Research Simon Scharpe

Abstract

this research project studies proline selective peptidases. It has the following aims : 1. Characterization of inhibitors and selection of potent and specific inhibitors of DPP4 related enzymes DPP8, DPP9 and FAP. 2. Study of the expression of the DPPP mambers in endothelia of different origin and this under normoxia as well as hypoxia. 3. In vitro study of the effect of selective ans not selective inhibition on endothelial cell activation. 4. The in vitro study of the effect of selective and non-selective DPP inhibition on collagen metabolism of fibroblasts.

Researcher(s)

• Promoter: De Meester Ingrid
• Co-promoter: Lambeir Anne-Marie
• Co-promoter: Scharpe Simon

Research team(s)

• Medical Biochemistry

Project type(s)

• Research Project

Abstract

This research plan aims to answer the following specific questions concerning FAP, DPPII, DP8 and DP9. The experimental objectives can be grouped around 3 themes: chromogenic and fluorogenic substrates, peptide substrates and inhibitors. The experimental results will be interpreted with the aid of available structural information (crystal structure of DPIV is published recently; DP8 and 9 show primary sequence homology, DPPII does not) in order to obtain a better insight in substrate binding and catalysis by the members of this family of serine type peptidases.

Researcher(s)

• Promoter: De Meester Ingrid
• Co-promoter: Lambeir Anne-Marie
• Co-promoter: Scharpe Simon

Research team(s)

• Medical Biochemistry

Project type(s)

• Research Project

Abstract

Prolyloligopeptidase (PO) and dipeptidyl peptidase IV (DPP-IV) are proline specific peptidases. Their biological function is connected with the metabolism of biologically active peptides. It is generally assumed that they exert their catalytic function through the classical serine protease mechanism. The specificity and the selectivity are mainly determined by the primary binding site and a few sub-binding sites for adjacent amino acids. The substrate-specificity of DPP-IV for natural peptides could not be predicted based on these assumptions and the data obtained by using small dipeptide-derived substrates. It was not possible to unambiguously identify the rate limiting step in the mechanism from solvent isotope effects. Under certain conditions a conformational change seems to be rate limiting for the hydrolysis of chromogenic substrates by PO. The interpretation of structure-activity-relationships of inhibitors also remains very difficult. The object of this project is to get a better insight in the details of the catalytic mechanism of PO and DPP-IV. Different approaches are being considered: kinetic experiments, site-directed mutagenesis in the active site and the substrate binding sites in PO, kwantitative structure-activity relationships of inhibitors and ligands.

Researcher(s)

• Promoter: Scharpe Simon
• Co-promoter: Lambeir Anne-Marie
• Fellow: Brandt Inger

Research team(s)

• Medical Biochemistry

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

• Medical Biochemistry

Project type(s)

• Research Project

Abstract

Prolyloligopeptidase (PO) and dipeptidyl peptidase IV (DPP-IV) are proline specific peptidases. Their biological function is connected with the metabolism of biologically active peptides. It is generally assumed that they exert their catalytic function through the classical serine protease mechanism. The specificity and the selectivity are mainly determined by the primary binding site and a few sub-binding sites for adjacent amino acids. The substrate-specificity of DPP-IV for natural peptides could not be predicted based on these assumptions and the data obtained by using small dipeptide-derived substrates. It was not possible to unambiguously identify the rate limiting step in the mechanism from solvent isotope effects. Under certain conditions a conformational change seems to be rate limiting for the hydrolysis of chromogenic substrates by PO. The interpretation of structure-activity-relationships of inhibitors also remains very difficult. The object of this project is to get a better insight in the details of the catalytic mechanism of PO and DPP-IV. Different approaches are being considered: kinetic experiments, site-directed mutagenesis in the active site and the substrate binding sites in PO, kwantitative structure-activity relationships of inhibitors and ligands.

Researcher(s)

• Promoter: Scharpe Simon
• Co-promoter: Lambeir Anne-Marie
• Fellow: Brandt Inger

Research team(s)

• Medical Biochemistry

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

• Medical Biochemistry

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

One woman out of nine will develop mammary cancer. Though clinical, biochemical and radiological investigation do not reveal tumour spread, haematogenic dissemination often present at the time of diagnosis will be responsible for morbidity and mortality of this disease. The detection of disseminated tumour cells in the blood stream and/or in the bone marrow of breast cancer patients could lead to a better staging and prognostication of these patients. Immunohistochemical analysis of bone marrow and lymph nodes for the demonstration of morphologically detectable tumour cells has been used since long. This microscopic methodology, however, has a low sensitivity whereby small numbers of tumour cells can be missed. Molecular biology techniques have a much higher sensitivity, yet a low specificity. The aim of this study is to develop a sensitive and specific molecular biological technology to detect micrometastatic disease in breast cancer patients and to compare the results with those obtained by immunohistochemistry. Tumour cells in peripheral blood and in bone marrow will be detected with RT-PCR amplifying mRNA of cytokeratin-19 (CM19). Using the cDNA sepcific primer/probe set for CK19 and the ABI Prism 7700 Real-Time PCR (TaqmanTM) results will be quantified. In a second phase of the investigation prognostic significance of these parameters with respect to metastasis and survival in operable breast cancer patients will be addressed. In a third part of the study the relationship between presence of disseminated tumour cells and tumour angiogenesis will be investigated

Researcher(s)

• Promoter: Van Marck Eric
• Co-promoter: Scharpe Simon
• Fellow: Benoy Ina

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Scharpe Simon
• Co-promoter: De Meester Ingrid

Research team(s)

• Medical Biochemistry

Project type(s)

• Research Project

Abstract

The impact of proline-specific peptidase on the molecular regulation of blood pressure, immunological systems and neurotransmission causes enzymes to play an important role in the modulation of biological functions.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: Durinx Christine

Research team(s)

Project type(s)

• Research Project

Abstract

This project concerns the study of the enzyme dipeptidyl peptidase IV, also identified as the activation antigen CD26. The study tries to get a more profound knowledge on the structure and function of this complex protein with proline-specific exopeptidase activity that is expressed on activated lymfocytes and certain endothelial and epithelial cells. At the moment we concentrate on the identification of natural substrates. Candidate-substrates include chemokines, neuropeptides and growth factors.

Researcher(s)

• Promoter: De Meester Ingrid
• Co-promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Hendriks Dirk
• Co-promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Evidence for the involvement of CD26 in T cell activation and proliferation is provided by several approaches using mAb and CD26 transfection in human leukemic T cell lines. Application of CD26 mAb recognizing the 5/9 epitope to deplete bone marrow for allegeneic bone marrow transplantation in leukemia results in low graft versus hart disease.

Researcher(s)

• Promoter: Scharpe Simon
• Co-promoter: De Meester Ingrid
• Co-promoter: Lambeir Anne-Marie

Research team(s)

Project type(s)

• Research Project

Abstract

In this study we explore the structure and function of the lymphocytic activation antigen CD26, identified as dipeptidyl peptidase IV, a proline specific serine protease. The involvement of CD26 in T lymphocyte activation in investigated using specific inhibitors and monoclonal antibodies. To obtain structural information, we will start the expression of the proteasedomain of this molecule.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: De Meester Ingrid

Research team(s)

Project type(s)

• Research Project

Abstract

The impact of proline-specific peptidase on the molecular regulation of blood pressure, immunological systems and neurotransmission causes enzymes to play an important role in the modulation of biological functions.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: Durinx Christine

Research team(s)

Project type(s)

• Research Project

Abstract

Evidence for the involvement of CD26 in T cell activation and proliferation is provided by several approaches using mAb and CD26 transfection in human leukemic T cell lines. Application of CD26 mAb recognizing the 5/9 epitope to deplete bone marrow for allegeneic bone marrow transplantation in leukemia results in low graft versus hart disease.

Researcher(s)

• Promoter: Scharpe Simon
• Co-promoter: De Meester Ingrid
• Co-promoter: Lambeir Anne-Marie

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Hendriks Dirk
• Co-promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

In this project we aim to study the structural determinants of the enzymatic activity, substrate specificity and stability of monomeric TlM-barrel proteins, in particular of monoTlM and two related chitinases. This understanding should in the end permit the use of the TlM-barrel scaffold for the design and construction of enzymes with desired properties. By changing sequences in specified loops it will be attempted to change the specificity of monoTlM into a xylose isomerase. The chitinase studies will be aimed at making a more simple, more active and more stable chitinase with a rationally designed substrate specificity.

Researcher(s)

• Promoter: Scharpe Simon
• Co-promoter: Lambeir Anne-Marie

Research team(s)

Project type(s)

• Research Project

Abstract

Prolinespecific-serine proteases constitute a new family characterized by a specific lineair sequence of the katalytic triade and common consensus sequence around the action serine. The purpose of this project is to obtain more information on the tridimensional molecular constitution of several members of this family (dipeptidylpeptidase IV prolyloligopeptidase).

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Co-promoter: Cosyns Paul
• Co-promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Dipeptydilpeptidase IV is an important enzym in the activation of T-lymphocytes. This activity is at least partly due to a stimulation of the secretion of interleukine-2. Inhibitors of this enzyme are potential drugs for the treatment of allergic and inflammatory diseases. These compounds will be developed by rational drug design

Researcher(s)

• Promoter: Haemers Achiel
• Co-promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

In this study we explore the structure and function of the lymphocytic activation antigen CD26, identified as dipeptidyl peptidase IV, a proline specific serine protease. The involvement of CD26 in T lymphocyte activation in investigated using specific inhibitors and monoclonal antibodies. To obtain structural information, we will start the expression of the proteasedomain of this molecule.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: De Meester Ingrid

Research team(s)

Project type(s)

• Research Project

Abstract

Evidence for the involvement of CD26 in T cell activation and proliferation is provided by several approaches using mAb and CD26 transfection in human leukemic T cell lines. Application of CD26 mAb recognizing the 5/9 epitope to deplete bone marrow for allegeneic bone marrow transplantation in leukemia results in low graft versus hart disease.

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Prolyl oligopeptidase (PO) is a member of a new serineprotease family. PO has a unique specificity for proline residues and cleaves a variety of fysiologically important substrates. The catalytic mechanism of the new serine protease family will be studied by sitedirected mutgenesis and expression of the gene encoding PO.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: Vanhoof Greta

Research team(s)

Project type(s)

• Research Project

Abstract

T-lymphocytic dipeptidylpeptidase IV plays an important role in the activation of the immune system. Inhibitors of this enzyme could play an important role in understanding the role of growth factors and cytokines.

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

The studies reported here should provide a significant improvement over previous attempts to test the hypothesis that cytokines and peptidase enzymes are involved in the pathogenesis of depressions and are related to HPA axis overdrive and lower L-TRP availability in that illness.

Researcher(s)

• Promoter: Cosyns Paul
• Co-promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Development and characterization of new cellmarkers for diagnostic purposes. Exploration of new sites of interferences in cellmetabolism for the design of inhibitors for therapeutic use.

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

In this study we explore the structure and function of the lymphocytic activation antigen CD26, identified as dipeptidyl peptidase IV, a proline specific serine protease. The involvement of CD26 in T lymphocyte activation in investigated using specific inhibitors and monoclonal antibodies. To obtain structural information, we will start the expression of the proteasedomain of this molecule.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: De Meester Ingrid

Research team(s)

Project type(s)

• Research Project

Abstract

The crucial role of cell-surface and cytosol-isomerases can be analyzed by the exploration of their structure function relationship. Therefore, we attempt to characterize their three-dimensional structure.

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

This serine proteïnase specifically cleaves the peptide bond at the carboxy side of a proline residue. After we defined the physico-chemical properties we'll start the purification. The purified enzyme will enable us to investigate the proteolytic action and his molecular structure.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: Goossens Filip Ja

Research team(s)

Project type(s)

• Research Project

Abstract

The proline-specific aminopeptidases dipeptidyl peptidase IV and aminopeptidase P are respectively purified from human lymfocytes and blood platelets. The biochemical and enzymatic characteristics of the purified enzymes, and their activity towards biologically active peptidases are explored.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: Vanhoof Greta

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Dipeptydilpeptidase IV is an important enzym in the activation of T-lymphocytes. This activity is at least partly due to a stimulation of the secretion of interleukine-2. Inhibitors of this enzyme are potential drugs for the treatment of allergic and inflammatory diseases. These compounds will be developed by rational drug design

Researcher(s)

• Promoter: Haemers Achiel
• Co-promoter: Scharpe Simon

Research team(s)

Project type(s)

• Research Project

Abstract

Dipeptidyl peptidase IV is purified from human lymphocytes; biochemical characteristics (like molecular mass, isoelectric point and glycorilation) are investigated together with its enzymatic properties.

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: De Meester Ingrid

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: Goossens Filip Ja

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Scharpe Simon
• Fellow: Vanhoof Greta

Research team(s)

Project type(s)

• Research Project