Analysis of acidic and phenolic biomass degradation products by isotachophoresis

1984 ◽  
Vol 318 (1) ◽  
pp. 30-32 ◽  
Author(s):  
G. K. Bonn ◽  
P. A. Pfeifer ◽  
H. Hörmeyer ◽  
O. Bobleter
Keyword(s):  
Degradation Products ◽  
Biomass Degradation

Collagen degradation products modulate matrix metalloproteinase expression in cultured articular chondrocytes

2005 ◽  
Vol 24 (1) ◽  
pp. 63-70 ◽  
Author(s):  
M. Fichter ◽  
U. Körner ◽  
J. Schömburg ◽  
L. Jennings ◽  
A. A. Cole ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Articular Chondrocytes ◽  
Degradation Products ◽  
Collagen Degradation ◽  
Collagen Degradation Products

Structural Studies of Fibrinolysis by Electron and Light Microscopy

1999 ◽  
Vol 82 (08) ◽  
pp. 277-282 ◽  
Author(s):  
Yuri Veklich ◽  
Jean-Philippe Collet ◽  
Charles Francis ◽  
John W. Weisel
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Plasminogen Activator ◽  
Structural Changes ◽  
Molecular Mechanisms ◽  
Degradation Products ◽  
Molecular Model ◽  
Three Dimensional ◽  
Tissue Type ◽  
Type Plasminogen Activator

IntroductionMuch is known about the fibrinolytic system that converts fibrin-bound plasminogen to the active protease, plasmin, using plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator. Plasmin then cleaves fibrin at specific sites and generates soluble fragments, many of which have been characterized, providing the basis for a molecular model of the polypeptide chain degradation.1-3 Soluble degradation products of fibrin have also been characterized by transmission electron microscopy, yielding a model for their structure.4 Moreover, high resolution, three-dimensional structures of certain fibrinogen fragments has provided a wealth of information that may be useful in understanding how various proteins bind to fibrin and the overall process of fibrinolysis (Doolittle, this volume).5,6 Both the rate of fibrinolysis and the structures of soluble derivatives are determined in part by the fibrin network structure itself. Furthermore, the activation of plasminogen by t-PA is accelerated by the conversion of fibrinogen to fibrin, and this reaction is also affected by the structure of the fibrin. For example, clots made of thin fibers have a decreased rate of conversion of plasminogen to plasmin by t-PA, and they generally are lysed more slowly than clots composed of thick fibers.7-9 Under other conditions, however, clots made of thin fibers may be lysed more rapidly.10 In addition, fibrin clots composed of abnormally thin fibers formed from certain dysfibrinogens display decreased plasminogen binding and a lower rate of fibrinolysis.11-13 Therefore, our increasing knowledge of various dysfibrinogenemias will aid our understanding of mechanisms of fibrinolysis (Matsuda, this volume).14,15 To account for these diverse observations and more fully understand the molecular basis of fibrinolysis, more knowledge of the physical changes in the fibrin matrix that precede solubilization is required. In this report, we summarize recent experiments utilizing transmission and scanning electron microscopy and confocal light microscopy to provide information about the structural changes occurring in polymerized fibrin during fibrinolysis. Many of the results of these experiments were unexpected and suggest some aspects of potential molecular mechanisms of fibrinolysis, which will also be described here.

Fibrinogen Bastia (γ 318 Asp → Tyr) a Novel Abnormal Fibrinogen Characterized by Defective Fibrin Polymerization

1999 ◽  
Vol 82 (12) ◽  
pp. 1639-1643 ◽  
Author(s):  
Karim Chabane Lounes ◽  
Claudine Soria ◽  
Antoine Valognes ◽  
Marie France Turchini ◽  
Jaap Koopman ◽  
...  
Keyword(s):  
Calcium Ions ◽  
Clinical Symptoms ◽  
Degradation Products ◽  
Base Substitution ◽  
Chain Gene ◽  
Fibrinogen Concentration ◽  
Clotting Time ◽  
Terminal Part ◽  
Fibrin Polymerization ◽  
Chain Sequence

SummaryA new congenital dysfibrinogen, Fibrinogen Bastia, was discovered in a 20-year-old woman with no clinical symptoms. The plasma thrombin-clotting time was severely prolonged. The functional plasma fibrinogen concentration was low (0.2 mg/ml), whereas the immunological concentration was normal (2.9 mg/ml). Purified fibrinogen Bastia displayed a markedly prolonged thrombin-clotting time related to a delayed thrombin-induced fibrin polymerization. Both the thrombin-clotting time and the fibrin polymerization were partially corrected by the addition of calcium ions. The anomaly of fibrinogen Bastia was found to be located in the γ-chain since by SDS-PAGE performed according to the method of Laemmli two γ-chains were detected, one normal and one with an apparently lower molecular weight. Furthermore, analysis of plasmin degradation products demonstrated that calcium ions only partially protect fibrinogen Bastia γ-chain against plasmin digestion, suggesting that the anomaly is located in the C-terminal part of the γ-chain. Sequence analysis of PCR-amplified genomic DNA fragments of the propositus demonstrated a single base substitution (G → T) in the exon VIII of the γ chain gene, resulting in the amino acid substitution 318 Asp (GAC) → Tyr (TAC). The PCR clones were recloned and 50% of them contained the mutation, indicating that the patient was heterozygous. These data indicate that residue Asp 318 is important for normal fibrin polymerization and the protective effect of calcium ions against plasmin degradation of the C-terminal part of the γ-chain.

Sign in / Sign up

Export Citation Format

Share Document