Publications by authors named "Susan Lorey"

4 Publications

  • Page 1 of 1

Ubiquitin is a versatile scaffold protein for the generation of molecules with de novo binding and advantageous drug-like properties.

FEBS Open Bio 2015 10;5:579-93. Epub 2015 Jul 10.

Scil Proteins GmbH, Heinrich-Damerow-Straße 1, D-06120 Halle (Saale), Germany.

In the search for effective therapeutic strategies, protein-based biologicals are under intense development. While monoclonal antibodies represent the majority of these drugs, other innovative approaches are exploring the use of scaffold proteins for the creation of binding molecules with tailor-made properties. Ubiquitin is especially suited for this strategy due to several key characteristics. Ubiquitin is a natural serum protein, 100% conserved across the mammalian class and possesses high thermal, structural and proteolytic stability. Because of its small size and lack of posttranslational modifications, it can be easily produced in Escherichia coli. In this work we provide evidence that ubiquitin is safe as tested experimentally in vivo. In contrast to previously published results, we show that, in our hands, ubiquitin does not act as a functional ligand of the chemokine receptor CXCR4. Cellular assays based on different signaling pathways of the receptor were conducted with the natural agonist SDF-1 as a benchmark. In none of the assays could a response to ubiquitin treatment be elicited. Furthermore, intravenous application to mice at high concentrations did not induce any detectable effect on cytokine levels or hematological parameters.
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http://dx.doi.org/10.1016/j.fob.2015.07.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4522466PMC
August 2015

Novel ubiquitin-derived high affinity binding proteins with tumor targeting properties.

J Biol Chem 2014 Mar 28;289(12):8493-507. Epub 2014 Jan 28.

From Scil Proteins GmbH, Heinrich-Damerow-Strasse 1, 06120 Halle (Saale), Germany.

Targeting effector molecules to tumor cells is a promising mode of action for cancer therapy and diagnostics. Binding proteins with high affinity and specificity for a tumor target that carry effector molecules such as toxins, cytokines, or radiolabels to their intended site of action are required for these applications. In order to yield high tumor accumulation while maintaining low levels in healthy tissues and blood, the half-life of such conjugates needs to be in an optimal range. Scaffold-based binding molecules are small proteins with high affinity and short systemic circulation. Due to their low molecular complexity, they are well suited for combination with effector molecules as well as half-life extension technologies yielding therapeutics with half-lives adapted to the specific therapy. We have identified ubiquitin as an ideal scaffold protein due to its outstanding biophysical and biochemical properties. Based on a dimeric ubiquitin library, high affinity and specific binding molecules, so-called Affilin® molecules, have been selected against the extradomain B of fibronectin, a target almost exclusively expressed in tumor tissues. Extradomain B-binding molecules feature high thermal and serum stability as well as strong in vitro target binding and in vivo tumor accumulation. Application of several half-life extension technologies results in molecules of largely unaffected affinity but significantly prolonged in vivo half-life and tumor retention. Our results demonstrate the utility of ubiquitin as a scaffold for the generation of high affinity binders in a modular fashion, which can be combined with effector molecules and half-life extension technologies.
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http://dx.doi.org/10.1074/jbc.M113.519884DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3961674PMC
March 2014

Different modes of dipeptidyl peptidase IV (CD26) inhibition by oligopeptides derived from the N-terminus of HIV-1 Tat indicate at least two inhibitor binding sites.

Eur J Biochem 2003 May;270(10):2147-56

Department of Biochemistry/Biotechnology, Institute of Biochemistry, Martin-Luther-University Halle-Wittenberg, Halle, Germany.

Dipeptidyl peptidase IV (DP IV, CD26) plays an essential role in the activation and proliferation of lymphocytes, which is shown by the immunosuppressive effects of synthetic DP IV inhibitors. Similarly, both human immunodeficiency virus-1 (HIV-1) Tat protein and the N-terminal peptide Tat(1-9) inhibit DP IV activity and T cell proliferation. Therefore, the N-terminal amino acid sequence of HIV-1 Tat is important for the inhibition of DP IV. Recently, we characterized the thromboxane A2 receptor peptide TXA2-R(1-9), bearing the N-terminal MWP sequence motif, as a potent DP IV inhibitor possibly playing a functional role during antigen presentation by inhibiting T cell-expressed DP IV [Wrenger, S., Faust, J., Mrestani-Klaus, C., Fengler, A., Stöckel-Maschek, A., Lorey, S., Kähne, T., Brandt, W., Neubert, K., Ansorge, S. & Reinhold, D. (2000) J. Biol. Chem.275, 22180-22186]. Here, we demonstrate that amino acid substitutions at different positions of Tat(1-9) can result in a change of the inhibition type. Certain Tat(1-9)-related peptides are found to be competitive, and others linear mixed-type or parabolic mixed-type inhibitors indicating different inhibitor binding sites on DP IV, at the active site and out of the active site. The parabolic mixed-type mechanism, attributed to both non-mutually exclusive inhibitor binding sites of the enzyme, is described in detail. From the kinetic investigations and molecular modeling experiments, possible interactions of the oligopeptides with specified amino acids of DP IV are suggested. These findings give new insights for the development of more potent and specific peptide-based DP IV inhibitors. Such inhibitors could be useful for the treatment of autoimmune and inflammatory diseases.
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http://dx.doi.org/10.1046/j.1432-1033.2003.03568.xDOI Listing
May 2003

Transcellular proteolysis demonstrated by novel cell surface-associated substrates of dipeptidyl peptidase IV (CD26).

J Biol Chem 2002 Sep 2;277(36):33170-7. Epub 2002 Jul 2.

Department of Biochemistry and Biotechnology, Institute of Biochemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 3, D-06120 Halle (Saale), Germany.

Proteolytic enzymes contribute to the regulation of cellular functions such as cell proliferation and death, cytokine production, and matrix remodeling. Dipeptidyl peptidase IV (DP IV) catalyzes the cleavage of several cytokines and thereby contributes to the regulation of cytokine production and the proliferation of immune cells. Here we show for the first time that cell surface-bound DP IV catalyzes the cleavage of specific substrates that are associated with the cellular surface of neighboring cells. Rhodamine 110 (R110), a highly fluorescent xanthene dye, was used to synthesize dipeptidyl peptidase IV (DP IV/CD26) substrates Gly(Ala)-Pro-R110-R, thus facilitating a stable binding of the fluorescent moiety on the cell surface. The fixation resulted from the interaction with the reactive anchor rhodamine and allowed the quantification of cellular DP IV activity on single cells. The reactivity, length, and hydrophobicity of rhodamine was characterized as the decisive factor that facilitated the determination of cellular DP IV activity. Using fluorescence microscopy, it was possible to differentiate between different DP IV activities. The hydrolysis of cell-bound substrates Xaa-Pro-R110-R by DP IV of neighboring cells and by soluble DP IV was shown using flow cytometry. These data demonstrate that ectopeptidases such as DP IV may be involved in communication between blood cells via proteolysis of cell-associated substrates.
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http://dx.doi.org/10.1074/jbc.M200798200DOI Listing
September 2002