Common Post-translational Modifications (PTMs) of Proteins: Analysis by Up-to-Date Analytical Techniques with an Emphasis on Barley.

Post-translational modifications (PTMs) of biomacromolecules can be useful for understanding the processes by which a relatively small number of individual genes in a particular genome can generate enormous biological complexity in different organisms. The proteomes of barley and the brewing process were investigated by different techniques. However, their diverse and complex PTMs remain understudied.

The Role of ATRA, Natural Ligand of Retinoic Acid Receptors, on EMT-Related Proteins in Breast Cancer: Minireview.

The knowledge of the structure, function, and abundance of specific proteins related to the EMT process is essential for developing effective diagnostic approaches to cancer with the perspective of diagnosis and therapy of malignancies. The success of all- retinoic acid (ATRA) differentiation therapy in acute promyelocytic leukemia has stimulated studies in the treatment of other tumors with ATRA. This review will discuss the impact of ATRA use, emphasizing epithelial-mesenchymal transition (EMT) proteins in breast cancer, of which metastasis and recurrence are major causes of death.

CD44 and vimentin, markers involved with epithelial-mesenchymal transition: A proteomic analysis of sequential proteins extraction of triple-negative breast cancer cells after treatment with all-trans retinoic acid.

This work aimed to provide, in one isolation and separation step, an overview of the content of proteins with different solubility after treatment with all-trans retinoic acid, which is considered to be an important therapeutic agent, predominantly in acute promyelocytic leukemia. Breast, ovarian, bladder, and skin cancers have been demonstrated to be suppressed by retinoic acid, as well. The bottom-up proteomic strategies were applied for the analysis of proteins extracted from triple-negative breast cancer MDA-MB-231 cells utilizing a commercially manufactured kit.

Use of Lectin-based Affinity Techniques in Breast Cancer Glycoproteomics: A Review.

Changes in glycoprotein content, altered glycosylations, and aberrant glycan structures are increasingly recognized as cancer hallmarks. Because breast cancer is one of the most common causes of cancer deaths in the world, it is highly urgent to find other reliable biomarkers for its initial diagnosis and to learn as much as possible about this disease. In this Review, the applications of lectins to a screening of potential breast cancer biomarkers published during recent years are overviewed.

Down-regulation of vimentin by triorganotin isothiocyanates-nuclear retinoid X receptor agonists: A proteomic approach.

An attempt has been made to delineate the role of natural and synthetic retinoid receptor ligands on vimentin expression in the human triple-negative breast cancer cells. The effects of currently synthesized triorganotin derivatives of the general formula RSnX (R is butyl or phenyl, X is isothiocyanate), which are considered RXR ligands, were investigated in the human MDA-MB-231 breast cancer cell line. Studies were evaluated in the presence and absence of all-trans retinoic acid (ATRA), a natural RAR ligand.

Novel insights into the combined effect of triorganotin compounds and all-trans retinoic acid on expression of selected proteins associated with tumor progression in breast cancer cell line MDA-MB-231: Proteomic approach.

Trialkyltins and triaryltins function as nuclear retinoid X receptors (RXR) agonists due to their affinity to the ligand-binding domain of RXR subtypes and function as transcriptional activators. We present the data on combined effects of all-trans retinoic acid (ATRA), retinoic acid receptor (RAR) ligand and tributyltin chloride or triphenyltin chloride (RXR ligands) on protein pattern in MDA-MB-231 cells. Proteomic strategies based on bottom-up method were applied in this study.

Investigation of Permeation of Theophylline through Skin Using Selected Piperazine-2,5-Diones.

Transdermal administration of drugs that penetrate, in this case directly into the blood circulation, has many advantages and is promising for many drugs thanks to its easy application and good patient compliance. ()-8-Methyl-6,9-diazaspiro[4.5]decan-7,10-dione (alaptide), has been studied as a potential chemical permeation enhancer.

Triple resonance ¹⁵Ν NMR relaxation experiments for studies of intrinsically disordered proteins.

Description of protein dynamics is known to be essential in understanding their function. Studies based on a well established [Formula: see text] NMR relaxation methodology have been applied to a large number of systems. However, the low dispersion of [Formula: see text] chemical shifts very often observed within intrinsically disordered proteins complicates utilization of standard 2D HN correlated spectra because a limited number of amino acids can be characterized.

An integrative study to identify novel scaffolds for sphingosine kinase 1 inhibitors.

Sphingosine kinase 1 (SphK1), the enzyme that produces the bioactive sphingolipid metabolite, sphingosine-1-phosphate, is a promising new molecular target for therapeutic intervention in cancer and inflammatory diseases. In view of its importance, the main objective of this work was to find new and more potent inhibitors for this enzyme possessing different structural scaffolds than those of the known inhibitors. Our theoretical and experimental study has allowed us to identify two new structural scaffolds (three new compounds), which could be used as starting structures for the design and then the development of new inhibitors of SphK1.

A comparative study of protein patterns of human estrogen receptor positive (MCF-7) and negative (MDA-MB-231) breast cancer cell lines.

In the present study, we analyzed the cell lysates of human tumour cell lines representing two major clinically different types of breast cancer. Our main goal was to show the differences between them on proteomic level. Gel electrophoresis followed by MALDI-TOF MS analysis was used for proteins determination.

An efficient chemoselective reduction of furan series unsaturated dinitriles.

An efficient reduction of double bonds conjugated with nitrile groups and acid or base sensitive furan rings with 2-phenylbenzimidazoline generated in situ has been successfully accomplished with high yields and excellent selectivity. The employed reducing agent was prepared in one step from ordinary chemicals. The other advantages of the presented method include mild and convenient reaction conditions, a benign and cost effective reagent, simple work-up and separation of the products.

Application of proteomics to hordein screening in the malting process.

This study was undertaken to investigate the effect of the malting process on hordein composition. For this purpose, combination of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and the method of isotopic peptides labeling iTRAQ was used. Barley proteins are essential components determining the quality of both malt and beer.

Rapid and efficient protein enzymatic digestion: an experimental comparison.

The major objective of proteomics is to identify and examine the large numbers of proteins extracted from complex biological systems. This is generally achieved by combining various techniques of protein separation with a mass spectrometric analysis of proteins that are digested enzymatically. Recently, several alternatives to this standard protocol have been developed for efficient and fast protein digestion.

Harmaline-resistant mutant of Methanothermobacter thermautotrophicus with a lesion in Na(+)/H(+) antiport.

A spontaneous mutant of Methanothermobacter thermautotrophicus resistant to the Na(+)/H(+) antiporter inhibitor harmaline was isolated. The Na(+)/H(+) exchange activity in the mutant cells was remarkably decreased in comparison with wild-type cells. Na(+)/H(+) antiport activity of wild-type cells grown in the high Na(+) concentration (125 mmol/l) was significantly increased as compared to the cells grown under low Na(+) concentration (6.

Monitoring of barley starch amylolysis by gravitational field flow fractionation and MALDI-TOF MS.

Background: In barley, starch occurs in the form of granules with bimodal size distribution. Enzymatic hydrolysis of the starch granule is one of the most important reactions occurring during malting and mashing. Previous studies revealed the discrepancies in the assumption that barley varieties with better malting qualities should have a higher A/B (large/small starch granules) ratio.

Early cytokinin response proteins and phosphoproteins of Arabidopsis thaliana identified by proteome and phosphoproteome profiling.

Cytokinins are plant hormones involved in regulation of diverse developmental and physiological processes in plants whose molecular mechanisms of action are being intensely researched. However, most rapid responses to cytokinin signals at the proteomic and phosphoproteomic levels are unknown. Early cytokinin responses were investigated through proteome-wide expression profiling based on image and mass spectrometric analysis of two-dimensionally separated proteins and phosphoproteins.

2D-HPLC and MALDI-TOF/TOF analysis of barley proteins glycated during brewing.

The barley proteins have been the subject of interests of many research groups dealing with barley grains, malt and beer. The proteins which remain intact after harsh malting conditions influence the quality and flavor of beer. The characteristic feature of the proteins present in malt and beer is their extensive modification with carbohydrates, mainly glucose that comes from the starch degradation during technological processes.

Tributyltin-resistant Methanothermobacter thermautotrophicus mutant with mutational substitutions in the A1A0-ATP synthase operon.

A spontaneous mutant of Methanothermobacter thermautotrophicus resistant to tributyltin chloride (TBT) was isolated. TBT, the inhibitor of the A(0) domain of A(1)A(0)-ATP synthase, inhibits methanogenesis in the wild-type cells; however, the TBT-resistant mutant exhibited methanogenesis even in the presence of 800 microM TBT. ATP synthesis driven by methanogenic electron transport was markedly diminished in the mutant strain.

MALDI-TOF mass spectrometry of hordeins: rapid approach for identification of malting barley varieties.

A procedure for identification of malting barley varieties using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of ethanol-soluble barley proteins (hordeins) is described. The hordeins were first extracted from milled barley grains by several extraction protocols (using different extraction agents and conditions). Hordein extracts were then analyzed directly via MALDI-TOF MS without any preliminary purification or separation step, and the protein profiles of analyzed hordein extracts were compared in order to find out the most suitable extraction procedure for mass spectrometric analysis.

Divergent flow isoelectric focusing: fast and efficient method for protein sample preparation for mass spectrometry.

A study of complex protein mixtures obtained from biological samples by MS demands proper purification and separation technique. The method of divergent flow isoelectric focusing (DF IEF) promises improvement of sample preparation in proteomic studies. DF IEF was carried out in a separation channel with increasing width.

Influence of different proteomic protocols on degree of high-coverage identification of nonspecific lipid transfer protein 1 modified during malting.

Both top-down (combining protein separation with MS analysis of intact proteins) and bottom-up (MS analysis of digested proteins) proteomic approaches were used for detailed characterization of nonspecific lipid transfer protein from barley malt. The aim was obtaining high-coverage of the primary structure of the proteins and the determination of PTMs such as lipid adduction and glycation. Here we present an influence of 15 proteomic protocols (differing in applied separation technique, enzyme and digestion procedure) on the extent of the coverage of the protein primary structure.

Proteomic identification of technologically modified proteins in malt by combination of protein fractionation using convective interaction media and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

A method for the fast separation of proteins and identification of their modifications based on the use of monolithic chromatographic media and mass spectrometric techniques is described. This method has been developed and applied to the analysis of malt proteins and its posttranslational modifications (glycation). Glycation, one of the most common forms of posttranslational modifications (PTM), can be detected in both biological and industrial samples.

Activation of the adenylyl cyclase/protein kinase A pathway facilitates neural release of beta-nicotinamide adenine dinucleotide in canine mesenteric artery.

Using high performance liquid chromatography techniques with fluorescence detection we demonstrate that overflow of beta-nicotinamide adenine dinucleotide evoked by electrical field stimulation (16 Hz, 0.3 ms) in the canine isolated mesenteric artery is increased by the activators of adenylyl cyclase (AC) forskolin and calcitonin gene-related peptide (CGRP), by dibutyryl cAMP, and by the inhibitors of phosphodiesterases III and IV milrinone and rolipram. The enhancing effect of forskolin is abolished by the AC inhibitor MDL 12,330A and by protein kinase A (PKA) inhibitors peptide 14-22 amide and 4-cyano-3-methylisoquinoline.

Release of beta-nicotinamide adenine dinucleotide upon stimulation of postganglionic nerve terminals in blood vessels and urinary bladder.

Chemical signaling in autonomic neuromuscular transmission involves agents that function as neurotransmitters and/or neuromodulators. Using high performance liquid chromatography techniques with fluorescence and electrochemical detection we observed that, in addition to ATP and norepinephrine (NE), electrical field stimulation (EFS, 4-16 Hz, 0.1-0.

Membrane-bound and releasable nucleotidase activities: differences in canine mesenteric artery and vein.

1. At least two enzymatic activities are proposed to degrade the extracellular ATP: (i) ubiquitously expressed membrane-bound enzymes (ecto-nucleotidases); and (ii) soluble (releasable) nucleotidases that are released during stimulation of sympathetic nerves and break down neuronal ATP. No quantitative data have placed the magnitude of these nucleotidase activities into a physiological perspective of neurovascular control.