National Repository of Grey Literature 113 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Production and characterization of protein isolates from different kinds of bran
Vybíral, Lukáš ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis deals with the use of various types of bran as a by-product in the milling of cereals. Mills create a huge amount of this material per year. The most common way of processing bran is mostly incineration and to a lesser extent it is used as feed for livestock. Depending on the type of cereal, bran contains 10-20% of protein, which disappears from the food chain due to combustion. Within the framework of sustainability and valorisation of waste, which has recently been largely discussed, great emphasis is placed on waste minimization whether in the field of its production or further processing. Due to the relatively high protein content, bran appears to be a suitable starting material to produce protein supplements. Proteins can be extracted from bran based on their different solubility at different pH. In the alkaline method, the proteins are first dissolved in an alkaline pH and then precipitated in an acidic medium. Lyophilization is followed by characterization of the extract in terms of yield, protein content, moisture, amino acid profile and digestibility. The highest yield was obtained with the oat bran isolate (13,5 ± 0,6 g of isolate per 100 g of bran). In terms of protein content, the best protein isolate was also obtained from oat bran (95,2 ± 0,4% protein in the isolate). Another determination was the analysis of the amino acid profile, in which a high content of arginine was found in all analyzed protein isolates from bran. Determination of digestibility showed very good digestibility of all produced protein extracts from bran.
Isolation of pure aminoacids from wheat bran
Sloupová, Klára ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
Wheat bran is a promising material containing a wide range of useful components, including proteins. In addition, it is produced in significant volumes. Currently, wheat bran is used for the production of energy by combustion and for feed purposes. Gradually, new methods of valorization of this material are being sought. One of the possibilities of using wheat bran is the isolation of proteins, hydrolysis, and separation of selected amino acids. This diploma thesis deals with this issue, it is focused on the recovery of arginine and leucine from a protein isolate. Proteins were extracted from wheat bran by changing the pH. Thanks to the subsequent lyophilization a protein isolate was gained. Prior to hydrolysis of the resulting isolate, a stability test of arginine and leucine amino acid standards was first performed, to which various hydrolysis methods were applied. Acid hydrolysis using a mineralizer, which was applied to the protein isolate, was proved to be the most effective. This was followed by the derivatization of the hydrolysates with OPA and analysis of the resulting hydrolysates by high-performance liquid chromatography with UV-VIS detection. Then, suitable adsorption and desorption conditions were optimized. It was found that the time dependence does not affect the amount of adsorbed material on the sorbent. Therefore, an application time of 15 minutes was chosen. While optimizing the amount of used standard, it was found that the optimal weight was 0.25 g of sorbent. The selected conditions were applied to the protein hydrolyzate. Two fractions were obtained by the separation of selected amino acids due to the change in the pH of the citrate buffer. After the application of this procedure, 0.26 g of arginine and 0.82 g of leucine were obtained from one kilogram after evaporation. From evaporation two, 1.01 g of arginine and 0.25 g of leucine were obtained after evaporation.
Study of interactions of the surfactant component of Septonex with selected proteins
Bohunská, Miroslava ; Pekař, Miloslav (referee) ; Krouská, Jitka (advisor)
The study of protein and surfactant interactions is of great significance in a number of applications, such as the cosmetic, food or pharmaceutical industries and many others. However, they require further study due to their compositional complexity and the limitations of current analytical approaches. In this thesis, the cationic surfactant septonex in combination with two differently charged proteins lysozyme and bovine serum albumin under different physiological conditions (temperature, surfactant concentration, environment and others) was selected to study the interactions. Characterization of protein-surfactant interactions is a very important but challenging task, therefore it is essential to use appropriate approaches to explore the nature of these interactions. In order to unify the information to provide rational models, calorimetric methods (DSC, ITC) and dynamic light scattering were used. Isothermal titration calorimetry monitors the evidence for the formation of the system of the mentioned substances and information on aggregation behavior, differential scanning calorimetry characterizes the thermal stability of proteins and dynamic light scattering made it possible to monitor changes in particle size. Both proteins have been proven to interact with positive septonex, even if the lysozyme molecule is also positively charged. However, significant differences were found between the two proteins. From the obtained results it is evident that the identical charge of the protein with the surfactant has an effect on the intensity of the measurement, although all measured interactions showed an endothermic character.
Fitness center clients nutrition focused on protein and magnesium intake
Pajič, Barbora ; Vilikus, Zdeněk (advisor) ; Petráková Doležalová, Radka (referee)
The diploma thesis deals with the importance of protein and magnesium in the diet of recreational visitors to fitness centers. Excessive protein intake at the expense of other macronutrients is a very common phenomenon in the fitness sector. Magnesium is an important element for muscle regeneration and its deficiency can have a negative effect on weight reduction and muscle gain, leading to fatigue and cramps, which many athletes encounter. As visits to the fitness center become more and more popular nowadays, it is important that athletes are not subject to misleading and confusing information from the internet and look for proven sources. The aim of the diploma thesis was to compare eating habits, especially protein and magnesium intake, in two groups of people divided according to the frequency of training in the fitness center. This work is divided into theoretical and practical part. The theoretical part deals with nutrition in the fitness industry in general, but more attention is focused on proteins and magnesium. Quantitative research using a questionnaire survey was chosen for the practical part of the work. A total of 30 respondents participated in the research, divided into two groups - athletes and non-athletes. Non-athletes were considered to be those who have two or fewer workouts per...
Protein radical footprinting as a tool for protein therapeutcs validation.
Binar, Michal ; Novák, Petr (advisor) ; Ječmen, Tomáš (referee)
Mass spectrometry techniques are very important and useful tool in studying of protein structure. One of these techniques is the covalent labeling of proteins. The covalent labeling can be used for determination of the accessibility of protein surface and their dynamics in general. Although a lot of reagents have already been developer for this method, most of them are limited by their ability to selectively react with only some of amino acids, mostly lysine, arginine or tyrosine, and non-selective methods such as fast photochemical oxidation of proteins are very demanding and costly. Therefore, there is still a endeavor to develop new methods of covalent labeling. This new method could be trifluoromethylation, which is increasingly used in the modification of organic molecules, and whose potential we have decided to study. In this work we used a new group of formally electrophilic agents, which is formed on the basis of a cyclic hypervalent iodide nucleus. This group so-called Togni reagents was used as a tool for radical protein labeling. Since the structure was well characterized by X-ray, NMR and MS, the human carbonic anhydrase has been selected as a model protein. The modified protein was analyzed by a bottom up approach using a combination of liquid chromatography and high resolution tandem...
Modeling interactions of proteins with ions and membranes
Kadlec, Jan ; Jungwirth, Pavel (advisor) ; Kolafa, Jiří (referee)
The protein recoverin, localized in the eye in the rod outer segment of the retina, is a neuronal calcium sensor involved in vision adaptation. Recoverin reversibly associates with cellular membranes via its calcium-activated myristoyl switch. This reversible interaction is vastly dependent on the concentration of calcium ions in the cytosol and on conformation of recoverin. By using methods of molecular dynamics simulations and free energy calculations this work presents a detailed analysis of the energetics of myristoyl insertion into a lipid bilayer and interactions of non-myristoylated recoverin with the membrane. These results are in a perfect agreement with experimental data. The thesis provides a piece of puzzle to the so far unexplored mechanism of myristamide insertion into the membrane and also to recoverin conformational change. It gives an important insight into binding of recoverin to a membrane, which has a significant biological role.
Analysis of proteins and their changes in biological tissues
Rudl Kulhavá, Lucie
(EN) Proteins are the important biologically active substances for the organism, their qualitative and quantitative composition determines thein function in the organism. Protein analysis in biological material is an important part of biological and medical research. This dissertation is focused on the optimalization of sample preparation - the biological materials - namely the pre-analytical phase of sample processing and their preparation for their own analases and also introducing new procedures in theie praparation. The conditions of individual analysis approaches were always optimized by means of one- dimensional and two-dimensional gel electrophoresis and mass spectrometry. The obtained results were statistically evaluated and other possible approaches to futher research were outlined. The main biological material studied was human saliva with regard to oral health. Comparative study of human saliva was performed (human saliva obtained from caries-free and caries-susceptible people). The saliva composition of individual fractions was investigated with regard to oral health. The study was carried out to compare differences in the abundances of proteins in the saliva of caries-free and caries-susceptible persons, based on label-free mass spectrometry quantification, and to perform a gender...
Synthesis and delivery of novel fluorescently-labelled nucleotides and their nucleic acids for bio-analytical applications
Güixens Gallardo, Pedro ; Hocek, Michal (advisor) ; Zimčík, Petr (referee) ; Klán, Petr (referee)
1 Abstract The goals of the thesis were to synthesise novel fluorescently labelled nucleotides and the corresponding nucleic acids for bio-analytical applications as well as their delivery into cells. The thesis also aimed at the development of an effective method to inhibit non-templated incorporation of nucleotides. The problematic non-templated enzymatic incorporation of nucleotides is addressed by using several commercially available 5'-modified-oligonucleotides. The oligonucleotides (ONs) that we tested bore ortho twisted intercalating nucleic acid (oTINA), a trityl group, or biotin at the 5'-end. The modified ONs were used as templates in the enzymatic primer extension (PEX) experiments in the presence of either modified nucleotides or only natural deoxynucleoside triphosphates (dNTPs). The oTINA templates underwent PEX reaction using natural dNTPs and different DNA polymerases of the A or B family. In parallel, two types of fluorescent nucleoside derivatives were independently designed and synthesised. Firstly, we envisaged new fluorescent nucleotide tags containing the hexamethylated BODIPY moiety as a bright fluorescent label. Conversely, we focused on the improvement of fluorescent nucleotide probes sensitive to the viscosity or polarity. The fluorescently labelled methylated BODIPY nucleotides...
Analysis of proteins and their changes in biological tissues
Rudl Kulhavá, Lucie
(EN) Proteins are the important biologically active substances for the organism, their qualitative and quantitative composition determines thein function in the organism. Protein analysis in biological material is an important part of biological and medical research. This dissertation is focused on the optimalization of sample preparation - the biological materials - namely the pre-analytical phase of sample processing and their preparation for their own analases and also introducing new procedures in theie praparation. The conditions of individual analysis approaches were always optimized by means of one- dimensional and two-dimensional gel electrophoresis and mass spectrometry. The obtained results were statistically evaluated and other possible approaches to futher research were outlined. The main biological material studied was human saliva with regard to oral health. Comparative study of human saliva was performed (human saliva obtained from caries-free and caries-susceptible people). The saliva composition of individual fractions was investigated with regard to oral health. The study was carried out to compare differences in the abundances of proteins in the saliva of caries-free and caries-susceptible persons, based on label-free mass spectrometry quantification, and to perform a gender...

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