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Cecilia Augustsson, Anders Svensson, Birgitte Kjaer, Tzu-Yuan Chao, Xia Wenjuan, Berit Olsen Krogh, Jens Breinholt, Jes Thorn Clausen, Ida Hilden, Helle Heibroch Petersen, Lars Christian Petersen
BACKGROUND: Initiation of coagulation is induced by binding of activated factor VII (FVIIa) to tissue factor (TF) and activation of factor X (FX) in a process regulated by tissue factor pathway inhibitor (TFPI). TFPI contains three Kunitz-type protease inhibitor domains (K1-K3) of which K1 and K2 block the active sites of FVIIa and FXa respectively. OBJECTIVE: To produce a monoclonal antibody (mAb) directed towards K1, to characterize the binding epitope, and to study its effect on TFPI inhibition...
March 12, 2018: Journal of Thrombosis and Haemostasis: JTH
Weronika Kotkowiak, Jolanta Lisowiec-Wachnicka, Jakub Grynda, Ryszard Kierzek, Jesper Wengel, Anna Pasternak
Thrombin is a serine protease that plays a crucial role in hemostasis, fibrinolysis, cell proliferation, and migration. Thrombin binding aptamer (TBA) is able to inhibit the activity of thrombin molecule via binding to its exosite I. This 15-nt DNA oligonucleotide forms an intramolecular, antiparallel G-quadruplex structure with a chair-like conformation. In this paper, we report on our investigations on the influence of certain modified nucleotide residues on thermodynamic stability, folding topology, and biological properties of TBA variants...
March 2, 2018: Molecular Therapy. Nucleic Acids
David Ulbricht, Catherine A Tindall, Kathrin Oertwig, Stefanie Hanke, Norbert Sträter, John T Heiker
Kallikrein-related peptidases KLK5, KLK7 and KLK14 are important proteases in skin desquamation and aberrant KLK activity is associated with inflammatory skin diseases such as Netherton syndrome but also with various serious forms of cancer. Previously, we have identified KLK7 as the first protease target of vaspin (Serpin A12). Here, we report KLK14 as a second KLK protease to be inhibited by vaspin. In conclusion, vaspin represents a multispecific serpin targeting the kallikrein proteases KLK7 and KLK14, with distinct exosites regulating recognition of these target proteases and opposing effects of heparin binding on the inhibition reaction...
February 1, 2018: Biological Chemistry
Salvatore Santamaria, Rens de Groot
The metzincin clan of metalloproteinases includes the MMP, ADAM and ADAMTS families, which cleave extracellular targets in a wide range of (patho)physiological processes. Antibodies constitute a powerful tool to modulate the activity of these enzymes for both therapeutic and research purposes. In this review, we give an overview of monoclonal antibodies (mAbs) that have been tested in preclinical disease models, human trials and important studies of metzincin structure and function. Initial attempts to develop therapeutic small molecule inhibitors against MMPs were hampered by structural similarities between metzincin active sites and, consequently, off-target effects...
February 27, 2018: British Journal of Pharmacology
Daniel K Afosah, Stephen Verespy, Rami A Al-Horani, Rio S Boothello, Rajesh Karuturi, Umesh R Desai
Despite the development of promising direct oral anticoagulants, which are all orthosteric inhibitors, a sizable number of patients suffer from bleeding complications. We have hypothesized that allosterism based on the heparin-binding exosites presents a major opportunity to induce sub-maximal inhibition of coagulation proteases, thereby avoiding/reducing bleeding risk. We present the design of a group of sulfated benzofuran dimers that display heparin-binding site-dependent partial allosteric inhibition of thrombin against fibrinogen (ΔY = 55-75%), the first time that a small molecule (MW < 800) has been found to thwart macromolecular cleavage by a monomeric protease in a controlled manner...
February 3, 2018: Bioorganic & Medicinal Chemistry Letters
Colin A Kretz, Kärt Tomberg, Alexander Van Esbroeck, Andrew Yee, David Ginsburg
We have combined random 6 amino acid substrate phage display with high throughput sequencing to comprehensively define the active site specificity of the serine protease thrombin and the metalloprotease ADAMTS13. The substrate motif for thrombin was determined by >6,700 cleaved peptides, and was highly concordant with previous studies. In contrast, ADAMTS13 cleaved only 96 peptides (out of >107 sequences), with no apparent consensus motif. However, when the hexapeptide library was substituted into the P3-P3' interval of VWF73, an exosite-engaging substrate of ADAMTS13, 1670 unique peptides were cleaved...
February 12, 2018: Scientific Reports
Tobias Kromann-Hansen, Eva Louise Lange, Ida K Lund, Gunilla Høyer-Hansen, Peter A Andreasen, Elizabeth A Komives
The catalytic activity of trypsin-like serine proteases is in many cases regulated by conformational changes initiated by binding of physiological modulators to exosites located distantly from the active site. A trypsin-like serine protease of particular interest is urokinase-type plasminogen activator (uPA), which is involved in extracellular tissue remodeling processes. Herein, we used hydrogen/deuterium exchange mass spectrometry (HDXMS) to study regulation of activity in the catalytic domain of the murine version of uPA (muPA) by two muPA specific monoclonal antibodies...
2018: PloS One
William E Plautz, Vijaya Satish Sekhar Pilli, Brian C Cooley, Rima Chattopadhyay, Pamela R Westmark, Todd Getz, David Paul, Wolfgang Bergmeier, John P Sheehan, Rinku Majumder
OBJECTIVE: PS (protein S) is a plasma protein that directly inhibits the coagulation FIXa (factor IXa) in vitro. Because elevated FIXa is associated with increased risk of venous thromboembolism, it is important to establish how PS inhibits FIXa function in vivo. The goal of this study is to confirm direct binding of PS with FIXa in vivo, identify FIXa amino acid residues required for binding PS in vivo, and use an enzymatically active FIXa mutant that is unable to bind PS to measure the significance of PS-FIXa interaction in hemostasis...
February 1, 2018: Arteriosclerosis, Thrombosis, and Vascular Biology
Monica L Gonzalez Ramirez, Marcin Poreba, Scott J Snipas, Katarzyna Groborz, Marcin Drag, Guy S Salvesen
Inflammatory cell death, or pyroptosis, is triggered by pathogenic infections or events. It is executed by caspase-1 (in the canonical pyroptosis pathway) or caspase-11 (noncanonical pathway), each via production of a cell-lytic domain from the pyroptosis effector protein gasdermin D through specific and limited proteolysis. Pyroptosis is accompanied by the release of inflammatory mediators, including the proteolytically processed forms of interleukin-1β (IL-1β) and IL-18. Given the similar inflammatory outcomes of the canonical and noncanonical pyroptosis pathways, we hypothesized that caspase-1 and -11 should have very similar activities and substrate specificities...
February 6, 2018: Journal of Biological Chemistry
Iva Hánová, Jiří Brynda, Radka Houštecká, Nawsad Alam, Daniel Sojka, Petr Kopáček, Lucie Marešová, Jiří Vondrášek, Martin Horn, Ora Schueler-Furman, Michael Mareš
Pepsin-family aspartic peptidases are biosynthesized as inactive zymogens in which the propeptide blocks the active site until its proteolytic removal upon enzyme activation. Here, we describe a novel dual regulatory function for the propeptide using a set of crystal structures of the parasite cathepsin D IrCD1. In the IrCD1 zymogen, intramolecular autoinhibition by the intact propeptide is mediated by an evolutionarily conserved exosite on the enzyme core. After activation, the mature enzyme employs the same exosite to rebind a small fragment derived from the cleaved propeptide...
January 26, 2018: Cell Chemical Biology
Ingrid Stroo, J Arnoud Marquart, Kamran Bakhtiari, Tom Plug, Alexander B Meijer, Joost C M Meijers
Coagulation factor XI is activated by thrombin or factor XIIa resulting in a conformational change that converts the catalytic domain into its active form and exposing exosites for factor IX on the apple domains. Although crystal structures of the zymogen factor XI and the catalytic domain of the protease are available, the structure of the apple domains and hence the interactions with the catalytic domain in factor XIa are unknown. We now used chemical footprinting to identify lysine residue containing regions that undergo a conformational change following activation of factor XI...
February 2018: Thrombosis and Haemostasis
Qiu-Fang Chen, Shuang Cui, Hui-Liang Shen, Xiang Chen, Yun-Zhan Li, Qian Wu, Yun-Gen Xu, Guo-Qing Gong
Thrombin has long been suggested as a desirable antithrombotic target, but anti-thrombin therapy without anti-platelet thereby has never achieved the ideal effect. HY023016 is a novel compound, in our previous study, it exerted better anti-thrombotic than dabigatran etexilate. The present study aims to illustrate the excess anti-thrombotic molecular mechanisms of HY023016 through thrombin anion exosites and the platelet membrane receptor subunit glycoprotein Ibα (GPIbα). HY023016 strongly inhibited the conversion of fibrinogen to fibrous may via blocking thrombin exosite I...
January 17, 2018: European Journal of Pharmacology
Lucas J Gutiérrez, Oscar Parravicini, Emilse Sánchez, Ricaurte Rodríguez, Justo Cobo, Ricardo D Enriz
We report in this work new substituted aminopyrimidine derivatives acting as inhibitors of the catalytic site of BACE1. These compounds were obtained from a molecular modelling study. The theoretical and experimental study reported here was carried out in several steps: docking analysis, Molecular Dynamics (MD) simulations, Quantum Theory Atom in Molecules (QTAIM) calculations, synthesis and bioassays and has allowed us to propose some compounds of this series as new inhibitors of the catalytic site of BACE1...
January 4, 2018: Journal of Biomolecular Structure & Dynamics
Fumiaki Nakamura, Norio Kudo, Yuki Tomachi, Akiko Nakata, Misao Takemoto, Akihiro Ito, Hodaka Tabei, Daisuke Arai, Nicole de Voogd, Minoru Yoshida, Yoichi Nakao, Nobuhiro Fusetani
Two new analogs of halistanol sulfate (1) were isolated from a marine sponge Halichondria sp. collected at Hachijo-jima Island. Structures of these new halistanol sulfates I (2) and J (3) were elucidated by spectral analyses. Compounds 1-3 showed inhibitory activity against SIRT 1-3 with IC50 ranges of 45.9-67.9, 18.9-21.1 and 21.8-37.5 μM, respectively. X-ray crystallography of the halistanol sulfate (1) and SIRT3 complex clearly indicates that 1 binds to the exosite of SIRT3 that we have discovered in this study...
February 2018: Journal of Antibiotics
Raheel Ahmad, Ghulam Destgeer, Muhammad Afzal, Jinsoo Park, Husnain Ahmed, Jin Ho Jung, Kwangseok Park, Tae-Sung Yoon, Hyung Jin Sung
We developed a hybrid microfluidic device that utilized acoustic waves to drive functionalized microparticles inside a continuous flow microchannel and to separate particle-conjugated target proteins from a complex fluid. The acoustofluidic device is composed of an interdigitated transducer that produces high-frequency surface acoustic waves (SAW) and a polydimethylsiloxane (PDMS) microfluidic channel. The SAW interacted with the sample fluid inside the microchannel and deflected particles from their original streamlines to achieve separation...
December 19, 2017: Analytical Chemistry
Ramya Billur, David Ban, T Michael Sabo, Muriel C Maurer
Thrombin participates in procoagulation, anticoagulation, and platelet activation. This enzyme contains anion binding exosites, ABE I and ABE II, which attract regulatory biomolecules. As prothrombin is activated to thrombin, pro-ABE I is converted into mature ABE I. Unexpectedly, certain ligands can bind to pro-ABE I specifically. Moreover, knowledge of changes in conformation and affinity that occur at the individual residue level as pro-ABE I is converted to ABE I is lacking. Such changes are transient and were not captured by crystallography...
December 5, 2017: Biochemistry
Enrico Guarnera, Zhen Wah Tan, Zejun Zheng, Igor N Berezovsky
Motivation: Allostery is an omnipresent mechanism of the function modulation in proteins via either effector binding or mutations in the exosites. Despite the growing number of online servers and databases devoted to prediction/classification of allosteric sites and their characteristics, there is a lack of resources for an efficient and quick estimation of the causality and energetics of allosteric communication. Results: The AlloSigMA server implements a unique approach on the basis of the recently introduced structure-based statistical mechanical models of allosteric signaling...
July 6, 2017: Bioinformatics
F Xavier Gomis-Rüth
Drug candidates against matrix metalloproteinases (MMPs) failed in the clinic in the past because their strong zinc-targeting warheads led to a lack of specificity. More recently, significant selectivity among MMPs was achieved by blocking the enzymes' specificity pockets, nearby exosites, and downstream domains. Scannevin and colleagues now elegantly twist the plot and achieve ultimate selectivity: They target MMP-9 by allosterically preventing activation of its zymogen.
October 27, 2017: Journal of Biological Chemistry
Siew Siew Pang, Lakshmi C Wijeyewickrema, Lilian Hor, Sheareen Tan, Emilie Lameignere, Edward M Conway, Anna M Blom, Frida C Mohlin, Xuyu Liu, Richard J Payne, James C Whisstock, Robert N Pike
Complement is crucial to the immune response, but dysregulation of the system causes inflammatory disease. Complement is activated by three pathways: classical, lectin, and alternative. The classical and lectin pathways are initiated by the C1r/C1s (classical) and MASP-1/MASP-2 (lectin) proteases. Given the role of complement in disease, there is a requirement for inhibitors to control the initiating proteases. In this article, we show that a novel inhibitor, gigastasin, from the giant Amazon leech, potently inhibits C1s and MASP-2, whereas it is also a good inhibitor of MASP-1...
December 1, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
Song Xue, Hajime Seki, Marek Remes, Peter Šilhár, Kim Janda
Botulinum neurotoxins (BoNT) are among the most toxic known substances and currently there are no effective treatments for intraneuronal BoNT intoxication. Chicoric acid (ChA) was previously reported as a BoNT/A inhibitor that binds to the enzyme's α-exosite. Herein, we report the synthesis and structure-activity relationships (SARs) of a series of ChA derivatives, which revealed essential binding interactions between ChA and BoNT/A. Moreover, several ChA-based inhibitors with improved potency against the BoNT/A were discovered...
November 15, 2017: Bioorganic & Medicinal Chemistry Letters
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