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Barley Proteomic Studies Related to Beer Production
Benkovská, Dagmar ; Márová, Ivana (referee) ; Ehrenbergerová, Jaroslava (referee) ; Zdráhal, Zbyněk (referee) ; Bobáľová, Janette (advisor)
Tato práce se zabývá proteomickými studiemi ječmene v souvislosti s výrobou piva. Ječmen patří mezi nejvýznamnější plodiny na světě a je využíván hlavně pro sladovnické účely, nejčastěji pro pivovarnictví. Studium proteinů ječmene během sladování a výroby piva poskytuje informace o změnách v proteinovém složení nebo jejich posttranslačních modifikacích. Jelikož jsou proteiny v ječmeni a jejich změny zásadní pro kvalitu sladu a piva, proteomické studie ječmene mají potenciál pro zlepšení procesu sladování a pivovarnictví. Hlavním cílem této práce je studium ve vodě rozpustných proteinů ječmene a jejich změn, ke kterým dochází během sladování a výroby piva. Rozdíly v proteinovém složení byly sledovány pomocí gelové elektroforézy, kapalinové chromatografie na reverzní fázi, gelové chromatografie a MALDI-TOF hmotnostní spektrometrie. Během sladování se vlivem klíčení zrna zvyšuje množství některých proteinů a také jsou tvořeny nové proteiny. V průběhu vaření piva se naopak v důsledku vysoké teploty a enzymatické aktivity proteáz mnoho proteinů rozkládá. Těmto drsným podmínkám odolají jen některé proteiny, které přechází až do piva a mohou ovlivnit jeho kvalitu. Dále byly zkoumány různé odrůdy ječmene a jejich rozdíly. Byly porovnány odrůdy povolené pro výrobu certifikovaného Českého piva s jednou osvědčenou sladovnickou odrůdou a jednou nesladovnickou odrůdou ječmene. Kromě toho byly studovány v alkoholu rozpustné proteiny ječmene a jejich změny v průběhu sladování. Zvláštní pozornost byla věnována vybrané skupině posttranslačních modifikací proteinů: glykosylacím. Neenzymaticky glykosylované proteiny ječmene (neboli glykované proteiny) jsou tvořeny v průběhu sladování kvůli přítomnosti velkého množství glukózy uvolněné z rozkladu škrobu. Glykované proteiny ovlivňují stabilitu proteinů a kvalitu piva, obzvlášť pěnotvorný účinek. Enzymatické N-glykosylace představují nejčastěji studované posttranslační modifikace u rostlin, protože glykoproteiny hrají klíčovou roli v různých biologických funkcích. Glykoproteiny jsou často přítomny v malém množství, a proto je pro jejich analýzu potřebné obohacení glykoproteinů z komplexní směsi. Pro studium glykoproteinů byla využita afinitní chromatografie s lektinem concanavalin A. Kromě toho byla také optimalizována analýza sacharidové části glykoproteinů. Tato disertační práce přináší důležité informace o proteinech ječmene, jejich změnách a analýze, které budou užitečné pro další studium.
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Role of glycosylation of ionotropic glutamate receptors in mammalian neurons
Danačíková, Šárka ; Horák, Martin (advisor) ; Kriška, Ján (referee)
Glutamate is the most abundant excitatory neurotransmitter in the mammalian central nervous system. There are two distinct types of glutamate receptors, ionotropic and metabotropic, present in the mammalian excitatory synapses. My thesis is focused on the ionotropic glutamate receptors, which play critical roles in learning and memory formation. The main subtypes of ionotropic glutamate receptors are α-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA) and kainate receptors. All types of the ionotropic glutamate receptors, which are assembled as tetramers, contain many glycosylation sites, which can be modified by glycans or monosaccharides. The glycans and monosaccharides attached to the ionotropic glutamate receptors have been shown to regulate key processes such as folding of the subunits, transport to the cell surface as well as their functional properties. Recent literature also suggests that many neurological and psychiatric disorders such as schizophrenia exhibit abnormal glycosylation of ionotropic glutamate receptors. Thus, understanding of the molecular mechanisms, which regulate the glycosylation of the ionotropic glutamate receptors, may be important for developing new therapies for the patients with altered functioning of the glutamatergic synapses in the...
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Effect of elution solution on the enrichment and purification of glycopeptides using SPE-HILIC
Chobotová, Michaela ; Kozlík, Petr (advisor) ; Křížek, Tomáš (referee)
Changes in protein glycosylation are related to various diseases such as cancer or Alzheimer's disease. Unfortunately, the analysis of glycoproteins remains a difficult task due to the low proportion of glycopeptides compared to peptides obtained after glycoprotein cleavage. As a result, it is almost impossible to analyze glycopeptides without specific enrichment steps. A suitable method for the enrichment of glycopeptides is solid phase extraction (SPE) using the principle of hydrophilic interaction liquid chromatography (HILIC). Since the choice of solvent significantly affects the enrichment of glycopeptides, the aim of this thesis was to compare the effect of different solvents on the efficiency of glycopeptide extraction using SPE-HILIC. The extraction was carried out on a silica column modified with aminopropyl groups. Model analytes were glycopeptides obtained by tryptic digestion of human IgG. During the comparsion of acetonitrile, methanol and isopropanol, acetonitrile was chosen as a suitable elution solvent. During the conditioning and washing step, the content of acetonitrile was changed (65%, 75% and 85%), whereby the elution of glycopeptides is accelerated as the amount of acetonitrile decreases. In the elution step, the effectiveness of different acetonitrile contents (5%, 10% and...
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Glycoprotein profile of human ejaculate as a marker of its quality
Pavlová, Hana ; Postlerová, Pavla (advisor) ; Krejčová, Tereza (referee)
Glycoproteins are an indispensable component of the sperm glycocalyx. They arise through the process of co-translational or post-translational modification, so-called glycosylation, during which carbohydrate chains are attached to a peptide chain. Glycoproteins are involved in reproductive processes and their presence is often key to successful fertilization. The degree of glycosylation of glycoproteins is highly variable and is determined by the representation of carbohydrate units in glycans. It has already been found that the degree of glycosylation can be related to the fertility of an individual. The diploma thesis is focused on the comparison of the representation of terminal saccharides, sialic acid and fucose, in the glycoproteins of sperm and seminal plasma of patients with normal and abnormal ejaculate parameters. The total rate of sialylation and fucosylation in the seminal plasma was determined, as well as the rate of sialylation and fucosylation of specifically detected glycoproteins of sperm and seminal plasma. A significant difference was noted only in the detection of total fucosylation of seminal plasma glycoproteins. However, subsequent correlation tests revealed important relationship between the degree of sialylation and fucosylation of glycoproteins and ejaculate parameters,...
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Salivary glycoproteins of bloodsucking arthropods
Sumová, Petra ; Volf, Petr (advisor) ; Mikeš, Libor (referee)
During obtaining their blood meal, bloodsucking arthropods salivate into their host. Bloodsucking arthropods' saliva contains wide array of bioactive macromolecules. Host organism develops antibody response against many of these molecules. Due to interspecies variability in salivary protein composition, detection of antibody response may serve as a marker of the exposure to individual species of bloodsucking arthropods. Host antibody response is mostly elicited by proteins or glycoproteins. Glycoproteins contain one or more oligosaccharide chains attached to the protein. Glycoprotein's antigenicity could be caused by either both parts, or by only the protein, or the sugar part. This fact has to be taken into consideration for choice of the expression system for recombinant glycoprotein synthesis. This work summarizes current knowledge about structure, function and features of salivary glycoproteins in various species of bloodsucking arthropods.
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Characterization of transgenic forms of dipeptidylpeptidase IV expressed in astrocytoma cell line U373MG
Vomelová, Ivana ; Bezouška, Karel (advisor) ; Vaníčková, Zdislava (referee)
Dipeptidyl peptidase IV (DPP-IV) is a serine protease, which executes its proteolytic activity by cleaving X-Pro dipeptides from the N-termini of its substrates. Furthermore, DPP-IV exhibits many biological functions independent of its enzymatic aktivity. Previous studies in our laboratory proved increased expression of DPP-IV in high-grade astrocytic tumours. To evaluate the enzymatic and non-enzymatic functions of DPP-IV in a glioma model, clones of asctrocytic cell line U373MG transfected by enzymatically inactive, mutated DPP-IV (mutDPP-IV) and enzymatically active, wild type DPP-IV (wtDPP-IV), were prepared. Enzymatically inactive mutDPP-IV was prepared using point mutation the active site serine residue. Cells U373MG were transfected using a doxycycline inducible Tet-On® system. For further analysis of the transgenic forms of DPP-IV, methods were used for verification of protein expression, enzymatic activity and subcellular localization. Doxycycline induced U373MG mutDPP-IV and U373MG wtDPP-IV cells, expressing mutated and wild type DPP-IV, respectivelly, exhibited increased expression of transgenic DPP-IV in a concentration and time dependent manner. Doxycycline induced U373MG wtDPP-IV cells exhibited both increased expression and enzymatic activity of DPP-IV. In contrast, DPP-IV enzymatic...
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Investigation of the molecular mechanisms of elimination of clinically relevant tumors by killer cells of the immune system.
Libigerová, Martina ; Bezouška, Karel (advisor) ; Bosáková, Zuzana (referee)
Carbohydrates have an essentials role in wide range of biological phenomena. It is well known that most of the eukaryotic proteins are glycosylated and that their glycosylation undergoes dynamic changes, nevertheless the biological imperative for these modifications is still not fully understood. However, one area in which the importace of cell surface glycosylation has recently been the subject of active investigations is the tumor plasma membrane biology, where many changes in glycosylation have been found useful for diagnosis, and mostly recent, even for the therapies of malignant disease. Interestingly cell surface glycoconjugates, namely N-linked and O-linked oligosaccharides have been found therapeutically attractive for treatment of certain tumors. And although our understanding of the participation of these principal glycan classes in tumorigenesis is far from complete, there are already several examples of carbohydrate-based antitumor vaccines. Therefore, we decided to give this issue more attention, especially the molecular mechanisms responsible for identifying changes in glycosylation of the surface of tumor cells of the immune system. Although in the past in our laboratory identified a receptor-type lectin specific lectin receptors on natural killer cells, very little is yet known...
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Characterization of hapt oglobin glycoforms in human serum
Darebná, Petra ; Pompach, Petr (advisor) ; Ptáčková, Renata (referee)
Characterization of haptoglobin glycoforms in human serum Petra Darebná (Katedra biochemie, Přírodovědecká fakulta, Univerzita Karlova v Praze, Česká republika) Changes in glycosylation of proteins are associated with several types of cancer, including hepatocelular carcinoma and colorectal carcinoma. This project deals with data independent analysis using ion cyclotron resonance with Fourier transform and tandem mass spectrometry with liquid chromatogramy and multiple reaction monitoring to quantify these changes in hepatocelular cancinoma and colorectal carcinoma with liver metastases. In the first part of the project the haptoglobin was enriched from pooled serum samples of pacients with hepatocellular carcinoma, colorectal cancer and colorectal carcinoma with metastases using hemoglobin immobilized on CNBr-activated Sepharose 4B and then purified by high pressure liquid chromatography. Individual haptoglobin glycopeptides were analyzed using ion cyclotron resonance with Fourier transform. In the second part of the project we analyzed changes in glycosylation depending on diferent tumor diseases in partially depleted serum of individual patients using ethanol precipitation. Individual fucosylated glycoforms of N-glycopeptides of serum proteins were compared with their nonfucosylated forms. In...
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