Search results for "cathepsin"
showing 10 items of 170 documents
Addition of thiols to the double bond of dipeptide C-terminal dehydroalanine as a source of new inhibitors of cathepsin C.
2017
Addition of thiols to double bond of glycyl-dehydroalanine and phenyl-dehydroalanine esters provided micromolar inhibitors of cathepsin C. The structure-activity studies indicated that dipeptides containing N-terminal phenylalanine exhibit higher affinity towards the enzyme. A series of C-terminal S-substituted cysteines are responsible for varying interaction with S1 binding pocket of cathepsin C. Depending on diastereomer these compounds most likely act as slowly reacting substrates or competitive inhibitors. This was proved by TLC analysis of the medium in which interaction of methyl (S)-phenylalanyl-(R,S)-(S-adamantyl)cysteinate (7i) with the enzyme was studied. Molecular modeling enabl…
Prospective Evaluation of Free Energy Calculations for the Prioritization of Cathepsin L Inhibitors.
2017
Improving the binding affinity of a chemical series by systematically probing one of its exit vectors is a medicinal chemistry activity that can benefit from molecular modeling input. Herein, we compare the effectiveness of four approaches in prioritizing building blocks with better potency: selection by a medicinal chemist, manual modeling, docking followed by manual filtering, and free energy calculations (FEP). Our study focused on identifying novel substituents for the apolar S2 pocket of cathepsin L and was conducted entirely in a prospective manner with synthesis and activity determination of 36 novel compounds. We found that FEP selected compounds with improved affinity for 8 out of …
Development of a New Antileishmanial Aziridine-2,3-Dicarboxylate-Based Inhibitor with High Selectivity for Parasite Cysteine Proteases
2015
ABSTRACT Leishmaniasis is one of the major neglected tropical diseases of the world. Druggable targets are the parasite cysteine proteases (CPs) of clan CA, family C1 (CAC1). In previous studies, we identified two peptidomimetic compounds, the aziridine-2,3-dicarboxylate compounds 13b and 13e, in a series of inhibitors of the cathepsin L (CL) subfamily of the papain clan CAC1. Both displayed antileishmanial activity in vitro while not showing cytotoxicity against host cells. In further investigations, the mode of action was characterized in Leishmania major . It was demonstrated that aziridines 13b and 13e mainly inhibited the parasitic cathepsin B (CB)-like CPC enzyme and, additionally, ma…
New aziridine-based inhibitors of cathepsin L-like cysteine proteases with selectivity for the Leishmania cysteine protease LmCPB2.8
2018
Abstract In the present work a series of aziridine-2,3-dicarboxylate inhibitors of papain-like cysteine proteases was designed, synthesized and tested. The compounds displayed selectivity for the parasitic protozoon Leishmania mexicana cathepsin L-like cysteine protease LmCPB2.8. The computational methods of homology modelling and molecular docking predicted some significant differences in the S2 pocket of LmCPB2.8 and cruzain, a related enzyme from Trypanosoma cruzi. Due to the presence of Tyr209 in LmCPB2.8 rather than Glu208 in cruzain sterically demanding, lipophilic ester groups (inhibitor 7d, 9d, 12d and 14d) are predicted to occupy the S2 pocket of the Leishmania protease, but do not…
Cabozantinib targets bone microenvironment modulating human osteoclast and osteoblast functions
2016
Cabozantinib, a c-MET and vascular endothelial growth factor receptor 2 inhibitor, demonstrated to prolong progression free survival and improve skeletal disease-related endpoints in castration-resistant prostate cancer and in metastatic renal carcinoma. Our purpose is to investigate the direct effect of cabozantinib on bone microenvironment using a total human model of primary osteoclasts and osteoblasts.Osteoclasts were differentiated from monocytes isolated from healthy donors; osteoblasts were derived from human mesenchymal stem cells obtained from bone fragments of orthopedic surgery patients. Osteoclast activity was evaluated by tartrate resistant acid phosphatase (TRAP) staining and …
Novel Opportunities for Cathepsin S Inhibitors in Cancer Immunotherapy by Nanocarrier-Mediated Delivery
2020
Cathepsin S (CatS) is a secreted cysteine protease that cleaves certain extracellular matrix proteins, regulates antigen presentation in antigen-presenting cells (APC), and promotes M2-type macrophage and dendritic cell polarization. CatS is overexpressed in many solid cancers, and overall, it appears to promote an immune-suppressive and tumor-promoting microenvironment. While most data suggest that CatS inhibition or knockdown promotes anti-cancer immunity, cell-specific inhibition, especially in myeloid cells, appears to be important for therapeutic efficacy. This makes the design of CatS selective inhibitors and their targeting to tumor-associated M2-type macrophages (TAM) and DC an attr…
2 H-1,2,3-Triazole-Based Dipeptidyl Nitriles: Potent, Selective, and Trypanocidal Rhodesain Inhibitors by Structure-Based Design.
2018
Macrocyclic inhibitors of rhodesain (RD), a parasitic cysteine protease and drug target for the treatment of human African trypanosomiasis, have shown low metabolic stability at the macrocyclic ether bridge. A series of acyclic dipeptidyl nitriles was developed using structure-based design (PDB ID: 6EX8). The selectivity against the closely related cysteine protease human cathepsin L (hCatL) was substantially improved, up to 507-fold. In the S2 pocket, 3,4-dichlorophenylalanine residues provided high trypanocidal activities. In the S3 pocket, aromatic residues provided enhanced selectivity against hCatL. RD inhibition (Ki values) and in vitro cell-growth of Trypanosoma brucei rhodesiense (I…
Targeting of the Leishmania Mexicana cysteine protease CPB2.8 ΔCTE by decorated fused benzo[b] thiophene scaffold.
2016
A potent and highly selective anhydride-based inhibitor of Leishmania mexicana cysteine protease CPB2.8ΔCTE (IC50 = 3.7 μM) was identified. The details of the interaction of the ligand with the enzyme active site were investigated by NMR biomimetic experiments and docking studies. Results of inhibition assays, NMR and theoretical studies indicate that the ligand acts initially as a non-covalent inhibitor and later as an irreversible covalent inhibitor by chemoselective attack of CYS 25 thiolate to an anhydride carbonyl.
Hierarchical architecture of sponge spicules: biocatalytic and structure-directing activity of silicatein proteins as model for bioinspired applicati…
2016
Since the first description of the silicateins, a group of enzymes that mediate the formation of the amorphous, hydrated biosilica of the skeleton of the siliceous sponges, much progress has been achieved in the understanding of this biomineralization process. These discoveries include, beside the proof of the enzymatic nature of the sponge biosilica formation, the dual property of the enzyme, to act both as a structure-forming and structure-guiding protein, and the demonstration that the initial product of silicatein is a soft, gel-like material that has to undergo a maturation process during which it achieves its favorable physical-chemical properties allowing the development of various t…
Alexander Disease Mutations Produce Cells with Coexpression of Glial Fibrillary Acidic Protein and NG2 in Neurosphere Cultures and Inhibit Differenti…
2017
Background Alexander disease (AxD) is a rare disease caused by mutations in the gene encoding glial fibrillary acidic protein (GFAP). The disease is characterized by presence of GFAP aggregates in the cytoplasm of astrocytes and loss of myelin. Objectives Determine the effect of AxD-related mutations on adult neurogenesis. Methods We transfected different types of mutant GFAP into neurospheres using the nucleofection technique. Results We find that mutations may cause coexpression of GFAP and NG2 in neurosphere cultures, which would inhibit the differentiation of precursors into oligodendrocytes and thus explain the myelin loss occurring in the disease. Transfection produces cells that diff…