ABSTRACT
The effect of original peptide derivatives of galantamine on scopolamine-induced memory impairment in mice was assessed using the passive avoidance test over 12 days. It was found that some galantamine derivatives administered in a dose of 1/20LD50 improved the memory in experimental mice, especially on days 5-12 of the experiment.
Subject(s)
Avoidance Learning/drug effects , Galantamine/pharmacology , Peptides/pharmacology , Scopolamine/pharmacology , Alzheimer Disease/drug therapy , Animals , Behavior, Animal , Disease Models, Animal , Learning/drug effects , Male , Memory/drug effects , Memory Disorders/drug therapy , Mice , Peptides/chemistryABSTRACT
The cysteine protease ATG4B is a key component of the autophagy machinery, acting to proteolytically prime and recycle its substrate MAP1LC3B. The roles of ATG4B in cancer and other diseases appear to be context dependent but are still not well understood. To help further explore ATG4B functions and potential therapeutic applications, we employed a chemical biology approach to identify ATG4B inhibitors. Here, we describe the discovery of 4-28, a styrylquinoline identified by a combined computational modeling, in silico screening, high content cell-based screening and biochemical assay approach. A structure-activity relationship study led to the development of a more stable and potent compound LV-320. We demonstrated that LV-320 inhibits ATG4B enzymatic activity, blocks autophagic flux in cells, and is stable, non-toxic and active in vivo. These findings suggest that LV-320 will serve as a relevant chemical tool to study the various roles of ATG4B in cancer and other contexts.
Subject(s)
Autophagy-Related Proteins/chemistry , Autophagy/drug effects , Cysteine Endopeptidases/chemistry , Quinolines/chemistry , Autophagy/genetics , Autophagy-Related Proteins/antagonists & inhibitors , Autophagy-Related Proteins/genetics , Cysteine Endopeptidases/genetics , Humans , Models, Molecular , Neoplasms/drug therapy , Neoplasms/genetics , Neoplasms/pathology , Proteolysis , Quinolines/pharmacology , Structure-Activity RelationshipABSTRACT
Based on the structure of Octreotide (SMS 201-995) some modified at positions 5 with Dap (diaminopropanoic acid), Dab (diaminobutanoic acid) and Orn new C-amide analogs were synthesized. The Thr6 was replaced by unnatural amino acids Tle (t-leucine). The cytotoxic effects of the novel compounds were tested in vitro against a panel of human tumor cell lines. All investigated compounds exhibited different concentration-dependent antiproliferative effects against the HT-29, MDA-MB-231, HepG2 and HeLa cell lines after 24 h treatment. The compound 2 (D-Phe-c(Cys-Phe-D-Trp- Dap-Tle-Cys)-Thr-NH2) had antiproliferative effects on MDA-MB-231 cells with the IC50 0.03 mM. The HeLa and HepG-2 cells were most sensitive towards tested compounds at various concentrations. Results demonstrated that the peptide analogs 3 (D-Phe-c(Cys-Phe-D-Trp-Lys-Tle-Cys)-Thr-NH2), 4 (D-Phe-c(Cys-Phe-D-Trp-Orn-Tle-Cys)-Thr-NH2) and 5 (RC-102) exert the most pronounced inhibition of the cell vitality up to 77% at higher concentrations and were not toxic to the normal Lep-3 cells.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Octreotide/analogs & derivatives , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Drug Screening Assays, Antitumor , HeLa Cells , Humans , Octreotide/chemical synthesis , Octreotide/chemistry , Octreotide/pharmacologyABSTRACT
We previously designed novel peptides-containing galantamine analogues. These compounds we analyzed for their putative inhibitory effect towards acetylcholinesterase, butyrylcholinesterase and γ-secretase, three activities of which could be central to various neurodegenerative pathologies including Alzheimer's disease. These pharmacological agents were virtually equipotent on acetylcholinesterase activity but display drastically higher inhibitory activities towards butyrylcholinesterase with several compounds displaying an about 100-fold higher activity than that harboured by galantamine. Strikingly, two of the galantamine amides that displayed low activity towards acetylcholinesterase exhibited the highest inhibitory potency towards butyrylcholinesterase (106 to 133 times more active than galantamine). Interestingly, five compounds show a rather good γ-secretase inhibitory potency while they retain their ability to inhibit AChE and/or BuChE activity. Thus, we have been able to design novel compounds with significant inhibitory activity against several of the enzymes responsible for key dysfunctions taking place in several neurodegenerative diseases. These mixed inhibitors could therefore be envisioned as potential pharmacological tools aimed at circumventing the degenerative processes taking place in these major pathologies.
Subject(s)
Acetylcholinesterase/drug effects , Amyloid Precursor Protein Secretases/drug effects , Butyrylcholinesterase/drug effects , Enzyme Inhibitors/pharmacology , Galantamine/analogs & derivatives , Oligopeptides/pharmacology , Drug Design , Galantamine/pharmacology , HEK293 Cells/drug effects , HEK293 Cells/enzymology , Humans , Neuroprotective Agents/pharmacologyABSTRACT
Based on template hexapeptides Ac-Arg-Tyr-Tyr-Arg-Trp-Lys-NH(2) and Ac-Arg-Tyr-Tyr-Arg-Ile-Lys-NH(2) analogues and corresponding deacylated homologues were synthesized substituting ornithine, diaminobutanoic (Dab) and diaminopropanoic (Dap) acids for lysine at position 6. The aim was to investigate the effect of the newly synthesized compounds on the neurogenic contractions of isolated rat vas deferens. Ac-Arg-Tyr-Tyr-Arg-Trp-Lys-NH(2) and its analogues manifested a strong inhibitory effect on the neurogenic contractions without effect on the muscle tone, which is characteristic effect of NOP receptor agonists. In contrast, Ac-Arg-Tyr-Tyr-Arg-Ile-Lys-NH(2) and its analogs manifested a strong inhibitory effect on the muscle tone and negligible effect on the neurogenic contractions which is characteristic effect of NOP receptor antagonists. The most active were the peptides in which Dab or Dap is the substitute. The study reveals that substitution of Lys with shorter amino acids could increase agonist or antagonist activity of the peptide.