- Conformational variability in short acyclic peptides. Stabilization of multiple ss-turn structures in organic solvents
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The conformational characteristics of three hexapeptides Boc-Leu-Xxx-Val-Leu-Aib-Val-OMe (Xxx - Ala 1, D-Ala 2, Gly 3; Aib = α-aminoisobutyryl) have been probed in CDCl3 solution by NMR methods using solvent perturbation of chemical shifts and radical broadening of NH resonances to delineate intramolecularly hydrogen bonded NH groups. Nuclear Overhauser effects (NOEs) provide additional information on preferred backbone conformations. The substituent at position 2 acts as a major conformational determinant. While a continuous 310 helical conformation is favoured for the peptide with Xxx = Ala, a multiple ss-turns conformation is supported by both NMR and CD data for the peptide with Xxx = D-Ala. In the peptide with Xxx = Gly CD and NMR data suggest that both 310 helical and multiple turns conformations are simultaneously populated. The results suggest that incorporation of D-amino acids and Aib residues into all L-sequences may prove useful in generating sequences containing multiple turns.
- Awasthi, Satish Kumar,Raghothama, Srinivasa Rao,Balaram, Padmanabhan
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Read Online
- Metal- and Base-Free Room-Temperature Amination of Organoboronic Acids with N-Alkyl Hydroxylamines
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We have found that readily available N-alkyl hydroxylamines are effective reagents for the amination of organoboronic acids in the presence of trichloroacetonitrile. This amination reaction proceeds rapidly at room temperature and in the absence of added metal or base, it tolerates a remarkable range of functional groups, and it can be used in the late-stage assembly of two complex units.
- Sun, Hong-Bao,Gong, Liang,Tian, Yu-Biao,Wu, Jin-Gui,Zhang, Xia,Liu, Jie,Fu, Zhengyan,Niu, Dawen
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supporting information
p. 9456 - 9460
(2018/07/29)
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- Design, synthesis and preliminary evaluation of α-sulfonyl γ-(glycinyl-amino)proline peptidomimetics as matrix metalloproteinase inhibitors
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A series of novel α-sulfonyl γ-(glycinyl-amino)proline peptidomimetic derivatives were designed, synthesized and assayed for their activities against matrix metalloproteinase-2 (MMP-2), aminopeptidase N (APN)/CD13 and HDACs. The results indicated that all the compounds exhibited highly selective inhibition against MMP-2 as compared with APN and HDACs. The antiproliferative activities of some compounds against SKOV3, HL60 and A549 cells were also investigated. Comparing with the control LY52, compound 12u, with excellent activity both in the enzymatic inhibition assay and cell-based assay, could be used as lead compound for the further development of MMP inhibitors.
- Zhang, Jian,Li, Xiaoyang,Jiang, Yuqi,Feng, Jinhong,Li, Xiaoguang,Zhang, Yingjie,Xu, Wenfang
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p. 3055 - 3064
(2014/05/20)
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- Synthesis and antitumor properties of the myelopeptide mp-1
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The bone marrow-derived peptide Phe-Leu-Gly-Phe-Pro-Thr (MP-1) has been synthesized by the classical methods of peptide chemistry in solution, and its antitumor properties have been studied. It has been shown that MP-1 enhances the efficacy of the cytosta
- Fonina, L. A.,Belevskaya, R. G.,Efremov, M. A.,Kirilina, E. A.,Az'Muko, A. A.,Treshchalina, E. M.,Sedakova, L. A.
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p. 354 - 359,6
(2020/08/31)
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- Design, synthesis and primary activity assay of bi- or tri-peptide analogues with the scaffold l-arginine as amino-peptidase N/CD13 inhibitors
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A series of bi- or tri-peptide analogues with the scaffold l-arginine were designed, synthesized and evaluated for their inhibitory activities against amino-peptidase N (APN) and metalloproteinase-2 (MMP-2). The primary activity assay showed that all the compounds exhibited higher inhibitory activities against APN than MMP-2. Within this series, compounds C6 and C7 (IC50 = 4.2 and 4.3 μM) showed comparable APN inhibitory activities with the positive control bestatin (IC50 = 3.8 μM).
- Mou, Jiajia,Fang, Hao,Liu, Yingzi,Shang, Luqing,Wang, Qiang,Zhang, Lei,Xu, Wenfang
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experimental part
p. 887 - 895
(2010/05/02)
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- Synthetic and cytotoxic and antimicrobial activity studies on annomuricatin B
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The first total synthesis of annomuricatin B (8) is described via coupling of the tripeptide Boc-L-asparaginyl(benzhydryl)-L-alanyl-L-tryptophan-OH and the tetrapeptide L-leucyl-glycyl-L-thryl-L-proline-OMe followed by cyclization of the linear heptapeptide fragment. On pharmacological investigation, it was observed that the cycloheptapeptide 8 displays moderate cytotoxicity against Datton's lymphoma ascites and Ehrlich's ascites carcinoma cell lines with cytotoxic inhibitory concentration (50%) values of 11.6 and 14.1 μM, in addition to potent antidermatophyte activity against Trichophyton mentagrophytes and Microsporum audouinii with a minimum inhibitory concentration of 6 μg mL-1. Moreover, Gram-negative bacteria and Candida albicans were found to be moderately sensitive towards the newly synthesized peptide.
- Dahiya, Rajiv,Maheshwari, Monika,Yadav, Rakesh
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scheme or table
p. 237 - 244
(2009/06/17)
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- Classical synthesis of and structural studies on a biologically active heptapeptide and a nonapeptide of bovine elastin
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The synthesis of two elastin sequences incorporating the structural unit X-G-G-X-G (X = A) is described. In particular, the following peptides and polypeptides were synthesized and characterized: TFA-H2+LGAGGAG-OH, TFA-H2+LGAGGAGVL-OH (both of these inducing stimulation of endogenous elastin production in cultured adult human fibroblast), poly(LGAGGAG), and poly(LGAGGAGVL). The synthesis was accomplished in solution by classical procedures, by using the diphenylphosphoryl azide for the polycondensation step, and the mixed anhydride method for the coupling steps. CD, NMR, and FT-IR measurements gave evidence of quasi-extended (PP II) structures as a peculiar structural feature in the heptapeptide, and a tendency towards flexible β-turns in the nonapeptide. Poly(LGAGGAG) showed greater disorder with respect to the "monomer", the molecular conformation being accountable for by unstructured polypeptide chains together with β-turns. The polymer is able to adopt supramolecular structures reminiscent of those found in elastin. Unlike that of the heptapeptide, polycondensation of the nonapeptide did not afford a linear polymer, but only cyclic derivatives. This could well be due to the tendency of the monomeric nonapeptide to adopt folded conformations.
- Spezzacatena, Caterina,Perri, Tiziana,Guantieri, Valeria,Sandberg, Lawrence B.,Mitts, Thomas F.,Tamburro, Antonio M.
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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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- Synthesis of the N-terminal N-myristoylated and S-palmitoylated undetrigintapeptide of endothelial NO-synthase
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Endothelial NO synthase (eNOS) is a membrane-bound protein involved in signaling from the blood stream to the surrounding smooth muscle cells. The synthesis of its N-myristolyated and doubly S-palmitoylated N-terminus 1, which determines the localization
- Machauer, Rainer,Waldmann, Herbert
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p. 1449 - 1453
(2007/10/03)
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- Peptide Enolates. C-Alkylation of Glycine Residues in Linear Tri-, Tetra-, and Pentapeptides via Dilithium Azadienediolates
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The Boc-protected tripeptides Boc-Val-Gly-Leu-OH (1), Boc-Leu-Sar-Leu-OH (2), Boc-Leu-Gly-MeLeu-OH (3), and Boc-Val-BzlGly-Leu-OMe (64), tetrapeptide Boc-Leu-Gly-Pro-Leu-OH (9), and pentapeptides Boc-Val-Leu-Gly-Abu-Ile-OH (4), Boc-Val-Leu-Sar-MeAbu-Ile-O
- Bossler, Hans G.,Seebach, Dieter
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p. 1124 - 1165
(2007/10/02)
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- Polypeptide derivatives and calcium metabolism improving agent
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Novel polypeptide derivatives, acid-addition salts thereof and complexes thereof, having the activities for inhibiting bone calcium absorption, for lowering the blood level of calcium, as analgesics, for inhibiting secretion of the gastric juice. Pharmaceutical composition can be prepared by formulating, at least one of the novel polypeptide derivatives, acid-addition salts thereof and complexes thereof, together with a proteolytic enzyme inhibitors and/or pharmaceutically acceptable acids. The pharmaceutical composition are quite effective as agents for curing hypercalcemia, for curing Peget's disease, for curing osteoporosis, analgetic agent, anti-ulcerative agent and the like.
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- Polypeptide derivatives
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Novel synthetic polypeptide derivatives, i.e., novel calcitonin derivatives, having improved basic physiological activities of the corresponding natural calcitonins, i.e., the activity for lowering the blood level of calcium, the activity as an analgesic, as well as the activity for inhibiting the secretion of the gastric juice. Thus these synthetic calcitonins are effective as agents for curing hypercalcemia, analgetic agents, anti-ulcerative agents and the like.
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- Studies on the β-turn of peptides. II. Syntheses and conformational properties of N-(2,4-dinitrophenyl)tetrapeptide p- nitroanilides related to the β-turn part of gramicidin S
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N-(2,4-Dinitrophenyl)tetrapeptide p-nitroanilides related to the beta -turn part of gramicidin S were synthesized and subjected to CD measurements. The beta -turn preference of the tetrapeptide derivatives had correlation with the antibiotic activities of
- Sato,Kawai,Nagai
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p. 1527 - 1531
(2007/10/02)
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