Search results for "eps"
showing 10 items of 1777 documents
Synthese sterisch gehinderter Peptide und Depsipeptide nach einem Säurechlorid-Verfahren mit 2-Phosphonioethoxycarbonyl-(Peoc-)Aminosäuren und -Hydro…
1982
2-(Triphenylphosphonio)ethoxycarbonyl-(Peoc-)aminosauren 1 und -hydroxysauren 5 werden mit Oxalylchlorid in bei Raumtemp. stabile Saurechloride 2 bzw. 6 ubergefuhrt. Mit diesen aktivierten Verbindungen werden sterisch gehinderte Amidbindungen — z. B. in den geschutzten Valin-Peptiden 3a—g und in Hydroxyacyl-Dipeptiden 7 — hergestellt. Nach Schutzgruppenabspaltung aus der voll geschutzten Form 7a entsteht so die Sporidesmolsaure B (9a), die in ihren Eigenschaften mit dem Abbauprodukt aus dem Sporidesmolid I ubereinstimmt. Trotz zweimaliger Anwendung der Saurechlorid-Kondensation ist keine Racemisierung eingetreten. Syntheses of Sterically Hindered Peptides and Depsipeptides by Means of an Ac…
Activities of some peptidases and proteinases in germinating kidney bean, Phaseolus vulgaris
1986
The activities of aminopeptidase (EC 3.4.11), dipeptidase (EC 3.4.13), carboxypeptidase (EC 3.4.16), naphthylamidase (EC 3.4.11) and proteinases (EC 3.4.21) were assayed in extracts from the cotyledons and the axial tissues of resting and germinating kidney beans (Phaseolus vulgaris L. cv. Processor). The activities of the alkaline peptidases (aminopeptidase hydrolyzing Leu-Tyr at pH 9.2 and dipeptidase acting on Ala-Gly at pH 8.5) and naphthylamidases (hydrolyzing Leu-β-naphthylamide at pH 6.4) were high in the cotyledons of resting seeds, but decreased during germination. This decrease was faster than the loss of the total nitrogen. On the contrary, the activities of carboxypeptidase (hyd…
Synthesis of dehydrodipeptide esters and their evaluation as inhibitors of cathepsin C
2015
The procedures for the synthesis of esters of dehydropeptides containing C-terminal (Z)-dehydrophenylalanine and dehydroalanine have been elaborated. These esters appeared to be moderate or weak inhibitors of cathepsin C, with some of them exhibiting slow-binding behavior. As shown by molecular modeling, they are rather bound at the surface of the enzyme and are not submersed in its binding cavities. Electronic supplementary material The online version of this article (doi:10.1007/s00044-015-1366-0) contains supplementary material, which is available to authorized users.
Characterization of HLA-DR- and TCR-binding residues of an immunodominant and genetically permissive peptide of the 16-kDa protein of Mycobacterium t…
2004
The 16-kDa protein of Mycobacterium tuberculosis represents an important antigenic target during bacillary latency and, consequently, should be considered as candidate subunit vaccine component. In this study, we have used CD4 T cell clones that recognize the peptide p91-110, an immunodominant and genetically permissive epitope, in the context of five different HLA-DR molecules and truncated and substituted variants of this peptide, to identify the minimal binding sequence (HLA-DR-binding core) and the minimal stimulatory sequence (TCR-binding core), as well as the residues that contact HLA-DR molecules and the TCR. We have found a common 9-mer sequence, spanning amino acids 93-101, as the …
Mode of action of herbicidal derivatives of aminomethylenebisphosphonic acid. Part II. Reversal of herbicidal action by aromatic amino acids
1997
The herbicidal action of N-pyridylaminomethylenebisphosphonic acids is accompanied by an impairment of anthocyanin biosynthesis. This suggests that they might act as inhibitors of some steps in aromatic amino acid biosynthesis. Herbicidal effects were reversed by aromatic amino acids using both bacterial and plant models, a finding that strongly supports this hypothesis. Structural features of these compounds suggest the sixth enzyme in the shikimate pathway 5-enol-pyruvoylshikimate-3-phosphate (EPSP) synthase as a possible target, since a strong structural similarity exists between aminomethylenebisphosphonic acid and an inhibitor of EPSP synthase, the herbicide glyphosate. This is, howeve…
Mapping antigenic epitopes of potato virus Y with antibodies affinity-purified by using overlapping synthetic peptides
1994
Synthetic, overlapping peptides representing the entire amino acid sequence of potato virus Y (PVY) coat protein were used to affinity-purify antibodies from polyclonal antisera to PVY. In testing the binding of the purified antibodies to PVY particles, antigenic epitopes were identified. The N-terminal and C-terminal regions of the PVY coat protein were found to contain most of the antigenic epitopes. The results will facilitate the development of detection methods for PVY based on synthetic peptides.
Cathepsin L in Normal and Pathological Bone Remodeling
2011
Abstract Cathepsin L is a ubiquitous lysosomal cysteine endopeptidase that is mainly involved in the metabolic turnover of intracellular proteins. However, it is now well established that this enzyme may also be implicated in the regulation of other important biological processes includ- ing bone resorption. Therefore, altered expression levels of Cathepsin L may result in disturbances of bone homeo- stasis and, eventually, in the onset of pathological condi- tions associated with altered bone turnover. These observations support the concept that Cathepsin L may be regarded as an additional target for the development of novel therapeutic options for the treatment of patients with bone disea…
Über die mikrobiologische Umwandlung N-haltiger Substrate. 3. Mitt.: Über die Konstitutionsaufklärung von Umwandlungsprodukten des 5-Hydroxyindols du…
1968
In Schuttelkulturen von Cordyceps militaris entstehen aus 5-Hydroxyindol zwei neue Substanzen, die nach Chromatographie an Polyamidsaulen und nachfolgender Isolierung auf Grund ihres chemischen Verhaltens gegenuber Diazomethan sowie ihrer Elementaranalysen, IR-, Massen-und NMR-Spektren als ω-N-Acetyl-5-hydroxy-tryptophan und ω-N-Acetyl-serotonin identifiziert wurden. Two new substances are produced in submerged cultures of Cordyceps militaris fed with 5-hydroxyindole. These substances, separated by column chromatography with polyamide and isolated afterwards, have been identified as ω-N-acetyl-5-hydroxytryptophan and ω-N-acetyl-serotonin by their reaction with diazomethane, by elementary an…
Zum Tryptophanabbau bei Cordyceps militaris-Stämmen in saprophytischen Kulturen
1973
Summary The degradation of tryptophan in two strains of the Cordyceps miliraris Link in saprophytic culture was examined: both fungi showed different behavior patterns. In the strain I all the tryptophan is subject to lateral catenoid oxidation and the metabolite of this catabolism process are fixed. In strain II under identical experimental conditions the tryptophan is decomposed by the “Ehrlich-mechanism”. Independently of the above, N-acetylization reactions occur in both strains. Here both the L-isomers and the D-isomers of tryptophan are metabolized. Both isomers can be acetylized.
Differential antiepileptic effects of the organic calcium antagonists verapamil and flunarizine in neurons of organotypic neocortical explants from n…
1988
Effects of the organic calcium antagonists verapamil and flunarizine on pentylenetetrazol induced paroxysmal depolarizations were tested in organotypic neocortical explants taken from neonatal rats. In these in vitro experiments the papaverin derivative verapamil depressed, and finally abolished, epileptic discharges in all cases. The piperazine derivative flunarizine, however, which is known to suppress epileptic discharges in hippocampal CA3 neurons (Bingmann and Speckmann 1986), showed no significant antiepileptic effects in the explanted neocortical neurons. Thus, the present findings may indicate that the suppressive action of flunarizine on the generation of paroxysmal depolarizations…