Studies on the Mechanism of Action of Synthetic Antifibrinolytics

Landmann, H

doi:10.1055/s-0038-1647769

Cited by 13 publications

(7 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It seems to be well established that plasmin possesses at least one site (other than the active site) that interacts with antifibrinolytic amino acids and that the second site(s) bind antifibrinolytic amino acids more strongly than does. the active site (Landmann, 1973;Richli & Otawsky, 1975;Christensen, 1978). The effects of antifibrinolytic amino acids on the reaction of the inhibitor with plasmin may be explained by assuming that the first step of the reaction is either dependent on second site(s) of plasmin or on some site(s) of the inhibitor at which antifibrinolytic amino acids bind.…”

Section: Discussionmentioning

confidence: 99%

“…KD is 5mM for 6-aminohexanoic acid. The dissociation constant for the 6-aminohexanoic acid-plasmin complex in which 6-aminohexanoic acid interacts with the active site ofplasmin (competitive inhibition) is 58 mM (Landmann, 1973;Christensen, 1978). The observed inhibition of the reaction ofthe inhibitor with plasmin therefore is not due to blocking of the active site of plasmin.…”

Section: Purification Step Plasmamentioning

confidence: 99%

See 1 more Smart Citation

Purification and reaction mechanism of the primary inhibitor of plasmin from human plasma

Christensen

Clemmensen

1978

Biochemical Journal

View full text Add to dashboard Cite

The primary inhibitor of plasmin in human plasma was purified by a four-step procedure involving fractional (NH(4))(2)SO(4) precipitation, ion-exchange chromatography on a column of DEAE-Sepharose CL-6B and affinity chromatography on both a plasminogen-CH-Sepharose 4B column and a column of 6-aminohexanoic acid covalently coupled through the carboxylate function to AH-Sepharose 4B. No impurities in the final preparation could be detected when tested by immunoelectrophoresis against a range of specific antisera or against rabbit anti-human serum. On polyacrylamide-gel electrophoresis the inhibitor preparation showed a single band. The dissociation constant for the inhibitor-plasminogen complex was determined to be approx. 3mum at pH7.8. The reactions of the inhibitor with human plasmin and with bovine trypsin were studied. Comparison of the results obtained confirms the hypothesis previously presented, namely that the reaction of the inhibitor with plasmin involves at least two steps, the initial rapid formation of an enzyme-inhibitor complex followed by a slow irreversible transition to another complex. The results also indicate that the reaction of the inhibitor with trypsin involves just a single, irreversible step, so that this reaction seems to be less complicated than that of the inhibitor with plasmin. The ways in which 6-aminohexanoic acid influences the reactions were studied. The same value for the dissociation constant (approx. 26mum) for 6-aminohexanoic acid is obtained for both its effect on the reaction of the inhibitor with trypsin and for competitive inhibition of trypsin. The inhibitory effect of 6-aminohexanoic acid thus seems to be due to its blocking of the active site of trypsin. In contrast with this, the inhibitory effects of l-lysine and 6-aminohexanoic acid on the inhibitor-plasmin reaction occur at concentrations much too low to affect the active site of plasmin. The possible dependence of the reaction of the inhibitor with plasmin on a second site(s) on plasmin is discussed.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Purification Step Plasmamentioning

confidence: 99%

Purification and reaction mechanism of the primary inhibitor of plasmin from human plasma

Christensen

Clemmensen

1978

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…Glu-plasminogen binds less strongly to fibrin than the partially degraded Lys-plasminogen [18]. Different sites in plasminogen may be involved in fibrin binding: lysine-binding sites [19] which interact with carboxy-terminal lysine residues, aminohexyl (AH) sites [20] which interact with intrachain lysine residues, and possibly benzamidine-binding sites [21,22] which interact with arginine residues. Fewer studies have been done on the t-PA-fibrin binding.…”

mentioning

confidence: 99%

Binding of tissue‐type plasminogen activator to fibrinogen fragments

Bosma¹,

Rijken²,

Nieuwenhuizen³

1988

European Journal of Biochemistry

View full text Add to dashboard Cite

In order to localize the binding site(s) for tissue-type plasminogen activator (t-PA) in the fibrin(ogen) molecule, the following binding assay was developed. Two-chain t-PA was immobilized onto microtitration plates. The t-PA-coated plates were then incubated with fibrinogen and various fibrinogen fragments. The extent of binding was quantified with enzyme-labelled antibodies against fibrin(ogen) and its fragments. Hardly any binding to t-PA was observed with fibrinogen or fragments X, Y and E; a moderate binding was observed with fragments D,,,, and DEGTA and a strong binding with the cyanogen bromide fragment FCB-2 ( K d apparent = 140 nM). The binding of fibrinogen and its fragments to immobilized Lys-plasminogen was measured by the same method as a control for the binding assay. Results were in line with literature data: virtually no binding to Lys-plasminogen with fibrinogen or fragments X and Y, a moderate binding with fragments D,,,,, DEGTA and E and a strong binding with FCB-2 (Kd apparent = 70 nM). The stimulatory capacity of the various fragments on the Lysplasminogen activation by t-PA, as studied in a spectrophotometric assay, was found to be absent for fragment E, low for fibrinogen, fragments X, Y , D,,,, and DEGTA, and high for FCB-2. It is concluded that a t-PA-binding site resides in the C-terminal globular domains of fibrinogen from which fragments D and FCB-2 originate. The site is hidden in the native fibrinogen molecule and in early fibrinogen degradation products. Binding of both Lys-plasminogen and t-PA appears to be required for a stimulator of the plasminogen activation, as illustrated by fragment E which only binds Lys-plasminogen and has no stimulatory capacity.Tissue-type plasminogen activator (t-PA) converts plasminogen, an inactive zymogen, into active plasmin and therefore plays an important role in fibrin clot dissolution. In the absence of fibrin, plasminogen is poorly activated by t-PA, but in the presence of fibrin (not fibrinogen) plasminogen activation by t-PA is greatly enhanced [l, 21. Fibrin polymerization is a decisive factor in the stimulatory effect [3, 41, and stimulation is further potentiated upon limited fibrin degradation [5 -81. Several plasmin-produced fragments of fibrinogen (e.g. fragments D,,,, and DEGTA) and a CNBrproduced fibrinogen fragment, FCB-2, also accelerate the plasminogen activation by t-PA, whereas no acceleration is seen with fragment E [9, 101. A stimulatory site is located on Kinetic studies suggest that acceleration of plasminogen activation by fibrin can be ascribed to the formation of a cyclic ternary complex of plasminogen, t-PA and fibrin [13, 141. This concept is supported by direct binding studies, showing that both t-PA and plasminogen form complexes with fibrin. The plasminogen -fibrin interaction has been studied quite extensively (for review see [15]). Plasminogen-binding sites are less well exposed in fibrinogen than in fibrin [16]. They are located both in fragments D and E [17]. Glu-plasminogen binds less strongly to fibrin than t...

show abstract

“…This organic compound belongs to type II anti‐fibrinolytic agent class. It is indicated in the treatment of fibrotic skin problems, such as the Peyronie's disease 78 …”

Section: Types Of Hemostatic Agentsmentioning

confidence: 99%

Hemostatic strategies for uncontrolled bleeding: A comprehensive update

et al. 2021

View full text Add to dashboard Cite

Uncontrolled bleeding remains the leading cause of morbidity and mortality across the entire macrocosm. It refers to excessive loss of blood that occurs inside of body, due to unsuccessful platelet plug formation at the injury site. It is not only limited to the battlefield, but remains the second leading cause of death amongst the civilians, as a result of traumatic injury. Startlingly, there are no effective treatments currently available, to cater the issue of internal bleeding, even though early intervention is of utmost significance in minimizing the mortality rates associated with it. The fatal issue of uncontrolled bleeding is ineffectively being dealt with the use of pressure dressings, tourniquet, and surgical procedures. This is not a practical approach in combat arenas or in emergency situations, where the traumatic injury inflicted is deep inside the body, and cannot be addressed externally, by the application of topical dressings. This review focuses on the traditional hemostatic agents that are used to augment the process of hemostasis, such as mineral zeolites, chitosan based products, biologically active agents, anti‐fibrinolytics, absorbable agents, and albumin and glutaraldehyde, as well as the micro‐ and nano‐based hemostatic agents such as synthocytes, thromboerythrocytes, thrombosomes, and the synthetic platelets.

show abstract

Studies on the Mechanism of Action of Synthetic Antifibrinolytics

Cited by 13 publications

References 20 publications

Purification and reaction mechanism of the primary inhibitor of plasmin from human plasma

Purification and reaction mechanism of the primary inhibitor of plasmin from human plasma

Binding of tissue‐type plasminogen activator to fibrinogen fragments

Hemostatic strategies for uncontrolled bleeding: A comprehensive update

Contact Info

Product

Resources

About