- Cyclo(l-proline-l-serine) Dipeptide Suppresses Seed Borne Fungal Pathogens of Rice: Altered Cellular Membrane Integrity of Fungal Hyphae and Seed Quality Benefits
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Five proline-containing diketopiperazines (Pro-DKPs) produced by antagonistic microorganisms as secondary metabolites were selected and synthesized under laboratory conditions. Out of five synthesized Pro-DKPs, cyclo(l-Pro-l-Ser) (DKP-6) revealed the best inhibition of fungal pathogens (Fusarium verticillioides and Fusarium fujikuroi) of rice under in vitro conditions with effective doses lower than standard fungicide carbendazim. DKP-6 induced stress on the fungal cell membrane integrity, which was revealed by calcofluor white and propidium iodide assays, endorsed by ultra-microscopic details and soluble protein leakage assays. In vivo seed treatment of infested rice seeds with DKP-6 at 2000 μg/mL for 10 h of seed treatment inflicted best reduction in seed rot and seedling blight with respect to control and carbendazim. Significant enhancement in seedling quality parameters were also observed. The work presented the strong influence of cyclo(l-Pro-l-Ser) as a mycocidal seed treatment agent better than synthetic toxic fungicides for rice.
- Poonia, Baninderjit Kaur,Sidhu, Anjali,Sharma, Anju Bala
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p. 2160 - 2168
(2022/02/23)
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- DPP-4 inhibitor
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A DPP-4 inhibitor comprising a peptide represented by the formula (1): Xe-Pro/Ala/Hyp-Xa-Xb-Xc-Xd (SEQ ID NO: 16) (wherein Xe is an amino acid residue with an isoelectric point of 5.9 to 6.3; Pro/Ala/Hyp represents Pro, Ala, or Hyp; Xa is an amino acid residue other than Hyp, Pro, and Arg, or deletion; 5 Xb is Gly, Pro, or deletion; Xc is Pro, Ala, or deletion; and Xd is an amino acid residue or deletion) as an active component. The inhibitor can be expected to bring out an effect of lowering blood glucose levels by enhancing effects of incretins; and the inhibitor may be used as a therapeutic agent for diabetes and, in addition, can act on the immune system or the like to be thus used in 10 treatment for skin diseases or the like.
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Page/Page column 11-12
(2016/06/06)
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- Zinc(II) complexes of Pro-Gly and Pro-Leu dipeptides: Synthesis, characterization, in vitro DNA binding and cleavage studies
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Dipeptide (Pro-Gly and Pro-Leu) Zinc(II) complexes 1 and 2 were designed and synthesized for potential use as cancer chemotherapeutic agents. In order to augment the DNA recognition of metallonuclease activity, zinc metal ion was tethered to peptide motif to carry out DNA site specific hydrolytic cleavage. The structural formulation of the complexes 1 and 2 was done by elemental analysis, spectroscopic methods (IR, NMR, electronic) and molar conductance measurements. Their in vitro DNA binding profile was investigated by UV-vis titrations, fluorescence titrations and circular dichroism which revealed that these complexes bind to CT DNA by electrostatic interactions via groove binding mode. Zn(II) Pro-Gly complex 1 showed greater binding affinity to CT DNA as compared to the Zn(II) Pro-Leu complex 2 due to steric constraints in the latter. The supercoiled pBR322 DNA cleavage activity of complex 1, ascertained by gel electrophoresis demonstrated efficient DNA cleaving ability via hydrolytic mechanistic pathway. Further, the molecular docking studies confirmed that complex 1 bind to the minor groove of DNA having AT-rich sequences with relative binding energy of -196.72 kJ mol-1.
- Parveen, Shazia,Arjmand, Farukh,Mohapatra
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- Thermal cleavage of the Fmoc protection group
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The Fmoc protection group is among the most commonly used protection groups for the amino function. A fast method for the thermal deavage of this protection group under base-free conditions without the need for dibenzofulvene scavengers is presented. The advantages of this method include straightforward testability by means of a simple high-temperature NMR experiment, usually high yields, and good selectivity towards the BOC protection group and t-butyl ethers.
- Hoeck, Stefan,Marti, Roger,Riedl, Rainer,Simeunovic, Marina
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experimental part
p. 200 - 202
(2011/08/05)
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- Functional identification and structure determination of two novel prolidases from cog1228 in the amidohydrolase superfamily
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Two uncharacterized enzymes from the amidohydrolase superfamily belonging to cog1228 were cloned, expressed, and purified to homogeneity. The two proteins, Sgx9260c (gi|44242006) and Sgx9260b (gi|44479596), were derived from environmental DNA samples originating from the Sargasso Sea. The catalytic function and substrate profiles for Sgx9260c and Sgx9260b were determined using a comprehensive library of dipeptides and N-acyl derivative of l-amino acids. Sgx9260c catalyzes the hydrolysis of Gly-l-Pro, l-Ala-l-Pro, and N-acyl derivatives of l-Pro. The best substrate identified to date is N-acetyl-l-Pro with a value of kcat/Km of 3 × 105 M -1 s-1. Sgx9260b catalyzes the hydrolysis of l-hydrophobic l-Pro dipeptides and N-acyl derivatives of l-Pro. The best substrate identified to date is N-propionyl-l-Pro with a value of kcat/Km of 1 × 105 M-1 s-1. Three-dimensional structures of both proteins were determined by X-ray diffraction methods (PDB codes 3MKV and 3FEQ). These proteins fold as distorted (β/α) 8-barrels with two divalent cations in the active site. The structure of Sgx9260c was also determined as a complex with the N-methylphosphonate derivative of l-Pro (PDB code 3N2C). In this structure the phosphonate moiety bridges the binuclear metal center, and one oxygen atom interacts with His-140. The α-carboxylate of the inhibitor interacts with Tyr-231. The proline side chain occupies a small substrate binding cavity formed by residues contributed from the loop that follows β-strand 7 within the (β/α)8-barrel. A total of 38 other proteins from cog1228 are predicted to have the same substrate profile based on conservation of the substrate binding residues. The structure of an evolutionarily related protein, Cc2672 from Caulobacter crecentus, was determined as a complex with the N-methylphosphonate derivative of l-arginine (PDB code 3MTW).
- Xiang, Dao Feng,Patskovsky, Yury,Xu, Chengfu,Fedorov, Alexander A.,Fedorov, Elena V.,Sisco, Abby A.,Sauder, J. Michael,Burley, Stephen K.,Almo, Steven C.,Raushel, Frank M.
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experimental part
p. 6791 - 6803
(2011/05/05)
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- SPECIFICITY AND MOLECULAR PROPERTIES OF PENICILLOLYSIN, A METALLOPROTEINASE FROM PENICILLUM CITRINUM
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The specificity and mode of action of penicillolysin, a metalloproteinase from Penicillum citrinum, were investigated with several bioactive-oligopeptides.The enzyme showed a high affinity toward the Pro-X (X = Gln, Lys, Leu or Arg) bonds of substance P, dynorphin A (1-13), neurotensin and chicken brain pentapeptide, and the R-R bonds in dynorphin A and neurotensin.Preferential cleavages of bonds by the enzyme with hydrophobic amino acid residues at the P1 position were observed on the peptides used.The specificity of penicillolysin differs from that of other metallopropteinases.The Mr and pI were determined as 18000 and 9.6, respectively.The first 50 amino acids in the N-terminal region were TKETCSNASRKSALEKALSNTVKLANAAATAARSGSASKFSEYEKTTSSS.CD spectra on the hollo- and apo-enzymes of penicillolysin were studied.
- Yamaguchi, Megumi,Hanzawa, Satoshi,Hirano, Ken-Ichi,Yamagata, Youhei,Ichishima, Eiji
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p. 1317 - 1322
(2007/10/02)
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- CYCLIZATION STUDIES OF TETRAPEPTIDE HOMOLOGS
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A synthetic method of achieving enhanced yields of monomer cyclotetrapeptide homologs (all L configuration, 14 and 15 membered ring size) is reported.
- Sheh, L.,Mokotoff, M.
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p. 5755 - 5758
(2007/10/02)
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