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Synthesis of the Var14 variant of 5'-UTR of GCPII gene as a standard for RT-PCR
Petrovová, Gabriela ; Ingr, Marek (advisor) ; Černá, Věra (referee)
The aim of this work was to prepare the synthetic 5'UTR sequence of splicing variant Var 14 of glutamate carboxypeptidase II (GCPII). A method of two-step PCA was used to this purpose. The sequence was divided into 8 overlapping oligonucleotides that were combined into a single dsDNA by two consecutive PCR. Product of the synthesis was cloned into the auxilliary cloning vector pUC19. After the sequencing analysis detected mutations were corrected. The product was subcloned into the target vector pcDNA4 His Var 14 which already contained the sequence GCPII gene. This construct was then used for the construction of the calibration curve, which will serve as a standard for RT-PCR for quantitative detection of this variant of GCP II in patients with prostate cancer. Construct will be further used as an expression vector to produce of the variants Var 14 GCPII in eucaryotic baculovirus expression system. Keywords: 5'UTR, two-step PCA, pUC19, RT-PCR, GCPII
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Targeting of viral nanoparticles to cancer specific receptors
Žáčková Suchanová, Jiřina ; Španielová, Hana (advisor) ; Němečková, Šárka (referee) ; Ulbrich, Pavel (referee)
The aim of this thesis is to reveal the potential of mouse polyomavirus (MPyV) based virus-like particles (VLPs) as possible nanocarriers for directed delivery of therapeutic or diagnostic compounds to specific cells or tissues. We have chosen mouse polyomavirus VLPs because they do not contain viral DNA and are considered safe for utilization in bio-applications. In our research, we used a chemical approach for retargeting of MPyV based VLPs from their natural receptor to cancer cells. The chemical modification of the capsid surface exposed lysines by an aldehyde-containing reagent enabled conjugation of VLPs to selected molecules: transferrin and inhibitor of glutamate carboxypeptidase II (GCPII). Transferrin, as a transporter of iron to metabolically active cells, targeted VLPs to numerous types of cancer cells overexpressing the transferrin receptor. On the other hand, GCPII serves as a transmembrane marker specific for prostate cancer cells and conjugation of its inhibitor to VLPs resulted in successful recognition of these cells. Electron microscopy was used for visualization of modified VLPs and flow cytometry together with confocal microscopy for investigation of cell specific interactions and VLP uptake. Furthermore, we explored the influence of serum proteins on VLPs. The abundance of...
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Mass Spectrometry-Based Identification of a Potential Binding Partner of Glutamate Carboxypetidase II
Tužil, Jan ; Konvalinka, Jan (advisor) ; Novák, Petr (referee)
English Abstract The incoming paradigm of the network (or systems) biology calls for a new high throughput tool for a wide scale study of protein-protein interactions. Mass spectrometry-based proteomics have experienced a great progress in recent years and have become an indispensable technology of elementary as well as clinical research. Glutamate carboxypeptidase II (GCPII; EC 3.5.17.21) is a transmembrane protein with two known enzymatic activities. Its expression is highly upregulated in some solid tumors and also in tumor-associated neovasculature in general. Nevertheless, none of the two enzymatic activities were shown to be physiologically relevant to these cells. Some facts point at a possible receptor function of GCPII, however, no specific binding partner has been found yet. In the search for potential binding partners and/or ligands of GCPII, a series of methods have been employed, including pull-down experiment, immunoprecipitation and mass spectrometry. Sample preparation and mass spectrometry data processing methodology was specifically developed in order to identify potential binding partners. As one of the outcome of that methodology, the interaction of β-subunit of F1 ATP synthase was selected for further detailed analysis as a putative ligand of GCPII.
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Zinc-Dependent Hydrolases: Structure-Function Study of Glutamate Carboxypeptidase II and Histone Deacetylase 6
Škultétyová, Ľubica ; Bařinka, Cyril (advisor) ; Obšil, Tomáš (referee) ; Novák, Petr (referee)
Zinc-binding proteins represent approximately one tenth of the proteome and a good portion of them are zinc-dependent hydrolases. This thesis focuses on biochemical and structural characterization of glutamate carboxypeptidase II (GCPII) and histone deacetylase 6 (HDAC6), two members of the zinc-dependent metallohydrolase superfamily. We describe here their interactions with natural substrates and inhibitors. GCPII is a homodimeric membrane protease catalyzing hydrolytic cleavage of glutamate from the neurotransmitter N-acetylaspartylglutamate (NAAG) and dietary folates in the central and peripheral nervous systems and small intestine, respectively. This enzyme is associated with several neurological disorders and also presents an ideal target for imaging and treatment of prostate cancer. GCPII inhibitors typically consist of a zinc-binding group (ZBG) linked to an S1' docking moiety (a glutamate moiety or its isostere). As such, these compounds are highly hydrophilic molecules therefore unable to cross the blood-brain barrier and this hampers targeting GCPII to the central nervous system. Different approaches are adopted to alter the S1' docking moiety of the existing inhibitors. As a part of this thesis, we present different strategies relying on replacement of the canonical P1' glutamate residue...
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Preparation, expression and characterization of mouse GCPIII
Bäumlová, Adriana ; Konvalinka, Jan (advisor) ; Šebo, Peter (referee)
English abstract Glutamate carboxypeptidase II (GCPII, EC 3.4.17.21) is a type II transmembrane glycoprotein which has been discovered in nervous system as an enzyme responsible for the hydrolysis of neuropeptide N-acetyl-L-aspartyl-L-glutamate to N-acetyl-L-aspartate and L-glutamate and that has been hypothesized to influence glutamatergic signaling processes. Except for brain, GCPII was mainly found in prostate, kidney, and small intestine. In small intestine, GCPII cleaves terminal glutamates from polyglutamylated folates facilitating thus absorption of dietary folates. In prostate, this enzyme is known as prostate-specific membrane antigen and is used as a cancer marker. Mus musculus is an important model for studing GCPII and its homologs as a therapeutic target. While human GCPII and its paralog GCPIII are relatively well characterized, no biochemical study of their mouse orthologs is available. That is why mouse glutamate carboxypeptidase III (mGCPIII) was cloned, prepared by recombinant expression in insect cells and characterized. We show that pure mouse GCPIII possesses α-glutamate carboxypeptidase activity which is effectively inhibited by specific inhibitor GCPII, 2-PMPA. We also analyzed sensitivity and specifity of monoclonal antibodies against mouse GCPIII. Immunoblots demonstrate that...
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Příprava a charakterisace rekombinantního dermcidinu jako potenciálního proteinového partnera glutamátkarboxypeptidasy II
Tužil, Jan ; Konvalinka, Jan (advisor) ; Pavlíček, Jiří (referee)
A process of forming new blood vessels is necessary for tumour viability and expansion. Without vasculature, tumour stops growing at a size of millimeters. Some tumours, however, undergo an angiogenic switch and start to build up their own vascular architecture. The rate of apoptosis then decreases and the tumour becomes invasive. There are many factors that control the process of physiological angiogenesis. These might or might not relate to tumour tissue as well. Glutamate carboxypeptidase II (GCPII; EC 3.4.17.21) is a type II transmembrane glycoprotein with two known enzymatic activities. GCPII expression is upregulated in prostate cancer and also highly expressed in tumour-associated neovasculature even though none of these enzymatic functions was observed on the endothelium. Although numerous researches suggested that GCPII might serve as a receptor, no natural ligand has been identified yet. Preliminary experiments performed in our laboratory indicated some proteins to be possible natural ligands of GCPII. Therefore, we chose one of them- dermcidin, cloned and expressed this protein in mammalian cells. We investigated its possible interaction with GCPII introducing new detection system utilizing FLAG-tag however, we were not able to approve neither disapprove its interaction in vitro.
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Physiological and pathophysiological role of GCPII in the body
Sedlák, František ; Konvalinka, Jan (advisor) ; Klener, Pavel (referee) ; Smetana, Karel (referee)
Glutamate carboxypeptidase II (GCPII) is a metalloprotease responsible for cleaving the neurotransmitter N-acetyl-aspartyl-glutamate in the central nervous system to N-acetyl aspartate and glutamate. At the same time, in the human small intestine, it facilitates folate absorption by cleaving γ-linked glutamate from folyl-poly-γ-glutamate. In humans, GCPII is also expressed in a number of other organs (e.g., kidney and prostate) and tumors, where its physiological function is unknown. In an attempt to characterize the physiological function of the enzyme, we first characterized the commercially available monoclonal antibodies against GCPII. Further, we developed a fully synthetic replacement based on a hydrophilic polymer with bound GCPII inhibitors. We evaluated the suitability of using a murine biomodel to study GCPII function in vivo. We found the difference in GCPII expression profile in mouse and human. We did not observe GCPII in either the mouse prostate or small intestine. To assess physiological and pathophysiological functions of the enzyme we analyzed a GCPII-deficient mouse model. Apart from the observation of enlarged seminal vesicles in older males, we did not detect any other obvious phenotype. Similarly, we confirmed that GCPII cannot cleave amyloid peptides (Aβ1-40 and Aβ1-42)....
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Targeting of viral nanoparticles to cancer specific receptors
Žáčková Suchanová, Jiřina
The aim of this thesis is to reveal the potential of mouse polyomavirus (MPyV) based virus-like particles (VLPs) as possible nanocarriers for directed delivery of therapeutic or diagnostic compounds to specific cells or tissues. We have chosen mouse polyomavirus VLPs because they do not contain viral DNA and are considered safe for utilization in bio-applications. In our research, we used a chemical approach for retargeting of MPyV based VLPs from their natural receptor to cancer cells. The chemical modification of the capsid surface exposed lysines by an aldehyde-containing reagent enabled conjugation of VLPs to selected molecules: transferrin and inhibitor of glutamate carboxypeptidase II (GCPII). Transferrin, as a transporter of iron to metabolically active cells, targeted VLPs to numerous types of cancer cells overexpressing the transferrin receptor. On the other hand, GCPII serves as a transmembrane marker specific for prostate cancer cells and conjugation of its inhibitor to VLPs resulted in successful recognition of these cells. Electron microscopy was used for visualization of modified VLPs and flow cytometry together with confocal microscopy for investigation of cell specific interactions and VLP uptake. Furthermore, we explored the influence of serum proteins on VLPs. The abundance of...
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Zinc-Dependent Hydrolases: Structure-Function Study of Glutamate Carboxypeptidase II and Histone Deacetylase 6
Škultétyová, Ľubica
Zinc-binding proteins represent approximately one tenth of the proteome and a good portion of them are zinc-dependent hydrolases. This thesis focuses on biochemical and structural characterization of glutamate carboxypeptidase II (GCPII) and histone deacetylase 6 (HDAC6), two members of the zinc-dependent metallohydrolase superfamily. We describe here their interactions with natural substrates and inhibitors. GCPII is a homodimeric membrane protease catalyzing hydrolytic cleavage of glutamate from the neurotransmitter N-acetylaspartylglutamate (NAAG) and dietary folates in the central and peripheral nervous systems and small intestine, respectively. This enzyme is associated with several neurological disorders and also presents an ideal target for imaging and treatment of prostate cancer. GCPII inhibitors typically consist of a zinc-binding group (ZBG) linked to an S1' docking moiety (a glutamate moiety or its isostere). As such, these compounds are highly hydrophilic molecules therefore unable to cross the blood-brain barrier and this hampers targeting GCPII to the central nervous system. Different approaches are adopted to alter the S1' docking moiety of the existing inhibitors. As a part of this thesis, we present different strategies relying on replacement of the canonical P1' glutamate residue...
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Protein engineering as a tool for the production of antibody derivatives
Šulc, Josef ; Bařinka, Cyril (advisor) ; Mikulecký, Pavel (referee)
This thesis deals with production and properties of disulfide-stabilized single-chain variable fragments of the 5D3 antibody (dsscFv), which specifically recognizes and binds to glutamate carboxypeptidase II (GCPII), an antigen closely related to the prostate carcinoma processes and other tumor diseases. Small antibody fragments are in current focus of development of diagnostic and therapeutic reagents. However, compromised stability of antibody derivatives often results in low production yield or loss of function. Introduction of structural changes by protein engineering is often used to solve the issue. The aim of the study was based on enhancement of protein stability by the introduction of interdomain disulfide bond into the structure of single-chain variable fragment. The effect of modification was evaluated by estimation of production yield and affinity of studied protein. The aforementioned antibody derivative was produced using an Escherichia coli expression system, using specific signal sequences leading the production to the bacterial periplasm. The attempted stabilization was carried out by introducing mutations at LV-G44 and HV-G100 positions, replacing glycines with cysteines. The binding affinity of the derivative for human GCPII was determined using ELISA. This thesis also shows a solved 3D...
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