1
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Morales Granda NC, Toldi V, Miczi M, Lassoued M, Szabó A. Inhibition of mouse trypsin isoforms by SPINK1 and effect of human pancreatitis-associated mutations. Pancreatology 2023:S1424-3903(23)00137-0. [PMID: 37149461 DOI: 10.1016/j.pan.2023.04.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/08/2023]
Abstract
Serine protease inhibitor Kazal type 1 (SPINK1) is a trypsin-selective inhibitor protein secreted by the exocrine pancreas. Loss-of-function SPINK1 mutations predispose to chronic pancreatitis through either reduced expression, secretion, or impaired trypsin inhibition. In this study, we aimed to characterize the inhibitory activity of mouse SPINK1 against cationic (T7) and anionic (T8, T9, T20) mouse trypsin isoforms. Kinetic measurements with a peptide substrate, and digestion experiments with β-casein indicated that the catalytic activity of all mouse trypsins is comparable. Human SPINK1 and its mouse ortholog inhibited mouse trypsins with comparable efficiency (KD range 0.7-2.2 pM), with the sole exception of T7 trypsin, which was inhibited less effectively by the human inhibitor (KD 21.9 pM). Characterization of four chronic pancreatitis-associated human SPINK1 mutations in the context of the mouse inhibitor revealed that the reactive-loop mutations R42N (human K41N) and I43M (human I42M) impaired SPINK1 binding to trypsin (KD 60 nM and 47.5 pM, respectively), whereas mutations D35S (human N34S) and A56S (human P55S) had no impact on trypsin inhibition. Our results confirmed that high-affinity trypsin inhibition by SPINK1 is conserved in the mouse, and the functional consequences of human pancreatitis-associated SPINK1 mutations can be replicated in the mouse inhibitor.
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Affiliation(s)
- Nataly C Morales Granda
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Doctoral School of Molecular, Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Vanda Toldi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Márió Miczi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Meriam Lassoued
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - András Szabó
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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2
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Nagel F, Susemihl A, Eulberg T, Delcea M. Identification of Kazal Inhibitor Scaffolds with Identical Canonical Binding Loops and Their Effects on Binding Properties. Biochemistry 2023; 62:535-542. [PMID: 36598875 PMCID: PMC9850914 DOI: 10.1021/acs.biochem.2c00573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Kazal inhibitors hold high potential as scaffolds for therapeutic molecules, taking advantage of the easily exchangeable canonical binding loop. Different Kazal inhibitor backbones have been suggested to be therapeutically useful, but the impact of different Kazal-like scaffolds on binding properties is still largely unknown. Here, we identified trypsin-targeting human serine protease inhibitor Kazal type 1 (SPINK1) homologues in different mammalian species that cluster in two P2-P1 combinations, implying the coevolution of these residues. We generated loop exchange variants of human SPINK1 for comparison with Kazal inhibitors from related species. Using comprehensive biophysical characterization of the inhibitor-enzyme interactions, we found not only affinity but also pH resistance to be highly backbone-dependent. Differences are mostly observed in complex stability, which varies by over one order of magnitude. We provide clear evidence for high backbone dependency within the Kazal family. Hence, when designing Kazal inhibitor-based therapeutic molecules, testing different backbones after optimizing the canonical binding loop can be beneficial and may result in increased affinity, complex stability, specificity, and pH resistance.
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Affiliation(s)
- Felix Nagel
- Biophysical
Chemistry, Institute of Biochemistry, University
of Greifswald, 17489Greifswald, Germany
| | - Anne Susemihl
- Biophysical
Chemistry, Institute of Biochemistry, University
of Greifswald, 17489Greifswald, Germany,Department
of Hematology and Oncology, Internal Medicine C, University of Greifswald, 17489Greifswald, Germany
| | - Tobias Eulberg
- Biophysical
Chemistry, Institute of Biochemistry, University
of Greifswald, 17489Greifswald, Germany
| | - Mihaela Delcea
- Biophysical
Chemistry, Institute of Biochemistry, University
of Greifswald, 17489Greifswald, Germany,
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3
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Németh BZ, Demcsák A, Micsonai A, Kiss B, Schlosser G, Geisz A, Hegyi E, Sahin-Tóth M, Pál G. Arg236 in human chymotrypsin B2 (CTRB2) is a key determinant of high enzyme activity, trypsinogen degradation capacity, and protection against pancreatitis. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140831. [PMID: 35934298 PMCID: PMC9426946 DOI: 10.1016/j.bbapap.2022.140831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Pancreatic chymotrypsins (CTRs) are digestive proteases that in humans include CTRB1, CTRB2, CTRC, and CTRL. The highly similar CTRB1 and CTRB2 are the products of gene duplication. A common inversion at the CTRB1-CTRB2 locus reverses the expression ratio of these isoforms in favor of CTRB2. Carriers of the inversion allele are protected against the inflammatory disorder pancreatitis presumably via their increased capacity for CTRB2-mediated degradation of harmful trypsinogen. To reveal the protective molecular determinants of CTRB2, we compared enzymatic properties of CTRB1, CTRB2, and bovine CTRA (bCTRA). By evolving substrate-like Schistocerca gregaria proteinase inhibitor 2 (SGPI-2) inhibitory loop variants against the chymotrypsins, we found that the substrate binding groove of the three enzymes had overlapping specificities. Based on the selected sequences, we produced eight SGPI-2 variants. Remarkably, CTRB2 and bCTRA bound these inhibitors with significantly higher affinity than CTRB1. Moreover, digestion of peptide substrates, beta casein, and human anionic trypsinogen unequivocally confirmed that CTRB2 is a generally better enzyme than CTRB1 while the potency of bCTRA lies between those of the human isoforms. Unexpectedly, mutation D236R alone converted CTRB1 to a CTRB2-like high activity protease. Modeling indicated that in CTRB1 Met210 partially obstructed the substrate binding groove, which was relieved by the D236R mutation. Taken together, we identify CTRB2 Arg236 as a key positive determinant, while CTRB1 Asp236 as a negative determinant for chymotrypsin activity. These findings strongly support the concept that in carriers of the CTRB1-CTRB2 inversion allele, the superior trypsinogen degradation capacity of CTRB2 protects against pancreatitis.
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Affiliation(s)
- Bálint Zoltán Németh
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary
| | - Alexandra Demcsák
- Department of Surgery, University of California Los Angeles, Los Angeles, California 90095, USA
| | - András Micsonai
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary
| | - Bence Kiss
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary
| | - Gitta Schlosser
- Department of Analytical Chemistry, MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Andrea Geisz
- Department of Molecular and Cell Biology, Boston University, Henry M. Goldman School of Dental Medicine, Boston, MA 02118, USA
| | - Eszter Hegyi
- Institute for Translational Medicine, University of Pécs, Medical School, Pécs, Hungary
| | - Miklós Sahin-Tóth
- Department of Surgery, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Gábor Pál
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.
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4
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Scaffold stability and P14' residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4. Biosci Rep 2022; 42:231253. [PMID: 35485437 PMCID: PMC9112662 DOI: 10.1042/bsr20220421] [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: 02/20/2022] [Revised: 04/07/2022] [Accepted: 04/29/2022] [Indexed: 11/17/2022] Open
Abstract
Kazal-type protease inhibitors strictly regulate Factor XIIa (FXIIa), a blood-clotting serine protease. However, when negatively-charged surface of prosthetic device come into contact with FXII, it undergoes conformational change and auto-activation, leading to thrombus formation. Some research suggests that Kazal-type protease inhibitor specificity against FXIIa is governed solely by the reactive-site loop sequence, as this sequence makes most-if not all-of the direct contacts with FXIIa. Here, we sought to compare the inhibitory properties of two Kazal-type inhibitors, Infestin-4 (Inf4), a potent inhibitor of FXIIa, and Aedes aegypti trypsin inhibitor (AaTI), which does not inhibit FXIIa, to better understand Kazal-type protease specificity and determine the structural components responsible for inhibition. There are only 3 residue differences in the reactive-site loop between AaTI and Inf4. Through site-directed mutagenesis, we show that the reactive-site loop is only partially responsible for the inhibitory specificity of these proteases. The protein scaffold of AaTI is unstable due to an elongated C5C6 region. Through chimeric study, we show that swapping the protease-binding loop and the C5C6 region from Inf4 with that of AaTI can partially enhance the inhibitory activity of the AaTI_Inf4 chimera. Furthermore, the additional substitution of Asn at the P14' position of AaTI with Gly (Gly27 in Inf4) absolves the steric clashing between AaTI and the surface 140-loop of FXIIa, and increases the inhibition of the chimeric AaTI to match that of wild-type Inf4. Our findings suggest that ancillary regions in addition to the reactive-site loop sequence are important factors driving Kazal-type inhibitor specificity.
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5
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Dürvanger Z, Boros E, Nagy ZA, Hegedüs R, Megyeri M, Dobó J, Gál P, Schlosser G, Ángyán AF, Gáspári Z, Perczel A, Harmat V, Mező G, Menyhárd DK, Pál G. Directed Evolution-Driven Increase of Structural Plasticity Is a Prerequisite for Binding the Complement Lectin Pathway Blocking MASP-Inhibitor Peptides. ACS Chem Biol 2022; 17:969-986. [PMID: 35378038 PMCID: PMC9016712 DOI: 10.1021/acschembio.2c00114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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MASP-1 and MASP-2
are key activator proteases of the complement
lectin pathway. The first specific mannose-binding lectin-associated
serine protease (MASP) inhibitors had been developed from the 14-amino-acid
sunflower trypsin inhibitor (SFTI) peptide by phage display, yielding
SFTI-based MASP inhibitors, SFMIs. Here, we present the crystal structure
of the MASP-1/SFMI1 complex that we analyzed in comparison to other
existing MASP-1/2 structures. Rigidified backbone structure has long
been accepted as a structural prerequisite for peptide inhibitors
of proteases. We found that a hydrophobic cluster organized around
the P2 Thr residue is essential for the structural stability of wild-type
SFTI. We also found that the same P2 Thr prevents binding of the rigid
SFTI-like peptides to the substrate-binding cleft of both MASPs as
the cleft is partially blocked by large gatekeeper enzyme loops. Directed
evolution removed this obstacle by replacing the P2 Thr with a Ser,
providing the SFMIs with high-degree structural plasticity, which
proved to be essential for MASP inhibition. To gain more insight into
the structural criteria for SFMI-based MASP-2 inhibition, we systematically
modified MASP-2-specific SFMI2 by capping its two termini and by replacing
its disulfide bridge with varying length thioether linkers. By doing
so, we also aimed to generate a versatile scaffold that is resistant
to reducing environment and has increased stability in exopeptidase-containing
biological environments. We found that the reduction-resistant disulfide-substituted l-2,3-diaminopropionic acid (Dap) variant possessed near-native
potency. As MASP-2 is involved in the life-threatening thrombosis
in COVID-19 patients, our synthetic, selective MASP-2 inhibitors could
be relevant coronavirus drug candidates.
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Affiliation(s)
- Zsolt Dürvanger
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Eszter Boros
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary
| | - Zoltán Attila Nagy
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary
| | - Rózsa Hegedüs
- MTA-ELTE Research Group of Peptide Chemistry, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
| | - Márton Megyeri
- Institute of Enzymology, Research Centre for Natural Sciences, Magyar tudósok krt 2, H-1117 Budapest, Hungary
| | - József Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Magyar tudósok krt 2, H-1117 Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Magyar tudósok krt 2, H-1117 Budapest, Hungary
| | - Gitta Schlosser
- Department of Analytical Chemistry, MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest, H-1117 Budapest, Hungary
| | - Annamária F. Ángyán
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter u. 50/A, H-1083 Budapest, Hungary
| | - Zoltán Gáspári
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter u. 50/A, H-1083 Budapest, Hungary
| | - András Perczel
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
- MTA-ELTE Protein Modelling Research Group, Eötvös
Loránd Research Network, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Veronika Harmat
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
- MTA-ELTE Protein Modelling Research Group, Eötvös
Loránd Research Network, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Gábor Mező
- MTA-ELTE Research Group of Peptide Chemistry, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
- Department of Organic Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
| | - Dóra K. Menyhárd
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
- MTA-ELTE Protein Modelling Research Group, Eötvös
Loránd Research Network, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Gábor Pál
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary
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6
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Nagel F, Palm GJ, Geist N, McDonnell TCR, Susemihl A, Girbardt B, Mayerle J, Lerch MM, Lammers M, Delcea M. Structural and Biophysical Insights into SPINK1 Bound to Human Cationic Trypsin. Int J Mol Sci 2022; 23:ijms23073468. [PMID: 35408828 PMCID: PMC8998336 DOI: 10.3390/ijms23073468] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 02/01/2023] Open
Abstract
(1) The serine protease inhibitor Kazal type 1 (SPINK1) inhibits trypsin activity in zymogen granules of pancreatic acinar cells. Several mutations in the SPINK1 gene are associated with acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP). The most common variant is SPINK1 p.N34S. Although this mutation was identified two decades ago, the mechanism of action has remained elusive. (2) SPINK1 and human cationic trypsin (TRY1) were expressed in E. coli, and inhibitory activities were determined. Crystals of SPINK1-TRY1 complexes were grown by using the hanging-drop method, and phases were solved by molecular replacement. (3) Both SPINK1 variants show similar inhibitory behavior toward TRY1. The crystal structures are almost identical, with minor differences in the mutated loop. Both complexes show an unexpected rotamer conformation of the His63 residue in TRY1, which is a member of the catalytic triad. (4) The SPINK1 p.N34S mutation does not affect the inhibitory behavior or the overall structure of the protein. Therefore, the pathophysiological mechanism of action of the p.N34S variant cannot be explained mechanistically or structurally at the protein level. The observed histidine conformation is part of a mechanism for SPINK1 that can explain the exceptional proteolytic stability of this inhibitor.
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Affiliation(s)
- Felix Nagel
- Biophysical Chemistry, Institute of Biochemistry, University of Greifswald, 17489 Greifswald, Germany; (F.N.); (N.G.); (A.S.)
| | - Gottfried J. Palm
- Synthetic and Structural Biochemistry, Institute of Biochemistry, University of Greifswald, 17489 Greifswald, Germany; (G.J.P.); (B.G.); (M.L.)
| | - Norman Geist
- Biophysical Chemistry, Institute of Biochemistry, University of Greifswald, 17489 Greifswald, Germany; (F.N.); (N.G.); (A.S.)
| | - Thomas C. R. McDonnell
- Biochemical Engineering Department, University College London, Bernard Katz, London WC1E 6BT, UK;
| | - Anne Susemihl
- Biophysical Chemistry, Institute of Biochemistry, University of Greifswald, 17489 Greifswald, Germany; (F.N.); (N.G.); (A.S.)
- Department of Hematology and Oncology, Internal Medicine C, University of Greifswald, 17489 Greifswald, Germany
| | - Britta Girbardt
- Synthetic and Structural Biochemistry, Institute of Biochemistry, University of Greifswald, 17489 Greifswald, Germany; (G.J.P.); (B.G.); (M.L.)
| | - Julia Mayerle
- Department of Medicine II, University Hospital Munich, Ludwig-Maximillian University Munich, 81377 Munich, Germany;
| | - Markus M. Lerch
- Department of Medicine A, University Medicine Greifswald, 17489 Greifswald, Germany;
| | - Michael Lammers
- Synthetic and Structural Biochemistry, Institute of Biochemistry, University of Greifswald, 17489 Greifswald, Germany; (G.J.P.); (B.G.); (M.L.)
| | - Mihaela Delcea
- Biophysical Chemistry, Institute of Biochemistry, University of Greifswald, 17489 Greifswald, Germany; (F.N.); (N.G.); (A.S.)
- Correspondence:
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7
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Walvekar VA, Ramesh K, Jobichen C, Kannan M, Sivaraman J, Kini RM, Mok YK. Crystal structure of Aedes aegypti trypsin inhibitor in complex with μ-plasmin reveals role for scaffold stability in Kazal-type serine protease inhibitor. Protein Sci 2022; 31:470-484. [PMID: 34800067 PMCID: PMC8820117 DOI: 10.1002/pro.4245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 02/03/2023]
Abstract
Kazal-type protease inhibitor specificity is believed to be determined by sequence of the reactive-site loop that make most, if not all, contacts with the serine protease. Here, we determined the complex crystal structure of Aedes aegypti trypsin inhibitor (AaTI) with μ-plasmin, and compared its reactivities with other Kazal-type inhibitors, infestin-1 and infestin-4. We show that the shortened 99-loop of plasmin creates an S2 pocket, which is filled by phenylalanine at the P2 position of the reactive-site loop of infestin-4. In contrast, AaTI and infestin-1 retain a proline at P2, rendering the S2 pocket unfilled, which leads to lower plasmin inhibitions. Furthermore, the protein scaffold of AaTI is unstable, due to an elongated Cys-V to Cys-VI region leading to a less compact hydrophobic core. Chimeric study shows that the stability of the scaffold can be modified by swapping of this Cys-V to Cys-VI region between AaTI and infestin-4. The scaffold instability causes steric clashing of the bulky P2 residue, leading to significantly reduced inhibition of plasmin by AaTI or infestin-4 chimera. Our findings suggest that surface loops of protease and scaffold stability of Kazal-type inhibitor are both necessary for specific protease inhibition, in addition to reactive site loop sequence. PDB ID code: 7E50.
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Affiliation(s)
| | - Karthik Ramesh
- Department of Biological SciencesNational University of SingaporeSingapore,Present address:
Department of Biophysics and BiochemistryUT Southwestern Medical CentreDallasTXUSA
| | - Chacko Jobichen
- Department of Biological SciencesNational University of SingaporeSingapore
| | - Muthu Kannan
- Department of Biological SciencesNational University of SingaporeSingapore
| | - J. Sivaraman
- Department of Biological SciencesNational University of SingaporeSingapore
| | - R. Manjunatha Kini
- Department of Biological SciencesNational University of SingaporeSingapore,Department of PharmacologyYong Loo Lin School of Medicine, National University of SingaporeSingapore
| | - Yu Keung Mok
- Department of Biological SciencesNational University of SingaporeSingapore
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8
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Stein A, Liang AD, Sahin R, Ward TR. Incorporation of Metal-Chelating Unnatural Amino Acids into HaloTag for Allylic Deamination. J Organomet Chem 2022. [DOI: 10.1016/j.jorganchem.2022.122272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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9
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The impact of physiological stress conditions on protein structure and trypsin inhibition of serine protease inhibitor Kazal type 1 (SPINK1) and its N34S variant. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1868:140281. [PMID: 31525466 PMCID: PMC6905150 DOI: 10.1016/j.bbapap.2019.140281] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/27/2019] [Accepted: 09/11/2019] [Indexed: 12/14/2022]
Abstract
One of the most common mutations in the serine protease inhibitor Kazal type 1 (SPINK1) gene is the N34S variant which is strongly associated with chronic pancreatitis. Although it is assumed that N34S mutation constitutes a high-risk factor, the underlying pathologic mechanism is still unknown. In the present study, we investigated the impact of physiological stress factors on SPINK1 protein structure and trypsin inhibitor function using biophysical methods. Our circular dichroism spectroscopy data revealed differences in the secondary structure of SPINK1 and N34S mutant suggesting protein structural changes induced by the mutation as an impairment that could be disease-relevant. We further confirmed that both SPINK1 (KD of 0.15 ± 0.06 nM) and its N34S variant (KD of 0.08 ± 0.02 nM) have similar binding affinity and inhibitory effect towards trypsin as shown by surface plasmon resonance and trypsin inhibition assay studies, respectively. We found that stress conditions such as altered ion concentrations (i.e. potassium, calcium), temperature shifts, as well as environmental pH lead to insignificant differences in trypsin inhibition between SPINK1 and N34S mutant. However, we have shown that the environmental pH induces structural changes in both SPINK1 constructs in a different manner. Our findings suggest protein structural changes in the N34S variant as an impairment of SPINK1 and environmental pH shift as a trigger that could play a role in disease progression of pancreatitis.
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10
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Szakács D, Kocsis A, Szász R, Gál P, Pál G. Novel MASP-2 inhibitors developed via directed evolution of human TFPI1 are potent lectin pathway inhibitors. J Biol Chem 2019; 294:8227-8237. [PMID: 30952698 PMCID: PMC6527154 DOI: 10.1074/jbc.ra119.008315] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/28/2019] [Indexed: 12/28/2022] Open
Abstract
The lectin pathway (LP) of the complement system is an important antimicrobial defense mechanism, but it also contributes significantly to ischemia reperfusion injury (IRI) associated with myocardial infarct, stroke, and several other clinical conditions. Mannan-binding lectin-associated serine proteinase 2 (MASP-2) is essential for LP activation, and therefore, it is a potential drug target. We have previously developed the first two generations of MASP-2 inhibitors by in vitro evolution of two unrelated canonical serine proteinase inhibitors. These inhibitors were selective LP inhibitors, but their nonhuman origin rendered them suboptimal lead molecules for drug development. Here, we present our third-generation MASP-2 inhibitors that were developed based on a human inhibitor scaffold. We subjected the second Kunitz domain of human tissue factor pathway inhibitor 1 (TFPI1 D2) to directed evolution using phage display to yield inhibitors against human and rat MASP-2. These novel TFPI1-based MASP-2 inhibitor (TFMI-2) variants are potent and selective LP inhibitors in both human and rat serum. Directed evolution of the first Kunitz domain of TFPI1 had already yielded the potent kallikrein inhibitor, Kalbitor® (ecallantide), which is an FDA-approved drug to treat acute attacks of hereditary angioedema. Like hereditary angioedema, acute IRI is also related to the uncontrolled activation of a specific plasma serine proteinase. Therefore, TFMI-2 variants are promising lead molecules for drug development against IRI.
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Affiliation(s)
- Dávid Szakács
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest
| | - Andrea Kocsis
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest
| | - Róbert Szász
- Department of Hematology, Institute of Internal Medicine, University of Debrecen, Nagyerdei krt. 98, H-4032 Debrecen
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest
| | - Gábor Pál
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest; EvolVeritas Biotechnology Ltd., Somogyi Béla u. 17, H-6600 Szentes, Hungary.
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