1
|
Vu K, Kar S, Goyal N, Mottamal M, Afosah DK, Al-Horani RA. Discovery of Heparin Mimetic, Potent, and Selective Inhibitors of Human Clotting Factor XIIIa. ACS OMEGA 2024; 9:31105-31119. [PMID: 39035933 PMCID: PMC11256326 DOI: 10.1021/acsomega.4c04518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 06/19/2024] [Accepted: 06/21/2024] [Indexed: 07/23/2024]
Abstract
Factor XIIIa (FXIIIa) is a cysteine transglutaminase that catalyzes the last step in the coagulation process. An anion-binding site inhibition of FXIIIa is a paradigm-shifting strategy that may offer key advantages of controlled inhibition. Such an approach is likely to lead to novel FXIIIa inhibitors that do not carry bleeding risks. We previously reported a flavonoid trimer-based allosteric inhibitor of FXIIIa with moderate potency and selectivity. To further advance this approach, we evaluated a series of 27 variably sulfonated heparin mimetics against human FXIIIa. Only 13 molecules exhibited inhibitory activity at the highest concentration tested with IC50 values of 2-286 μM. Specifically, inhibitor 16 demonstrated an IC50 value of 2.4 ± 0.5 μM in a bisubstrate, fluorescence-based trans-glutamination assay. It also demonstrated a significant selectivity over other clotting factors including thrombin, factor Xa, and factor XIa as well as other cysteine enzymes including papain and tissue transglutaminase 2. Inhibitor 16 did not affect the viability of three human cell lines at a concentration that is 5-fold its FXIIIa-IC50. The molecule had a very weak effect on the activated partial thromboplastin time of human plasma at a concentration of >700 μM, further supporting its functional selectivity. Importantly, molecule 16 inhibited FXIIIa-mediated polymerization of fibrin(ogen) in a concentration-dependent manner as shown by the gel electrophoresis experiment. Michaelis-Menten kinetics revealed that the molecule competes with the Gln-donor protein substrate, i.e., dimethylcasein, but not with the Lys-donor small substrate, i.e., dansylcadaverine. Molecular modeling studies revealed that this type of molecule likely binds to an anion-binding site comprising the basic amino acids of Lys54, Lys61, Lys73, Lys156, and Arg244 among others. Overall, our work puts forward a new anion-binding site, selective, nontoxic, sulfonated heparin mimetic FXIIIa inhibitor 16 for further development as an effective and safer anticoagulant.
Collapse
Affiliation(s)
- Kayla
T. Vu
- Division
of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Srabani Kar
- Division
of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Navneet Goyal
- Department
of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Madhusoodanan Mottamal
- Department
of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Daniel K. Afosah
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23219, United States
| | - Rami A. Al-Horani
- Division
of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| |
Collapse
|
2
|
Al-Horani RA. Revisiting the effect of cholesteryl sulfate on clotting and fibrinolysis: Inhibition of human thrombin and other human blood proteases. Heliyon 2024; 10:e28017. [PMID: 38533078 PMCID: PMC10963326 DOI: 10.1016/j.heliyon.2024.e28017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 03/28/2024] Open
Abstract
Cholesteryl sulfate (CS) was quantitatively synthesized by microwave-assisted sulfonation of cholesterol followed by sodium exchange chromatography. In vitro effects of CS on human thrombin and other serine proteases of the coagulation and fibrinolysis processes were investigated using a series of biochemical and biophysical techniques. CS was found to inhibit thrombin with an IC50 value of 140.8 ± 21.8 μM at pH 7.4 and 25 ○C. Michaelis-Menten kinetics indicated that thrombin inhibition by CS is non-competitive (allosteric) in nature. Fluorescence-based binding studies indicated that CS binds to thrombin with a KD value of 180.9 ± 18.9 μM. Given the lack of competition with heparins and a hirudin peptide in competitive inhibition assays, it appears that CS does not bind to thrombin's exosites 1 or 2 and it rather recognizes a different allosteric exosite. CS was found to partially inhibit thrombin-mediated fibrinogen activation with an IC50 value of 175.5 ± 17.5 μM and efficacy of ∼26.0 ± 6.6%. Likewise, CS selectively doubled the activated partial thromboplastin time with EC2x of 521 μM. Interestingly, CS was found to also inhibit factors Xa and XIa as well as plasmin with IC50 values of ∼85-250 μM and efficacy of 94-100%. Nevertheless, CS most potently inhibited factor XIIa with an IC50 Value of ∼17 μM and efficacy of 60%. Surprisingly, CS did not inhibit factor IXa. These results encourage further in vitro and in vivo investigation of CS to better understand its (patho-) physiological roles in coagulation and hemostasis.
Collapse
Affiliation(s)
- Rami A. Al-Horani
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans LA 70125, USA
| |
Collapse
|
3
|
Woodland M, Thompson A, Lipford A, Goyal N, Schexnaildre JC, Mottamal M, Afosah DK, Al-Horani RA. New Triazole-Based Potent Inhibitors of Human Factor XIIa as Anticoagulants. ACS OMEGA 2024; 9:10694-10708. [PMID: 38463342 PMCID: PMC10918664 DOI: 10.1021/acsomega.3c09335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/10/2024] [Accepted: 02/06/2024] [Indexed: 03/12/2024]
Abstract
Factor XIIa (FXIIa) functions as a plasma serine protease within the contact activation pathway. Various animal models have indicated a substantial role for FXIIa in thromboembolic diseases. Interestingly, individuals and animals with FXII deficiency seem to maintain normal hemostasis. Consequently, inhibiting FXIIa could potentially offer a viable therapeutic approach for achieving effective and safer anticoagulation without the bleeding risks associated with the existing anticoagulants. Despite the potential, only a limited number of small molecule inhibitors targeting human FXIIa have been documented. Thus, we combined a small library of 32 triazole and triazole-like molecules to be evaluated for FXIIa inhibition by using a chromogenic substrate hydrolysis assay under physiological conditions. Initial screening at 200 μM involved 18 small molecules, revealing that 4 molecules inhibited FXIIa more than 20%. In addition to being the most potent inhibitor identified in the first round, inhibitor 8 also exhibited a substantial margin of selectivity against related serine proteases, including factors XIa, Xa, and IXa. However, the molecule also inhibited thrombin with a similar potency. It also prolonged the clotting time of human plasma, as was determined in the activated partial thromboplastin time and prothrombin time assays. Subsequent structure-activity relationship studies led to the identification of several inhibitors with submicromolar activity, among which inhibitor 22 appears to demonstrate significant selectivity not only over factors IXa, Xa, and XIa, but also over thrombin. In summary, this study introduces novel triazole-based small molecules, specifically compounds 8 and 22, identified as potent and selective inhibitors of human FXIIa. The aim is to advance these inhibitors for further development as anticoagulants to provide a more effective and safer approach to preventing and/or treating thromboembolic diseases.
Collapse
Affiliation(s)
- Ma’Lik
D. Woodland
- Division
of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Anthony Thompson
- Department
of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Amanda Lipford
- Department
of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Navneet Goyal
- Department
of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - John C. Schexnaildre
- Division
of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Madhusoodanan Mottamal
- Department
of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Daniel K. Afosah
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23219, United States
| | - Rami A. Al-Horani
- Division
of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| |
Collapse
|
4
|
Al-Horani RA, Aliter KF. Triple Action of Lignosulfonic Acid Sodium: Anti-protease, Antioxidant, and Anti-inflammatory Effects of a Polymeric Heparin Mimetic. Med Chem 2024; 20:414-421. [PMID: 38192144 PMCID: PMC11228124 DOI: 10.2174/0115734064275120231222111145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/06/2023] [Accepted: 11/13/2023] [Indexed: 01/10/2024]
Abstract
BACKGROUND Heparins are sulfated glycosaminoglycans that are used as anticoagulants to treat thrombosis. Heparins exhibit other potential therapeutic effects, such as anti-inflammatory, anti-viral, and anti-malarial effects. However, the strong anticoagulant activity of heparins poses a risk of life-threatening bleeding, limiting their therapeutic use for other diseases beyond thrombosis. To exploit the other effects of heparins and eliminate the bleeding risk, we explored an alternative polymer called lignosulfonic acid sodium (LSAS), which acts as a sulfonated heparin mimetic. LSAS targets factor XIa to exert an anticoagulant effect, and thus, unlike heparins, it is unlikely to cause bleeding. METHODS This study investigated the multiple effects of LSAS to identify potential leads for complex pathologies treatment. A series of chromogenic substrate hydrolysis assays were used to evaluate the inhibition of three inflammation-related proteases by LSAS. Its chemical antioxidant activity against the system of ABTS/hydrogen peroxide/metmyoglobin was also determined. Lastly, the effect of LSAS on TNFα-induced activation of the NF-κB pathway in HEK-293 cells was also tested to determine its cellular anti-inflammatory activity. RESULTS The results showed that LSAS effectively inhibited human neutrophil elastase, cathepsin G, and plasmin, with IC50 values ranging from 0.73 to 212.5 μg/mL. Additionally, LSAS demonstrated a significant chemical antioxidant effect, with an IC50 value of 44.1 μg/mL. Furthermore, at a concentration of approximately 530 μg/mL, LSAS inhibited the TNFα-induced activation of the NF-κB pathway in HEK-293 cells, indicating a substantial anti-inflammatory effect. An essential advantage of LSAS is its high water solubility and virtual non-toxicity, making it a safe and readily available polymer. CONCLUSION Based on these findings, LSAS is put forward as a polymeric heparin mimetic with multiple functions, serving as a potential platform for developing novel therapeutics to treat complex pathologies.
Collapse
Affiliation(s)
- Rami A Al-Horani
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA
| | - Kholoud F Aliter
- Department of Chemistry, School of STEM, Dillard University, New Orleans, LA, 70122, USA
| |
Collapse
|
5
|
Chiles R, Afosah DK, Al-Horani RA. Investigation of the anticoagulant activity of cyclic sulfated glycosaminoglycan mimetics. Carbohydr Res 2023; 529:108831. [PMID: 37209666 PMCID: PMC10330556 DOI: 10.1016/j.carres.2023.108831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/27/2023] [Accepted: 05/03/2023] [Indexed: 05/22/2023]
Abstract
Thrombotic disorders are among the leading causes of deaths worldwide. Anticoagulants are frequently prescribed for their prevention and/or treatment. Current anticoagulants, which target either thrombin or factor Xa, are plagued with a number of drawbacks, the most important of which is the increased risk of internal bleeding. To develop better antithrombotic agents, the anticoagulant activity of cyclic glycosaminoglycan mimetics was evaluated. Human plasma clotting assays and enzyme inhibition assays were exploited to evaluate the anticoagulant activity of sulfated β-cyclodextrin (SBCD) and its three analogs: sulfated α-cyclodextrin, β-cyclodextrin, and methylated β-cyclodextrin. In normal human plasma, SBCD selectively doubled the activated partial thromboplastin time (APTT) at ∼9 μg/mL, with no effect on prothrombin time (PT) at the same concentration. Likewise, SBCD doubled APTT at ∼9 μg/mL and at ∼8 μg/mL in antithrombin-deficient plasma and heparin cofactor II-deficient plasma, respectively. Interestingly, the three SBCD derivatives were inactive at the highest concentrations tested which highlighted the importance of the sulfate groups and the size of the molecule. Enzyme assays revealed that SBCD inhibits factor XIa (FXIa) with an IC50 value of ∼20 μg/mL and efficacy of near 100%. SBCD did not inhibit other related proteins including thrombin, factor IXa, factor Xa, factor XIIa, factor XIIIa, plasmin, chymotrypsin, or trypsin at the highest concentrations tested demonstrating a significant selectivity. In Michaelis-Menten kinetics, SBCD decreased the VMAX and increased the KM of FXIa hydrolysis of a tripeptide chromogenic substrate indicating a mixed inhibition mechanism. Together, it appears that SBCD is a potent and selective inhibitor of human FXIa with substantial anticoagulant activity in human plasma. Overall, this study introduces SBCD as a promising lead for further development as a safer anticoagulant.
Collapse
Affiliation(s)
- Raquel Chiles
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA, 70125, USA
| | - Daniel K Afosah
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23219, USA
| | - Rami A Al-Horani
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA, 70125, USA.
| |
Collapse
|
6
|
Abdelfadiel E, Gunta R, Villuri BK, Afosah DK, Sankaranarayanan NV, Desai UR. Designing Smaller, Synthetic, Functional Mimetics of Sulfated Glycosaminoglycans as Allosteric Modulators of Coagulation Factors. J Med Chem 2023; 66:4503-4531. [PMID: 37001055 PMCID: PMC10108365 DOI: 10.1021/acs.jmedchem.3c00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Indexed: 04/03/2023]
Abstract
Natural glycosaminoglycans (GAGs) are arguably the most diverse collection of natural products. Unfortunately, this bounty of structures remains untapped. Decades of research has realized only one GAG-like synthetic, small-molecule drug, fondaparinux. This represents an abysmal output because GAGs present a frontier that few medicinal chemists, and even fewer pharmaceutical companies, dare to undertake. GAGs are heterogeneous, polymeric, polydisperse, highly water soluble, synthetically challenging, too rapidly cleared, and difficult to analyze. Additionally, GAG binding to proteins is not very selective and GAG-binding sites are shallow. This Perspective attempts to transform this negative view into a much more promising one by highlighting recent advances in GAG mimetics. The Perspective focuses on the principles used in the design/discovery of drug-like, synthetic, sulfated small molecules as allosteric modulators of coagulation factors, such as antithrombin, thrombin, and factor XIa. These principles will also aid the design/discovery of sulfated agents against cancer, inflammation, and microbial infection.
Collapse
Affiliation(s)
- Elsamani
I. Abdelfadiel
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
| | - Rama Gunta
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Bharath Kumar Villuri
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Daniel K. Afosah
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Nehru Viji Sankaranarayanan
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Umesh R. Desai
- Institute
for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, United States
- Department
of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| |
Collapse
|
7
|
Xie Z, Meng Z, Yang X, Duan Y, Wang Q, Liao C. Factor XIa Inhibitors in Anticoagulation Therapy: Recent Advances and Perspectives. J Med Chem 2023; 66:5332-5363. [PMID: 37037122 DOI: 10.1021/acs.jmedchem.2c02130] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Factor XIa (FXIa) in the intrinsic pathway of the coagulation process has been proven to be an effective and safe target for anticoagulant discovery with limited or no bleeding. Numerous small-molecule FXIa inhibitors (SMFIs) with various scaffolds have been identified in the early stages of drug discovery. They have served as the foundation for the recent discovery of additional promising SMFIs with improved potency, selectivity, and pharmacokinetic profiles, some of which have entered clinical trials for the treatment of thrombosis. After reviewing the coagulation process and structure of FXIa, this perspective discusses the rational or structure-based design, discovery, structure-activity relationships, and development of SMFIs disclosed in recent years. Strategies for identifying more selective and druggable SMFIs are provided, paving the way for the design and discovery of more useful SMFIs for anticoagulation therapy.
Collapse
Affiliation(s)
- Zhouling Xie
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Zhiwei Meng
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Xiaoxiao Yang
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Yajun Duan
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Qin Wang
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, P. R. China
| | - Chenzhong Liao
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| |
Collapse
|
8
|
Al-Horani RA, Afosah DK, Kar S, Aliter KF, Mottamal M. Sulphated penta-galloyl glucopyranoside (SPGG) is glycosaminoglycan mimetic allosteric inhibitor of cathepsin G. RPS PHARMACY AND PHARMACOLOGY REPORTS 2023; 2:rqad001. [PMID: 36844783 PMCID: PMC9942669 DOI: 10.1093/rpsppr/rqad001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023]
Abstract
Objective Cathepsin G (CatG) is a cationic serine protease with wide substrate specificity. CatG is reported to play a role in several inflammatory pathologies. Thus, we aimed at identifying a potent and allosteric inhibitor of CatG to be used as a platform in further drug development opportunities. Methods Chromogenic substrate hydrolysis assays were used to evaluate the inhibition potency and selectivity of SPGG towards CatG. Salt-dependent studies, Michaelis-Menten kinetics and SDS-PAGE were exploited to decipher the mechanism of CatG inhibition by SPGG. Molecular modelling was also used to identify a plausible binding site. Key findings SPGG displayed an inhibition potency of 57 nM against CatG, which was substantially selective over other proteases. SPGG protected fibronectin and laminin against CatG-mediated degradation. SPGG reduced VMAX of CatG hydrolysis of a chromogenic substrate without affecting KM, suggesting an allosteric mechanism. Resolution of energy contributions indicated that non-ionic interactions contribute ~91% of binding energy, suggesting a substantial possibility of specific recognition. Molecular modelling indicated that SPGG plausibly binds to an anion-binding sequence of 109SRRVRRNRN117. Conclusion We present the discovery of SPGG as the first small molecule, potent, allosteric glycosaminoglycan mimetic inhibitor of CatG. SPGG is expected to open a major route to clinically relevant allosteric CatG anti-inflammatory agents.
Collapse
Affiliation(s)
- Rami A Al-Horani
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA, USA
| | - Daniel K Afosah
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, USA
| | - Srabani Kar
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA, USA
| | - Kholoud F Aliter
- Department of Chemistry, School of STEM, Dillard University, New Orleans, LA, USA
| | | |
Collapse
|
9
|
Al-Horani RA, Afosah DK, Mottamal M. Triazol-1-yl Benzamides Promote Anticoagulant Activity via Inhibition of Factor XIIa. Cardiovasc Hematol Agents Med Chem 2023; 21:108-119. [PMID: 36321236 PMCID: PMC10249145 DOI: 10.2174/1871525721666221031141323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 09/13/2022] [Accepted: 10/03/2022] [Indexed: 01/12/2023]
Abstract
BACKGROUND Human factor XIIa (FXIIa) is a plasma serine protease that plays a significant role in several physiological and pathological processes. Animal models have revealed an important contribution of FXIIa to thromboembolic diseases. Remarkably, animals and patients with FXII deficiency appear to have normal hemostasis. Thus, FXIIa inhibition may serve as a promising therapeutic strategy to attain safer and more effective anticoagulation. Very few small molecule inhibitors of FXIIa have been reported. We synthesized and investigated a focused library of triazol-1-yl benzamide derivatives for FXIIa inhibition. METHODS We chemically synthesized, characterized, and investigated a focused library of triazol- 1-yl benzamide derivatives for FXIIa inhibition. Using a standardized chromogenic substrate hydrolysis assay, the derivatives were evaluated for inhibiting human FXIIa. Their selectivity over other clotting factors was also evaluated using the corresponding substrate hydrolysis assays. The best inhibitor affinity to FXIIa was also determined using fluorescence spectroscopy. Effects on the clotting times (prothrombin time (PT) and activated partial thromboplastin time (APTT)) of human plasma were also studied. RESULTS We identified a specific derivative (1) as the most potent inhibitor in this series. The inhibitor exhibited nanomolar binding affinity to FXIIa. It also exhibited significant selectivity against several serine proteases. It also selectively doubled the activated partial thromboplastin time of human plasma. CONCLUSION Overall, this work puts forward inhibitor 1 as a potent and selective inhibitor of FXIIa for further development as an anticoagulant.
Collapse
Affiliation(s)
- Rami A. Al-Horani
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA
| | - Daniel K. Afosah
- Department of Chemistry and Biochemistry, Washington and Lee University, Lexington VA 24450, USA
| | | |
Collapse
|
10
|
Al-Horani RA, Parsaeian E, Mohammad M, Mottamal M. Sulfonated non-saccharide molecules and human factor XIa: Enzyme inhibition and computational studies. Chem Biol Drug Des 2022; 100:64-79. [PMID: 35377529 DOI: 10.1111/cbdd.14053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/26/2022] [Accepted: 03/31/2022] [Indexed: 11/28/2022]
Abstract
Human factor XIa (FXIa) is a serine protease in the intrinsic coagulation pathway. FXIa has been actively targeted to develop new anticoagulants that are associated with a reduced risk of bleeding. Thousands of FXIa inhibitors have been reported, yet none has reached the clinic thus far. We describe here a novel class of sulfonated molecules that allosterically inhibit FXIa with moderate potency. A library of 18 sulfonated molecules was evaluated for the inhibition of FXIa using a chromogenic substrate hydrolysis assay. Only six molecules inhibited FXIa with IC50 values of 4.6-29.5 μM. Michaelis-Menten kinetics indicated that sulfonated molecules are allosteric inhibitors of FXIa. Inhibition of FXIa by these molecules was reversed by protamine. The molecules also showed moderate anticoagulant effects in human plasma with preference to prolong activated partial thromboplastin time. Their binding to an allosteric site in the catalytic domain of FXIa was modeled to illustrate potential binding mode and potential important Arg/Lys residues. Particularly, inhibitor 16 (IC50 = 4.6 µM) demonstrated good selectivity over a panel of serine proteases including those in the coagulation process. Inhibitor 16 did not significantly compromise the viability of three cell lines. Overall, the reported sulfonated molecules serve as a new platform to design selective, potent, and allosteric inhibitors of FXIa for therapeutic applications.
Collapse
Affiliation(s)
- Rami A Al-Horani
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana, USA
| | - Elnaz Parsaeian
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana, USA
| | - Mariam Mohammad
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, Louisiana, USA
| | - Madhusoodanan Mottamal
- Department of Chemistry, RCMI Cancer Research Center, Xavier University of Louisiana, New Orleans, Louisiana, USA
| |
Collapse
|