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ChemMedChem Mar 2023Two series of macrocyclic plasmin inhibitors with a C-terminal benzylamine group were synthesized. The substitution of the N-terminal phenylsulfonyl group of a...
Two series of macrocyclic plasmin inhibitors with a C-terminal benzylamine group were synthesized. The substitution of the N-terminal phenylsulfonyl group of a previously described inhibitor provided two analogues with sub-nanomolar inhibition constants. Both compounds possess a high selectivity against all other tested trypsin-like serine proteases. Furthermore, a new approach was used to selectively introduce asymmetric linker segments. Two of these compounds inhibit plasmin with K values close to 2 nM. For the first time, four crystal structures of these macrocyclic inhibitors could be determined in complex with a Ser195Ala microplasmin mutant. The macrocyclic core segment of the inhibitors binds to the open active site of plasmin without any steric hindrance. This binding mode is incompatible with other trypsin-like serine proteases containing a sterically demanding 99-hairpin loop. The crystal structures obtained experimentally explain the excellent selectivity of this inhibitor type as previously hypothesized.
Topics: Fibrinolysin; Antifibrinolytic Agents; Trypsin; Protein Binding; Serine Proteinase Inhibitors
PubMed: 36710259
DOI: 10.1002/cmdc.202200632 -
Gematologiia I Transfuziologiia 1992
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Journal of Thrombosis and Haemostasis :... Jul 2011Two issues have held the focus of thrombolysis research for over 50 years, namely, choosing between a plasminogen activator (PA) or plasmin as the best therapeutic agent... (Review)
Review
Two issues have held the focus of thrombolysis research for over 50 years, namely, choosing between a plasminogen activator (PA) or plasmin as the best therapeutic agent and choosing between systemic or local administration. The original plasmin product of the 1950s was both ineffective and contaminated with PA, and catheter technology was not yet developed for routine clinical use. For decades, clinical practice has focused on PA and systemic administration, but today, PAs are often administered by catheter into thrombosed vessels, notably for peripheral arterial and graft occlusion and deep vein thrombosis, and increasingly for acute ischaemic stroke. Despite using catheter-delivered therapy, bleeding complications still occur, most severely expressed as symptomatic intracranial haemorrhage. New experimental data indicate that we should now reconsider plasmin as a viable, even preferable, thrombolytic agent. Plasmin requires catheter delivery to achieve thrombolysis, but this technical issue has been solved with modern technology and widespread presence of interventional suites. After local administration, plasmin will lyse thrombi; thereafter, any plasmin in the circulation will be rapidly neutralised. Pre-clinical studies confirm that plasmin has marked haemostatic safety advantage over t-PA. After more than 50 years, the field has come full circle, and plasmin as the thrombolytic agent and catheter use for local delivery of agent may represent a step forward in thrombolytic therapy.
Topics: Biomedical Research; Clinical Trials as Topic; Fibrinolysin; Fibrinolysis; History, 20th Century; History, 21st Century; Thrombosis
PubMed: 21781273
DOI: 10.1111/j.1538-7836.2011.04370.x -
ChemMedChem Nov 2022There is an emerging interest in utilizing synthetic multivalent inhibitors that comprise of multiple inhibitor moieties linked on a common scaffold to achieve strong...
There is an emerging interest in utilizing synthetic multivalent inhibitors that comprise of multiple inhibitor moieties linked on a common scaffold to achieve strong and selective enzyme inhibition. As multivalent inhibition is impacted by valency and linker length, in this study, we explore the effect of multivalent benzamidine inhibitors of varying valency and linker length on plasmin inhibition. Plasmin is an endogenous enzyme responsible for digesting fibrin present in blood clots. Monovalent plasmin(ogen) inhibitors are utilized clinically to treat hyperfibrinolysis-associated bleeding events. Benzamidine is a reversible inhibitor that binds to plasmin's active site. Herein, multivalent benzamidine inhibitors of varying valencies (mono-, bi- and tri-valent) and linker lengths (∼1-12 nm) were synthesized to systematically study their effect on plasmin inhibition. Inhibition assays were performed using a plasmin substrate (S-2251) to determine inhibition constants (Ki). Pentamidine (shortest bivalent) and Tri-AMB (shortest trivalent) were the strongest inhibitors with Ki values of 2.1±0.8 and 3.9±1.7 μM, respectively. Overall, increasing valency and decreasing linker length, increases effective local concentration of the inhibitor and therefore, resulted in stronger inhibition of plasmin via statistical rebinding. This study aids in the design of multivalent inhibitors that can achieve desired enzyme inhibition by means of modulating valency and linker length.
Topics: Fibrinolysin; Benzamidines
PubMed: 36111842
DOI: 10.1002/cmdc.202200364 -
Nature Communications Dec 2021Cardiac ATTR amyloidosis, a serious but much under-diagnosed form of cardiomyopathy, is caused by deposition of amyloid fibrils derived from the plasma protein...
Cardiac ATTR amyloidosis, a serious but much under-diagnosed form of cardiomyopathy, is caused by deposition of amyloid fibrils derived from the plasma protein transthyretin (TTR), but its pathogenesis is poorly understood and informative in vivo models have proved elusive. Here we report the generation of a mouse model of cardiac ATTR amyloidosis with transgenic expression of human TTR. The model is characterised by substantial ATTR amyloid deposits in the heart and tongue. The amyloid fibrils contain both full-length human TTR protomers and the residue 49-127 cleavage fragment which are present in ATTR amyloidosis patients. Urokinase-type plasminogen activator (uPA) and plasmin are abundant within the cardiac and lingual amyloid deposits, which contain marked serine protease activity; knockout of α-antiplasmin, the physiological inhibitor of plasmin, enhances amyloid formation. Together, these findings indicate that cardiac ATTR amyloid deposition involves local uPA-mediated generation of plasmin and cleavage of TTR, consistent with the previously described mechano-enzymatic hypothesis for cardiac ATTR amyloid formation. This experimental model of ATTR cardiomyopathy has potential to allow further investigations of the factors that influence human ATTR amyloid deposition and the development of new treatments.
Topics: Amyloid; Amyloid Neuropathies, Familial; Animals; Cardiomyopathies; Fibrinolysin; Humans; Mice, Transgenic; Plaque, Amyloid; Prealbumin; Protein Folding; Proteolysis
PubMed: 34876572
DOI: 10.1038/s41467-021-27416-z -
Current Opinion in Structural Biology Dec 2013Plasminogen is the zymogen form of plasmin, an enzyme that plays a fundamental role in the dissolution of fibrin clots, the extracellular matrix and other key proteins... (Review)
Review
Plasminogen is the zymogen form of plasmin, an enzyme that plays a fundamental role in the dissolution of fibrin clots, the extracellular matrix and other key proteins involved in immunity and tissue repair. Comprising seven distinct domains (an N-terminal Pan-apple domain (PAp), 5 kringle domains (KR) and the serine protease domain (SP)), plasminogen undergoes a complex, incompletely understood conformational change that is key to its activation. Here, we review our current understanding of the structural basis for plasminogen activation with regard to new insights derived from crystallographic and biochemical studies.
Topics: Bacterial Physiological Phenomena; Carbohydrate Metabolism; Disease; Fibrinolysin; Humans; Plasminogen
PubMed: 24252474
DOI: 10.1016/j.sbi.2013.10.006 -
Methods in Enzymology 1981
Topics: Fibrinolysin; Humans; Kinetics; Peptide Fragments; Plasminogen; Streptokinase
PubMed: 6210828
DOI: 10.1016/s0076-6879(81)80032-8 -
Journal of Biomedicine & Biotechnology 2012Plasmin, one of the most potent and reactive serine proteases, is involved in various physiological processes, including embryo development, thrombolysis, wound healing... (Review)
Review
Plasmin, one of the most potent and reactive serine proteases, is involved in various physiological processes, including embryo development, thrombolysis, wound healing and cancer progression. The proteolytic activity of plasmin is tightly regulated through activation of its precursor, plasminogen, only at specific times and in defined locales as well as through inhibition of active plasmin by its abundant natural inhibitors. By exploiting the plasminogen activating system and overexpressing distinct components of the plasminogen activation cascade, such as pro-uPA, uPAR and plasminogen receptors, malignant cells can enhance the generation of plasmin which in turn, modifies the tumor microenvironment to sustain cancer progression. While plasmin-mediated degradation and modification of extracellular matrix proteins, release of growth factors and cytokines from the stroma as well as activation of several matrix metalloproteinase zymogens, all have been a focus of cancer research studies for decades, the ability of plasmin to cleave transmembrane molecules and thereby to generate functionally important cleaved products which induce outside-in signal transduction, has just begun to receive sufficient attention. Herein, we highlight this relatively understudied, but important function of the plasmin enzyme as it is generated de novo at the interface between cross-talking cancer and host cells.
Topics: Animals; Cell Communication; Cell Membrane; Fibrinolysin; Humans; Models, Biological
PubMed: 23097597
DOI: 10.1155/2012/564259 -
Thrombosis Research 2008The physiological or pharmacological dissolution of thrombi is ultimately accomplished by the serine protease plasmin. Plasmin is derived from its precursor plasminogen... (Review)
Review
The physiological or pharmacological dissolution of thrombi is ultimately accomplished by the serine protease plasmin. Plasmin is derived from its precursor plasminogen in a reaction catalyzed by plasminogen activators (PAs) such as tissue-type plasminogen activator (tPA). In the middle of the last century, plasmin was investigated as a potential thrombolytic agent. However, technical obstacles led to the abandonment of this agent, and by the 1970s PAs had become the standard of care for pharmacological management of various thrombotic conditions. Talecris Biotherapeutics has developed a methodology to prepare the plasmin product (Human) TAL-05-00018 that is rendered inactive by low pH (pH 3.0-4.0) until it is delivered directly to the neutral environment of a thrombus by catheter-assisted administration. TAL-05-00018 undergoes a rigorous manufacturing process to ensure a final product free from unactivated plasminogen, streptokinase, enveloped and non-enveloped viruses and prion proteins; generating an extremely high-purity product with a shelf life of three years at ambient temperature. TAL-05-00018 has shown promise in in vitro and pre-clinical studies, and in early clinical trials, demonstrating a dose-dependant reduction in clot weight that compares favorably to that seen with tPA. Several other direct thrombolytics have also been developed, including the recombinant, modified deletion mutant of plasmin TAL6003 (Talecris Biotherapeutics), which retains all the major functional attributes of full-length plasmin.
Topics: Fibrinolysin; Fibrinolytic Agents; Humans; Structure-Activity Relationship; Thrombosis
PubMed: 18718639
DOI: 10.1016/j.thromres.2008.06.018 -
Thrombosis Et Diathesis Haemorrhagica.... 1967
Review
Topics: Aging; Antifibrinolytic Agents; Arteriosclerosis; Blood Coagulation; Fibrinolysin; Fibrinolysis; Hemodynamics; Humans; Wound Healing
PubMed: 4231071
DOI: No ID Found