d-Galacturonic Acid: A Highly Reactive Compound in Nonenzymatic Browning. 2. Formation of Amino-Specific Degradation Products

2015 ◽  
Vol 63 (28) ◽  
pp. 6457-6465 ◽  
Author(s):  
Steffen Wegener ◽  
Maria-Anna Bornik ◽  
Lothar W. Kroh
1987 ◽  
Author(s):  
F Keller ◽  
P Schanzenbächer ◽  
F Dati ◽  
J Huber ◽  
K kochsiek

The new drug pro-urokinase, a proenzyme of urokinase (scu-PA), seems to have advantages in comparison with other fibrinolytic agents. Properties like higher fibrin specifity, non-systemic activity and lower antigenity may lead to a lower rate of complications. In a pilot study 10 patients with acute myocardial infarction have been treated under angiographical control with pro-urokinase (3-9 millions IU) by i.v. application. In case of no perfusion a further administration of streptokinase was carried on. The blood samples were obtained at therapy begin and after 5, 10, 30, 60 and 120 minutes. The therapy monitoring was performed by determination of established haemostasis parameters, like fibrinogen, fibrin(ogen)-split products (FSP), a2-antiplasmin. Plasminogen and batroxobin-time. Furthermore, the diagnostic relevance of new laboratory tests for fibrinolysis, D-Dimer and thrombin-anti thrombin Ill-complex (TAT) has been investigated considering some typical follow-ups. D-Dimer were determined by latex agglutination test and TAT by enzyme immunoassay.Generally the application of pro-urokinase in contrast to streptokinase results in minimal changes of the classic fibrinolysis parameters like fibrinogen, FSP, batroxobin-time etc. demonstrating no systemic lysis. The appearance of plasmic degradation products of cross-linked fibrin (D-Dimer) is a specific indi-cater of the release of thrombotic material. Other non-specific degradation products (fibrinogenolysis) were detected by the measurement of FSP. In some cases in which perfusion ocurred an increase of TAT followed by a rapid decrease was observed. This indicates a higher thromboplastic activity which may originate from the infarcted area producing TAT complex formation.


2001 ◽  
Vol 333 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Paul W Needs ◽  
Neil M Rigby ◽  
Stephen G Ring ◽  
Alistair J MacDougall

Holzforschung ◽  
2000 ◽  
Vol 54 (1) ◽  
pp. 39-54 ◽  
Author(s):  
T. I. Eglinton ◽  
M. A. Goñi ◽  
J. J. Boon ◽  
E. R. E. van der Hage ◽  
N. Terashima ◽  
...  

Summary A suite of four samples of xylem tissue from Ginkgo (Ginkgo biloba L.) shoots grown in a medium containing coniferin 13C-labeled at differing side-chain carbon atoms were studied using thermal and chemical degradation methods in combination with molecular-level isotopic analyses. The aims of the study were threefold: (1) to verify conclusions drawn from Nuclear Magnetic Resonance experiments previously performed on the same tissue samples, (2) to investigate degradation mechanisms and (3) to quantify the proportion of labeled material in each sample. Isotopic analysis of specific degradation products revealed the presence of the label exclusively within lignin-derived (phenolic) products and that the label is retained in its original position on the side-chain. These two results clearly indicate that there is no “scrambling” of carbon atoms as a result of thermal or chemical degradation, and thus lend strong support to analytical pyrolysis and chemolysis as viable approaches for structural investigations of the lignin macromolecule. Indeed, the isotopic enrichment of specific degradation products provides new evidence for certain types of linkages within the lignin polymer. The distribution and isotopic composition of the degradation products also strongly suggest an origin from newly-formed lignin as opposed to DHP-type products or unreacted substrate. As such, the data provides added confidence in the selective labeling approach for elucidation of the structure and biosynthesis of lignin. Isotopic mass balance calculations reveal that certain pyrolysis and CuO oxidation products show enhanced labeling which may be indicative of preferential incorporation of their specific precursors into the growing lignin macromolecule or heterogeneous lignin deposition.


1999 ◽  
Vol 209 (3-4) ◽  
pp. 261-265 ◽  
Author(s):  
Bettina Cämmerer ◽  
Bronislaw L. Wedzicha ◽  
L. W. Kroh

1987 ◽  
Vol 65 (9) ◽  
pp. 2069-2076 ◽  
Author(s):  
Gerald Oliver Aspinall ◽  
Lev Khondo ◽  
Bruce Alan Williams

Reduction of uronic acid residues in permethylated polysaccharides from Sterculiaurens and S. caudata gums, followed by transformation of the resulting hexose into 6-deoxy-6-iodohexose residues, affords modified polysaccharides that undergo depolymerization on treatment with zinc dust. The main products after reduction with sodium borohydride are hexenitolterminated oligosaccharides. Their structures have been assigned as members of a series of O-[α-L-rhamnopyranosyl]-(1 → 3)-1,2-dideoxyhex-1-enitol derivatives, with and without attendant β-D-galactopyranosyl substituents, on the basis of nuclear magnetic resonance and mass spectral data and compositional analysis of trideuteriomethylated derivatives. The structures of the polysaccharides have been reassessed in the light of these and other experiments, and may now be formulated as containing a backbone of alternating 4-linked α-D-galacturonic acid and 2-linked α-L-rhamnopyranose residues bearing a minimum of three types of side chains attached at specific sites. Characterization of some of the degradation products provides evidence that limited degradation had occurred during methylation of the glycuronans.


2019 ◽  
Vol 20 (2) ◽  
pp. 447 ◽  
Author(s):  
Kathrin Maly ◽  
Inna Schaible ◽  
Jana Riegger ◽  
Rolf Brenner ◽  
Andrea Meurer ◽  
...  

Osteoarthritis (OA) is a progressive joint disease characterized by a continuous degradation of the cartilage extracellular matrix (ECM). The expression of the extracellular glycoprotein thrombospondin-4 (TSP-4) is known to be increased in injured tissues and involved in matrix remodeling, but its role in articular cartilage and, in particular, in OA remains elusive. In the present study, we analyzed the expression and localization of TSP-4 in healthy and OA knee cartilage by reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry, and immunoblot. We found that TSP-4 protein expression is increased in OA and that expression levels correlate with OA severity. TSP-4 was not regulated at the transcriptional level but we detected changes in the anchorage of TSP-4 in the altered ECM using sequential protein extraction. We were also able to detect pentameric and fragmented TSP-4 in the serum of both healthy controls and OA patients. Here, the total protein amount was not significantly different but we identified specific degradation products that were more abundant in sera of OA patients. Future studies will reveal if these fragments have the potential to serve as OA-specific biomarkers.


2021 ◽  
Author(s):  
Bernhard Timo Werner ◽  
Aline Koch ◽  
Ena Secic ◽  
Jonas Engelhardt ◽  
Lukas Jelonek ◽  
...  

In filamentous fungi, gene silencing by RNA interference (RNAi) shapes many biological processes, including pathogenicity. Recently, fungal small RNAs (sRNAs) have been shown to act as effectors that disrupt gene activity in interacting plant hosts, thereby undermining their defence responses. We show here that the devastating mycotoxin-producing ascomycete Fusarium graminearum ( Fg ) utilizes DICER-like (DCL)-dependent sRNAs to target defence genes in two Poaceae hosts, barley ( Hordeum vulgare Hv ) and Brachypodium distachyon ( Bd ). We identified 104 Fg -sRNAs with sequence homology to host genes that were repressed during interactions of Fg and Hv , while they accumulated in plants infected by the DCL double knock-out (dKO) mutant PH1- dcl1/2 . The strength of target gene expression correlated with the abundance of the corresponding Fg -sRNA. Specifically, the abundance of three tRNA-derived fragments (tRFs) targeting immunity-related Ethylene overproducer 1-like 1 ( HvEOL1) and three Poaceae orthologues of Arabidopsis thaliana BRI1-associated receptor kinase 1 ( HvBAK1, HvSERK2 and BdSERK2 ) was dependent on fungal DCL. Additionally, RNA-ligase-mediated Rapid Amplification of cDNA Ends (RLM-RACE) identified infection-specific degradation products for the three barley gene transcripts, consistent with the possibility that tRFs contribute to fungal virulence via targeted gene silencing.


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