| 1. |
- Erdélyi, Máté, et al.
(författare)
-
Chemistry and folding of photomodulable peptides : stilbene and thioaurone-type candidates for conformational switches
- 2008
-
Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 6:23, s. 4356-4373
-
Tidskriftsartikel (refereegranskat)abstract
- Optimized synthetic strategies for the preparation of photoswitchable molecular scaffolds based on stilbene or on thioaurone chromophores and their conformationally directing properties, as studied by computations and by NMR spectroscopy, are addressed. For the stilbene peptidomimetics 1, 2 and 3, the length of connecting linkers between the chromophore and the peptide strands was varied, resulting in photochromic dipeptidomimetics with various flexibility. Building blocks of higher rigidity, based on para-substituted thioaurone ( 4 and 6) and meta-substituted thioaurone chromophores ( 5 and 7) are shown to have a stronger conformationally directing effect. Design, synthesis, theoretical and experimental conformational analyses are presented.
|
|
| 2. |
- Erdelyi, Mate, 1975, et al.
(författare)
-
Chemistry and Folding of Photomodulable Peptides - Stilbene and Thioaurone-type Conformational Switches
- 2008
-
Ingår i: Organic & Biomolecular Chemistry. - 1477-0520. ; 6:23, s. 5346-4373
-
Tidskriftsartikel (refereegranskat)abstract
- Optimized synthetic strategies for the preparation of photoswitchable molecular scaffolds based on stilbene or on thioaurone chromophores and their conformationally directing properties, as studied by computations and by NMR spectroscopy, are addressed. For the stilbene peptidomimetics 1, 2 and 3, the length of connecting linkers between the chromophore and the peptide strands was varied, resulting in photochromic dipeptidomimetics with various flexibility. Building blocks of higher rigidity, based on para-substituted thioaurone (4 and 6) and meta-substituted thioaurone chromophores (5 and 7) are shown to have a stronger conformationally directing effect. Design, synthesis, theoretical and experimental conformational analyses are presented.
|
|
| 3. |
|
|
| 4. |
- Ericsson, Daniel J., et al.
(författare)
-
Identification of small peptides mimicking the R2 C-terminus of Mycobacterium tuberculosis ribonucleotide reductase
- 2010
-
Ingår i: Journal of Peptide Science. - : Wiley. - 1075-2617 .- 1099-1387. ; 16:3, s. 159-164
-
Tidskriftsartikel (refereegranskat)abstract
- Ribonucleotide reductase (RNR) is a viable target for new drugs against the causative agent of tuberculosis, Mycobacterium tuberculosis. Previous work has shown that an N-acetylated heptapeptide based on the C-terminal sequence of the smaller RNR subunit can disrupt the formation of the holoenzyme sufficiently to inhibit its function. Here the synthesis and binding affinity, evaluated by competitive fluorescence polarization, of several truncated and N-protected peptides are described. The protected single-amino acid Fmoc-Trp shows binding affinity comparable to the N-acetylated heptapeptide, making it an attractive candidate for further development of non-peptidic RNR inhibitors.
|
|
| 5. |
- Muthas, Daniel, et al.
(författare)
-
Focused hierarchical design of peptide libraries - follow the lead
- 2007
-
Ingår i: Journal of Chemometrics. - : Wiley. - 0886-9383 .- 1099-128X. ; 21:10-11, s. 486-495
-
Tidskriftsartikel (refereegranskat)abstract
- A novel design strategy based on the hierarchical design of experiments (HDoE) method named focused hierarchical design of experiments (FHDoE) is presented. FHDoE combine two design layers and use focused substitutions to increase the probability of obtaining active peptides when designing libraries through a selection of compounds biased towards a lead structure. Increasing the number of peptides with measurable activity will increase the information gained and the likelihood of constructing good quantitative structure-activity relationship (QSAR) models. The utility of the novel design method is verified using two different approaches. First, a library designed with the novel FHDoE method was compared with libraries generated from classical positional scanning techniques (e.g., alanine scan) as well as with general and centered minimum analog peptide sets (MAPS) libraries by using an example found in the literature. Secondly, the same design strategies were applied to a dataset of 58 angiotensin converting enzyme (ACE) dipeptide inhibitors. QSAR models were generated from designed sublibraries and the activities of the remaining compounds were predicted. These two examples show that the use of FHDoE renders peptide libraries close in physicochemical space to the native ligand, yielding a more thorough screening of the area of interest as compared to the classical positional scans and fractional factorial design (FFD). It is also shown that an FHDoE library of six dipeptides could produce a QSAR model that better described the requisites of high activity ACE inhibitors than could QSAR models built from either a nine-dipeptide library designed with MAPS or a 58-dipeptide library.
|
|
| 6. |
- Nurbo, Johanna, et al.
(författare)
-
Design, synthesis and evaluation of peptide inhibitors of Mycobacterium tuberculosis ribonucleotide reductase
- 2007
-
Ingår i: Journal of Peptide Science. - : Wiley. - 1075-2617 .- 1099-1387. ; 13:12, s. 822-832
-
Tidskriftsartikel (refereegranskat)abstract
- Mycobacterium tuberculosis ribonucleotide reductase (RNR) is a potential target for new antitubercular drugs. Herein we describe the synthesis and evaluation of peptide inhibitors of RNR derived from the C-terminus of the small subunit of M. tuberculosis RNR. An N-terminal truncation, an alanine scan and a novel statistical molecular design (SMD) approach based on the heptapeptide Ac-Glu-Asp-Asp-Asp-Trp-Asp-Phe-OH were applied in this study. The alanine scan showed that TrP5 and Phe7 were important for inhibitory potency. A quantitative structure relationship (QSAR) model was developed based on the synthesized peptides which showed that a negative charge in positions 2, 3, and 6 is beneficial for inhibitory potency. Finally, in position 5 the model coefficients indicate that there is room for a larger side chain., as compared to Trp5.
|
|
| 7. |
|
|
| 8. |
- Nurbo, Johanna, et al.
(författare)
-
Novel pseudopeptides incorporating a benzodiazepine-based turn mimetic – targeting Mycobacterium tuberculosis ribonucleotide reductase
- 2013
-
Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 21:7, s. 1992-2000
-
Tidskriftsartikel (refereegranskat)abstract
- Peptides mimicking the C-terminus of the small subunit (R2) of Mycobacterium tuberculosis ribonucleotide reductase (RNR) can compete for binding to the large subunit (R1) and thus inhibit RNR activity. Moreover, it has been suggested that the binding of the R2 C-terminus is very similar in M. tuberculosis and Salmonella typhimurium. Based on modeling studies of a crystal structure of the holocomplex of the S. typhimurium enzyme, a benzodiazepine-based turn mimetic was identified and a set of novel compounds incorporating the benzodiazepine scaffold was synthesized. The compounds were evaluated in a competitive fluorescence polarization assay and in an RNR activity assay. These studies revealed that the compounds incorporating the benzodiazepine scaffold have the ability to compete for the M. tuberculosis R2 binding site with low-micromolar affinity.
|
|
| 9. |
- Nurbo, Johanna, 1979-
(författare)
-
Peptidomimetic Enzyme Inhibitors : Targeting M. tuberculosis Ribonucleotide Reductase and Hepatitis C Virus NS3 Protease
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focuses on the design and synthesis of inhibitors targeting Mycobacterium tuberculosis ribonucleotide reductase (RNR) and hepatitis C virus (HCV) NS3 protease; enzymes that have been identified as potential drug targets for the treatment of tuberculosis and hepatitis C, respectively. Small peptides have been recognized as inhibitors of these enzymes. However, the use of peptides as drugs is limited due to their unfavorable properties. These can be circumvented by the development of less peptidic molecules, often referred to as peptidomimetics. When this work was initiated, only a few inhibitors targeting M. tuberculosis RNR had been identified, whereas the HCV NS3 protease was an established drug target. Therefore, early peptidomimetic design strategies were applied to inhibitors of RNR while the NS3 protease inhibitors were subjected to modifications in a later stage of development. It has previously been shown that peptides derived from the C-terminus of the small subunit of M. tuberculosis RNR can compete for binding to the large subunit, and thus inhibit enzyme activity. To investigate the structural requirements of these inhibitors, different series of peptides were evaluated. First, peptides from an N-terminal truncation, an alanine scan and a designed library were synthesized and evaluated to examine the importance of the individual amino acid residues. Then, a set of N-terminally Fmoc-protected peptides was evaluated, and it was found that the N-terminal group improved the affinity of the peptides even when the length of the compounds was reduced. Furthermore, potential inhibitors of less peptidic character were generated by the introduction of a benzodiazepine-based scaffold. To further reduce the peptidic character and investigate the binding properties of HCV NS3 protease inhibitors, a series of tripeptides incorporating a β-amino acid was synthesized. Inhibition was evaluated and docking studies were performed to understand how the structural changes affected inhibitory potency. The results illustrated the importance of preserving the hydrogen bonding network and retaining electrostatic interactions in the oxyanion hole between inhibitor and protein.
|
|
| 10. |
- Nurbo, Johanna, et al.
(författare)
-
β-Amino acid substitutions and structure-based CoMFA modeling of hepatitis C virus NS3 protease inhibitors
- 2008
-
Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 16:10, s. 5590-5605
-
Tidskriftsartikel (refereegranskat)abstract
- In an effort to develop a new type of HCV NS3 peptidomimetic inhibitor, a series of tripeptide inhibitors incorporating a mix of alpha- and beta-amino acids has been synthesized. To understand the structural implications of beta-amino acid substitution, the P(1), P(2), and P(3) positions of a potent tripeptide scaffold were scanned and combined with carboxylic acid and acyl sulfonamide C-terminal groups. Inhibition was evaluated and revealed that the structural changes resulted in a loss in potency compared with the alpha-peptide analogues. However, several compounds exhibited muM potency. Inhibition data were compared with modeled ligand-protein binding poses to understand how changes in ligand structure affected inhibition potency. The P(3) position seemed to be the least sensitive position for beta-amino acid substitution. Moreover, the importance of a proper oxyanion hole interaction for good potency was suggested by both inhibition data and molecular modeling. To gain further insight into the structural requirements for potent inhibitors, a three-dimensional quantitative structure-activity relationship (3D-QSAR) model has been constructed using comparative molecular field analysis (CoMFA). The most predictive CoMFA model has q(2)=0.48 and r(pred)(2)=0.68.
|
|
