intestinal epithelial cells was investigated using Caco-2 cell monolayers, and their interaction with aminopeptidase N (APN) was analyzed...

Ascidiacyclamide [cyclo(-Ile1,5 -oxazoline2,6 -d-Val3,7 -thiazole4,8 -)2 ] is a cytotoxic cyclic peptide from ascidian. Through structural analyses using monosubstituted analogues (Xaa1 : Ala, 2-aminobutyric acid, Val, cyclohexylglycine, and phenylglycine), we previously demonstrated the conformational equilibrium between its square and folded forms. As the bulkiness of the Xaa1 residue side chain was reduced, spontaneous folding was promoted, and the cytotoxicity decreased accordingly. In the present study, five disubstituted analogues in which a tert-leucine residue (Tle) was incorporated at the 5-position of the abovementioned monosubstituted analogues were synthesized, after which their structures were analyzed using X-ray diffraction, circular dichroism (CD) spectral measurements, and 1 H NMR-based quantitative analysis...

A simple probe BHN based on naphthol and benzothiazole is reported for detecting of arginine (Arg) and lysine (Lys) with high selectivity and sensitivity. The BHN in aqueous solution upon reacting with Arg or Lys induced a visible color change from colorless to yellow. The probe BHN can also be employed for fluorescence turn-on sensing of Arg and Lys with the limits of detection (LOD) of 5.20 × 10-2 μM and 3.69 × 10-2 μM, respectively. The naked eye colorimetric and fluorimetric detecting is lack of sensitive to other common amino acids including Gly, Ala, Ser, Pro, Val, Thr, Cys, Leu, Ile, Asn, Asp, Glu, Gln, Met, His, and Phe...

The emetic Bacillus cereus toxin cereulide presents an enormous safety hazard in the food industry, inducing emesis and nausea after the consumption of contaminated foods. Additional to cereulide itself, seven structurally related isoforms, namely the isocereulides A-G, have already been elucidated in their chemical structure and could further be identified in B. cereus contaminated food samples. The newly performed isolation of isocereulide A allowed, for the first time, 1D- and 2D-NMR spectroscopy of a biosynthetically produced isocereulide, revealing results that contradict previous assumptions of an l- O -Leu moiety within its chemical structure...

We prepare various amino-acid functionalized silica pores with diameters of ∼6 nm and study the temperature-dependent reorientation dynamics of water in these confinements. Specifically, we link basic Lys, neutral Ala, and acidic Glu to the inner surfaces and combine 2 H nuclear magnetic resonance spin-lattice relaxation and line shape analyses to disentangle the rotational motions of the surfaces groups and the crystalline and liquid water fractions coexisting below partial freezing. Unlike the crystalline phase, the liquid phase shows reorientation dynamics, which strongly depends on the chemistry of the inner surfaces...

ETHNOPHARMACOLOGICAL RELEVANCE: Pulicaria incisa sub. candolleana E. Gamal-Eldin (Asteraceae) was traditionally used by Bedouins as a refreshing tea and as hypoglycemic, in gastrointestinal ailments, sinusitis and headache. Recently a great correlation has been established between liver cirrhosis and gastrointestinal dysfunction reflected by abdominal bloating, pain, diarrhea, constipation, besides decreased food intake. So far, the hepatoprotective effect of P. incisa sub. candolleana E...

Double electron-electron resonance (DEER, also known as PELDOR) and circular dichroism (CD) spectroscopies were explored for the purpose of studying the specificity of the conformation of peptides induced by their assembly into a self-recognizing system. The E and K peptides are known to form a coiled-coil heterodimer. Two paramagnetic TOAC α-amino acid residues were incorporated into each of the peptides (denoted as K** and E**), and a three-dimensional structural investigation in the presence or absence of their unlabeled counterparts E and K was performed...

OBJECTIVE: To conduct a comprehensive analysis of circulating metabolites and incident stroke in large prospective population-based settings. METHODS: We investigated the association of metabolites with risk of stroke in seven prospective cohort studies including 1,791 incident stroke events among 38,797 participants in whom circulating metabolites were measured by Nuclear Magnetic Resonance (1 H-NMR) technology. The relationship between metabolites and stroke was assessed using Cox proportional hazards regression models...

In the present study, nine compounds ( 1 - 9 ) were isolated from Talaromyces wortmannii LGT-4 (an endophytic fungus from Tripterygium wilfordi ) which was cultured in CYM Medium. Their structures were determined as 4-hydroxyphthalide ( 1 ), Fumitremorgin C ( 2 ), Ergosterol ( 3 ), 3-(2-hydroxypropyl)-8-hydroxy-3,4- dihydroisocoumarin ( 4 ), Cis-cyclo( L -Ala- L -Pro) ( 5 ), 6-Amino-3-(4-hydroxybenzyl)- 1,4-diazonane-2,5-dione ( 6 ), Aspergillumarin B ( 7 ), Deacetylisowortmin B ( 8 ), and Entonaemin A ( 9 ) based on NMR spectral data, as well as comparing with previous literature data...

To address biophysical principles and lipid interactions that underlie the properties of membrane proteins, modifications that vary the neighbors of tryptophan residues in the highly dynamic transmembrane helix of GW4,20 ALP23 (acetyl-GGAW4 A(LA)6 LAW20 AGA-amide) were examined using deuterium NMR spectroscopy. It was found that L5,19 GW4,20 ALP23, a sequence isomer of the low to moderately dynamic GW5,19 ALP23, remains highly dynamic. By contrast, a removal of W4 to produce F4,5 GW20 ALP23 restores a low level of dynamic averaging, similar to that of the F4,5 GW19 ALP23 helix...

Solid-state NMR is a powerful analytical technique to determine the composite structure of Bombyx mori silk fibroin (SF). In our previous paper, we proposed a lamellar structure for Ala-Gly copolypeptides as a model of the crystalline fraction in Silk II. In this paper, the structure and dynamics of the crystalline fraction and of a better mimic of the crystalline fraction, (Ala-Gly-Ser-Gly-Ala-Gly)n (n = 2-5, 8), and 13 C selectively labeled [3-13 C]Ala-(AGSGAG)5 in Silk II forms, were studied using structural and dynamical analyses of the Ala Cβ peaks in 13 C cross polarization/ magic angle spinning NMR and 13 C solid-state spin-lattice relaxation time (T1 ) measurements, respectively...

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a common lung disorder characterized by persistent and progressive airflow limitation as well as systemic changes. Metabolic changes in blood may help detect COPD in an earlier stage and predict prognosis. METHODS: We conducted a comprehensive study of circulating metabolites, measured by proton Nuclear Magnetic Resonance Spectroscopy, in relation with COPD and lung function. The discovery sample consisted of 5557 individuals from two large population-based studies in the Netherlands, the Rotterdam Study and the Erasmus Rucphen Family study...

Photodynamic therapy induced by protoporphyrin IX (PpIX) is widely used to treat precancerous skin lesions. The penetration depth of the prodrug 5-aminolevulinic acid (5-ALA) using topical application is currently limited, which hampers the production of PpIX in deep seated lesions. To enhance 5-ALA delivery in deep skin layers, a soluble microneedles patch (MN-patch) containing 5-ALA has been successfully developed by using a fast solvent casting molding method which could be easily up-scaled. The shape, number and height of the needles have been designed according to the medical application and the mechanical strain necessary for skin insertion...

Stable-isotope-labeled probes suitable for magnetic resonance imaging (MRI) would have various potential medical applications, such as tumor imaging. Here, with the aim of developing MRI probes targeting peptide transporters, we synthesized a series of [19 F]dipeptides by introducing one or two fluorine atoms or a trifluoromethyl group into the benzene ring of L-phenylalanyl-ψ[CS-N]-L-alanine (Phe-ψ-Ala), which is resistant to cleavage by peptidases. The mono- and difluoro dipeptides were efficiently transported by PEPT1 and PEPT2...

The CHARMM Drude-2013 polarizable force field (FF) was developed to include the explicit treatment of induced electronic polarizability, resulting in a more accurate description of the electrostatic interactions in molecular dynamics (MD) simulations. While the Drude-2013 protein FF has shown success in improving the folding properties of α-helical peptides and to reproduce experimental observables in simulations up to 1 μs, some limitations were noted regarding the stability of β-sheet structures in simulations longer than 100 ns as well as larger deviations from crystal structures in simulations of a number of proteins compared to the additive CHARMM36 protein FF...