| 1 | Author
| Dorothee Petz, Friedhelm Schneider | Requires cookie* | | Title
| Kinetic Analysis of the Catalytic Properties of Peptides in Ester Hydrolysis  | | | Abstract
| The catalytic properties of peptides containing histidine, cysteine and aspartic acid in ester hydrolysis were studied. Saturation kinetics were found for the reaction of p-nitrophenyl acetate (NPA) with Z-His-Ala-Asp-Gly-Cys-NH2 and Z-His-Ala-Gly-Gly-Cys-NH2 . The Brönsted equation for the hydrolysis of Zer«-butyloxycarbonyl-L-alanine-p-nitrophenylester (Boc-Ala-ONp) catalyzed by simple imidazole and SH-compounds was determined. The catalytic behaviour of the peptides in ester hydrolysis could not be described by the Brönsted equations for imidazole or thiole catalyzed hydrolysis of NPA and Boc-Ala-ONp. The pH dependence of the rate constants of the catalyzed ester hydrolysis gave no linear plots in 1 Jk versus H+ diagrams. | | |
Reference
| (Z. Naturforsch. 31c, 675 [1976]; received September 20 1976) | | |
Published
| 1976 | | |
Keywords
| Kinetic Properties, Peptides, Ester Hydrolysis | | |
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| default:Reihe_C/31/ZNC-1976-31c-0675.pdf | | | Identifier
| ZNC-1976-31c-0675 | | | Volume
| 31 | |
2 | Author
| Amelia Thereza, Roberto Soares3, Ricardo Dias Lins3, RichardG. Longo3, Ricardo Arrattb, Ferreira3 | Requires cookie* | | Title
| Plural Origins of Molecular Homochirality in Our Biota Part II. The Relative Stabilities of Homochiral and Mixed Oligoribotides and Peptides  | | | Abstract
| By computer simulations -molecular mechanics and molecular dynamics with the amber force field (Weiner et al., (1986), J. Comp. Chem. 7, 2 3 0 -2 5 2) -we have determined the stabilities of oligoribotide strands built with d -and L-riboses, and of peptide chains with d -and L-amino acid residues. In particular, complementary double-chains of oligoribotides were studied, since they are an important feature of the growing mechanism o f modern nucleic acids. Peptide chains on the other hand, grow without need of a template. We found that mixed oligoribotides are less stable than homochiral ones, and that this chiral effect is less noticeable in peptide chains. The results support the interpretation that L-riboses act as termi nators to the template-assisted growth of oligo-r-GD (enantiomeric cross-inhibition; Joyce et al., (1987), Proc. Natl. Acad. Sei. U S A 84, 4 398-4402). Based on this effect, a chemical pathway is proposed which could, under assumed prebiotic conditions, bypass the hindrance of homochiral growth. | | |
Reference
| Z. Naturforsch. 52c, 89 (1997); received July 10/September 4 1996 | | |
Published
| 1997 | | |
Keywords
| Chirality, Peptides, Oligoribotides, Computer Simulations | | |
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| default:Reihe_C/52/ZNC-1997-52c-0089.pdf | | | Identifier
| ZNC-1997-52c-0089 | | | Volume
| 52 | |
4 | Author
| Karl Folkers, Cyril Bowers, Pui-FunL. Tang, Minoru Kobota, Xiao Shao-Bo, Wolf Gang Bender, Liu Yin-Zeng | Requires cookie* | | Title
| Relative Potencies of Antagonists of the Luteinizing Hormone Releasing Hormone with Lys8 and Arg8 and Substitutions in Positions 3 ,5 ,6 ,7 and 8d-Ala10] — N H 2 and [N -A c—D-2  | | | Abstract
| Antagonists of the luteinizing hormone releasing hormone (L H R H) of increased potency is a goal for control of ovulation. In the design and synthesis of 26 decapeptides, emphasis was given to analogs with Lys8 and Arg8 and with various substitutions in positions 3, 5, 6, 7 and 8. Two antagonists, [N — A c—D-2-Nal]-N H 2 showed 80-85% antiovulatory activity (A O A) at 0.25 (ig in the rat. The latter antagonist showed 60% A O A at 0.125 ^.g. O f four pairs of analogs with Arg8 and Lys8, respectively, two pairs favored Lys8 over Arg8 for potency. One pair showed negligible difference and another pair favored Arg8 over Lys8. There is specificity of substitution for potency. In other antagonists, d -3-Pal3, Tyr5 or Phe5, D-Arg6 and Leu7 or Nie7 or Val7 and Arg8 were variously effective substitutions for increase of potency and reduction of histamine release. | | |
Reference
| Z. Naturforsch. 41c, 1087—1091 (1986); received June 10 1986 | | |
Published
| 1986 | | |
Keywords
| Luteinizing Hormone Releasing Hormone, Ovulation, Peptide, Antagonist, Histamine Release | | |
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| default:Reihe_C/41/ZNC-1986-41c-1087.pdf | | | Identifier
| ZNC-1986-41c-1087 | | | Volume
| 41 | |
5 | Author
| Ernst Bayer, Heribert Hellstern, Heiner Eckstein | Requires cookie* | | Title
| Synthese von immobilisierten Peptidfragmenten an Polystyrol-Polyoxyethylen zur Affinitätschromatographie Synthesis of Immobilized Peptide Fragments on Polystyrene-Polyoxyethylene for Affinity Chromatography  | | | Abstract
| Polystyrene-polyoxyethylene craft copolymers have been used for step-wise peptide synthesis. After completion of synthesis the protecting groups are cleaved under acidic conditions, where the polymer-peptide bond is stable. These gels in comparison to polystyrene peptide gels, show better properties for applications in affinity chromatography as well as synthesis on solid supports, because the advantageous properties of polystyrene beads are combined with the excellent spacer behavior of polyoxyethylene chains (mobility, solvation by water and organic solvents). Peptide gels with polylysine sequences have been synthesized as highly selective stationary phases for the separation of the homologous oligo desoxyribonucleotides (d7)n with n = 1—3. The principal possibilities of these gels for affinity chromatography | | |
Reference
| Z. Naturforsch. 42c, 455—460 (1987); received December 1 1986 | | |
Published
| 1987 | | |
Keywords
| birthday Affinity Chromatography, Immobilization, Liquid-Solid-Phase, Peptides, Synthesis | | |
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| default:Reihe_C/42/ZNC-1987-42c-0455.pdf | | | Identifier
| ZNC-1987-42c-0455 | | | Volume
| 42 | |
6 | Author
| Toshiro Matsui, Tomoyuki Oki, Yutaka Osajima | Requires cookie* | | Title
| Isolation and Identification of Peptidic a-Glucosidase Inhibitors Derived from Sardine Muscle Hydrolyzate  | | | Abstract
| We report here the isolation of a-glucosidase (A G H) inhibitory peptides derived from sardine muscle hydrolyzate, which was prepared by digestion with Bacillus licheniformis alka line protease. A s a result of reversed-phase HPLC purification, two A G H inhibitory peptides were isolated from a D EA E -Sephadex A-25 column eluate. The peptides were identified as follows: V al-Trp (IC50 = 22.6 mM) and T ry -T y r -P r o -L e u (IC50 = 3.7 mM). A G H inhibitory studies of T r y -T y r -P r o -L e u and its derivatives demonstrated the importance of the tri peptide chain length as well as the hydrophobic aromatic amino acid tyrosine at the N-terminus, aliphatic amino acids at the C-terminus, as well as an amide proton from the peptide chain at the middle position of the tri-peptide to develop AGH inhibition activity. | | |
Reference
| Z. Naturforsch. 54c, 259 (1999); received August 25/October 5 1998 | | |
Published
| 1999 | | |
Keywords
| a-G lucosidase Inhibition, Diabetes, Sardine Muscle Hydrolyzate, Peptide | | |
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| default:Reihe_C/54/ZNC-1999-54c-0259.pdf | | | Identifier
| ZNC-1999-54c-0259 | | | Volume
| 54 | |
9 | Author
| IvankaG. Stankova3, M. Ario, F. Simeonovb, Vera Maximova0, AngelS. Galabov0, EvgenyV. Golovinskyd | Requires cookie* | | Title
| Synthesis and Anti-Virus Activity of Some Nucleosides Analogues  | | | Abstract
| New 3'-, 5'-, 5-bromo-2'-deoxyuridine (3 a -g) and 3'-, 5'-thymidine (4 a -i) analogues with amino acid and peptide residues were synthesized and evaluated for antiviral activity. The influence of long peptide chains, essential amino acids and the effect of this structural modifi cation on the antiviral activity has been also reported. Three 5-bromo-2'-deoxyuridine derivatives containing glycyl-, glycyl-glycyl-and glycyl-gly-cyl-glycyl-residues (3a, 3b, 3c) showed a strong activity against the herpes virus PsRV and a moderate one vs. HSV-1. The corresponding thymidine analogues were considerably less effective, and only com pounds 4d and 4h showed a borderline effect against PsRV. | | |
Reference
| Z. Naturforsch. 54c, 75—83 (1999); received August lO/October 20 1998 | | |
Published
| 1999 | | |
Keywords
| 5-Bromo-2'-Deoxyuridine, Thymidine, Amino Acids, Peptides, Antiherpes Activity | | |
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| default:Reihe_C/54/ZNC-1999-54c-0075.pdf | | | Identifier
| ZNC-1999-54c-0075 | | | Volume
| 54 | |
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