- Synthesis and In Vitro Neuroprotective Activity of Glycine Analogs of Gk-2 Dimeric Dipeptide Mimetic of Nerve Growth Factor 4th Loop
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A dimeric dipeptide mimetic of nerve growth factor (NGF), bis-(N-monosuccinyl-L-glutamyl-L-lysine) hexamethylenediamide (GK-2), was previously developed at V. V. Zakusov State Institute of Pharmacology, activated specific TrkA receptors, and exhibited neuroprotective activity in vitro (10–5 – 10–9 M) and in vivo (0.1 – 10 mg/kg i.p. and p.o.). GK-2 was designed based on the beta-turn (-Asp94-Glu95-Lys96-Gln97-) of the NGF 4th loop and preserved the central dipeptide fragment (-Glu95-Lys96-). The Asp94 residue was replaced by its monosuccinyl bioisostere. The dimeric structure of NGF was reproduced using a bivalent hexamethylenediamine spacer. The structure—activity (neuroprotective) relationship for GK-2 was studied in the present work using a glycine scan, i.e., successive replacement of the peptide side groups by H. The bis-(N-acetyl-L-glutamyl-L-lysine) (GK-2Ac), bis-(N-monosuccinylglycyl-L-lysine) (GK-2-Gly1), and bis-(N-monosuccinyl-L-glutamylglycine) hexamethylenediamides (GK-2-Gly2) were less active with neuroprotective activity in vitro under oxidative stress for HT22 cells at concentrations 10 – 100 times greater than GK-2. The conclusion was drawn that each side radical of GK-2 was important for manifestation of the full neuroprotective activity of dimeric dipeptide GK-2, a mimetic of the NGF 4th loop. However, removal of any of the side radicals would probably not change the active structure of the beta-turn so that the two remaining side radicals should retain the ability to bind to their TrkA subsites. This could explain the retention of neuroprotective activity in the GK-2 glycine analogs.
- Antipov, P. I.,Antipova, T. A.,Firsova, Yu. N.,Gudasheva, T. A.,Nikolaev, S. V.,Rebeko, A. G.,Sazonova, N. M.,Tarasyuk, A. V.,Zvyagintsev, A. A.
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- DIPEPTIDE MIMETICS OF NGF AND BDNF NEUROTROPHINS
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The invention relates to compounds having either agonist or antagonist activities for the neurotrophins NGF and BDNF and represented by monomeric or dimeric substituted dipeptides that are analogs of the exposed portions of loop 1 or loop 4 regions of these neurotrophins near or at a beta-turn of the respective loop. N-acylated substituents of these dipeptides are biostereoisomers of the amino acid residues preceding these dipeptide sequences in the neurotrophin primary structure. The dimeric structure is produced advantageously by using hexatnethylenediaanine to which dipeptides are attached via their carboxyl groups. The claimed compounds displayed neuroprotective and differentiation-inducing activities in cellular models and enhanced the amount of phosphorylated tyrosine kinase A and the heat shock proteins Hsp32 and Hsp70 in the concentration range of 10 -9 to 10 -5 M. They also displayed neuroprotective, anti-parkinsonian, anti-stroke, anti-ischemic, anti-depressant and anti-amnestic activities in animal models and were active in experimental models of Alzheimer's disease. These in vivo effects of the claimed compounds are displayed in the dose range of 0.01 to 10 mg/kg when administered intraperitoneally.
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- Searching for improved mimetic peptides inhibitors preventing conformational transition of amyloid-β42 monomer
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A series of novel mimetic peptides were designed, synthesised and biologically evaluated as inhibitors of Aβ42 aggregation. One of the synthesised peptidic compounds, termed compound 7 modulated Aβ42 aggregation as demonstrated by thioflavin T fluorescence, acting also as an inhibitor of the cytotoxicity exerted by Aβ42 aggregates. The early stage interaction between compound 7 and the Aβ42 monomer was investigated by replica exchange molecular dynamics (REMD) simulations and docking studies. Our theoretical results revealed that compound 7 can elongate the helical conformation state of an early stage Aβ42 monomer and it helps preventing the formation of β-sheet structures by interacting with key residues in the central hydrophobic cluster (CHC). This strategy where early “on-pathway” events are monitored by small molecules will help the development of new therapeutic strategies for Alzheimer's disease.
- Gera, János,Sz?gi, Titanilla,Bozsó, Zsolt,Fül?p, Livia,Barrera, Exequiel E.,Rodriguez, Ana M.,Méndez, Luciana,Delpiccolo, Carina M.L.,Mata, Ernesto G.,Cioffi, Federica,Broersen, Kerensa,Paragi, Gabor,Enriz, Ricardo D.
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p. 211 - 221
(2018/08/24)
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- Synthesis of lipidated eNOS peptides by combining enzymatic, noble metal- and acid-mediated protecting group techniques with solid phase peptide synthesis and fragment condensation in solution
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Lipid-modified proteins play decisive roles in important biological processes such as signal transduction, organization of the cytoskeleton, and vesicular transport. Lipidated peptides embodying the characteristic partial structures of their parent lipida
- Machauer, Rainer,Waldmann, Herbert
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p. 2940 - 2956
(2007/10/03)
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- Somatostatin receptor-binding peptides labeled with technetium-99m: Chemistry and initial biological studies
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The synthesis of peptides which possess a high affinity for the somatostatin receptor and contain a chelator for the radionuclide technetium- 99m is described. The target compounds were designed such that they would form stable, oxotechnetium(V) chelate c
- Pearson, Daniel A.,Lister-James, John,McBride, William J.,Wilson, David M.,Martel, Lawrence J.,Civitello, Edgar R.,Taylor, John E.,Moyer, Brian R.,Dean, Richard T.
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p. 1361 - 1371
(2007/10/03)
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- Novel Preparation of N-Protected Amino Acid Active Esters Using 1,2,2,2-Tetrachloroethyl Carbonates
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1,2,2,2-Tetrachloroethyl chloroformate reacts with substituted phenols or N-hydroxy imides to yield crystalline and stable mixed aryl or oximido tetrachloroethyl carbonates.When allowed to react with an N-protected amino acid derivative, these compounds proved to be efficient for the syntheses of the corresponding active esters.A series of active esters including p-nitrophenol, trichlorophenol, pentafluorophenol, and N-hydroxysuccinimide derivatives were prepared by this new procedure.
- Jaoudai, Mahmoud,Martinez, Jean,Castro, Bertrand
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p. 2364 - 2367
(2007/10/02)
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