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Al-Otaibi JS, Sheena Mary Y, Fazil S, Mary YS, Sarala S. Modeling the structure and reactivity landscapes of a pyrazole-ammonium ionic derivative using wavefunction-dependent characteristics and screening for potential anti-inflammatory activity. J Biomol Struct Dyn 2022; 40:11190-11202. [PMID: 34328395 DOI: 10.1080/07391102.2021.1957020] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Spectroscopic investigations of 1-phenyl -2,3-dimethyl-5-oxo-1,2-dihydro-1H-pyrazol-4-ammonium 2[(2-carboxyphenyl) disulfanyl]benzoate (PACB) reported experimentally and theoretically. NH-O interaction is observed and there is a very large downshift for NH-O stretching frequency. Reactive sites are identified from the chemical and electronic properties. For PACB the maximum repulsion was around H33, H55 and H57 atom. LOL shows red regions between C-C and blue around C atoms are surrounded by a delocalized electron cloud. The red ring is a hallmark of electron density depletion from the NCI plot due to electrostatic repulsion and its existences suggests that coordination sphere for PACB is minimally strained around the central ion. Atomic contact energy values and high score of the docking results obtained propose that, PACB may have inhibitory properties and have a significant function in pharmacological chemistry. Molecular dynamics simulation was performed to validate the stability of the title compound with the Bovine thrombin-activatable fibrinolysis inhibitor protein.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Jamelah S Al-Otaibi
- Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | | | - Shiji Fazil
- Department of Chemistry, Mannaniya College of Arts and Science, Pangode, Kerala, India
| | | | - S Sarala
- Department of Physics, Kanchi Shri Krishna College of Arts and Science, Kanchipuram, Tamil Nadu, India
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2
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Enhanced Production of ECM Proteins for Pharmaceutical Applications Using Mammalian Cells and Sodium Heparin Supplementation. Pharmaceutics 2022; 14:pharmaceutics14102138. [PMID: 36297573 PMCID: PMC9609459 DOI: 10.3390/pharmaceutics14102138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/29/2022] [Accepted: 10/04/2022] [Indexed: 11/17/2022] Open
Abstract
The yields of soluble ECM proteins recombinantly produced with mammalian cells can be significantly enhanced by exploiting the stabilizing properties of heparin. Here, we propose a simple and straightforward scalable protocol for the mammalian cell production of ECM proteins with affinity for heparin, using heparin as a supplement. As proof of concept, we have demonstrated the high-level expression of four biomedically relevant human enzymes such as carboxypeptidase Z (CPZ), carboxypeptidase A6 (CPA6), beta-galactoside alpha-2,6-sialyltransferase 2 (ST6GAL1) and thrombin-activable fibrinolysis inhibitor (TAFI). We found a strong linear correlation between the isoelectric point (pI) of a protein and the improvement in protein expression levels upon heparin addition, providing a reference for selecting novel protein targets that would benefit from heparin supplementation. Finally, we demonstrated the compatibility of this approach with a three-step purification strategy that includes an initial heparin affinity purification step. Using CPZ as a representative example, we performed a preparative purification of this enzyme. The purified protein is enzymatically active and can be used for pharmaceutical applications as well as for high-throughput functional and structural studies.
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Fang P, Cai D, Du L, Shen F, Zhang C, Li M. Relationship Between Polymorphism of Thrombin-Activatable Fibrinolysis Inhibitor Gene +1040C/T and a Cohort of Chinese Women With Recurrent Spontaneous Abortion. Clin Appl Thromb Hemost 2021; 27:10760296211029720. [PMID: 34189940 PMCID: PMC8252372 DOI: 10.1177/10760296211029720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The balance between coagulation and fibrinolysis is essential for a successful pregnancy. This study aimed to explore the genetic variant of +1040C/T in the coding region of thrombin-activatable fibrinolysis inhibitor (TAFI) gene in women with recurrent spontaneous abortion (RSA) and in unrelated healthy controls and to investigate the possible association between TAFI +1040C/T polymorphism and RSA. Peripheral blood samples were collected from 137 Chinese patients with RSA and 103 unrelated healthy Chinese controls. The TAFI +1040C/T polymorphism was analyzed using SNaPshot SNP typing after DNA extraction. The frequency of the C allele was lower in RSA patients compared with the controls (0.78 vs 0.84). A subanalysis of the TAFI +1040C/T polymorphism in the 2 populations of RSA women (groups 2RSA and >2RSA) showed that the +1040CT genotype was significantly higher and the +1040CC genotype was significantly lower than from that found in controls. The allele +1040C was associated with a reduced risk of RSA in both group 2RSA (OR = 0.418, 95%CI, 0.255-0.685) and group >2RSA (OR = 0.473, 95%CI, 0.274-0.819) compared with controls. Our data indicate a protective role for TAFI +1040C allele against RSA, and may be associated with the genetic susceptibility of RSA.
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Affiliation(s)
- Ping Fang
- Department of Medical Laboratory, Affiliated Huadu Hospital, Southern Medical University (People's Hospital of Huadu District), Guangzhou, Guangdong, People's Republic of China
| | - Decheng Cai
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Lijun Du
- Department of Medical Laboratory, Affiliated Huadu Hospital, Southern Medical University (People's Hospital of Huadu District), Guangzhou, Guangdong, People's Republic of China
| | - Fei Shen
- Department of Medical Laboratory, Affiliated Huadu Hospital, Southern Medical University (People's Hospital of Huadu District), Guangzhou, Guangdong, People's Republic of China
| | - Chengfang Zhang
- Department of Medical Laboratory, Affiliated Huadu Hospital, Southern Medical University (People's Hospital of Huadu District), Guangzhou, Guangdong, People's Republic of China
| | - Meijuan Li
- Department of Medical Laboratory, Affiliated Huadu Hospital, Southern Medical University (People's Hospital of Huadu District), Guangzhou, Guangdong, People's Republic of China
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Sansilvestri-Morel P, Rupin A, Schaffner AP, Bertin F, Mennecier P, Lapret I, Declerck PJ, Baumy P, Vallez MO, Petit-Dop F, Tupinon-Mathieu I, Delerive P. S62798, a potent TAFIa inhibitor, accelerates endogenous fibrinolysis in a murine model of pulmonary thromboembolism. Thromb Res 2021; 204:81-87. [PMID: 34153648 DOI: 10.1016/j.thromres.2021.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/12/2021] [Accepted: 06/08/2021] [Indexed: 10/21/2022]
Abstract
Enhancement of fibrinolysis constitutes a promising approach to treat thrombotic diseases. Venous thrombosis and thromboembolism risks are associated with increased plasma levels of TAFI (Thrombin Activatable Fibrinolysis Inhibitor) as well as its active form TAFIa. A new TAFIa inhibitor, namely S62798 has been identified. Its ability to enhance fibrinolysis was investigated both in vitro and in vivo in a mouse model of pulmonary thromboembolism, as well as its effect on bleeding. S62798 is a highly selective human, mouse and rat TAFIa inhibitor (IC50 = 11; 270; 178 nmol/L, respectively). It accelerates lysis of a human clot in vitro, evaluated by thromboelastometry (EC50 = 27 nmol/L). In a rat tail bleeding model, no effect of S62798 treatment was observed up to 20 mg/kg. Enhancement of endogenous fibrinolysis by S62798 was investigated in a mouse model of Tissue Factor-induced pulmonary thromboembolism. Intravenous administration of S62798 decreased pulmonary fibrin clots with a minimal effective dose of 0.03 mg/kg. Finally, effect of S62798 in combination with heparin was evaluated. When treatment of heparin was done in a curative setting, no effect was observed whereas a significantly decreased pulmonary fibrin deposition was observed in response to S62798 alone or in combination with heparin. This study demonstrates that S62798 is a potent TAFIa inhibitor with minimal risk of bleeding. In vivo, curative S62798 intravenous treatment, alone or associated with heparin, accelerated clot lysis by potentiating endogenous fibrinolysis and thus decreased pulmonary fibrin clots. S62798 is expected to be a therapeutic option for pulmonary embolism patients on top of anticoagulants.
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Affiliation(s)
| | - Alain Rupin
- Cardiovascular and Metabolic Diseases Research, Institut de Recherches Servier, Suresnes, France
| | | | - Florence Bertin
- Cardiovascular and Metabolic Diseases Research, Institut de Recherches Servier, Suresnes, France
| | - Philippe Mennecier
- Cardiovascular and Metabolic Diseases Research, Institut de Recherches Servier, Suresnes, France
| | - Isabelle Lapret
- Cardiovascular and Metabolic Diseases Research, Institut de Recherches Servier, Suresnes, France
| | - Paul J Declerck
- Laboratory for Therapeutic and Diagnostic Antibodies, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Philippe Baumy
- Biokinetics Department, Technologie Servier, Orleans, France
| | - Marie-Odile Vallez
- Cardiovascular and Metabolic Diseases Research, Institut de Recherches Servier, Suresnes, France
| | - Florence Petit-Dop
- Cardiovascular and Metabolic Diseases, Institut de Recherches Internationales Servier, Suresnes, France
| | - Isabelle Tupinon-Mathieu
- Cardiovascular and Metabolic Diseases, Institut de Recherches Internationales Servier, Suresnes, France
| | - Philippe Delerive
- Cardiovascular and Metabolic Diseases Research, Institut de Recherches Servier, Suresnes, France
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Sillen M, Declerck PJ. Thrombin Activatable Fibrinolysis Inhibitor (TAFI): An Updated Narrative Review. Int J Mol Sci 2021; 22:ijms22073670. [PMID: 33916027 PMCID: PMC8036986 DOI: 10.3390/ijms22073670] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 01/02/2023] Open
Abstract
Thrombin activatable fibrinolysis inhibitor (TAFI), a proenzyme, is converted to a potent attenuator of the fibrinolytic system upon activation by thrombin, plasmin, or the thrombin/thrombomodulin complex. Since TAFI forms a molecular link between coagulation and fibrinolysis and plays a potential role in venous and arterial thrombotic diseases, much interest has been tied to the development of molecules that antagonize its function. This review aims at providing a general overview on the biochemical properties of TAFI, its (patho)physiologic function, and various strategies to stimulate the fibrinolytic system by interfering with (activated) TAFI functionality.
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Burke LC, Ezeribe HO, Kwon AY, Dockery D, Lyons PJ. Carboxypeptidase O is a lipid droplet-associated enzyme able to cleave both acidic and polar C-terminal amino acids. PLoS One 2018; 13:e0206824. [PMID: 30388170 PMCID: PMC6214572 DOI: 10.1371/journal.pone.0206824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 10/19/2018] [Indexed: 11/18/2022] Open
Abstract
Carboxypeptidase O (CPO) is a member of the M14 family of metallocarboxypeptidases with a preference for the cleavage of C-terminal acidic amino acids. CPO is largely expressed in the small intestine, although it has been detected in other tissues such as the brain and ovaries. CPO does not contain a prodomain, nor is it strongly regulated by pH, and hence appears to exist as a constitutively active enzyme. The goal of this study was to investigate the intracellular distribution and activity of CPO in order to predict physiological substrates and function. The distribution of CPO, when expressed in MDCK cells, was analyzed by immunofluorescence microscopy. Soon after addition of nutrient-rich media, CPO was found to associate with lipid droplets, causing an increase in lipid droplet quantity. As media became depleted, CPO moved to a broader ER distribution, no longer impacting lipid droplet numbers. Membrane cholesterol levels played a role in the distribution and in vitro enzymatic activity of CPO, with cholesterol enrichment leading to decreased lipid droplet association and enzymatic activity. The ability of CPO to cleave C-terminal amino acids within the early secretory pathway (in vivo) was examined using Gaussia luciferase as a substrate, C-terminally tagged with variants of an ER retention signal. While no effect of cholesterol was observed, these data show that CPO does function as an active enzyme within the ER where it removes C-terminal glutamates and aspartates, as well as a number of polar amino acids.
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Affiliation(s)
- Linnea C. Burke
- Department of Biology, Andrews University, Berrien Springs, Michigan, United States of America
| | - Hazel O. Ezeribe
- Department of Biology, Andrews University, Berrien Springs, Michigan, United States of America
| | - Anna Y. Kwon
- Department of Biology, Andrews University, Berrien Springs, Michigan, United States of America
| | - Donnel Dockery
- Department of Biology, Andrews University, Berrien Springs, Michigan, United States of America
| | - Peter J. Lyons
- Department of Biology, Andrews University, Berrien Springs, Michigan, United States of America
- * E-mail:
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Lu Z, Shi P, You H, Liu Y, Chen S. Transcriptomic analysis of the salivary gland of medicinal leech Hirudo nipponia. PLoS One 2018; 13:e0205875. [PMID: 30339694 PMCID: PMC6195274 DOI: 10.1371/journal.pone.0205875] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 10/03/2018] [Indexed: 12/31/2022] Open
Abstract
Hirudo nipponia (known as Shui Zhi in Chinese) is a well-known Chinese medicine with numerous active ingredients in its body, especially in its saliva. This native Chinese blood-sucking leech has been used for therapeutic purposes since before 100 AD. Modern Chinese physicians use it for a wide range of diseases. Genomic data and molecular information about the pharmacologically active substances produced by this medicinal leech are presently unavailable despite this organism’s medicinal importance. In this study, we performed transcriptome profiling of the salivary glands of medicinal leech H. nipponia using the Illumina platform. In total, 84,657,362 clean reads were assembled into 50,535 unigenes. The obtained unigenes were compared to public databases. Furthermore, a unigene sequence similarity search and comparisons with the whole transcriptome of medical leech were performed to identify potential proteins. Finally, more than 21 genes were predicted to be involved in anticoagulatory, antithrombotic, antibacterial, anti-inflammatory and antitumor processes, which might play important roles in the treatment of various diseases. This study is the first analysis of a sialotranscriptome in H. nipponia. The transcriptome profile will shed light on its genetic background and provide a useful tool to deepen our understanding of the medical value of H. nipponia.
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Affiliation(s)
- Zenghui Lu
- Chongqing Academy of Chinese Materia Medica, Chongqing, China
- Chongqing Sub-center of National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Science, Chongqing, China
- Chongqing Key Laboratory of Chinese Medicine Resources, Chongqing, China
| | - Ping Shi
- Chongqing Academy of Chinese Materia Medica, Chongqing, China
- Chongqing Sub-center of National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Science, Chongqing, China
| | - Huajian You
- Chongqing Academy of Chinese Materia Medica, Chongqing, China
- Chongqing Key Laboratory of Chinese Medicine Resources, Chongqing, China
| | - Yanqi Liu
- Chongqing Academy of Chinese Materia Medica, Chongqing, China
- Chongqing Key Laboratory of Chinese Medicine Resources, Chongqing, China
| | - Shijiang Chen
- Chongqing Academy of Chinese Materia Medica, Chongqing, China
- Chongqing Sub-center of National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Science, Chongqing, China
- Chongqing Key Laboratory of Chinese Medicine Resources, Chongqing, China
- * E-mail:
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8
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Porter LM, Radulović ŽM, Mulenga A. A repertoire of protease inhibitor families in Amblyomma americanum and other tick species: inter-species comparative analyses. Parasit Vectors 2017; 10:152. [PMID: 28330502 PMCID: PMC5361777 DOI: 10.1186/s13071-017-2080-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 03/06/2017] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Protease inhibitors (PIs) are important regulators of physiology and represent anti-parasitic druggable and vaccine targets. We conducted bioinformatic analyses of genome and transcriptome data to determine the protease inhibitor (PI) repertoire in Amblyomma americanum and in 25 other ixodid tick species. For A. americanum, we compared the PI repertoires in fed and unfed, male and female A. americanum ticks. We also analyzed PI repertoires of female 48, 96 and 120 h-fed midgut (MG) and salivary gland (SG) tissues. RESULTS We found 1,595 putative non-redundant PI sequences across 26 ixodid tick species. Ticks express PIs from at least 18 different families: I1, I2, I4, I8, I21, I25, I29, I31, I32, I35, I39, I43, I51, I53, I63, I68, I72 and I74 (MEROPS). The largest PI families were I2, I4 and I8 and lowest in I21, I31, I32, I35 and I68. The majority (75%) of tick PIs putatively inhibit serine proteases, with ~11 and 9% putatively regulating cysteine or metalloprotease-mediated pathways, respectively, and ~4% putatively regulating multiple/mixed protease types. In A. americanum, we found 370 PIs in female and 354 in male ticks. In A. americanum we found 231 and 442 in unfed and fed ticks, respectively. In females, we found 206 and 164 PIs in SG and MG, respectively. The majority of highly cross-tick species conserved PIs were in families I1, I2, I8, I21, I25, I29, I39 and I43. CONCLUSIONS Ticks appear to express large and diverse repertoires of PIs that primarily target serine protease-mediated pathways. We speculate that PI families with the highest repertoires may contain functionally redundant members while those with the lowest repertoires are functionally non-redundant PIs. We found some highly conserved PIs in the latter category, which we propose as potential candidates for broad-spectrum anti-tick vaccine candidates or druggable targets in tick control.
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Affiliation(s)
- Lindsay M Porter
- Department of Veterinary Pathobiology, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, 4647 TAMU, College Station, TX, 77843, USA
| | - Željko M Radulović
- Department of Veterinary Pathobiology, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, 4647 TAMU, College Station, TX, 77843, USA
| | - Albert Mulenga
- Department of Veterinary Pathobiology, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, 4647 TAMU, College Station, TX, 77843, USA.
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Zhou X, Weeks SD, Ameloot P, Callewaert N, Strelkov SV, Declerck PJ. Elucidation of the molecular mechanisms of two nanobodies that inhibit thrombin-activatable fibrinolysis inhibitor activation and activated thrombin-activatable fibrinolysis inhibitor activity. J Thromb Haemost 2016; 14:1629-38. [PMID: 27279497 DOI: 10.1111/jth.13381] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Indexed: 11/30/2022]
Abstract
UNLABELLED Essentials Thrombin-activatable fibrinolysis inhibitor (TAFI) is a risk factor for cardiovascular disorders. TAFI inhibitory nanobodies represent a promising step in developing profibrinolytic therapeutics. We have solved three crystal structures of TAFI in complex with inhibitory nanobodies. Nanobodies inhibit TAFI through distinct mechanisms and represent novel profibrinolytic leads. SUMMARY Background Thrombin-activatable fibrinolysis inhibitor (TAFI) is converted to activated TAFI (TAFIa) by thrombin, plasmin, or the thrombin-thrombomodulin complex (T/TM). TAFIa is antifibrinolytic, and high levels of TAFIa are associated with an increased risk for cardiovascular disorders. TAFI-inhibitory nanobodies represent a promising approach for developing profibrinolytic therapeutics. Objective To elucidate the molecular mechanisms of inhibition of TAFI activation and TAFIa activity by nanobodies with the use of X-ray crystallography and biochemical characterization. Methods and results We selected two nanobodies for cocrystallization with TAFI. VHH-a204 interferes with all TAFI activation modes, whereas VHH-i83 interferes with T/TM-mediated activation and also inhibits TAFIa activity. The 3.05-Å-resolution crystal structure of TAFI-VHH-a204 reveals that the VHH-a204 epitope is localized to the catalytic moiety (CM) in close proximity to the TAFI activation site at Arg92, indicating that VHH-a204 inhibits TAFI activation by steric hindrance. The 2.85-Å-resolution crystal structure of TAFI-VHH-i83 reveals that the VHH-i83 epitope is located close to the presumptive thrombomodulin-binding site in the activation peptide (AP). The structure and supporting biochemical assays suggest that VHH-i83 inhibits TAFIa by bridging the AP to the CM following TAFI activation. In addition, the 3.00-Å-resolution crystal structure of the triple TAFI-VHH-a204-VHH-i83 complex demonstrates that the two nanobodies can simultaneously bind to TAFI. Conclusions This study provides detailed insights into the molecular mechanisms of TAFI inhibition, and reveals a novel mode of TAFIa inhibition. VHH-a204 and VHH-i83 merit further evaluation as potential profibrinolytic therapeutics.
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Affiliation(s)
- X Zhou
- Department of Pharmaceutical and Pharmacologic Sciences, Laboratory for Therapeutic and Diagnostic Antibodies, KU Leuven, Belgium
| | - S D Weeks
- Department of Pharmaceutical and Pharmacologic Sciences, Laboratory for Biocrystallography, KU Leuven, Belgium
| | - P Ameloot
- Flanders Institute for Biotechnology, Medical Biotechnology Center, Ghent, Belgium
- Department of Biochemistry and Microbiology, Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, Ghent, Belgium
| | - N Callewaert
- Flanders Institute for Biotechnology, Medical Biotechnology Center, Ghent, Belgium
- Department of Biochemistry and Microbiology, Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, Ghent, Belgium
| | - S V Strelkov
- Department of Pharmaceutical and Pharmacologic Sciences, Laboratory for Biocrystallography, KU Leuven, Belgium
| | - P J Declerck
- Department of Pharmaceutical and Pharmacologic Sciences, Laboratory for Therapeutic and Diagnostic Antibodies, KU Leuven, Belgium
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10
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Plug T, Meijers JCM. Structure-function relationships in thrombin-activatable fibrinolysis inhibitor. J Thromb Haemost 2016; 14:633-44. [PMID: 26786060 DOI: 10.1111/jth.13261] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Indexed: 11/30/2022]
Abstract
Thrombin-activatable fibrinolysis inhibitor (TAFI) is an important regulator in the balance of coagulation and fibrinolysis. TAFI is a metallocarboxypeptidase that circulates in plasma as zymogen. Activated TAFI (TAFIa) cleaves C-terminal lysine or arginine residues from peptide substrates. The removal of C-terminal lysine residues from partially degraded fibrin leads to reduced plasmin formation and thus attenuation of fibrinolysis. TAFI also plays a role in inflammatory processes via the removal of C-terminal arginine or lysine residues from bradykinin, thrombin-cleaved osteopontin, C3a, C5a and chemerin. TAFI has been studied extensively over the past three decades and recent publications provide a wealth of information, including crystal structures, mutants and structural data obtained with antibodies and peptides. In this review, we combined and compared available data on structure/function relationships of TAFI.
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Affiliation(s)
- T Plug
- Department of Experimental Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - J C M Meijers
- Department of Experimental Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- Department of Plasma Proteins, Sanquin Research, Amsterdam, the Netherlands
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11
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Sudha G, Singh P, Swapna LS, Srinivasan N. Weak conservation of structural features in the interfaces of homologous transient protein-protein complexes. Protein Sci 2015; 24:1856-73. [PMID: 26311309 DOI: 10.1002/pro.2792] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 08/13/2015] [Accepted: 08/17/2015] [Indexed: 12/21/2022]
Abstract
Residue types at the interface of protein-protein complexes (PPCs) are known to be reasonably well conserved. However, we show, using a dataset of known 3-D structures of homologous transient PPCs, that the 3-D location of interfacial residues and their interaction patterns are only moderately and poorly conserved, respectively. Another surprising observation is that a residue at the interface that is conserved is not necessarily in the interface in the homolog. Such differences in homologous complexes are manifested by substitution of the residues that are spatially proximal to the conserved residue and structural differences at the interfaces as well as differences in spatial orientations of the interacting proteins. Conservation of interface location and the interaction pattern at the core of the interfaces is higher than at the periphery of the interface patch. Extents of variability of various structural features reported here for homologous transient PPCs are higher than the variation in homologous permanent homomers. Our findings suggest that straightforward extrapolation of interfacial nature and inter-residue interaction patterns from template to target could lead to serious errors in the modeled complex structure. Understanding the evolution of interfaces provides insights to improve comparative modeling of PPC structures.
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Affiliation(s)
- Govindarajan Sudha
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, Karnataka, India
| | - Prashant Singh
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, Karnataka, India
| | - Lakshmipuram S Swapna
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, Karnataka, India
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12
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Holocyclotoxin-1, a cystine knot toxin from Ixodes holocyclus. Toxicon 2014; 90:308-17. [DOI: 10.1016/j.toxicon.2014.08.068] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 08/20/2014] [Accepted: 08/20/2014] [Indexed: 01/31/2023]
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13
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Otero A, Rodríguez de la Vega M, Tanco S, Lorenzo J, Avilés FX, Reverter D. The novel structure of a cytosolic M14 metallocarboxypeptidase (CCP) from Pseudomonas aeruginosa: a model for mammalian CCPs. FASEB J 2012; 26:3754-64. [PMID: 22645247 DOI: 10.1096/fj.12-209601] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PaCCP is a metallocarboxypeptidase (MCP) of the M14 family from Pseudomonas aeruginosa, which belongs to a bacterial clade of carboxypeptidases that are homologous to the recently discovered M14D subfamily of human nonsecretory cytosolic carboxypeptidases (CCPs). CCPs are intracellular peptidases involved, among other roles, in the post-translational modifications of tubulin. Here we report the crystal structure of PaCCP at high resolution (1.6 Å). Its 375 residues are folded in a novel β-sandwich N-terminal domain followed by the classical carboxypeptidase α/β-hydrolase domain, this one in a shorter and more compact form. The former is unique in the whole family and does not have sequential or structural homology with other domains that are usually flanking the latter, like the prodomain of the M14A subfamily or the C-terminal transthyretin/prealbumin-like domains of the M14B subfamily. PaCCP does not display activity against small carboxypeptidase substrates, so in this form it might constitute an inactive precursor of the protease. Structural results derived from cocrystallization with well-known inhibitors of MCPs indicate that the enzyme might only possess C-terminal hydrolase activity against cellular substrates of particular specificity and/or when undergoes structural rearrangements. The derived PaCCP structure allows a first structural insight into the more complex and largely unknown mammalian CCP subfamily.
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Affiliation(s)
- Anabel Otero
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i de Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
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Declerck PJ. Thrombin activatable fibrinolysis inhibitor. Hamostaseologie 2011; 31:165-6, 168-73. [PMID: 21629966 DOI: 10.5482/ha-1155] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 05/26/2011] [Indexed: 12/14/2022] Open
Abstract
Thrombin activatable fibrinolysis inhibitor (TAFI) was discovered two decades ago as a consequence of the identification of an unstable carboxypeptidase (CPU), which was formed upon thrombin activation of the respective pro-enzyme (proCPU). The antifibrinolytic function of the activated form (TAFIa, CPU) is directly linked to its capacity to remove C-terminal lysines from the surface of the fibrin clot. No endogenous inhibitors have been identified, but TAFIa activity is regulated by its intrinsic temperature-dependent instability with a half-life of 8 to 15 min at 37 °C. A variety of studies have demonstrated a role for TAFI/TAFIa in venous and arterial diseases. In addition, a role in inflammation and cell migration has been shown. Since an elevated level of TAFIa it is a potential risk factor for thrombotic disorders, many inhibitors, both at the level of activation or at the level of activity, have been developed and were proven to exhibit a profibrinolytic effect in animal models. Pharmacologically active inhibitors of the TAFI/TAFIa system may open new ways for the prevention of thrombotic diseases or for the establishment of adjunctive treatments during thrombolytic therapy.
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Affiliation(s)
- P J Declerck
- Katholieke Universiteit Leuven, Campus Gasthuisberg, Herestraat 49, Leuven, Belgium.
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15
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Bijak M, Bobrowski M, Borowiecka M, Podsędek A, Golański J, Nowak P. Anticoagulant effect of polyphenols-rich extracts from black chokeberry and grape seeds. Fitoterapia 2011; 82:811-7. [PMID: 21596108 DOI: 10.1016/j.fitote.2011.04.017] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 04/18/2011] [Accepted: 04/23/2011] [Indexed: 11/15/2022]
Abstract
Blood coagulation consists of a series of zymogens that can be converted by limited proteolysis to active enzymes leading to the generation of thrombin. Fresh plasma and human thrombin was incubated with extracts from berries of Aronia melanocarpa or seeds of Vitis vinifera (0.5; 5; 50 μg/ml). The in vitro experiments showed that both extracts prolonged clotting time and decreased the maximal velocity of fibrin polymerization in human plasma. Moreover thrombin incubation with both extracts results in the inhibition of amidolytic activity of this enzyme. It gives hopes for development of diet supplements, which may be preventing thrombosis in pathological states.
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Affiliation(s)
- Michał Bijak
- Department of General Biochemistry, University of Lodz, Banacha12/16, 90-237 Lodz, Poland.
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Valnickova Z, Sanglas L, Arolas JL, Petersen SV, Schar C, Otzen D, Aviles FX, Gomis-Rüth FX, Enghild JJ. Flexibility of the thrombin-activatable fibrinolysis inhibitor pro-domain enables productive binding of protein substrates. J Biol Chem 2010; 285:38243-50. [PMID: 20880845 DOI: 10.1074/jbc.m110.150342] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously reported that thrombin-activatable fibrinolysis inhibitor (TAFI) exhibits intrinsic proteolytic activity toward large peptides. The structural basis for this observation was clarified by the crystal structures of human and bovine TAFI. These structures evinced a significant rotation of the pro-domain away from the catalytic moiety when compared with other pro-carboxypeptidases, thus enabling access of large peptide substrates to the active site cleft. Here, we further investigated the flexible nature of the pro-domain and demonstrated that TAFI forms productive complexes with protein carboxypeptidase inhibitors from potato, leech, and tick (PCI, LCI, and TCI, respectively). We determined the crystal structure of the bovine TAFI-TCI complex, revealing that the pro-domain was completely displaced from the position observed in the TAFI structure. It protruded into the bulk solvent and was disordered, whereas TCI occupied the position previously held by the pro-domain. The authentic nature of the presently studied TAFI-inhibitor complexes was supported by the trimming of the C-terminal residues from the three inhibitors upon complex formation. This finding suggests that the inhibitors interact with the active site of TAFI in a substrate-like manner. Taken together, these data show for the first time that TAFI is able to form a bona fide complex with protein carboxypeptidase inhibitors. This underlines the unusually flexible nature of the pro-domain and implies a possible mechanism for regulation of TAFI intrinsic proteolytic activity in vivo.
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Affiliation(s)
- Zuzana Valnickova
- Center for Insoluble Protein Structure (inSPIN), Department of Molecular Biology, Science Park, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
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Abstract
Carboxypeptidase A6 (CPA6) is an extracellular matrix-bound metallocarboxypeptidase (CP) that has been implicated in Duane syndrome, a neurodevelopmental disorder in which the lateral rectus extraocular muscle is not properly innervated. Consistent with a role in Duane syndrome, CPA6 is expressed in a number of chondrocytic and nervous tissues during embryogenesis. To better characterize the enzymatic function and specificity of CPA6 and to compare this with other CPs, CPA6 was expressed in HEK293 cells and purified. Kinetic parameters were determined using a panel of synthetic carboxypeptidase substrates, indicating a preference of CPA6 for large hydrophobic C-terminal amino acids and only very weak activity toward small amino acids and histidine. A quantitative peptidomics approach using a mixture of peptides representative of the neuropeptidome allowed the characterization of CPA6 preferences at the P1 substrate position and suggested that small and acidic P1 residues significantly inhibit CPA6 cleavage. Finally, a comparison of available kinetic data for CPA enzymes shows a gradient of specificity across the subfamily, from the very restricted specificity of CPA2 to the very broad activity of CPA4. Structural data and modeling for all CPA/B subfamily members suggests the structural basis for the unique specificities observed for each member of the CPA/B subfamily of metallocarboxypeptidases.
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Affiliation(s)
- Peter J Lyons
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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18
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+1040 C/T polymorphism in coding region of thrombin-activatable fibrinolysis inhibitor gene and the risk of idiopathic recurrent fetal loss. Blood Coagul Fibrinolysis 2010; 21:679-82. [PMID: 20729722 DOI: 10.1097/mbc.0b013e32833e426d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recurrent fetal loss (RFL) is common health problem affecting up to 5% of women of reproductive age. It has been shown that plasma thrombin-activatable fibrinolysis inhibitor (TAFI) concentrations increase during pregnancy and return to baseline levels soon after delivery. The +1040C/T single nucleotide polymorphism in coding region of TAFI gene is associated with TAFI blood levels. The aim of our study was to investigate the relationship between +1040C/T polymorphism in TAFI gene and idiopathic RFL. Study was carried out in a group of 120 women (61 controls and 59 women with idiopathic RFL). The +1040C/T polymorphism was detected by restriction fragment length polymorphism PCR. Increased frequency of +1040T/T genotype was observed in a study group, but without statistically significant difference. Carriers of T/T genotype have increased risk of fetal loss by 1.23-fold, compared with carriers of C/C (95% CI 0.462-3.277; P = 0.7) and 1.34-fold compared with carriers of C/T genotype (95% CI 0.501-3.601; P = 0.6). C allele is associated with reduced risk of recurrent fetal loss compared with T allele (OR 0.91; 95% CI 0.545-1.533; P = 0.7). In conclusion, we observed increased frequency of +1040T/T genotype in a patient group, suggesting that this genotype could be potential risk factor for idiopathic RFL. Further investigation should be carried out in order to establish the role of this polymorphism in the etiology of idiopathic recurrent miscarriages.
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Puertas JM, Nannenga BL, Dornfeld KT, Betton JM, Baneyx F. Enhancing the secretory yields of leech carboxypeptidase inhibitor in Escherichia coli: influence of trigger factor and signal recognition particle. Protein Expr Purif 2010; 74:122-8. [PMID: 20600941 DOI: 10.1016/j.pep.2010.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 06/07/2010] [Accepted: 06/17/2010] [Indexed: 11/29/2022]
Abstract
The signal recognition particle (SRP) dependent secretion pathway is as an attractive alternative to Sec-dependent export for the production of disulfide-bonded and/or fast-folding recombinant proteins in the Escherichia coli periplasm. SRP, which shares a ribosomal attachment site with the molecular chaperone trigger factor (TF), recognizes highly hydrophobic signal sequence as they emerge from the ribosome and delivers ribosome nascent chain complexes to FtsY for subsequent cotranslational translocation of target proteins across the SecYEG pore. However, like in the case of Sec-dependent export, secretory yields can be limited by the accumulation of precursor proteins in the cytoplasm. Using leech carboxypeptidase inhibitor (LCI) fused to the SRP-dependent DsbA signal sequence as a model system, we show that a null mutation in the gene encoding TF (Deltatig) or SRP co-expression reduce pre-LCI accumulation by half, and that quantitative export can be achieved by combining the two strategies. Interestingly, enhanced precursor processing did not alter periplasmic LCI levels but increased the amount of protein excreted in the growth medium. All mature LCI was nearly fully active and an 80% increase in productivity was achieved in Deltatig cells alone due to their faster growth. Our results show that competition between SRP and TF can interfere with efficient export of recombinant proteins targeted to the SRP pathway and establish TF-deficient strains and SRP co-expression as a simple solution to improve yields.
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Affiliation(s)
- Juan-Miguel Puertas
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195-1750, USA
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20
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Fernández D, Pallarès I, Vendrell J, Avilés FX. Progress in metallocarboxypeptidases and their small molecular weight inhibitors. Biochimie 2010; 92:1484-500. [PMID: 20466032 DOI: 10.1016/j.biochi.2010.05.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 05/04/2010] [Indexed: 01/11/2023]
Abstract
In what corresponds to a life span, metallocarboxypeptidases (MCPs) have jumped from being mere contaminants in animal pancreas powders (in depression year 1929) to be key players in cellular and molecular processes (in yet-another-depression years 2009-2010). MCPs are unique zinc-dependent enzymes that catalyze the breakdown of the amide bond at the C-terminus of peptide and protein substrates and participate in the recovery of dietary amino acids, tissue organogenesis, neurohormone and cytokine maturation and other important physiological processes. More than 26 genes code for MCPs in the human genome, many of them still waiting to be fully understood in terms of physiological function. A variety of MCPs have been linked to diseases in man: acute pancreatitis and pancreas cancer, type 2 diabetes, Alzheimer's Disease, various types of cancer, and fibrinolysis and inflammation. Many of these discoveries have been made possible thanks to recent advances, as exemplified by plasma carboxypeptidases N and B, known for fifty and twenty years, respectively, which have had their structures released only very recently. Plasma carboxypeptidase B is a biological target for therapy because of its involvement in the coagulation/fibrinolysis processes. Besides, the widespread use of carboxypeptidase A as a benchmark metalloprotease since the early days of Biochemistry has allowed the identification and design of an increasingly vast repertory of small molecular weight inhibitors. With these two examples we wish to emphasize that MCPs have become part of the drug discovery portfolio of pharmaceutical companies and academic research laboratories. This paper will review key developments in the discovery and design of MCP small molecular weight inhibitors, with an emphasis on the discovery of chemically diverse entities. Although encouraging advances have been achieved in the last few years, the specificity and oral bioavailability of the new chemotherapeutic agents seem to pose a challenge to medicinal chemists.
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Affiliation(s)
- Daniel Fernández
- Departament de Bioquímica i Biologia Molecular, Facultat de Biociències and Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
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21
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Abstract
See also Sanglas L, Arolas JL, Valnickova Z, Aviles FX, Enghild JJ, Gomis-Rüth FX. Insights into the molecular inactivation mechanism of human activated thrombin-activatable fibrinolysis inhibitor. This issue, pp 1056-65.
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Affiliation(s)
- A Gils
- Laboratory for Pharmaceutical Biology, Faculty of Pharmaceutical Sciences, Katholieke Universiteit Leuven, Leuven, Belgium.
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22
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Sanglas L, Arolas JL, Valnickova Z, Aviles FX, Enghild JJ, Gomis-Rüth FX. Insights into the molecular inactivation mechanism of human activated thrombin-activatable fibrinolysis inhibitor. J Thromb Haemost 2010; 8:1056-65. [PMID: 20088943 DOI: 10.1111/j.1538-7836.2010.03740.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
SUMMARY BACKGROUND Thrombin-activatable fibrinolysis inhibitor (TAFI) is a validated target for thrombotic diseases. TAFI is converted in vivo to activated TAFI (TAFIa) by removal of its pro-domain. Whereas TAFI is stable and persists in the circulation, possibly in complex with plasminogen, TAFIa is unstable and poorly soluble, with a half-life of minutes. OBJECTIVES In order to study the molecular determinants of this instability, we studied the influence of protein inhibitors on human TAFIa. RESULTS We found that protein inhibitors significantly reduced the instability and insolubility of TAFIa. In addition, we solved the 2.5-A resolution crystal structure of human TAFIa in complex with a potent protein inhibitor, tick-derived carboxypeptidase inhibitor, which gives rise to a stable and soluble TAFIa species. The structure revealed a significant reduction in the flexibility of dynamic segments when compared with the structures of bovine and human TAFI. We also identified two latent hotspots, loop Lbeta2beta3 and segment alpha5-Lalpha5beta7-beta7, where conformational destabilization may begin. These hotspots are also present in TAFI, but the pro-domain may provide sufficient stabilization and solubility to guarantee protein persistence in vivo. When the pro-domain is removed, the free TAFIa moiety becomes unstable, its activity is suppressed, and the molecule becomes insoluble. CONCLUSIONS The present study corroborates the function of protein inhibitors in stabilizing human TAFIa and it provides a rigid and high-resolution mold for the design of small molecule inhibitors of this enzyme, thus paving the way for novel therapy for thrombotic disorders.
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Affiliation(s)
- L Sanglas
- Departament de Bioquímica i Biologia Molecular, Facultat de Ciències, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
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Cagliani R, Fumagalli M, Riva S, Pozzoli U, Fracassetti M, Bresolin N, Comi GP, Sironi M. Polymorphisms in the CPB2 Gene Are Maintained by Balancing Selection and Result in Haplotype-Preferential Splicing of Exon 7. Mol Biol Evol 2010; 27:1945-54. [DOI: 10.1093/molbev/msq082] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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Willemse JL, Heylen E, Nesheim ME, Hendriks DF. Carboxypeptidase U (TAFIa): a new drug target for fibrinolytic therapy? J Thromb Haemost 2009; 7:1962-71. [PMID: 19719827 PMCID: PMC3170991 DOI: 10.1111/j.1538-7836.2009.03596.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Procarboxypeptidase U (TAFI) is a recently discovered plasma procarboxypeptidase that upon activation by thrombin or thrombin-thrombomodulin turns into a potent antifibrinolytic enzyme. Its prominent bridging function between coagulation and fibrinolysis raised the interest of many research groups and of the pharmaceutical industry. The development of carboxypeptidase U (CPU) inhibitors as profibrinolytic agents is an attractive concept and possibilities for rational drug design will become more readily available in the near future as a result of the recently published crystal structure. Numerous studies have been performed and many of them show beneficial effects of CPU inhibitors for the improvement of endogenous fibrinolysis in different animal sepsis and thrombosis models. CPU inhibitors combined with tissue-type plasminogen activator (t-PA) seem to increase the efficiency of pharmacological thrombolysis allowing lower dosing of t-PA and subsequently fewer bleeding complications. This review will focus on recently obtained in vivo data and the benefits/risks of targeting CPU for the treatment of thrombotic disorders.
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Affiliation(s)
- Johan L. Willemse
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Evelien Heylen
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Michael. E. Nesheim
- Departments of Biochemistry and Medicine, Queen’s University, Ontario, Canada
| | - Dirk F. Hendriks
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
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Puertas JM, Betton JM. Engineering an efficient secretion of leech carboxypeptidase inhibitor in Escherichia coli. Microb Cell Fact 2009; 8:57. [PMID: 19874597 PMCID: PMC2775724 DOI: 10.1186/1475-2859-8-57] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Accepted: 10/29/2009] [Indexed: 11/11/2022] Open
Abstract
Background Despite advances in expression technologies, the efficient production of heterologous secreted proteins in Escherichia coli remains a challenge. One frequent limitation relies on their inability to be exported to the E. coli periplasm. However, recent studies have suggested that translational kinetics and signal sequences act in concert to modulate the export process. Results In order to produce leech carboxypeptidase inhibitor (LCI) in the bacterial periplasm, we compared expression of the natural and optimized gene sequences, and evaluated export efficiency of LCI fused to different signal sequences. The best combination of these factors acting on translation and export was obtained when the signal sequence of DsbA was fused to an E. coli codon-optimized mature LCI sequence. When tested in high cell density cultures, the protein was primarily found in the growth medium. Under these conditions, the engineered expression system yields over 470 mg.l-1 of purified active LCI. Conclusion These results support the hypothesis that heterologous secreted proteins require proper coupling between translation and translocation for optimal high-level production in E. coli.
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Affiliation(s)
- Juan-Miguel Puertas
- Unité de Biochimie Structurale, Institut Pasteur, URA-CNRS 2185, 75724 Paris Cedex 15, France.
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Arolas JL, Castillo V, Bronsoms S, Aviles FX, Ventura S. Designing Out Disulfide Bonds of Leech Carboxypeptidase Inhibitor: Implications for Its Folding, Stability and Function. J Mol Biol 2009; 392:529-46. [DOI: 10.1016/j.jmb.2009.06.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 05/04/2009] [Accepted: 06/18/2009] [Indexed: 11/26/2022]
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Valnickova Z, Thaysen-Andersen M, Højrup P, Christensen T, Sanggaard KW, Kristensen T, Enghild JJ. Biochemical characterization of bovine plasma thrombin-activatable fibrinolysis inhibitor (TAFI). BMC BIOCHEMISTRY 2009; 10:13. [PMID: 19416536 PMCID: PMC2684115 DOI: 10.1186/1471-2091-10-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Accepted: 05/05/2009] [Indexed: 11/18/2022]
Abstract
Background TAFI is a plasma protein assumed to be an important link between coagulation and fibrinolysis. The three-dimensional crystal structures of authentic mature bovine TAFI (TAFIa) in complex with tick carboxypeptidase inhibitor, authentic full lenght bovine plasma thrombin-activatable fibrinolysis inhibitor (TAFI), and recombinant human TAFI have recently been solved. In light of these recent advances, we have characterized authentic bovine TAFI biochemically and compared it to human TAFI. Results The four N-linked glycosylation sequons within the activation peptide were all occupied in bovine TAFI, similar to human TAFI, while the sequon located within the enzyme moiety of the bovine protein was non-glycosylated. The enzymatic stability and the kinetic constants of TAFIa differed somewhat between the two proteins, as did the isoelectric point of TAFI, but not TAFIa. Equivalent to human TAFI, bovine TAFI was a substrate for transglutaminases and could be proteolytically cleaved by trypsin or thrombin/solulin complex, although small differences in the fragmentation patterns were observed. Furthermore, bovine TAFI exhibited intrinsic activity and TAFIa attenuated tPA-mediated fibrinolysis similar to the human protein. Conclusion The findings presented here suggest that the properties of these two orthologous proteins are similar and that conclusions reached using the bovine TAFI may be extrapolated to the human protein.
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Affiliation(s)
- Zuzana Valnickova
- Center for Insoluble Protein Structures and Interdisciplinary Nanoscience Center, Department of Molecular Biology, Science Park, University of Aarhus, Gustav Wieds Vej 10c, 8000 Aarhus C, Denmark.
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Mammalian metallopeptidase inhibition at the defense barrier of Ascaris parasite. Proc Natl Acad Sci U S A 2009; 106:1743-7. [PMID: 19179285 DOI: 10.1073/pnas.0812623106] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Roundworms of the genus Ascaris are common parasites of the human gastrointestinal tract. A battery of selective inhibitors protects them from host enzymes and the immune system. Here, a metallocarboxypeptidase (MCP) inhibitor, ACI, was identified in protein extracts from Ascaris by intensity-fading MALDI-TOF mass spectrometry. The 67-residue amino acid sequence of ACI showed no significant homology with any known protein. Heterologous overexpression and purification of ACI rendered a functional molecule with nanomolar equilibrium dissociation constants against MCPs, which denoted a preference for digestive and mast cell A/B-type MCPs. Western blotting and immunohistochemistry located ACI in the body wall, intestine, female reproductive tract, and fertilized eggs of Ascaris, in accordance with its target specificity. The crystal structure of the complex of ACI with human carboxypeptidase A1, one of its potential targets in vivo, revealed a protein with a fold consisting of two tandem homologous domains, each containing a beta-ribbon and two disulfide bonds. These domains are connected by an alpha-helical segment and a fifth disulfide bond. Binding and inhibition are exerted by the C-terminal tail, which enters the funnel-like active-site cavity of the enzyme and approaches the catalytic zinc ion. The findings reported provide a basis for the biological function of ACI, which may be essential for parasitic survival during infection.
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Abstract
Fibrinolysis is regulated by specific molecular interactions between its main components. Activation of plasminogen by tissue-type plasminogen activator (t-PA) is enhanced in the presence of fibrin or at the endothelial cell surface. Urokinase-type plasminogen activator (u-PA) binds to a specific cellular u-PA receptor (u-PAR), resulting in enhanced activation of cell-bound plasminogen. Inhibition of fibrinolysis occurs at the level of plasminogen activation or at the level of plasmin. Assembly of fibrinolytic components at the surface of fibrin results in fibrin degradation. Assembly at the surface of cells provides a mechanism for generation of localized cell-associated proteolytic activity. This review includes novel proteins such a thrombin-activatable fibrinolysis inhibitor (TAFI) and discusses new insights into molecular mechanisms obtained from the rapidly growing knowledge of crystal structures of proteins.
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Affiliation(s)
- D C Rijken
- Department of Hematology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands.
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31
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Arolas JL, Pantoja-Uceda D, Ventura S, Blanco FJ, Aviles FX. The NMR Structures of the Major Intermediates of the Two-domain Tick Carboxypeptidase Inhibitor Reveal Symmetry in Its Folding and Unfolding Pathways. J Biol Chem 2008; 283:27110-20. [DOI: 10.1074/jbc.m803978200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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