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Li R, Zou X, Luan P, Liu X, Wang N, Wang Q, Guan H, Xu Z. Direct Determination of Enzymes in Dried Blood Spots by High-Performance Liquid Chromatography – Mass Spectrometry (HPLC-MS) for the Screening of Antithrombotic Agents. ANAL LETT 2022. [DOI: 10.1080/00032719.2022.2053700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Ru Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao, China
| | - Xuan Zou
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao, China
| | - Pan Luan
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao, China
| | - Xiaokun Liu
- Marine Biomedical Research Institute of Qingdao, Qingdao, China
| | - Ning Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao, China
| | - Qian Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao, China
| | - Huashi Guan
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao, China
- Marine Biomedical Research Institute of Qingdao, Qingdao, China
| | - Zhe Xu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao, China
- Marine Biomedical Research Institute of Qingdao, Qingdao, China
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Lu Y, Villoutreix BO, Biswas I, Ding Q, Wang X, Rezaie AR. Antithrombin Resistance Rescues Clotting Defect of Homozygous Prothrombin-Y510N Dysprothrombinemia. Thromb Haemost 2021; 122:679-691. [PMID: 34256393 PMCID: PMC8755856 DOI: 10.1055/a-1549-6407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A patient with hematuria in our clinic was diagnosed with urolithiasis. Analysis of the patient's plasma clotting time indicated that both activated partial thromboplastin time (52.6 seconds) and prothrombin time (19.4 seconds) are prolonged and prothrombin activity is reduced to 12.4% of normal, though the patient exhibited no abnormal bleeding phenotype and a prothrombin antigen level of 87.9%. Genetic analysis revealed the patient is homozygous for prothrombin Y510N mutation. We expressed and characterized the prothrombin-Y510N variant in appropriate coagulation assays and found that the specificity constant for activation of the mutant zymogen by factor Xa is impaired approximately fivefold. Thrombin generation assay using patient's plasma and prothrombin-deficient plasma supplemented with either wild-type or prothrombin-Y510N revealed that both peak height and time to peak for the prothrombin mutant are decreased; however, the endogenous thrombin generation potential is increased. Further analysis indicated that the thrombin mutant exhibits resistance to antithrombin and is inhibited by the serpin with approximately 12-fold slower rate constant. Protein C activation by thrombin-Y510N was also decreased by approximately 10-fold; however, thrombomodulin overcame the catalytic defect. The Na+-concentration-dependence of the amidolytic activities revealed that the dissociation constant for the interaction of Na+ with the mutant has been elevated approximately 20-fold. These results suggest that Y510 (Y184a in chymotrypsin numbering) belongs to network of residues involved in binding Na+. A normal protein C activation by thrombin-Y510N suggests that thrombomodulin modulates the conformation of the Na+-binding loop of thrombin. The clotting defect of thrombin-Y510N appears to be compensated by its markedly lower reactivity with antithrombin, explaining patient's normal hemostatic phenotype.
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Affiliation(s)
- Yeling Lu
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States.,Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bruno O Villoutreix
- INSERM 1141, NeuroDiderot, Université de Paris, Hôpital Robert-Debré, Paris, France
| | - Indranil Biswas
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States
| | - Qiulan Ding
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xuefeng Wang
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Alireza R Rezaie
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States.,Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
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3
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Lu Y, Mehta-D'souza P, Biswas I, Villoutreix BO, Wang X, Ding Q, Rezaie AR. Ile73Asn mutation in protein C introduces a new N-linked glycosylation site on the first EGF-domain of protein C and causes thrombosis. Haematologica 2019; 105:1712-1722. [PMID: 31399531 PMCID: PMC7271577 DOI: 10.3324/haematol.2019.227033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/07/2019] [Indexed: 12/24/2022] Open
Abstract
Activated protein C exerts its anticoagulant activity by protein S-dependent inactivation of factors Va and VIIIa by limited proteolysis. We identified a venous thrombosis patient who has plasma protein C antigen level of 63% and activity levels of 44% and 23%, as monitored by chromogenic and clotting assays. Genetic analysis revealed the proband carries compound heterozygous mutations (c.344T>A, p.I73N and c.1181G>A, p.R352Q) in PROC. We individually expressed protein C mutations and discovered that thrombin-thrombomodulin activates both variants normally and the resulting activated protein C mutants exhibit normal amidolytic and proteolytic activities. However, while protein S-dependent catalytic activity of activated protein C-R352Q toward factor Va was normal, it was significantly impaired for activated protein C-I73N. These results suggest that the Ile to Asn substitution impairs interaction of activated protein C-I73N with protein S. This conclusion was supported by a normal anticoagulant activity for activated protein C-I73N in protein S-deficient but not in normal plasma. Further analysis revealed Ile to Asn substitution introduces a new glycosylation site on first EGF-like domain of protein C, thereby adversely affecting interaction of activated protein C with protein S. Activated protein C-R352Q only exhibited reduced activity in sub-physiological concentrations of Na+ and Ca2+, suggesting that this residue contributes to metal ion-binding affinity of the protease, with no apparent adverse effect on its function in the presence of physiological levels of metal ions. These results provide insight into the mechanism by which I73N/R352Q mutations in activated protein C cause thrombosis in proband carrying this compound heterozygous mutation.
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Affiliation(s)
- Yeling Lu
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Padmaja Mehta-D'souza
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Indranil Biswas
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Bruno O Villoutreix
- Université Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000 Lille, France
| | - Xuefeng Wang
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Qiulan Ding
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Alireza R Rezaie
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA .,Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Abdel Aziz MH, Desai UR. Novel heparin mimetics reveal cooperativity between exosite 2 and sodium-binding site of thrombin. Thromb Res 2018; 165:61-67. [PMID: 29573721 DOI: 10.1016/j.thromres.2018.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 02/28/2018] [Accepted: 03/16/2018] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Thrombin is a primary target of most anticoagulants. Yet, thrombin's dual and opposing role in pro- as well as anti- coagulant processes imposes considerable challenges in discovering finely tuned regulators that maintain homeostasis, rather than disproportionately changing the equilibrium to one side. In this connection, we have been studying exosite 2-mediated allosteric modulation of thrombin activity using synthetic agents called low molecular weight lignins (LMWLs). Although the aromatic scaffold of LMWLs is completely different from the polysaccharidic scaffold of heparin, the presence of multiple negatively charged groups on both ligands induces binding to exosite 2 of thrombin. This work characterizes the nature of interactions between LMWLs and thrombin to understand the energetic cooperativity between exosite 2 and active site of thrombin. MATERIALS AND METHODS The thermodynamics of thrombin-LMWL complexes was studied using spectrofluorimetric titrations as a function of ionic strength and temperature of the buffer. The contributions of enthalpy and entropy to binding were evaluated using classic thermodynamic equations. Label-free surface plasmon resonance was used to assess the role of sodium ion in LMWL binding to thrombin at a fixed ionic strength. RESULTS AND CONCLUSIONS Exosite 2-induced conformational change in thrombin's active site is strongly dependent on the structure of the ligand, which has consequences with respect to regulation of thrombin. The ionic and non-ionic contributions to binding affinity and the thermodynamic signature were highly ligand specific. Interestingly, LMWLs display preference for the sodium-bound form of thrombin, which supports the existence of an energetic coupling between exosite 2 and sodium-binding site of thrombin.
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Affiliation(s)
- May H Abdel Aziz
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23219, United States
| | - Umesh R Desai
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23219, United States; Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, United States.
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5
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Xu Z, Liu R, Guan H. Dual-target inhibitor screening against thrombin and factor Xa simultaneously by mass spectrometry. Anal Chim Acta 2017; 990:1-10. [PMID: 29029731 DOI: 10.1016/j.aca.2017.07.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 07/19/2017] [Accepted: 07/28/2017] [Indexed: 12/12/2022]
Abstract
An accurate, rapid, and cost-effective methodology for enzyme assay is highly demanded to screen the effect of compounds on target at the molecular level. Thrombin (EC 3.4.21.5) and factor Xa (FXa, EC 3.4.21.6) have been identified as the critical targets for the development of potential drugs with anticoagulant activity. In this study, a rapid, sensitive and accurate assay based on UHPLC-MS/MS method has been developed for inhibitor screening against thrombin and factor Xa simultaneously. For thrombin and factor Xa, the Michaelis-Menten constants (Km) were calculated to be 6.14 and 57.27 μM, respectively. The inhibition constants (Ki) for two known inhibitors, argatroban and rivaroxaban, were determined to be 16.23 and 0.41 nM, respectively. The assay was further validated through the determination of a high Z' factor value of 0.89. Finally, the developed assay was applied to screen a chemical library against two enzymes. Three hit compounds belonging to a class of sulfated polysaccharides were identified and their targets of inhibition action were further evaluated. The results indicated that the dual-target assay by UHPLC-MS/MS analysis could be used as a reliable method for screening anticoagulant agents.
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Affiliation(s)
- Zhe Xu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, Qingdao 266003, China; Laboratory for Marine Drugs and Bioproducts, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266273, China; Marine Biomedical Research Institute of Qingdao, Qingdao 266271, China.
| | - Ruonan Liu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, Qingdao 266003, China
| | - Huashi Guan
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, Qingdao 266003, China; Laboratory for Marine Drugs and Bioproducts, Innovation Center for Marine Drugs Screening and Evaluation, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266273, China; Marine Biomedical Research Institute of Qingdao, Qingdao 266271, China
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6
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Chen K, Stafford AR, Wu C, Yeh CH, Kim PY, Fredenburgh JC, Weitz JI. Exosite 2-Directed Ligands Attenuate Protein C Activation by the Thrombin–Thrombomodulin Complex. Biochemistry 2017; 56:3119-3128. [DOI: 10.1021/acs.biochem.7b00250] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kai Chen
- Department of Medicine, ‡Department of Biochemistry
and Biomedical Sciences, and §Thrombosis and
Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Alan R. Stafford
- Department of Medicine, ‡Department of Biochemistry
and Biomedical Sciences, and §Thrombosis and
Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Chengliang Wu
- Department of Medicine, ‡Department of Biochemistry
and Biomedical Sciences, and §Thrombosis and
Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Calvin H. Yeh
- Department of Medicine, ‡Department of Biochemistry
and Biomedical Sciences, and §Thrombosis and
Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Paul Y. Kim
- Department of Medicine, ‡Department of Biochemistry
and Biomedical Sciences, and §Thrombosis and
Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - James C. Fredenburgh
- Department of Medicine, ‡Department of Biochemistry
and Biomedical Sciences, and §Thrombosis and
Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Jeffrey I. Weitz
- Department of Medicine, ‡Department of Biochemistry
and Biomedical Sciences, and §Thrombosis and
Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
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Glynn JJ, Hinds MT. Bioactive Anti-Thrombotic Modification of Decellularized Matrix for Vascular Applications. Adv Healthc Mater 2016; 5:1439-46. [PMID: 27072858 PMCID: PMC5753589 DOI: 10.1002/adhm.201600020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/04/2016] [Indexed: 12/20/2022]
Abstract
The decellularized matrix derived from porcine small intestinal submucosa (SIS) is a widely used biomaterial being investigated for numerous applications. Currently, thrombus deposition and neointimal hyperplasia have limited the use of SIS in some vascular applications. To limit these detrimental processes, this work applies bioactive, endothelial-inspired properties to the material. SIS is modified with the endothelial cell membrane protein thrombomodulin and the glycosaminoglycan heparin to facilitate protein C activation and anticoagulant activity, respectively. Modifying SIS with thrombomodulin alone enables robust activated protein C (APC) generation, and thrombomodulin activity is maintained after prolonged exposure to fluid shear and blood plasma. Heparin-modified SIS has a potent anticoagulant activity. When both modifications are applied sequentially, SIS modified first with thrombomodulin then with heparin retains the full activity of each individual modification. Tubular SIS devices are connected to a baboon arteriovenous shunt to quantify thrombus deposition on these materials. After being exposed to flowing whole blood for 60 min, SIS devices modified first with thrombomodulin then with heparin have significantly less platelet accumulation compared to unmodified SIS devices. These studies demonstrate that modifying SIS with thrombomodulin and heparin confers APC generation and anticoagulant activity that results in reduced thrombogenesis.
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Affiliation(s)
- Jeremy J Glynn
- Department of Biomedical Engineering, Oregon Health & Science University, Mail Code: CH13B 3303 SW Bond Ave, Portland, OR, 97239, USA
| | - Monica T Hinds
- Department of Biomedical Engineering, Oregon Health & Science University, Mail Code: CH13B 3303 SW Bond Ave, Portland, OR, 97239, USA
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8
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Exploiting the antithrombotic effect of the (pro)thrombin inhibitor bothrojaracin. Toxicon 2016; 119:46-51. [PMID: 27179421 DOI: 10.1016/j.toxicon.2016.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/04/2016] [Accepted: 05/10/2016] [Indexed: 11/20/2022]
Abstract
Bothrojaracin is a 27 kDa C-type lectin-like protein from Bothrops jararaca snake venom. It behaves as a potent thrombin inhibitor upon high-affinity binding to thrombin exosites. Bothrojaracin also forms a stable complex with prothrombin that can be detected in human plasma. Formation of the zymogen-inhibitor complex severely decreases prothrombin activation and contributes to the anticoagulant activity of bothrojaracin. In the present study, we employed two rodent models to evaluate the antithrombotic effect of bothrojaracin in vivo: stasis-induced thrombosis and thrombin-induced pulmonary thromboembolism. It was observed that bothrojaracin interacts with rat prothrombin in plasma. Ex-vivo assays showed stable complex formation even after 24 h of a single bothrojaracin dose. As a result, bothrojaracin showed significant antithrombotic activity in a rat venous thrombosis model elicited by thromboplastin combined with stasis. The antithrombotic activity of bothrojaracin (1 mg/kg) persisted for up to 24 h and it was associated with moderate bleeding as assessed by a tail transection method. Formation of bothrojaracin-prothrombin complex has been also observed following intravenous administration of the inhibitor into mice. As a result, bothrojaracin effectively protected mice from thrombin-induced fatal thromboembolism. We conclude that bothrojaracin is a potent antithrombotic agent in vivo and may serve as a prototype for the development of new zymogen-directed drugs that could result in prolonged half-life and possible decreased hemorrhagic risk.
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9
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Pathak R, Shao L, Ghosh SP, Zhou D, Boerma M, Weiler H, Hauer-Jensen M. Thrombomodulin contributes to gamma tocotrienol-mediated lethality protection and hematopoietic cell recovery in irradiated mice. PLoS One 2015; 10:e0122511. [PMID: 25860286 PMCID: PMC4393275 DOI: 10.1371/journal.pone.0122511] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 02/12/2015] [Indexed: 01/09/2023] Open
Abstract
Systemic administration of recombinant thrombomodulin (TM) confers radiation protection partly by accelerating hematopoietic recovery. The uniquely potent radioprotector gamma tocotrienol (GT3), in addition to being a strong antioxidant, inhibits the enzyme hydroxy-methyl-glutaryl-coenzyme A reductase (HMGCR) and thereby likely modulates the expression of TM. We hypothesized that the mechanism underlying the exceptional radioprotective properties of GT3 partly depends on the presence of endothelial TM. In vitro studies confirmed that ionizing radiation suppresses endothelial TM (about 40% at 4 hr after 5 Gy γ-irradiation) and that GT3 induces TM expression (about 2 fold at the mRNA level after 5 μM GT3 treatment for 4 hr). In vivo survival studies showed that GT3 was significantly more effective as a radioprotector in TM wild type (TM+/+) mice than in mice with low TM function (TMPro/-). After exposure to 9 Gy TBI, GT3 pre-treatment conferred 85% survival in TM+/+ mice compared to only 50% in TMPro/-. Thus, GT3-mediated radiation lethality protection is partly dependent on endothelial TM. Significant post-TBI recovery of hematopoietic cells, particularly leukocytes, was observed in TM+/+ mice (p = 0.003), but not in TMPro/- mice, despite the fact that GT3 induced higher levels of granulocyte colony stimulating factor (G-CSF) in TMPro/- mice (p = 0.0001). These data demonstrate a critical, G-CSF-independent, role for endothelial TM in GT3-mediated lethality protection and hematopoietic recovery after exposure to TBI and may point to new strategies to enhance the efficacy of current medical countermeasures in radiological/nuclear emergencies.
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Affiliation(s)
- Rupak Pathak
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
- * E-mail:
| | - Lijian Shao
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Sanchita P. Ghosh
- Armed Forces Radiobiology Research Institute, USUHS, Bethesda, MD, United States of America
| | - Daohong Zhou
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Marjan Boerma
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Hartmut Weiler
- Blood Research Institute, Blood Center of Wisconsin and the Medical College of Wisconsin, Milwaukee, WI, United States of America
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
- Surgical Service, Central Arkansas Veterans Healthcare System, Little Rock, AR, United States of America
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10
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Kurisaki I, Takayanagi M, Nagaoka M. Toward understanding allosteric activation of thrombin: a conjecture for important roles of unbound Na(+) molecules around thrombin. J Phys Chem B 2015; 119:3635-42. [PMID: 25654267 DOI: 10.1021/jp510657n] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We shed light on important roles of unbound Na(+) molecules in enzymatic activation of thrombin. Molecular mechanism of Na(+)-activation of thrombin has been discussed in the context of allostery. However, the recent challenge to redesign K(+)-activated thrombin revealed that the allosteric interaction is insufficient to explain the mechanism. Under these circumstances, we have examined the roles of unbound Na(+) molecule in maximization of thrombin-substrate association reaction rate. We performed all-atomic molecular dynamics (MD) simulations of thrombin in the presence of three different cations; Li(+), Na(+), and Cs(+). Although these cations are commonly observed in the vicinity of the S1-pocket of thrombin, smaller cations are distributed more densely and extensively than larger ones. This suggests the two observation rules: (i) thrombin surrounded by Na(+) is at an advantage in the initial step of association reaction, namely, the formation of an encounter complex ensemble, and (ii) the presence of Na(+) molecules does not necessarily have an advantage in the final step of association reaction, namely, the formation of the stereospecific complex. In conclusion, we propose a conjecture that unbound Na(+) molecules also affect the maximization of rate constant of thrombin-substrate association reaction through optimally forming an encounter complex ensemble.
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Affiliation(s)
- Ikuo Kurisaki
- Graduate School of Information Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
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11
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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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12
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Abstract
Caspases are a powerful class of cysteine proteases. Introduction of activated caspases in healthy or cancerous cells results in induction of apoptotic cell death. In this study, we have designed and characterized a version of caspase-7 that can be inactivated under oxidizing extracellular conditions and then reactivated under reducing intracellular conditions. This version of caspase-7 is allosterically inactivated when two of the substrate-binding loops are locked together via an engineered disulfide. When this disulfide is reduced, the protein regains its full function. The inactive loop-locked version of caspase-7 can be readily observed by immunoblotting and mass spectrometry. The reduced and reactivated form of the enzyme observed crystallographically is the first caspase-7 structure in which the substrate-binding groove is properly ordered even in the absence of an active-site ligand. In the reactivated structure, the catalytic-dyad cysteine-histidine are positioned 3.5 Å apart in an orientation that is capable of supporting catalysis. This redox-controlled version of caspase-7 is particularly well suited for targeted cell death in concert with redox-triggered delivery vehicles.
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Affiliation(s)
- Witold A Witkowski
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
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13
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Jones LM, B Sperry J, A Carroll J, Gross ML. Fast photochemical oxidation of proteins for epitope mapping. Anal Chem 2011; 83:7657-61. [PMID: 21894996 PMCID: PMC3193551 DOI: 10.1021/ac2007366] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The growing use of monoclonal antibodies as therapeutics underscores the importance of epitope mapping as an essential step in characterizing antibody-antigen complexes. The use of protein footprinting coupled with mass spectrometry, which is emerging as a tool in structural biology, offers opportunities to map antibody-binding regions of antigens. We report here the use of footprinting via fast photochemical oxidation of proteins (FPOP) with OH radicals to characterize the epitope of the serine protease thrombin. The data correlate well with previously published results that determined the epitope of thrombin. This study marks the first time oxidative labeling has been used for epitope mapping.
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Affiliation(s)
- Lisa M Jones
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA.
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