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Nazarzadeh Zare E, Khorsandi D, Zarepour A, Yilmaz H, Agarwal T, Hooshmand S, Mohammadinejad R, Ozdemir F, Sahin O, Adiguzel S, Khan H, Zarrabi A, Sharifi E, Kumar A, Mostafavi E, Kouchehbaghi NH, Mattoli V, Zhang F, Jucaud V, Najafabadi AH, Khademhosseini A. Biomedical applications of engineered heparin-based materials. Bioact Mater 2024; 31:87-118. [PMID: 37609108 PMCID: PMC10440395 DOI: 10.1016/j.bioactmat.2023.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/03/2023] [Accepted: 08/01/2023] [Indexed: 08/24/2023] Open
Abstract
Heparin is a negatively charged polysaccharide with various chain lengths and a hydrophilic backbone. Due to its fascinating chemical and physical properties, nontoxicity, biocompatibility, and biodegradability, heparin has been extensively used in different fields of medicine, such as cardiovascular and hematology. This review highlights recent and future advancements in designing materials based on heparin for various biomedical applications. The physicochemical and mechanical properties, biocompatibility, toxicity, and biodegradability of heparin are discussed. In addition, the applications of heparin-based materials in various biomedical fields, such as drug/gene delivery, tissue engineering, cancer therapy, and biosensors, are reviewed. Finally, challenges, opportunities, and future perspectives in preparing heparin-based materials are summarized.
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Affiliation(s)
| | - Danial Khorsandi
- Terasaki Institute for Biomedical Innovation, Los Angeles, CA, 90024, United States
| | - Atefeh Zarepour
- Department of Biomedical Engineering, Faculty of Engineering and Natural Sciences, Istinye University, Sariyer, Istanbul, 34396, Turkey
| | - Hulya Yilmaz
- Nanotechnology Research and Application Center (SUNUM), Sabanci University, Istanbul, 34956, Turkey
| | - Tarun Agarwal
- Department of Bio-Technology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, AP, India
| | - Sara Hooshmand
- Nanotechnology Research and Application Center (SUNUM), Sabanci University, Istanbul, 34956, Turkey
| | - Reza Mohammadinejad
- Research Center of Tropical and Infectious Diseases, Kerman University of Medical Sciences, Kerman, Iran
| | - Fatma Ozdemir
- Nanotechnology Research and Application Center (SUNUM), Sabanci University, Istanbul, 34956, Turkey
| | - Onur Sahin
- Department of Basic Pharmacy Sciences, Faculty of Pharmacy, Istinye University, Istanbul, Turkey
| | - Sevin Adiguzel
- Nanotechnology Research and Application Center (SUNUM), Sabanci University, Istanbul, 34956, Turkey
| | - Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University, Mardan, 23200, Pakistan
| | - Ali Zarrabi
- Department of Biomedical Engineering, Faculty of Engineering and Natural Sciences, Istinye University, Sariyer, Istanbul, 34396, Turkey
| | - Esmaeel Sharifi
- Department of Tissue Engineering and Biomaterials, School of Advanced Medical Sciences and Technologies, Hamadan University of Medical Sciences, Hamadan, Iran
- Institute of Polymers, Composites and Biomaterials - National Research Council (IPCB-CNR), Viale J.F. Kennedy 54 - Mostra D'Oltremare pad. 20, 80125, Naples, Italy
| | - Arun Kumar
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Ebrahim Mostafavi
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Stanford Cardiovascular Institute, Stanford University, School of Medicine, Stanford, CA, 94305, USA
| | | | - Virgilio Mattoli
- Istituto Italiano di Tecnologia, Centre for Materials Interfaces, Viale Rinaldo Piaggio 34, Pontedera, Pisa, 56025, Italy
| | - Feng Zhang
- The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, Zhejiang, China
| | - Vadim Jucaud
- Terasaki Institute for Biomedical Innovation, Los Angeles, CA, 90024, United States
| | | | - Ali Khademhosseini
- Terasaki Institute for Biomedical Innovation, Los Angeles, CA, 90024, United States
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2
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Wu D, Prem A, Xiao J, Salsbury FR. Thrombin - A Molecular Dynamics Perspective. Mini Rev Med Chem 2024; 24:1112-1124. [PMID: 37605420 DOI: 10.2174/1389557523666230821102655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/08/2023] [Accepted: 07/15/2023] [Indexed: 08/23/2023]
Abstract
Thrombin is a crucial enzyme involved in blood coagulation, essential for maintaining circulatory system integrity and preventing excessive bleeding. However, thrombin is also implicated in pathological conditions such as thrombosis and cancer. Despite the application of various experimental techniques, including X-ray crystallography, NMR spectroscopy, and HDXMS, none of these methods can precisely detect thrombin's dynamics and conformational ensembles at high spatial and temporal resolution. Fortunately, molecular dynamics (MD) simulation, a computational technique that allows the investigation of molecular functions and dynamics in atomic detail, can be used to explore thrombin behavior. This review summarizes recent MD simulation studies on thrombin and its interactions with other biomolecules. Specifically, the 17 studies discussed here provide insights into thrombin's switch between 'slow' and 'fast' forms, active and inactive forms, the role of Na+ binding, the effects of light chain mutation, and thrombin's interactions with other biomolecules. The findings of these studies have significant implications for developing new therapies for thrombosis and cancer. By understanding thrombin's complex behavior, researchers can design more effective drugs and treatments that target thrombin.
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Affiliation(s)
- Dizhou Wu
- Department of Physics, Wake Forest University, Winston-Salem, NC, 27106, USA
| | - Athul Prem
- Department of Physics, Wake Forest University, Winston-Salem, NC, 27106, USA
| | - Jiajie Xiao
- Department of Physics, Wake Forest University, Winston-Salem, NC, 27106, USA
- Freenome, South San Francisco, CA, 94080, USA
| | - Freddie R Salsbury
- Department of Physics, Wake Forest University, Winston-Salem, NC, 27106, USA
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3
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Kosinski R, Perez JM, Schöneweiß EC, Ruiz-Blanco YB, Ponzo I, Bravo-Rodriguez K, Erkelenz M, Schlücker S, Uhlenbrock G, Sanchez-Garcia E, Saccà B. The role of DNA nanostructures in the catalytic properties of an allosterically regulated protease. SCIENCE ADVANCES 2022; 8:eabk0425. [PMID: 34985948 PMCID: PMC8730604 DOI: 10.1126/sciadv.abk0425] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 11/10/2021] [Indexed: 06/04/2023]
Abstract
DNA-scaffolded enzymes typically show altered kinetic properties; however, the mechanism behind this phenomenon is still poorly understood. We address this question using thrombin, a model of allosterically regulated serine proteases, encaged into DNA origami cavities with distinct structural and electrostatic features. We compare the hydrolysis of substrates that differ only in their net charge due to a terminal residue far from the cleavage site and presumably involved in the allosteric activation of thrombin. Our data show that the reaction rate is affected by DNA/substrate electrostatic interactions, proportionally to the degree of DNA/enzyme tethering. For substrates of opposite net charge, this leads to an inversion of the catalytic response of the DNA-scaffolded thrombin when compared to its freely diffusing counterpart. Hence, by altering the electrostatic environment nearby the encaged enzyme, DNA nanostructures interfere with charge-dependent mechanisms of enzyme-substrate recognition and may offer an alternative tool to regulate allosteric processes through spatial confinement.
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Affiliation(s)
- Richard Kosinski
- Bionanotechnology, CENIDE and ZMB, University of Duisburg-Essen, 45117 Essen, Germany
| | - Joel Mieres Perez
- Computational Biochemistry, ZMB, University of Duisburg-Essen, 45117 Essen, Germany
| | - Elisa-C. Schöneweiß
- Bionanotechnology, CENIDE and ZMB, University of Duisburg-Essen, 45117 Essen, Germany
| | | | - Irene Ponzo
- Dynamic Biosensors GmbH, 82152 Martinsried, Germany
| | | | - Michael Erkelenz
- Physical Chemistry, CENIDE and ZMB, University of Duisburg-Essen, 45117 Essen, Germany
| | - Sebastian Schlücker
- Physical Chemistry, CENIDE and ZMB, University of Duisburg-Essen, 45117 Essen, Germany
| | | | - Elsa Sanchez-Garcia
- Computational Biochemistry, ZMB, University of Duisburg-Essen, 45117 Essen, Germany
| | - Barbara Saccà
- Bionanotechnology, CENIDE and ZMB, University of Duisburg-Essen, 45117 Essen, Germany
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Abstract
COVID-19 brought a scientific revolution since its emergence in Wuhan, China, in December 2019. Initially, the SARS-CoV-2 virus came to attention through its effects on the respiratory system. However, its actions in many other organs also have been discovered almost daily. As enzymes are indispensable to uncountable biochemical reactions in the human body, it is not surprising that some enzymes are of relevance to COVID-19 pathophysiology. Past evidence from SARS-CoV and MERS-CoV outbreaks provided hints about the role of enzymes in SARS-CoV-2 infection. In this setting, ACE-2 is an enzyme of great importance since it is the cell entry receptor for SARS-CoV-2. Clinical data elucidate patterns of enzymatic alterations in COVID-19, which could be associated with organ damage, prognosis, and clinical complications. Further, viral mutations can create new disease behaviors, and these effects are related to the activity of enzymes. This review will discuss the main enzymes related to COVID-19, summarizing the findings on their role in viral entry mechanism, the consequences of their dysregulation, and the effects of SARS-CoV-2 mutations on them.
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Exosite Binding in Thrombin: A Global Structural/Dynamic Overview of Complexes with Aptamers and Other Ligands. Int J Mol Sci 2021; 22:ijms221910803. [PMID: 34639143 PMCID: PMC8509272 DOI: 10.3390/ijms221910803] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/24/2021] [Accepted: 10/01/2021] [Indexed: 12/13/2022] Open
Abstract
Thrombin is the key enzyme of the entire hemostatic process since it is able to exert both procoagulant and anticoagulant functions; therefore, it represents an attractive target for the developments of biomolecules with therapeutic potential. Thrombin can perform its many functional activities because of its ability to recognize a wide variety of substrates, inhibitors, and cofactors. These molecules frequently are bound to positively charged regions on the surface of protein called exosites. In this review, we carried out extensive analyses of the structural determinants of thrombin partnerships by surveying literature data as well as the structural content of the Protein Data Bank (PDB). In particular, we used the information collected on functional, natural, and synthetic molecular ligands to define the anatomy of the exosites and to quantify the interface area between thrombin and exosite ligands. In this framework, we reviewed in detail the specificity of thrombin binding to aptamers, a class of compounds with intriguing pharmaceutical properties. Although these compounds anchor to protein using conservative patterns on its surface, the present analysis highlights some interesting peculiarities. Moreover, the impact of thrombin binding aptamers in the elucidation of the cross-talk between the two distant exosites is illustrated. Collectively, the data and the work here reviewed may provide insights into the design of novel thrombin inhibitors.
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Kovach IM. Proton Bridging in Catalysis by and Inhibition of Serine Proteases of the Blood Cascade System. Life (Basel) 2021; 11:396. [PMID: 33925363 PMCID: PMC8146069 DOI: 10.3390/life11050396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/24/2021] [Accepted: 04/26/2021] [Indexed: 11/24/2022] Open
Abstract
Inquiries into the participation of short hydrogen bonds in stabilizing transition states and intermediate states in the thrombin, factor Xa, plasmin and activated protein C-catalyzed reactions revealed that specific binding of effectors at Sn, n = 1-4 and S'n, n = 1-3 and at remote exosites elicit complex patterns of hydrogen bonding and involve water networks. The methods employed that yielded these discoveries include; (1) kinetics, especially partial or full kinetic deuterium solvent isotope effects with short cognate substrates and also with the natural substrates, (2) kinetic and structural probes, particularly low-field high-resolution nuclear magnetic resonance (1H NMR), of mechanism-based inhibitors and substrate-mimic peptide inhibitors. Short hydrogen bonds form at the transition states of the catalytic reactions at the active site of the enzymes as they do with mechanism-based covalent inhibitors of thrombin. The emergence of short hydrogen bonds at the binding interface of effectors and thrombin at remote exosites has recently gained recognition. Herein, I describe our contribution, a confirmation of this discovery, by low-field 1H NMR. The principal conclusion of this review is that proton sharing at distances below the sum of van der Waals radii of the hydrogen and both donor and acceptor atoms contribute to the remarkable catalytic prowess of serine proteases of the blood clotting system and other enzymes that employ acid-base catalysis. Proton bridges also play a role in tight binding in proteins and at exosites, i.e., allosteric sites, of enzymes.
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Affiliation(s)
- Ildiko M Kovach
- Department of Chemistry, The Catholic University of America, Washington, DC 20064, USA
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Lira AL, Ferreira RS, Oliva MLV, Sousa AA. Regulation of Thrombin Activity with Ultrasmall Nanoparticles: Effects of Surface Chemistry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:7991-8001. [PMID: 32590899 DOI: 10.1021/acs.langmuir.0c01352] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nanomaterials displaying well-tailored sizes and surface chemistries can provide novel ways with which to modulate the structure and function of enzymes. Recently, we showed that gold nanoparticles (AuNPs) in the ultrasmall size regime could perform as allosteric effectors inducing partial inhibition of thrombin activity. We now find that the nature of the AuNP surface chemistry controls the interactions to the anion-binding exosites 1 and 2 on the surface of thrombin, the allosterically induced changes to the active-site conformation, and, by extension, the enzymatic activity. Ultrasmall AuNPs passivated with p-mercaptobenzoic acid ligands (AuMBA) and a peptide-based (Ac-ECYN) biomimetic coat (AuECYN) were utilized in our investigations. Remarkably, we found that while AuMBA binds to exosites 1 and 2, AuECYN interacts primarily with exosite 2. It was further established that AuMBA behaves as a "mild denaturant" of thrombin leading to catalytic dysfunction over time. Conversely, AuECYN resembles a proper allosteric effector leading to partial and reversible inhibition of the activity. Collectively, our findings reveal how the distinct binding modes of different AuNP types may uniquely influence thrombin structure and catalysis. The present study further contributes to our understanding of how synthetic nanomaterials could be exploited in the allosteric regulation of enzymes.
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Affiliation(s)
- André L Lira
- Department of Biochemistry, Federal University of São Paulo, São Paulo, SP 04044-020, Brazil
| | - Rodrigo S Ferreira
- Department of Biochemistry, Federal University of São Paulo, São Paulo, SP 04044-020, Brazil
| | - Maria Luiza V Oliva
- Department of Biochemistry, Federal University of São Paulo, São Paulo, SP 04044-020, Brazil
| | - Alioscka A Sousa
- Department of Biochemistry, Federal University of São Paulo, São Paulo, SP 04044-020, Brazil
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8
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Sodium-induced population shift drives activation of thrombin. Sci Rep 2020; 10:1086. [PMID: 31974511 PMCID: PMC6978324 DOI: 10.1038/s41598-020-57822-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 01/06/2020] [Indexed: 02/04/2023] Open
Abstract
The equilibrium between active E and inactive E* forms of thrombin is assumed to be governed by the allosteric binding of a Na+ ion. Here we use molecular dynamics simulations and Markov state models to sample transitions between active and inactive states. With these calculations we are able to compare thermodynamic and kinetic properties depending on the presence of Na+. For the first time, we directly observe sodium-induced conformational changes in long-timescale computer simulations. Thereby, we are able to explain the resulting change in activity. We observe a stabilization of the active form in presence of Na+ and a shift towards the inactive form in Na+-free simulations. We identify key structural features to quantify and monitor this conformational shift. These include the accessibility of the S1 pocket and the reorientation of W215, of R221a and of the Na+ loop. The structural characteristics exhibit dynamics at various timescales: Conformational changes in the Na+ binding loop constitute the slowest observed movement. Depending on its orientation, it induces conformational shifts in the nearby substrate binding site. Only after this shift, residue W215 is able to move freely, allowing thrombin to adopt a binding-competent conformation.
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9
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Shi CC, Chen TR, Zhang QH, Wei LH, Huang C, Zhu YD, Liu HB, Bai YK, Wang FJ, Guo WZ, Zhang LR, Ge GB. Inhibition of human thrombin by the constituents of licorice: inhibition kinetics and mechanistic insights through in vitro and in silico studies. RSC Adv 2020; 10:3626-3635. [PMID: 35492646 PMCID: PMC9048847 DOI: 10.1039/c9ra09203j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/13/2020] [Indexed: 12/30/2022] Open
Abstract
Thrombin inhibition therapy is a practical strategy to reduce thrombotic and cardiovascular risks via blocking the formation of blood clots. This study aimed to identify naturally occurring thrombin inhibitors from licorice (one of the most popular edible herbs), as well as to investigate their inhibitory mechanisms. Among all tested licorice constituents, licochalcone A was found as the most efficacious agent against human thrombin (IC50 = 7.96 μM). Inhibition kinetic analyses demonstrated that licochalcone A was a mixed inhibitor against thrombin-mediated Z-Gly-Gly-Arg-AMC acetate hydrolysis, with a Ki value of 12.23 μM. Furthermore, mass spectrometry-based chemoproteomic assays and molecular docking simulations revealed that licochalcone A could bind to human thrombin at both exosite I and the catalytic site. In summary, our findings demonstrated that the chalcones isolated from licorice were a new class of direct thrombin inhibitors, also suggesting that licochalcone A was a promising lead compound for developing novel anti-thrombotic agents. Licochalcone A, a bioactive compound from licorice, displayed strong inhibition of thrombin.![]()
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10
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Active thrombin produced by the intestinal epithelium controls mucosal biofilms. Nat Commun 2019; 10:3224. [PMID: 31324782 PMCID: PMC6642099 DOI: 10.1038/s41467-019-11140-w] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 06/25/2019] [Indexed: 01/07/2023] Open
Abstract
Proteolytic homeostasis is important at mucosal surfaces, but its actors and their precise role in physiology are poorly understood. Here we report that healthy human and mouse colon epithelia are a major source of active thrombin. We show that mucosal thrombin is directly regulated by the presence of commensal microbiota. Specific inhibition of luminal thrombin activity causes macroscopic and microscopic damage as well as transcriptomic alterations of genes involved in host-microbiota interactions. Further, luminal thrombin inhibition impairs the spatial segregation of microbiota biofilms, allowing bacteria to invade the mucus layer and to translocate across the epithelium. Thrombin cleaves the biofilm matrix of reconstituted mucosa-associated human microbiota. Our results indicate that thrombin constrains biofilms at the intestinal mucosa. Further work is needed to test whether thrombin plays similar roles in other mucosal surfaces, given that lung, bladder and skin epithelia also express thrombin. The roles played by thrombin in the human intestinal mucosa are unclear. Here, the authors show that the commensal microbiota modulates epithelial production of active thrombin, which controls biofilm growth and contributes to protection of the mucosa from bacterial invasion.
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11
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Xiao J, Salsbury FR. Na +-binding modes involved in thrombin's allosteric response as revealed by molecular dynamics simulations, correlation networks and Markov modeling. Phys Chem Chem Phys 2019; 21:4320-4330. [PMID: 30724273 PMCID: PMC6993936 DOI: 10.1039/c8cp07293k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The monovalent sodium ion (Na+) is a critical modulator of thrombin. However, the mechanism of thrombin's activation by Na+ has been widely debated for more than twenty years. Details of the linkage between thrombin and Na+ remain vague due to limited temporal and spatial resolution in experiments. In this work, we combine microsecond scale atomic-detailed molecular dynamics simulations with correlation network analyses and hidden Markov modeling to probe the detailed thermodynamic and kinetic picture of Na+-binding events and their resulting allosteric responses in thrombin. We reveal that ASP189 and ALA190 comprise a stable Na+-binding site (referred as "inner" Na+-binding site) along with the previously known one (referred as "outer" Na+-binding site). The corresponding newly identified Na+-binding mode introduces significant allosteric responses in thrombin's regulatory regions by stabilizing selected torsion angles of residues responsive to Na+-binding. Our Markov model indicates that the bound Na+ prefers to transfer between the two Na+-binding sites when an unbinding event takes place. These results suggest a testable hypothesis of a substrate-driven Na+ migration (ΔG ∼ 1.7 kcal mol-1) from the "inner" Na+-binding site to the "outer" one during thrombin's catalytic activities. The binding of a Na+ ion at the "inner" Na+-binding site should be inferred as a prerequisite for thrombin's efficient recognition to the substrate, which opens a new angle for our understanding of Na+-binding's allosteric activation on thrombin and sheds light on detailed processes in thrombin's activation.
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Affiliation(s)
- Jiajie Xiao
- Department of Physics, Wake Forest University, Winston Salem, NC, USA.
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13
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Lira AL, Ferreira RS, Torquato RJS, Oliva MLV, Schuck P, Sousa AA. Allosteric inhibition of α-thrombin enzymatic activity with ultrasmall gold nanoparticles. NANOSCALE ADVANCES 2019; 1:378-388. [PMID: 30931428 PMCID: PMC6394888 DOI: 10.1039/c8na00081f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/21/2018] [Indexed: 05/20/2023]
Abstract
The catalytic activity of enzymes can be regulated by interactions with synthetic nanoparticles (NPs) in a number of ways. To date, however, the potential use of NPs as allosteric effectors has not been investigated in detail. Importantly, targeting allosteric (distal) sites on the enzyme surface could afford unique ways to modulate the activity, allowing for either enzyme activation, partial or full inhibition. Using p-mercaptobenzoic acid-coated ultrasmall gold NPs (AuMBA) and human α-thrombin as a model system, here we experimentally tested the hypothesis that enzyme activity could be regulated through ultrasmall NP interactions at allosteric sites. We show that AuMBA interacted selectively and reversibly around two positively charged regions of the thrombin surface (exosites 1 and 2) and away from the active site. NP complexation at the exosites transmitted long-range structural changes over to the active site, altering both substrate binding affinity and catalysis. Significantly, thrombin activity was partially reduced - but not completely inhibited - by interactions with AuMBA. These findings indicate that interactions of proteins with ultrasmall NPs may mimic a typical biomolecular complexation event, and suggest the prospect of using ultrasmall particles as synthetic receptors to allosterically regulate protein function.
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Affiliation(s)
- André L Lira
- Department of Biochemistry , Federal University of São Paulo , São Paulo , SP , Brazil .
| | - Rodrigo S Ferreira
- Department of Biochemistry , Federal University of São Paulo , São Paulo , SP , Brazil .
| | - Ricardo J S Torquato
- Department of Biochemistry , Federal University of São Paulo , São Paulo , SP , Brazil .
| | - Maria Luiza V Oliva
- Department of Biochemistry , Federal University of São Paulo , São Paulo , SP , Brazil .
| | - Peter Schuck
- National Institute of Biomedical Imaging and Bioengineering , National Institutes of Health , Bethesda , MD , USA
| | - Alioscka A Sousa
- Department of Biochemistry , Federal University of São Paulo , São Paulo , SP , Brazil .
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14
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Recent advances in transition-metal dichalcogenides based electrochemical biosensors: A review. Biosens Bioelectron 2017; 97:305-316. [DOI: 10.1016/j.bios.2017.06.011] [Citation(s) in RCA: 236] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/25/2017] [Accepted: 06/07/2017] [Indexed: 11/22/2022]
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15
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Xiao J, Salsbury FR. Molecular dynamics simulations of aptamer-binding reveal generalized allostery in thrombin. J Biomol Struct Dyn 2017; 35:3354-3369. [PMID: 27794633 PMCID: PMC6876308 DOI: 10.1080/07391102.2016.1254682] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 10/21/2016] [Indexed: 01/11/2023]
Abstract
Thrombin is an attractive target for antithrombotic therapy due to its central role in thrombosis and hemostasis as well as its role in inducing tumor growth, metastasis, and tumor invasion. The thrombin-binding DNA aptamer (TBA), is under investigation for anticoagulant drugs. Although aptamer binding experiments have been revealed various effects on thrombin's enzymatic activities, the detailed picture of the thrombin's allostery from TBA binding is still unclear. To investigate thrombin's response to the aptamer-binding at the molecular level, we compare the mechanical properties and free energy landscapes of the free and aptamer-bound thrombin using microsecond-scale all-atom GPU-based molecular dynamics simulations. Our calculations on residue fluctuations and coupling illustrate the allosteric effects of aptamer-binding at the atomic level, highlighting the exosite II, 60s, γ and the sodium loops, and the alpha helix region in the light chains involved in the allosteric changes. This level of details clarifies the mechanisms of previous experimentally demonstrated phenomena, and provides a prediction of the reduced autolysis rate after aptamer-binding. The shifts in thrombin's ensemble of conformations and free energy surfaces after aptamer-binding demonstrate that the presence of bound-aptamer restricts the conformational freedom of thrombin suggesting that conformational selection, i.e. generalized allostery, is the dominant mechanism of thrombin-aptamer binding. The profound perturbation on thrombin's mechanical and thermodynamic properties due to the aptamer-binding, which was revealed comprehensively as a generalized allostery in this work, may be exploited in further drug discovery and development.
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Affiliation(s)
- Jiajie Xiao
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
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16
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Xiao J, Melvin RL, Salsbury FR. Mechanistic insights into thrombin's switch between "slow" and "fast" forms. Phys Chem Chem Phys 2017; 19:24522-24533. [PMID: 28849814 PMCID: PMC5719506 DOI: 10.1039/c7cp03671j] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Thrombin is a multifunctional enzyme that plays an important role in blood coagulation, cell growth, and metastasis. Depending upon the binding of sodium ions, thrombin presents significantly different enzymatic activities. In the environment with sodium ions, thrombin is highly active in cleaving the coagulated substrates and this is referred to as the "fast" form; in the environment without sodium ions, thrombin turns catalytically less active and is in the "slow" form. Although many experimental studies over the last two decades have attempted to reveal the structural and kinetic differences between these two forms, it remains vague and disputed how the functional switch between the "fast" and "slow" forms is mediated by Na+ cations. In this work, we employ microsecond-scale all-atom molecular dynamics simulations to investigate the differences in the structural ensembles in sodium-bound/unbound and potassium-bound/unbound thrombin. Our calculations indicate that the regulatory regions, including the 60s, γ loops, and exosite I and II, are primarily affected by both the bound and unbound cations. Conformational free energy surfaces, estimated from principal component analysis, further reveal the existence of multiple conformational states. The binding of a cation introduces changes in the distribution of these states. Through comparisons with potassium-binding, the binding of sodium ions appears to shift the population toward conformational states that might be catalytically favorable. Our study of thrombin in the presence of sodium/potassium ions suggests Na+-mediated generalized allostery is the mechanism of thrombin's functional switch between the "fast" and "slow" forms.
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Affiliation(s)
- Jiajie Xiao
- Department of Physics, Wake Forest University, Winston Salem, NC, USA.
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17
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Ryzhkova EP. Alternative enzymes as a special strategy for the adaptation of procaryotic organisms (Review). APPL BIOCHEM MICRO+ 2017. [DOI: 10.1134/s0003683817050131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Esterson YB, Pellerito JS. Recurrence of Thrombin-Injected Pseudoaneurysms Under Ultrasound Guidance: A 10-Year Retrospective Analysis. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2017; 36:1617-1624. [PMID: 28407277 DOI: 10.7863/ultra.16.09063] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 10/14/2016] [Indexed: 06/07/2023]
Abstract
OBJECTIVES Ultrasound-guided thrombin injection has become standard treatment for extremity pseudoaneurysms. Our specific aims were to determine the procedural success rate, the procedural complication rate, and the factors associated with pseudoaneurysm recurrence. METHODS A total of 262 consecutive cases of ultrasound-guided thrombin repair of pseudoaneurysms were identified between January 1, 2006, and March 20, 2016. The procedural and follow-up ultrasound studies were reviewed. Outcomes of interest included procedural success (defined as complete thrombosis at the time of injection and on a follow-up examination), incomplete pseudoaneurysm thrombosis, and postprocedural recurrence. Postprocedural pseudoaneurysm recurrences were compared to procedural successes with regard to patient demographics, pseudoaneurysm characteristics, amount of thrombin injected, and periprocedural laboratory values. RESULTS Procedural success occurred in 85.7% of cases. Complications occurred in 3.0% of cases. The mean patient age ± SD was 72.3 ± 11.3 years. The median amount of thrombin injected was 500 U (interquartile range, 400 U). The median follow-up time was 1 day (interquartile range, 0 days). A pseudoaneurysm size of 2 cm or larger and thrombocytopenia were significant independent predictors of pseudoaneurysm recurrence (P = .003 and .03, respectively). The odds ratios for pseudoaneurysm recurrence were 2.29 for pseudoaneurysm size of 2 cm or larger (P = .03) and 1.04 for thrombocytopenia (P = .04). CONCLUSIONS Thrombin injection of pseudoaneurysms is an off-label procedure with few complications and a high success rate. Follow-up imaging is recommended in all pseudoaneurysms that are 2 cm or larger and in patients with thrombocytopenia.
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Affiliation(s)
- Yonah B Esterson
- Department of Radiology, Northwell Health System, Hofstra Northwell School of Medicine, Manhasset, New York, USA
| | - John S Pellerito
- Department of Radiology, Northwell Health System, Hofstra Northwell School of Medicine, Manhasset, New York, USA
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19
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Discovery of a novel conformational equilibrium in urokinase-type plasminogen activator. Sci Rep 2017; 7:3385. [PMID: 28611361 PMCID: PMC5469797 DOI: 10.1038/s41598-017-03457-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 04/27/2017] [Indexed: 01/15/2023] Open
Abstract
Although trypsin-like serine proteases have flexible surface-exposed loops and are known to adopt higher and lower activity conformations, structural determinants for the different conformations have remained largely obscure. The trypsin-like serine protease, urokinase-type plasminogen activator (uPA), is central in tissue remodeling processes and also strongly implicated in tumor metastasis. We solved five X-ray crystal structures of murine uPA (muPA) in the absence and presence of allosteric molecules and/or substrate-like molecules. The structure of unbound muPA revealed an unsuspected non-chymotrypsin-like protease conformation in which two β-strands in the core of the protease domain undergoes a major antiparallel-to-parallel conformational transition. We next isolated two anti-muPA nanobodies; an active-site binding nanobody and an allosteric nanobody. Crystal structures of the muPA:nanobody complexes and hydrogen-deuterium exchange mass spectrometry revealed molecular insights about molecular factors controlling the antiparallel-to-parallel equilibrium in muPA. Together with muPA activity assays, the data provide valuable insights into regulatory mechanisms and conformational flexibility of uPA and trypsin-like serine proteases in general.
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20
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Bufadienolides from Kalanchoe daigremontiana as thrombin inhibitors— In vitro and in silico study. Int J Biol Macromol 2017; 99:141-150. [DOI: 10.1016/j.ijbiomac.2017.02.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 02/03/2017] [Indexed: 11/22/2022]
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21
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Wu S. Loop-driven conformational transition between the alternative and collapsed form of prethrombin-2: targeted molecular dynamics study. J Biomol Struct Dyn 2016; 35:119-127. [PMID: 27471844 DOI: 10.1080/07391102.2015.1134347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Two distinct crystal structures of prethrombin-2, the alternative and collapsed forms, are elucidated by X-ray crystallogrphy. We analyzed the conformational transition from the alternative to the collapsed form employing targeted molecular dynamics (TMD) simulation. Despite small RMSD difference in the two X-ray crystal structures, some hydrophobic residues (W60d, W148, W215, and F227) show a significant difference between the two conformations. TMD simulation shows that the four hydrophobic residues undergo concerted movement from dimer to trimer transition via tetramer state in the conformational change from the alternative to the collapsed form. We reveal that the concerted movement of the four hydrophobic residues is controlled by movement of specific loop regions behind. In this paper, we propose a sequential scenario for the conformational transition from the alternative form to the collapsed form, which is partially supported by the mutant W148A simulation.
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Affiliation(s)
- Sangwook Wu
- a Department of Physics , Pukyong National University , Busan 608-737 , Republic of Korea
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22
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Fechner LE, Albanyan B, Vieira VMP, Laurini E, Posocco P, Pricl S, Smith DK. Electrostatic binding of polyanions using self-assembled multivalent (SAMul) ligand displays - structure-activity effects on DNA/heparin binding. Chem Sci 2016; 7:4653-4659. [PMID: 30155113 PMCID: PMC6013769 DOI: 10.1039/c5sc04801j] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 04/07/2016] [Indexed: 01/11/2023] Open
Abstract
This paper reports that modifying the ligands in self-assembled multivalent (SAMul) displays has an impact on apparent binding selectivity towards two nanoscale biological polyanions - heparin and DNA. For the nanostructures assayed here, spermidine ligands are optimal for heparin binding but spermine ligands are preferred for DNA. Probing subtle differences in such nanoscale binding interfaces is a significant challenge, and as such, several experimental binding assays - competition assays and isothermal calorimetry - are employed to confirm differences in affinity and provide thermodynamic insights. Given the dynamic nature and hierarchical binding processes involved in SAMul systems, we employed multiscale modelling to propose reasons for the origins of polyanion selectivity differences. The modelling results, when expressed in thermodynamic terms and compared with the experimental data, suggest that DNA is a shape-persistent polyanion, and selectivity originates only from ligand preferences, whereas heparin is more flexible and adaptive, and as such, actively reinforces ligand preferences. As such, this study suggests that inherent differences between polyanions may underpin subtle binding selectivity differences, and that even simple electrostatic interfaces such as these can have a degree of tunability, which has implications for biological control and regulation on the nanoscale.
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Affiliation(s)
- Loryn E Fechner
- Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK .
| | - Buthaina Albanyan
- Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK .
| | - Vânia M P Vieira
- Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK .
| | - Erik Laurini
- Simulation Engineering (MOSE) Laboratory , Department of Engineering and Architectures (DEA) , University of Trieste , Trieste , 34127 , Italy .
| | - Paola Posocco
- Simulation Engineering (MOSE) Laboratory , Department of Engineering and Architectures (DEA) , University of Trieste , Trieste , 34127 , Italy .
| | - Sabrina Pricl
- Simulation Engineering (MOSE) Laboratory , Department of Engineering and Architectures (DEA) , University of Trieste , Trieste , 34127 , Italy .
| | - David K Smith
- Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK .
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23
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Allosteric Partial Inhibition of Monomeric Proteases. Sulfated Coumarins Induce Regulation, not just Inhibition, of Thrombin. Sci Rep 2016; 6:24043. [PMID: 27053426 PMCID: PMC4823711 DOI: 10.1038/srep24043] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/14/2016] [Indexed: 11/26/2022] Open
Abstract
Allosteric partial inhibition of soluble, monomeric proteases can offer major regulatory advantages, but remains a concept on paper to date; although it has been routinely documented for receptors and oligomeric proteins. Thrombin, a key protease of the coagulation cascade, displays significant conformational plasticity, which presents an attractive opportunity to discover small molecule probes that induce sub-maximal allosteric inhibition. We synthesized a focused library of some 36 sulfated coumarins to discover two agents that display sub-maximal efficacy (~50%), high potency (<500 nM) and high selectivity for thrombin (>150-fold). Michaelis-Menten, competitive inhibition, and site-directed mutagenesis studies identified exosite 2 as the site of binding for the most potent sulfated coumarin. Stern-Volmer quenching of active site-labeled fluorophore suggested that the allosteric regulators induce intermediate structural changes in the active site as compared to those that display ~80–100% efficacy. Antithrombin inactivation of thrombin was impaired in the presence of the sulfated coumarins suggesting that allosteric partial inhibition arises from catalytic dysfunction of the active site. Overall, sulfated coumarins represent first-in-class, sub-maximal inhibitors of thrombin. The probes establish the concept of allosteric partial inhibition of soluble, monomeric proteins. This concept may lead to a new class of anticoagulants that are completely devoid of bleeding.
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24
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Dynamics Govern Specificity of a Protein-Protein Interface: Substrate Recognition by Thrombin. PLoS One 2015; 10:e0140713. [PMID: 26496636 PMCID: PMC4619833 DOI: 10.1371/journal.pone.0140713] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 09/28/2015] [Indexed: 12/01/2022] Open
Abstract
Biomolecular recognition is crucial in cellular signal transduction. Signaling is mediated through molecular interactions at protein-protein interfaces. Still, specificity and promiscuity of protein-protein interfaces cannot be explained using simplistic static binding models. Our study rationalizes specificity of the prototypic protein-protein interface between thrombin and its peptide substrates relying solely on binding site dynamics derived from molecular dynamics simulations. We find conformational selection and thus dynamic contributions to be a key player in biomolecular recognition. Arising entropic contributions complement chemical intuition primarily reflecting enthalpic interaction patterns. The paradigm “dynamics govern specificity” might provide direct guidance for the identification of specific anchor points in biomolecular recognition processes and structure-based drug design.
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25
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A glassy carbon electrode modified with in-situ generated chromium-loaded CdS nanoprobes and heparin for ultrasensitive electrochemiluminescent determination of thrombin. Mikrochim Acta 2015. [DOI: 10.1007/s00604-015-1611-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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26
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Atkins WM. Biological messiness vs. biological genius: Mechanistic aspects and roles of protein promiscuity. J Steroid Biochem Mol Biol 2015; 151:3-11. [PMID: 25218442 PMCID: PMC4920067 DOI: 10.1016/j.jsbmb.2014.09.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/28/2014] [Accepted: 09/09/2014] [Indexed: 02/06/2023]
Abstract
In contrast to the traditional biological paradigms focused on 'specificity', recent research and theoretical efforts have focused on functional 'promiscuity' exhibited by proteins and enzymes in many biological settings, including enzymatic detoxication, steroid biochemistry, signal transduction and immune responses. In addition, divergent evolutionary processes are apparently facilitated by random mutations that yield promiscuous enzyme intermediates. The intermediates, in turn, provide opportunities for further evolution to optimize new functions from existing protein scaffolds. In some cases, promiscuity may simply represent the inherent plasticity of proteins resulting from their polymeric nature with distributed conformational ensembles. Enzymes or proteins that bind or metabolize noncognate substrates create 'messiness' or noise in the systems they contribute to. With our increasing awareness of the frequency of these promiscuous behaviors it becomes interesting and important to understand the molecular bases for promiscuous behavior and to distinguish between evolutionarily selected promiscuity and evolutionarily tolerated messiness. This review provides an overview of current understanding of these aspects of protein biochemistry and enzymology.
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Affiliation(s)
- William M Atkins
- Department of Medicinal Chemistry, Box 357610, University of Washington, Seattle, WA 98195-7610, USA.
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27
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Fernandes LG, de Morais ZM, Vasconcellos SA, Nascimento ALTO. Leptospira interrogans reduces fibrin clot formation by modulating human thrombin activity via exosite I. Pathog Dis 2015; 73:ftv001. [PMID: 25834144 DOI: 10.1093/femspd/ftv001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2014] [Indexed: 01/08/2023] Open
Abstract
Pathogenic bacteria of the genus Leptospira are the etiological agents of leptospirosis, a disease that affects humans and animals worldwide. Although there are an increasing number of studies on the biology of Leptospira, the mechanisms of pathogenesis are not yet understood. We report in this work that Leptospira interrogans FIOCRUZ L1-130 virulent, M20 culture attenuated and the saprophyte L. biflexa Patoc 1 strains do not bind prothrombin. Leptospiral binding to thrombin was detected with the virulent, followed by culture-attenuated M20, and practically none was observed with the saprophyte strain. The interaction of Leptospira with thrombin mostly occurs via exosite I, with a minor participation of catalytic site, as determined by employing the thrombin inhibitors hirugen, hirudin and argatroban. Leptospira interrogans binding to thrombin inhibits its catalytic activity reducing fibrin clot formation in thrombin-catalyzed reaction of fibrinogen. This inhibition was more efficient with the virulent FIOCRUZ L1-130 than with the M20 culture attenuated, while none was seen with the saprophyte strain, suggesting that this binding might be important for bacterial virulence. This is the first study reporting the binding of pathogenic Leptospira to thrombin promoting a decrease in fibrin clotting that could lead to hemorrhage, helping bacteria dissemination.
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Affiliation(s)
- Luis G Fernandes
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, São Paulo, SP 05503-900, Brazil Programa de Pós-Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, São Paulo 05508-900, Brazil
| | - Zenaide M de Morais
- Laboratório de Zoonoses Bacterianas do VPS, Faculdade de MedicinaVeterinária e Zootecnia da Universidade de São Paulo, São Paulo 05508-270, Brazil
| | - Silvio A Vasconcellos
- Laboratório de Zoonoses Bacterianas do VPS, Faculdade de MedicinaVeterinária e Zootecnia da Universidade de São Paulo, São Paulo 05508-270, Brazil
| | - Ana L T O Nascimento
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, São Paulo, SP 05503-900, Brazil Programa de Pós-Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, São Paulo 05508-900, Brazil
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28
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Zhao Q, Gao J. Sensitive and selective detection of thrombin by using a cyclic peptide as affinity ligand. Biosens Bioelectron 2014; 63:21-25. [PMID: 25048449 DOI: 10.1016/j.bios.2014.07.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/23/2014] [Accepted: 07/03/2014] [Indexed: 11/16/2022]
Abstract
Here we describe a sensitive assay for thrombin by using a high binding-affinity cyclic peptide against thrombin as affinity ligand. The cyclic peptide is immobilized on the magnetic beads or microplates to selectively capture thrombin. The enriched thrombin then catalyzes the cleavage of a substrate of thrombin to a detectable product. The detection of thrombin is finally achieved by measuring the generated product. This assay enables the detection of thrombin at tens fM in 100 µL of sample solution when fluorogenic substrate was applied, while detection limits reached pM level when chromogenic substrate was used. Thrombin in plasma sample can be detected with this assay. This cyclic peptide affinity ligand shows potentials for thrombin analysis in other detection formats.
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Affiliation(s)
- Qiang Zhao
- Research Institute of Environmental Science, College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Jie Gao
- Research Institute of Environmental Science, College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China
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29
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Landgraf KE, Steffek M, Quan C, Tom J, Yu C, Santell L, Maun HR, Eigenbrot C, Lazarus RA. An allosteric switch for pro-HGF/Met signaling using zymogen activator peptides. Nat Chem Biol 2014; 10:567-73. [DOI: 10.1038/nchembio.1533] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 04/17/2014] [Indexed: 12/17/2022]
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30
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Mehta AY, Thakkar JN, Mohammed BM, Martin EJ, Brophy DF, Kishimoto T, Desai UR. Targeting the GPIbα binding site of thrombin to simultaneously induce dual anticoagulant and antiplatelet effects. J Med Chem 2014; 57:3030-9. [PMID: 24635452 PMCID: PMC4203406 DOI: 10.1021/jm4020026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
![]()
Exosite 2 of human thrombin contributes
to two opposing pathways, the anticoagulant pathway and the platelet
aggregation pathway. We reasoned that an exosite 2 directed allosteric
thrombin inhibitor should simultaneously induce anticoagulant and
antiplatelet effects. To assess this, we synthesized SbO4L based on
the sulfated tyrosine-containing sequence of GPIbα. SbO4L was
synthesized in three simple steps in high yield and found to be a
highly selective, direct inhibitor of thrombin. Michelis–Menten
kinetic studies indicated a noncompetitive mechanism of inhibition.
Competitive inhibition studies suggested ideal competition with heparin
and glycoprotein Ibα, as predicted. Studies with site-directed
mutants of thrombin indicated that SbO4L binds to Arg233, Lys235,
and Lys236 of exosite 2. SbO4L prevented thrombin-mediated platelet
activation and aggregation as expected on the basis of competition
with GPIbα. SbO4L presents a novel paradigm of simultaneous
dual anticoagulant and antiplatelet effects achieved through the GPIbα
binding site of thrombin.
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Affiliation(s)
- Akul Y Mehta
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University , Richmond, Virginia 23219, United States
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31
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Forneris F, Burnley BT, Gros P. Ensemble refinement shows conformational flexibility in crystal structures of human complement factor D. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:733-43. [PMID: 24598742 PMCID: PMC3949522 DOI: 10.1107/s1399004713032549] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 11/29/2013] [Indexed: 11/16/2022]
Abstract
Human factor D (FD) is a self-inhibited thrombin-like serine proteinase that is critical for amplification of the complement immune response. FD is activated by its substrate through interactions outside the active site. The substrate-binding, or `exosite', region displays a well defined and rigid conformation in FD. In contrast, remarkable flexibility is observed in thrombin and related proteinases, in which Na(+) and ligand binding is implied in allosteric regulation of enzymatic activity through protein dynamics. Here, ensemble refinement (ER) of FD and thrombin crystal structures is used to evaluate structure and dynamics simultaneously. A comparison with previously published NMR data for thrombin supports the ER analysis. The R202A FD variant has enhanced activity towards artificial peptides and simultaneously displays active and inactive conformations of the active site. ER revealed pronounced disorder in the exosite loops for this FD variant, reminiscent of thrombin in the absence of the stabilizing Na(+) ion. These data indicate that FD exhibits conformational dynamics like thrombin, but unlike in thrombin a mechanism has evolved in FD that locks the unbound native state into an ordered inactive conformation via the self-inhibitory loop. Thus, ensemble refinement of X-ray crystal structures may represent an approach alternative to spectroscopy to explore protein dynamics in atomic detail.
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Affiliation(s)
- Federico Forneris
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - B. Tom Burnley
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Piet Gros
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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32
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Dickey SW, Baker RP, Cho S, Urban S. Proteolysis inside the membrane is a rate-governed reaction not driven by substrate affinity. Cell 2014; 155:1270-81. [PMID: 24315097 DOI: 10.1016/j.cell.2013.10.053] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 08/04/2013] [Accepted: 10/28/2013] [Indexed: 10/25/2022]
Abstract
Enzymatic cleavage of transmembrane anchors to release proteins from the membrane controls diverse signaling pathways and is implicated in more than a dozen diseases. How catalysis works within the viscous, water-excluding, two-dimensional membrane is unknown. We developed an inducible reconstitution system to interrogate rhomboid proteolysis quantitatively within the membrane in real time. Remarkably, rhomboid proteases displayed no physiological affinity for substrates (K(d) ~190 μM/0.1 mol%). Instead, ~10,000-fold differences in proteolytic efficiency with substrate mutants and diverse rhomboid proteases were reflected in k(cat) values alone. Analysis of gate-open mutant and solvent isotope effects revealed that substrate gating, not hydrolysis, is rate limiting. Ultimately, a single proteolytic event within the membrane normally takes minutes. Rhomboid intramembrane proteolysis is thus a slow, kinetically controlled reaction not driven by transmembrane protein-protein affinity. These properties are unlike those of other studied proteases or membrane proteins but are strikingly reminiscent of one subset of DNA-repair enzymes, raising important mechanistic and drug-design implications.
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Affiliation(s)
- Seth W Dickey
- Howard Hughes Medical Institute, Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Room 507 PCTB, 725 North Wolfe Street, Baltimore, MD 21205, USA
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33
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Fuchs JE, von Grafenstein S, Huber RG, Wallnoefer HG, Liedl KR. Specificity of a protein-protein interface: local dynamics direct substrate recognition of effector caspases. Proteins 2013; 82:546-55. [PMID: 24085488 PMCID: PMC4282588 DOI: 10.1002/prot.24417] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 09/03/2013] [Indexed: 12/29/2022]
Abstract
Proteases are prototypes of multispecific protein–protein interfaces. Proteases recognize and cleave protein and peptide substrates at a well-defined position in a substrate binding groove and a plethora of experimental techniques provide insights into their substrate recognition. We investigate the caspase family of cysteine proteases playing a key role in programmed cell death and inflammation, turning caspases into interesting drug targets. Specific ligand binding to one particular caspase is difficult to achieve, as substrate specificities of caspase isoforms are highly similar. In an effort to rationalize substrate specificity of two closely related caspases, we investigate the substrate promiscuity of the effector Caspases 3 and 7 by data mining (cleavage entropy) and by molecular dynamics simulations. We find a strong correlation between binding site rigidity and substrate readout for individual caspase subpockets explaining more stringent substrate readout of Caspase 7 via its narrower conformational space. Caspase 3 subpockets S3 and S4 show elevated local flexibility explaining the more unspecific substrate readout of that isoform in comparison to Caspase 7. We show by in silico exchange mutations in the S3 pocket of the proteases that a proline residue in Caspase 7 contributes to the narrowed conformational space of the binding site. These findings explain the substrate specificities of caspases via a mechanism of conformational selection and highlight the crucial importance of binding site local dynamics in substrate recognition of proteases. Proteins 2014; 82:546–555.
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Affiliation(s)
- Julian E Fuchs
- Institute of General, Inorganic and Theoretical Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria
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34
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Mehta AY, Jin Y, Desai UR. An update on recent patents on thrombin inhibitors (2010 – 2013). Expert Opin Ther Pat 2013; 24:47-67. [DOI: 10.1517/13543776.2014.845169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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35
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Arachiche A, Mumaw MM, de la Fuente M, Nieman MT. Protease-activated receptor 1 (PAR1) and PAR4 heterodimers are required for PAR1-enhanced cleavage of PAR4 by α-thrombin. J Biol Chem 2013; 288:32553-32562. [PMID: 24097976 DOI: 10.1074/jbc.m113.472373] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thrombin is a potent platelet agonist that activates platelets and other cells of the cardiovascular system by cleaving its G-protein-coupled receptors, protease-activated receptor 1 (PAR1), PAR4, or both. We now show that cleaving PAR1 and PAR4 with α-thrombin induces heterodimer formation. PAR1-PAR4 heterodimers were not detected when unstimulated; however, when the cells were stimulated with 10 nm α-thrombin, we were able to detect a strong interaction between PAR1 and PAR4 by bioluminescence resonance energy transfer. In contrast, activating the receptors without cleavage using PAR1 and PAR4 agonist peptides (TFLLRN and AYPGKF, respectively) did not enhance heterodimer formation. Preventing PAR1 or PAR4 cleavage with point mutations or hirugen also prevented the induction of heterodimers. To further characterize the PAR1-PAR4 interactions, we mapped the heterodimer interface by introducing point mutations in transmembrane helix 4 of PAR1 or PAR4 that prevented heterodimer formation. Finally, we show that mutations in PAR1 or PAR4 at the heterodimer interface prevented PAR1-assisted cleavage of PAR4. These data demonstrate that PAR1 and PAR4 require allosteric changes induced via receptor cleavage by α-thrombin to mediate heterodimer formation, and we have determined the PAR1-PAR4 heterodimer interface. Our findings show that PAR1 and PAR4 have dynamic interactions on the cell surface that should be taken into account when developing and characterizing PAR antagonists.
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Affiliation(s)
- Amal Arachiche
- From the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Michele M Mumaw
- From the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - María de la Fuente
- From the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Marvin T Nieman
- From the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106.
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36
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Sidhu PS, Abdel Aziz MH, Sarkar A, Mehta AY, Zhou Q, Desai UR. Designing allosteric regulators of thrombin. Exosite 2 features multiple subsites that can be targeted by sulfated small molecules for inducing inhibition. J Med Chem 2013; 56:5059-70. [PMID: 23718540 DOI: 10.1021/jm400369q] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We recently designed a group of novel exosite-2-directed sulfated, small, allosteric inhibitors of thrombin. To develop more potent inhibitors, monosulfated benzofuran tri- and tetrameric homologues of the parent designed dimers were synthesized in seven to eight steps and found to exhibit a wide range of potencies. Among these, trimer 9a was found to be nearly 10-fold more potent than the first generation molecules. Michaelis-Menten studies indicated an allosteric mechanism of inhibition. Competitive studies using a hirudin peptide (exosite 1 ligand) and unfractionated heparin, heparin octasaccharide, and γ'-fibrinogen peptide (exosite 2 ligands) demonstrated exosite 2 recognition in a manner different from that of the parent dimers. Alanine scanning mutagenesis of 12 Arg/Lys residues of exosite 2 revealed a defect in 9a potency for Arg233Ala thrombin only confirming the major difference in site of recognition between the two structurally related sulfated benzofurans. The results suggest that multiple avenues are available within exosite 2 for inducing thrombin inhibition.
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Affiliation(s)
- Preetpal Singh Sidhu
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, Virginia 23219, USA
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37
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Abstract
An important regulatory mechanism of serine proteases is the proteolytic conversion of the inactive pro-enzyme, or zymogen, into the active enzyme. This activation process is generally considered an irreversible process. In the present study, we demonstrate that an active enzyme can be converted back into its zymogen form. We determined the crystal structure of uPA (urokinase-type plasminogen activator) in complex with an inhibitory antibody, revealing that the antibody 'rezymogenizes' already activated uPA. The present study demonstrates a new regulatory mechanism of protease activity, which is also an extreme case of protein allostery. Mechanistically, the antibody binds a single surface-exposed loop, named the autolysis loop, thereby preventing the stabilization of uPA in its active conformation. We argue that this autolysis loop is a key structural element for rezymogenation of other proteases, and will be a new target site for pharmacological intervention with serine protease activity.
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38
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Fuglestad B, Gasper PM, Tonelli M, McCammon JA, Markwick PRL, Komives EA. The dynamic structure of thrombin in solution. Biophys J 2012; 103:79-88. [PMID: 22828334 DOI: 10.1016/j.bpj.2012.05.047] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 05/04/2012] [Accepted: 05/30/2012] [Indexed: 10/28/2022] Open
Abstract
The backbone dynamics of human α-thrombin inhibited at the active site serine were analyzed using R(1), R(2), and heteronuclear NOE experiments, variable temperature TROSY 2D [(1)H-(15)N] correlation spectra, and R(ex) measurements. The N-terminus of the heavy chain, which is formed upon zymogen activation and inserts into the protein core, is highly ordered, as is much of the double beta-barrel core. Some of the surface loops, by contrast, remain very dynamic with order parameters as low as 0.5 indicating significant motions on the ps-ns timescale. Regions of the protein that were thought to be dynamic in the zymogen and to become rigid upon activation, in particular the γ-loop, the 180s loop, and the Na(+) binding site have order parameters below 0.8. Significant R(ex) was observed in most of the γ-loop, in regions proximal to the light chain, and in the β-sheet core. Accelerated molecular dynamics simulations yielded a molecular ensemble consistent with measured residual dipolar couplings that revealed dynamic motions up to milliseconds. Several regions, including the light chain and two proximal loops, did not appear highly dynamic on the ps-ns timescale, but had significant motions on slower timescales.
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Affiliation(s)
- Brian Fuglestad
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California, USA
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39
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Liu Z, Kromann-Hansen T, Lund IK, Hosseini M, Jensen KJ, Høyer-Hansen G, Andreasen PA, Sørensen HP. Interconversion of active and inactive conformations of urokinase-type plasminogen activator. Biochemistry 2012; 51:7804-11. [PMID: 22950516 DOI: 10.1021/bi3005957] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The catalytic activity of serine proteases depends on a salt-bridge between the amino group of residue 16 and the side chain of Asp194. The salt-bridge stabilizes the oxyanion hole and the S1 specificity pocket of the protease. Some serine proteases exist in only partially active forms, in which the amino group of residue 16 is exposed to the solvent. Such a partially active state is assumed by a truncated form of the murine urokinase-type plasminogen activator (muPA), consisting of residues 16-243. Here we investigated the allosteric interconversion between partially active states and the fully active state. Both a monoclonal antibody (mU3) and a peptidic inhibitor (mupain-1--16) stabilize the active state. The epitope of mU3 is located in the 37- and 70-loops at a site homologous to exosite I of thrombin. The N-terminus((Ile16)) of muPA((16--243)) was less exposed upon binding of mU3 or mupain-1--16. In contrast, introduction of the mutations F40Y or E137A into muPA((16--243)) increased exposure of the N-terminus((Ile16)) and resulted in large changes in the thermodynamic parameters for mupain-1--16 binding. We conclude that the distorted state of muPA((16--243)) is conformationally ordered upon binding of ligands to the active site and upon binding of mU3 to the 37- and 70-loops. Our study establishes the 37- and 70-loops as a unique site for binding to compounds stabilizing the active state of serine proteases.
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Affiliation(s)
- Zhuo Liu
- Danish-Chinese Centre for Proteases and Cancer, Aarhus University, Denmark
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40
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Abstract
The Monod-Wyman-Changeux (MWC) model was conceived in 1965 to account for the signal transduction and cooperative properties of bacterial regulatory enzymes and hemoglobin. It was soon extended to pharmacological receptors for neurotransmitters and other macromolecular entities involved in intracellular and intercellular communications. Five decades later, the two main hypotheses of the model are reexamined on the basis of a variety of regulatory proteins with known X-ray structures: (a) Regulatory proteins possess an oligomeric structure with symmetry properties, and (b) the allosteric interactions between topographically distinct sites are mediated by a conformational transition established between a few preestablished states with conservation of symmetry and ligand-directed conformational selection. Several well-documented examples are adequately represented by the MWC model, yet a few possible exceptions are noted. New questions are raised concerning the dynamics of the allosteric transitions and more complex supramolecular ensembles.
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Affiliation(s)
- Jean-Pierre Changeux
- Collège de France & Institut Pasteur, URA CNRS 2182, Paris Cedex 15 75724, France.
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41
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Abdel Aziz MH, Mosier PD, Desai UR. Identification of the site of binding of sulfated, low molecular weight lignins on thrombin. Biochem Biophys Res Commun 2011; 413:348-52. [PMID: 21893043 PMCID: PMC3183121 DOI: 10.1016/j.bbrc.2011.08.102] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 08/20/2011] [Indexed: 10/17/2022]
Abstract
Sulfated, low molecular weight lignins (LMWLs), designed recently as macromolecular mimetics of the low molecular weight heparins (LMWHs), were found to exhibit a novel allosteric mechanism of inhibition of human thrombin, factor Xa and plasmin, which translates into potent human blood anticoagulation potential. To identify the site of binding of sulfated LMWLs, a panel of site-directed thrombin mutants was studied. Substitution of alanine for Arg(93) or Arg(175) induced a 7-8-fold decrease in inhibition potency, while Arg(165)Ala, Lys(169)Ala, Arg(173)Ala and Arg(233)Ala thrombin mutants displayed a 2-4-fold decrease. Other exosite 2 residues including those that play an important role in heparin binding, such as Arg(101), Lys(235), Lys(236) and Lys(240), did not induce any deficiency in sulfated LMWL activity. Thrombin mutants with multiple alanine substitution of basic residues showed a progressively greater defect in inhibition potency. Comparison of thrombin, factor Xa, factor IXa and factor VIIa primary sequences reiterated Arg(93) and Arg(175) as residues likely to be targeted by sulfated LMWLs. The identification of a novel site on thrombin with capability of allosteric modulation is expected to greatly assist the design of new regulators based on the sulfated LMWL scaffold.
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Affiliation(s)
- May H. Abdel Aziz
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298
| | - Philip D. Mosier
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298
| | - Umesh R. Desai
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298
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