1
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Pesei ZG, Jancsó Z, Demcsák A, Németh BC, Vajda S, Sahin-Tóth M. Preclinical testing of dabigatran in trypsin-dependent pancreatitis. JCI Insight 2022; 7:161145. [PMID: 36136430 PMCID: PMC9675574 DOI: 10.1172/jci.insight.161145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 09/13/2022] [Indexed: 02/06/2023] Open
Abstract
Pancreatitis, the inflammatory disorder of the pancreas, has no specific therapy. Genetic, biochemical, and animal model studies revealed that trypsin plays a central role in the onset and progression of pancreatitis. Here, we performed biochemical and preclinical mouse experiments to offer proof of concept that orally administered dabigatran etexilate can inhibit pancreatic trypsins and shows therapeutic efficacy in trypsin-dependent pancreatitis. We found that dabigatran competitively inhibited all human and mouse trypsin isoforms (Ki range 10-79 nM) and dabigatran plasma concentrations in mice given oral dabigatran etexilate well exceeded the Ki of trypsin inhibition. In the T7K24R trypsinogen mutant mouse model, a single oral gavage of dabigatran etexilate was effective against cerulein-induced progressive pancreatitis, with a high degree of histological normalization. In contrast, spontaneous pancreatitis in T7D23A mice, which carry a more aggressive trypsinogen mutation, was not ameliorated by dabigatran etexilate, given either as daily gavages or by mixing it with solid chow. Taken together, our observations showed that benzamidine derivatives such as dabigatran are potent trypsin inhibitors and show therapeutic activity against trypsin-dependent pancreatitis in T7K24R mice. Lack of efficacy in T7D23A mice is probably related to the more severe pathology and insufficient drug concentrations in the pancreas.
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Affiliation(s)
- Zsófia Gabriella Pesei
- Department of Surgery, University of California Los Angeles, Los Angeles, California, USA
| | - Zsanett Jancsó
- Department of Surgery, University of California Los Angeles, Los Angeles, California, USA
| | - Alexandra Demcsák
- Department of Surgery, University of California Los Angeles, Los Angeles, California, USA
| | - Balázs Csaba Németh
- Department of Surgery, University of California Los Angeles, Los Angeles, California, USA
| | - Sandor Vajda
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Miklós Sahin-Tóth
- Department of Surgery, University of California Los Angeles, Los Angeles, California, USA
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2
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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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3
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Orekhova A, Németh BC, Jancsó Z, Geisz A, Mosztbacher D, Demcsák A, Sahin-Tóth M. Evolutionary expansion of polyaspartate motif in the activation peptide of mouse cationic trypsinogen limits autoactivation and protects against pancreatitis. Am J Physiol Gastrointest Liver Physiol 2021; 321:G719-G734. [PMID: 34643096 PMCID: PMC8668397 DOI: 10.1152/ajpgi.00265.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The activation peptide of mammalian trypsinogens typically contains a tetra-aspartate motif (positions P2-P5 in Schechter-Berger numbering) that inhibits autoactivation and facilitates activation by enteropeptidase. This evolutionary mechanism protects the pancreas from premature trypsinogen activation while allowing physiological activation in the gut lumen. Inborn mutations that disrupt the tetra-aspartate motif cause hereditary pancreatitis in humans. A subset of trypsinogen paralogs, including the mouse cationic trypsinogen (isoform T7), harbor an extended penta-aspartate motif (P2-P6) in their activation peptide. Here, we demonstrate that deletion of the extra P6 aspartate residue (D23del) increased the autoactivation of T7 trypsinogen threefold. Mutagenesis of the P6 position in wild-type T7 trypsinogen revealed that bulky hydrophobic side chains are preferred for maximal autoactivation, and deletion-induced shift of the P7 Leu to P6 explains the autoactivation increase in the D23del mutant. Accordingly, removal of the P6 Leu by NH2-terminal truncation with chymotrypsin C reduced the autoactivation of the D23del mutant. Homozygous T7D23del mice carrying the D23del mutation did not develop spontaneous pancreatitis and severity of cerulein-induced acute pancreatitis was comparable with that of C57BL/6N controls. However, sustained stimulation with cerulein resulted in markedly increased histological damage in T7D23del mice relative to C57BL/6N mice. Furthermore, when the T7D23del allele was crossed to a chymotrypsin-deficient background, the double-mutant mice developed spontaneous pancreatitis at an early age. Taken together, the observations argue that evolutionary expansion of the polyaspartate motif in mouse cationic trypsinogen contributes to the natural defenses against pancreatitis and validate the role of the P6 position in autoactivation control of mammalian trypsinogens.NEW & NOTEWORTHY Unwanted autoactivation of the digestive protease trypsinogen can result in pancreatitis. The trypsinogen activation peptide contains a polyaspartate motif that suppresses autoactivation. This study demonstrates that evolutionary expansion of these aspartate residues in mouse cationic trypsinogen further inhibits autoactivation and enhances protection against pancreatitis.
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Affiliation(s)
- Anna Orekhova
- 1Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts
| | - Balázs Csaba Németh
- 1Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts,2Department of Surgery, University of California Los Angeles, Los Angeles, California
| | - Zsanett Jancsó
- 1Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts,2Department of Surgery, University of California Los Angeles, Los Angeles, California
| | - Andrea Geisz
- 1Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts
| | - Dóra Mosztbacher
- 1Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts
| | - Alexandra Demcsák
- 1Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts,2Department of Surgery, University of California Los Angeles, Los Angeles, California
| | - Miklós Sahin-Tóth
- 1Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts,2Department of Surgery, University of California Los Angeles, Los Angeles, California
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Mouse model suggests limited role for human mesotrypsin in pancreatitis. Pancreatology 2021; 21:342-352. [PMID: 33526384 PMCID: PMC7969449 DOI: 10.1016/j.pan.2021.01.007] [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: 11/15/2020] [Revised: 12/30/2020] [Accepted: 01/12/2021] [Indexed: 12/11/2022]
Abstract
Mesotrypsin is a low-abundance human trypsin isoform with a unique evolutionary mutation that conferred resistance to trypsin inhibitors and restricted substrate specificity. Mesotrypsin degrades the serine protease inhibitor Kazal type 1 (SPINK1) and thereby might increase risk for pancreatitis. Here, we report a mouse model designed to test the role of mesotrypsin in pancreatitis. We introduced the human mesotrypsin evolutionary signature mutation into mouse cationic trypsinogen (isoform T7), resulting in a Gly to Arg change at the corresponding position 199. In biochemical experiments using purified proteins, the p.G199R T7 mutant recapitulated all salient features of human mesotrypsin. T7G199R mice developed normally with no spontaneous pancreatitis or other obvious phenotypic changes. Cerulein-induced acute pancreatitis in C57BL/6N and T7G199R mice showed similar severity with respect to inflammatory parameters and acinar cell necrosis while plasma amylase activity was higher in T7G199R mice. Neither SPINK1 degradation nor elevated intrapancreatic trypsin activation was apparent in T7G199R mice. The results indicate that in T7G199R mice the newly created mesotrypsin-like activity has no significant impact on cerulein-induced pancreatitis. The observations suggest that human mesotrypsin is unimportant for pancreatitis; a notion that is consistent with published human genetic studies.
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5
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Szabó A, Toldi V, Gazda LD, Demcsák A, Tőzsér J, Sahin-Tóth M. Defective binding of SPINK1 variants is an uncommon mechanism for impaired trypsin inhibition in chronic pancreatitis. J Biol Chem 2021; 296:100343. [PMID: 33515547 PMCID: PMC7949130 DOI: 10.1016/j.jbc.2021.100343] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/11/2021] [Accepted: 01/22/2021] [Indexed: 12/20/2022] Open
Abstract
The serine protease inhibitor Kazal type 1 (SPINK1) protects the pancreas from intrapancreatic trypsin activation that can lead to pancreatitis. Loss-of-function genetic variants of SPINK1 increase the risk for chronic pancreatitis, often by diminishing inhibitor expression or secretion. Variants that are secreted normally have been presumed to be pathogenic because of defective trypsin inhibition, but evidence has been lacking. Here, we report quantitative studies on the inhibition of human trypsins by wildtype SPINK1 and seven secreted missense variants. We found that tyrosine sulfation of human trypsins weakens binding of SPINK1 because of altered interactions with Tyr43 in the SPINK1 reactive loop. Using authentic sulfated human trypsins, we provide conclusive evidence that SPINK1 variants N34S, N37S, R65Q, and Q68R have unimpaired inhibitory activity, whereas variant P55S exhibits a small and clinically insignificant binding defect. In contrast, rare variants K41N and I42M that affect the reactive-site peptide bond of SPINK1 decrease inhibitor binding by 20,000- to 30,000-fold and three- to sevenfold, respectively. Taken together, the observations indicate that defective trypsin inhibition by SPINK1 variants is an uncommon mechanism in chronic pancreatitis. The results also strengthen the notion that a decline in inhibitor levels explains pancreatitis risk associated with the large majority of SPINK1 variants.
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Affiliation(s)
- András Szabó
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Center for Exocrine Disorders, Department of Molecular and Cell Biology, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA.
| | - Vanda Toldi
- 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
| | - Lívia Diána Gazda
- 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
| | - Alexandra Demcsák
- Department of Surgery, University of California Los Angeles, Los Angeles, California, USA
| | - József Tőzsér
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Miklós Sahin-Tóth
- Center for Exocrine Disorders, Department of Molecular and Cell Biology, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, USA; Department of Surgery, University of California Los Angeles, Los Angeles, California, USA.
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6
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Toldi V, Szabó A, Sahin-Tóth M. Inactivation of mesotrypsin by chymotrypsin C prevents trypsin inhibitor degradation. J Biol Chem 2020; 295:3447-3455. [PMID: 32014997 DOI: 10.1074/jbc.ra120.012526] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Indexed: 01/27/2023] Open
Abstract
Mesotrypsin is an unusual human trypsin isoform with inhibitor resistance and the ability to degrade trypsin inhibitors. Degradation of the protective serine protease inhibitor Kazal type 1 (SPINK1) by mesotrypsin in the pancreas may contribute to the pathogenesis of pancreatitis. Here we tested the hypothesis that the regulatory digestive protease chymotrypsin C (CTRC) mitigates the harmful effects of mesotrypsin by cleaving the autolysis loop. As human trypsins are post-translationally sulfated in the autolysis loop, we also assessed the effect of this modification. We found that mesotrypsin cleaved in the autolysis loop by CTRC exhibited catalytic impairment on short peptides due to a 10-fold increase in Km , it digested β-casein poorly and bound soybean trypsin inhibitor with 10-fold decreased affinity. Importantly, CTRC-cleaved mesotrypsin degraded SPINK1 with markedly reduced efficiency. Sulfation increased mesotrypsin activity but accelerated CTRC-mediated cleavage of the autolysis loop and did not protect against the detrimental effect of CTRC cleavage. The observations indicate that CTRC-mediated cleavage of the autolysis loop in mesotrypsin decreases protease activity and thereby protects the pancreas against unwanted SPINK1 degradation. The findings expand the role of CTRC as a key defense mechanism against pancreatitis through regulation of intrapancreatic trypsin activity.
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Affiliation(s)
- Vanda Toldi
- 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; Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118.
| | - Miklós Sahin-Tóth
- Department of Molecular and Cell Biology, Center for Exocrine Disorders, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118; Department of Surgery, University of California Los Angeles, Los Angeles, California 90095.
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7
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Abstract
The domestic ferret (Mustela putorius furo) recently emerged as a novel model for human pancreatic diseases. To investigate whether the ferret would be appropriate to study hereditary pancreatitis associated with increased trypsinogen autoactivation, we purified and cloned the trypsinogen isoforms from the ferret pancreas and studied their functional properties. We found two highly expressed isoforms, anionic and cationic trypsinogen. When compared to human cationic trypsinogen (PRSS1), ferret anionic trypsinogen autoactivated only in the presence of high calcium concentrations but not in millimolar calcium, which prevails in the secretory pathway. Ferret cationic trypsinogen was completely defective in autoactivation under all conditions tested. However, both isoforms were readily activated by enteropeptidase and cathepsin B. We conclude that ferret trypsinogens do not autoactivate as their human paralogs and cannot be used to model the effects of trypsinogen mutations associated with human hereditary pancreatitis. Intra-pancreatic trypsinogen activation by cathepsin B can occur in ferrets, which might trigger pancreatitis even in the absence of trypsinogen autoactivation.
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8
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Jancsó Z, Sahin-Tóth M. Tighter Control by Chymotrypsin C (CTRC) Explains Lack of Association between Human Anionic Trypsinogen and Hereditary Pancreatitis. J Biol Chem 2016; 291:12897-905. [PMID: 27129265 DOI: 10.1074/jbc.m116.725374] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Indexed: 01/28/2023] Open
Abstract
The human pancreas expresses two major trypsinogen isoforms, cationic trypsinogen (PRSS1) and anionic trypsinogen (PRSS2). Mutations in PRSS1 cause hereditary pancreatitis by altering cleavage of regulatory nick sites by chymotrypsin C (CTRC) resulting in reduced trypsinogen degradation and increased autoactivation. Despite 90% identity with PRSS1 and a strong propensity for autoactivation, mutations in PRSS2 are not found in hereditary pancreatitis suggesting that activation of this isoform is more tightly regulated. Here, we demonstrated that CTRC promoted degradation and thereby markedly suppressed autoactivation of human anionic trypsinogen more effectively than previously observed with cationic trypsinogen. Increased sensitivity of anionic trypsinogen to CTRC-mediated degradation was due to an additional cleavage site at Leu-148 in the autolysis loop and the lack of the conserved Cys-139-Cys-206 disulfide bond. Significant stabilization of anionic trypsinogen against degradation was achieved by simultaneous mutations of CTRC cleavage sites Leu-81 and Leu-148, autolytic cleavage site Arg-122, and restoration of the missing disulfide bridge. This stands in stark contrast to cationic trypsinogen where single mutations of either Leu-81 or Arg-122 resulted in almost complete resistance to CTRC-mediated degradation. Finally, processing of the trypsinogen activation peptide at Phe-18 by CTRC inhibited autoactivation of anionic trypsinogen, although cationic trypsinogen was strongly stimulated. Taken together, the observations indicate that human anionic trypsinogen is controlled by CTRC in a manner that individual natural mutations are unlikely to increase stability enough to promote intra-pancreatic activation. This unique biochemical property of anionic trypsinogen explains the lack of association of PRSS2 mutations with hereditary pancreatitis.
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Affiliation(s)
- Zsanett Jancsó
- From the Center for Exocrine Disorders, Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118
| | - Miklós Sahin-Tóth
- From the Center for Exocrine Disorders, Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118
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9
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Balázs A, Hegyi P, Sahin-Tóth M. Pathogenic cellular role of the p.L104P human cationic trypsinogen variant in chronic pancreatitis. Am J Physiol Gastrointest Liver Physiol 2016; 310:G477-86. [PMID: 26822915 PMCID: PMC4824176 DOI: 10.1152/ajpgi.00444.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 01/27/2016] [Indexed: 01/31/2023]
Abstract
Mutations in the PRSS1 gene encoding human cationic trypsinogen are associated with hereditary and sporadic chronic pancreatitis. High-penetrance PRSS1 mutations found in hereditary pancreatitis alter activation and/or degradation of cationic trypsinogen, thereby promoting intrapancreatic trypsinogen activation. In contrast, a number of rare PRSS1 variants identified in subjects with sporadic chronic pancreatitis cause misfolding and endoplasmic reticulum (ER) stress. Mutation p.L104P is unique among natural PRSS1 variants, since it affects the substrate binding site of trypsin. The aim of the present study was to establish the clinical significance of variant p.L104P through functional analysis. We found that p.L104P trypsin exhibited decreased activity on peptide and protein substrates; however, autoactivation was slightly accelerated. Remarkably, binding of the physiological trypsin inhibitor serine protease inhibitor Kazal type 1 (SPINK1) was decreased by 70-fold. In the presence of the trypsinogen-degrading enzyme chymotrypsin C, mutant p.L104P autoactivated to higher trypsin levels than wild-type trypsinogen. This apparent resistance to degradation was due to slower cleavage at Arg(122) rather than Leu(81) Finally, secretion of mutant p.L104P from transfected cells was markedly reduced due to intracellular retention and aggregation with concomitant elevation of ER stress markers. We conclude that PRSS1 variant p.L104P exhibits a variety of phenotypic changes that can increase risk for chronic pancreatitis. Mutation-induced misfolding and associated ER stress are the dominant effects that support a direct pathogenic role in chronic pancreatitis.
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Affiliation(s)
- Anita Balázs
- 1Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts; ,2First Department of Medicine, University of Szeged, Szeged, Hungary;
| | - Péter Hegyi
- 2First Department of Medicine, University of Szeged, Szeged, Hungary; ,3MTA-SZTE Translational Gastroenterology Research Group, Szeged, Hungary; and ,4Institute for Translational Medicine and 1st Department of Medicine, University of Pécs, Pécs, Hungary
| | - Miklós Sahin-Tóth
- Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts;
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10
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Rygiel AM, Beer S, Simon P, Wertheim-Tysarowska K, Oracz G, Kucharzik T, Tysarowski A, Niepokój K, Kierkus J, Jurek M, Gawliński P, Poznański J, Bal J, Lerch MM, Sahin-Tóth M, Weiss FU. Gene conversion between cationic trypsinogen (PRSS1) and the pseudogene trypsinogen 6 (PRSS3P2) in patients with chronic pancreatitis. Hum Mutat 2015; 36:350-6. [PMID: 25546417 DOI: 10.1002/humu.22747] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/18/2014] [Indexed: 01/20/2023]
Abstract
Mutations of the human cationic trypsinogen gene (PRSS1) are frequently found in association with hereditary pancreatitis. The most frequent variants p.N29I and p.R122H are recognized as disease-causing mutations. Three pseudogene paralogs in the human trypsinogen family, including trypsinogen 6 (PRSS3P2), carry sequence variations in exon 3 that mimic the p.R122H mutation. In routine genetic testing of patients with chronic pancreatitis, we identified in two unrelated individuals similar gene conversion events of 24-71 nucleotides length between exon 3 of the PRSS1 (acceptor) and PRSS3P2 (donor) genes. The converted allele resulted in three nonsynonymous alterations c.343T>A (p.S115T), c.347G>C (p.R116P), and c.365_366delinsAT (p.R122H). Functional analysis of the conversion triple mutant revealed markedly increased autoactivation resulting in high and sustained trypsin activity in the presence of chymotrypsin C. This activation phenotype was identical to that of the p.R122H mutant. In addition, cellular secretion of the triple mutant from transfected HEK 293T cells was increased about twofold and this effect was attributable to mutation p.R116P. Our observations confirm and extend the notion that recombination events between members of the trypsinogen family can generate high-risk PRSS1 alleles. The pathogenic phenotype of the novel conversion is explained by a unique combination of increased trypsinogen activation and secretion.
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11
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Alloy AP, Kayode O, Wang R, Hockla A, Soares AS, Radisky ES. Mesotrypsin Has Evolved Four Unique Residues to Cleave Trypsin Inhibitors as Substrates. J Biol Chem 2015; 290:21523-35. [PMID: 26175157 DOI: 10.1074/jbc.m115.662429] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Indexed: 01/18/2023] Open
Abstract
Human mesotrypsin is highly homologous to other mammalian trypsins, and yet it is functionally unique in possessing resistance to inhibition by canonical serine protease inhibitors and in cleaving these inhibitors as preferred substrates. Arg-193 and Ser-39 have been identified as contributors to the inhibitor resistance and cleavage capability of mesotrypsin, but it is not known whether these residues fully account for the unusual properties of mesotrypsin. Here, we use human cationic trypsin as a template for engineering a gain of catalytic function, assessing mutants containing mesotrypsin-like mutations for resistance to inhibition by bovine pancreatic trypsin inhibitor (BPTI) and amyloid precursor protein Kunitz protease inhibitor (APPI), and for the ability to hydrolyze these inhibitors as substrates. We find that Arg-193 and Ser-39 are sufficient to confer mesotrypsin-like resistance to inhibition; however, compared with mesotrypsin, the trypsin-Y39S/G193R double mutant remains 10-fold slower at hydrolyzing BPTI and 2.5-fold slower at hydrolyzing APPI. We identify two additional residues in mesotrypsin, Lys-74 and Asp-97, which in concert with Arg-193 and Ser-39 confer the full catalytic capability of mesotrypsin for proteolysis of BPTI and APPI. Novel crystal structures of trypsin mutants in complex with BPTI suggest that these four residues function cooperatively to favor conformational dynamics that assist in dissociation of cleaved inhibitors. Our results reveal that efficient inhibitor cleavage is a complex capability to which at least four spatially separated residues of mesotrypsin contribute. These findings suggest that inhibitor cleavage represents a functional adaptation of mesotrypsin that may have evolved in response to positive selection pressure.
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Affiliation(s)
- Alexandre P Alloy
- From the Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Jacksonville, Florida 32224 and
| | - Olumide Kayode
- From the Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Jacksonville, Florida 32224 and
| | - Ruiying Wang
- From the Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Jacksonville, Florida 32224 and
| | - Alexandra Hockla
- From the Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Jacksonville, Florida 32224 and
| | - Alexei S Soares
- the Biology Department, Brookhaven National Laboratory, Upton, New York 11973
| | - Evette S Radisky
- From the Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Jacksonville, Florida 32224 and
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12
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Szabó A, Ludwig M, Hegyi E, Szépeová R, Witt H, Sahin-Tóth M. Mesotrypsin Signature Mutation in a Chymotrypsin C (CTRC) Variant Associated with Chronic Pancreatitis. J Biol Chem 2015; 290:17282-92. [PMID: 26013824 DOI: 10.1074/jbc.m114.618439] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Indexed: 12/14/2022] Open
Abstract
Human chymotrypsin C (CTRC) protects against pancreatitis by degrading trypsinogen and thereby curtailing harmful intra-pancreatic trypsinogen activation. Loss-of-function mutations in CTRC increase the risk for chronic pancreatitis. Here we describe functional analysis of eight previously uncharacterized natural CTRC variants tested for potential defects in secretion, proteolytic stability, and catalytic activity. We found that all variants were secreted from transfected cells normally, and none suffered proteolytic degradation by trypsin. Five variants had normal enzymatic activity, whereas variant p.R29Q was catalytically inactive due to loss of activation by trypsin and variant p.S239C exhibited impaired activity possibly caused by disulfide mispairing. Surprisingly, variant p.G214R had increased activity on a small chromogenic peptide substrate but was markedly defective in cleaving bovine β-casein or the natural CTRC substrates human cationic trypsinogen and procarboxypeptidase A1. Mutation p.G214R is analogous to the evolutionary mutation in human mesotrypsin, which rendered this trypsin isoform resistant to proteinaceous inhibitors and conferred its ability to cleave these inhibitors. Similarly to the mesotrypsin phenotype, CTRC variant p.G214R was inhibited poorly by eglin C, ecotin, or a CTRC-specific variant of SGPI-2, and it readily cleaved the reactive-site peptide bonds in eglin C and ecotin. We conclude that CTRC variants p.R29Q, p.G214R, and p.S239C are risk factors for chronic pancreatitis. Furthermore, the mesotrypsin-like CTRC variant highlights how the same natural mutation in homologous pancreatic serine proteases can evolve a new physiological role or lead to pathology, determined by the biological context of protease function.
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Affiliation(s)
- András Szabó
- From the Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118
| | - Maren Ludwig
- From the Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118, Pediatric Nutritional Medicine and Else Kröner-Fresenius-Zentrum (EKFZ) für Ernährungsmedizin, Technische Universität München (TUM), 85350 Munich, Germany
| | - Eszter Hegyi
- the Second Department of Pediatrics, Comenius University Faculty of Medicine in Bratislava, University Children's Hospital in Bratislava, 833 40 Bratislava, Slovakia, and
| | - Renata Szépeová
- the Clinic of Children and Adolescents, Comenius University Jessenius Faculty of Medicine in Martin, Martin University Hospital, 036 01 Martin, Slovakia
| | - Heiko Witt
- Pediatric Nutritional Medicine and Else Kröner-Fresenius-Zentrum (EKFZ) für Ernährungsmedizin, Technische Universität München (TUM), 85350 Munich, Germany
| | - Miklós Sahin-Tóth
- From the Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118,
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Szabó A, Salameh MA, Ludwig M, Radisky ES, Sahin-Tóth M. Tyrosine sulfation of human trypsin steers S2' subsite selectivity towards basic amino acids. PLoS One 2014; 9:e102063. [PMID: 25010489 PMCID: PMC4092071 DOI: 10.1371/journal.pone.0102063] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 06/15/2014] [Indexed: 01/29/2023] Open
Abstract
Human cationic and anionic trypsins are sulfated on Tyr154, a residue which helps to shape the prime side substrate-binding subsites. Here, we used phage display technology to assess the significance of tyrosine sulfation for the specificity of human trypsins. The prime side residues P1′–P4′ in the binding loop of bovine pancreatic trypsin inhibitor (BPTI) were fully randomized and tight binding inhibitor phages were selected against non-sulfated and sulfated human cationic trypsin. The selection pattern for the two targets differed mostly at the P2′ position, where variants selected against non-sulfated trypsin contained primarily aliphatic residues (Leu, Ile, Met), while variants selected against sulfated trypsin were enriched also for Arg. BPTI variants carrying Arg, Lys, Ile, Leu or Ala at the P2′ position of the binding loop were purified and equilibrium dissociation constants were determined against non-sulfated and sulfated cationic and anionic human trypsins. BPTI variants harboring apolar residues at P2′ exhibited 3–12-fold lower affinity to sulfated trypsin relative to the non-sulfated enzyme, whereas BPTI variants containing basic residues at P2′ had comparable affinity to both trypsin forms. Taken together, the observations demonstrate that the tyrosyl sulfate in human trypsins interacts with the P2′ position of the substrate-like inhibitor and this modification increases P2′ selectivity towards basic side chains.
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Affiliation(s)
- András Szabó
- Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
- * E-mail:
| | - Moh’d A. Salameh
- Department of Cancer Biology, Mayo Clinic Cancer Center, Jacksonville, Florida, United States of America
| | - Maren Ludwig
- Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
- Pediatric Nutritional Medicine & EKFZ, Technische Universität München (TUM), Munich, Germany
| | - Evette S. Radisky
- Department of Cancer Biology, Mayo Clinic Cancer Center, Jacksonville, Florida, United States of America
| | - Miklós Sahin-Tóth
- Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
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Szabó A, Radisky ES, Sahin-Tóth M. Zymogen activation confers thermodynamic stability on a key peptide bond and protects human cationic trypsin from degradation. J Biol Chem 2014; 289:4753-61. [PMID: 24403079 DOI: 10.1074/jbc.m113.538884] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Human cationic trypsinogen, precursor of the digestive enzyme trypsin, can be rapidly degraded to protect the pancreas when pathological conditions threaten, while trypsin itself is impressively resistant to degradation. For either form, degradation is controlled by two necessary initial proteolytic events: cleavage of the Leu81-Glu82 peptide bond by chymotrypsin C (CTRC) and cleavage of the Arg122-Val123 peptide bond by trypsin. Here we demonstrate that the Leu81-Glu82 peptide bond of human cationic trypsin, but not trypsinogen, is thermodynamically stable, such that cleavage by CTRC leads to an equilibrium mixture containing 10% cleaved and 90% uncleaved trypsin. When cleaved trypsin was incubated with CTRC, the Leu81-Glu82 peptide bond was re-synthesized to establish the same equilibrium. The thermodynamic stability of the scissile peptide bond was not dependent on CTRC or Leu-81, as re-synthesis was also accomplished by other proteases acting on mutated cationic trypsin. The Leu81-Glu82 peptide bond is located within a calcium binding loop, and thermodynamic stability of the bond was strictly dependent on calcium and on the calcium-coordinated residue Glu-85. Trypsinolytic cleavage of the Arg122-Val123 site was also delayed in trypsin relative to trypsinogen in a calcium-dependent manner, but for this bond cleavage was modulated by kinetic rather than thermodynamic control. Our results reveal that the trypsinogen to trypsin conformational switch modulates cleavage susceptibility of nick sites by altering both the thermodynamics and kinetics of cleavage to protect human cationic trypsin from premature degradation.
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Affiliation(s)
- András Szabó
- From the Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118 and
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15
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Németh BC, Wartmann T, Halangk W, Sahin-Tóth M. Autoactivation of mouse trypsinogens is regulated by chymotrypsin C via cleavage of the autolysis loop. J Biol Chem 2013; 288:24049-62. [PMID: 23814066 DOI: 10.1074/jbc.m113.478800] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Chymotrypsin C (CTRC) is a proteolytic regulator of trypsinogen autoactivation in humans. CTRC cleavage of the trypsinogen activation peptide stimulates autoactivation, whereas cleavage of the calcium binding loop promotes trypsinogen degradation. Trypsinogen mutations that alter these regulatory cleavages lead to increased intrapancreatic trypsinogen activation and cause hereditary pancreatitis. The aim of this study was to characterize the regulation of autoactivation of mouse trypsinogens by mouse Ctrc. We found that the mouse pancreas expresses four trypsinogen isoforms to high levels, T7, T8, T9, and T20. Only the T7 activation peptide was cleaved by mouse Ctrc, causing negligible stimulation of autoactivation. Surprisingly, mouse Ctrc poorly cleaved the calcium binding loop in all mouse trypsinogens. In contrast, mouse Ctrc readily cleaved the Phe-150-Gly-151 peptide bond in the autolysis loop of T8 and T9 and inhibited autoactivation. Mouse chymotrypsin B also cleaved the same peptide bond but was 7-fold slower. T7 was less sensitive to chymotryptic regulation, which involved slow cleavage of the Leu-149-Ser-150 peptide bond in the autolysis loop. Modeling indicated steric proximity of the autolysis loop and the activation peptide in trypsinogen, suggesting the cleaved autolysis loop may directly interfere with activation. We conclude that autoactivation of mouse trypsinogens is under the control of mouse Ctrc with some notable differences from the human situation. Thus, cleavage of the trypsinogen activation peptide or the calcium binding loop by Ctrc is unimportant. Instead, inhibition of autoactivation via cleavage of the autolysis loop is the dominant mechanism that can mitigate intrapancreatic trypsinogen activation.
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Affiliation(s)
- Balázs Csaba Németh
- Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118, USA
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Szabó A, Sahin-Tóth M. Increased activation of hereditary pancreatitis-associated human cationic trypsinogen mutants in presence of chymotrypsin C. J Biol Chem 2012; 287:20701-10. [PMID: 22539344 DOI: 10.1074/jbc.m112.360065] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Mutations in human cationic trypsinogen (PRSS1) cause autosomal dominant hereditary pancreatitis. Increased intrapancreatic autoactivation of trypsinogen mutants has been hypothesized to initiate the disease. Autoactivation of cationic trypsinogen is proteolytically regulated by chymotrypsin C (CTRC), which mitigates the development of trypsin activity by promoting degradation of both trypsinogen and trypsin. Paradoxically, CTRC also increases the rate of autoactivation by processing the trypsinogen activation peptide to a shorter form. The aim of this study was to investigate the effect of CTRC on the autoactivation of clinically relevant trypsinogen mutants. We found that in the presence of CTRC, trypsinogen mutants associated with classic hereditary pancreatitis (N29I, N29T, V39A, R122C, and R122H) autoactivated at increased rates and reached markedly higher active trypsin levels compared with wild-type cationic trypsinogen. The A16V mutant, known for its variable disease penetrance, exhibited a smaller increase in autoactivation. The mechanistic basis of increased activation was mutation-specific and involved resistance to degradation (N29I, N29T, V39A, R122C, and R122H) and/or increased N-terminal processing by CTRC (A16V and N29I). These observations indicate that hereditary pancreatitis is caused by CTRC-dependent dysregulation of cationic trypsinogen autoactivation, which results in elevated trypsin levels in the pancreas.
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Affiliation(s)
- András Szabó
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, Massachusetts 02118, USA
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17
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Abstract
OBJECTIVES In a hereditary pancreatitis family from Denmark, we identified a novel intragenic duplication of 9 nucleotides in exon-2 of the human cationic trypsinogen (PRSS1) gene (c.63_71dup) which at the amino-acid level resulted in the insertion of 3 amino acids within the activation peptide of cationic trypsinogen (p.K23_I24insIDK). The aim of the present study was to characterize the effect of this unique genetic alteration on the function of human cationic trypsinogen. METHODS Wild-type and mutant cationic trypsinogens were produced recombinantly and purified to homogeneity. Trypsinogen activation was followed by enzymatic assays and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Trypsinogen secretion was measured from transfected HEK 293T cells. RESULTS Recombinant cationic trypsinogen carrying the p.K23_I24insIDK mutation exhibited greater than 10-fold increased autoactivation. Activation by human cathepsin B also was accelerated by 10-fold. Secretion of the p.K23_I24insIDK mutant from transfected cells was diminished, consistent with intracellular autoactivation. CONCLUSIONS This is the first report of an intragenic duplication within the PRSS1 gene causing hereditary pancreatitis. The accelerated activation of p.K23_I24insIDK by cathepsin B is a unique biochemical property not found in any other pancreatitis-associated trypsinogen mutant. In contrast, the robust autoactivation of the novel mutant confirms the notion that increased autoactivation is a disease-relevant mechanism in hereditary pancreatitis.
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18
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Szabó A, Héja D, Szakács D, Zboray K, Kékesi KA, Radisky ES, Sahin-Tóth M, Pál G. High affinity small protein inhibitors of human chymotrypsin C (CTRC) selected by phage display reveal unusual preference for P4' acidic residues. J Biol Chem 2011; 286:22535-45. [PMID: 21515688 DOI: 10.1074/jbc.m111.235754] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Human chymotrypsin C (CTRC) is a pancreatic protease that participates in the regulation of intestinal digestive enzyme activity. Other chymotrypsins and elastases are inactive on the regulatory sites cleaved by CTRC, suggesting that CTRC recognizes unique sequence patterns. To characterize the molecular determinants underlying CTRC specificity, we selected high affinity substrate-like small protein inhibitors against CTRC from a phage library displaying variants of SGPI-2, a natural chymotrypsin inhibitor from Schistocerca gregaria. On the basis of the sequence pattern selected, we designed eight inhibitor variants in which amino acid residues in the reactive loop at P1 (Met or Leu), P2' (Leu or Asp), and P4' (Glu, Asp, or Ala) were varied. Binding experiments with CTRC revealed that (i) inhibitors with Leu at P1 bind 10-fold stronger than those with P1 Met; (ii) Asp at P2' (versus Leu) decreases affinity but increases selectivity, and (iii) Glu or Asp at P4' (versus Ala) increase affinity 10-fold. The highest affinity SGPI-2 variant (K(D) 20 pm) bound to CTRC 575-fold tighter than the parent molecule. The most selective inhibitor variant exhibited a K(D) of 110 pm and a selectivity ranging from 225- to 112,664-fold against other human chymotrypsins and elastases. Homology modeling and mutagenesis identified a cluster of basic amino acid residues (Lys(51), Arg(56), and Arg(80)) on the surface of human CTRC that interact with the P4' acidic residue of the inhibitor. The acidic preference of CTRC at P4' is unique among pancreatic proteases and might contribute to the high specificity of CTRC-mediated digestive enzyme regulation.
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Affiliation(s)
- András Szabó
- Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118, USA
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19
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Abstract
Heterologously expressed proteins in Escherichia coli may undergo unwanted N-terminal processing by methionine and proline aminopeptidases. To overcome this problem, we present a system where the gene of interest is cloned as a fusion to a self-splicing mini-intein. This fusion construct is expressed in an engineered E. coli strain from which the pepP gene coding for aminopeptidase P has been deleted. We describe a protocol using human cationic trypsinogen as an example to demonstrate that recombinant proteins produced in this expression system contain homogeneous, unprocessed N-termini.
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Affiliation(s)
- Orsolya Király
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA.
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20
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Szmola R, Bence M, Carpentieri A, Szabó A, Costello CE, Samuelson J, Sahin-Tóth M. Chymotrypsin C is a co-activator of human pancreatic procarboxypeptidases A1 and A2. J Biol Chem 2010; 286:1819-27. [PMID: 21098023 DOI: 10.1074/jbc.m110.187369] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Human digestive carboxypeptidases CPA1, CPA2, and CPB1 are secreted by the pancreas as inactive proenzymes containing a 94-96-amino acid-long propeptide. Activation of procarboxypeptidases is initiated by proteolytic cleavage at the C-terminal end of the propeptide by trypsin. Here, we demonstrate that subsequent cleavage of the propeptide by chymotrypsin C (CTRC) induces a nearly 10-fold increase in the activity of trypsin-activated CPA1 and CPA2, whereas CPB1 activity is unaffected. Other human pancreatic proteases such as chymotrypsin B1, chymotrypsin B2, chymotrypsin-like enzyme-1, elastase 2A, elastase 3A, or elastase 3B are inactive or markedly less effective at promoting procarboxypeptidase activation. On the basis of these observations, we propose that CTRC is a physiological co-activator of proCPA1 and proCPA2. Furthermore, the results confirm and extend the notion that CTRC is a key regulator of digestive zymogen activation.
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Affiliation(s)
- Richárd Szmola
- Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118, USA
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21
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Kereszturi E, Sahin-Tóth M. Intracellular autoactivation of human cationic trypsinogen mutants causes reduced trypsinogen secretion and acinar cell death. J Biol Chem 2009; 284:33392-9. [PMID: 19801634 DOI: 10.1074/jbc.m109.056812] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Mutations in the activation peptide of human cationic trypsinogen have been found in patients with chronic pancreatitis. Previous biochemical studies demonstrated that mutations p.D19A, p.D22G, and p.K23R strongly stimulate trypsinogen autoactivation. In the present study, we characterized the cell biological effects of these mutants using human embryonic kidney 293T and AR42J rat acinar cells. We found that relative to wild-type trypsinogen, secretion of the mutants from transfected cells was markedly decreased. This apparent secretion defect was completely rescued by inhibition of autoactivation via (1) inclusion of the small molecule trypsin inhibitor benzamidine in the growth medium; or (2) cotransfection with the physiological trypsin inhibitor SPINK1; or (3) by mutation of the catalytic Ser(200) residue in trypsinogen. In contrast, extracellularly added SPINK1 or other nonpermeable proteinaceous trypsin inhibitors did not restore normal secretion of the mutants, indicating that intracellular autoactivation is responsible for the observed secretion loss. Acinar cells expressing the p.D22G mutant detached from the culture plate over time, became terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive, and exhibited elevated levels of the proapoptotic transcription factor CHOP. The observations indicate that activation peptide mutants of human cationic trypsinogen undergo autoactivation intracellularly, which leads to decreased trypsinogen secretion and eventual acinar cell death. The results thus define a novel pathological pathway for parenchymal injury in hereditary chronic pancreatitis.
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Affiliation(s)
- Eva Kereszturi
- Department of Molecular and Cell Biology, Boston University, Henry M. Goldman School of Dental Medicine, Boston, Massachusetts 02118, USA
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22
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Sathler PC, Craik CS, Takeuchi T, Zingali RB, Castro HC. Engineering ecotin for identifying proteins with a trypsin fold. Appl Biochem Biotechnol 2009; 160:2355-65. [PMID: 19728173 DOI: 10.1007/s12010-009-8711-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Accepted: 07/05/2009] [Indexed: 11/29/2022]
Abstract
Ecotin is a bidentate, fold-specific inhibitor of mammalian serine-proteases produced by Escherichia coli. This molecule may be engineered to increase and/or change its affinity and specificity providing significant biotechnological potential. Since ecotin binds tightly to serine proteases of the trypsin fold, it may help to identify the role of these enzymes in different biological processes. In this work, we tested ecotin variants as an affinity purification reagent for identifying enzymes in samples of tumor progression and mammary gland involution. Initially, we used a commercial source of urokinase-type plasminogen activator (u-PA) that remained fully active after elution from an affinity column of the ecotin variant (M84R, M85R). We then successfully identified u-PA from more complex mixtures including lysates from a prostate cancer cell line and involuting mouse mammary glands. Interestingly, a membrane-type serine protease 1 was isolated from the Triton X-100-solubilized PC-3 cell lysates, and surprisingly, haptoglobin, a serine-protease homolog protein, was also identified in mammary gland lysates and in blood. Haptoglobin does not prevent ecotin inhibition of u-PA, but it may act as a carrier within blood when ecotin is used in vivo. Finally, this affinity purification matrix was also able to identify a thrombin-like enzyme from snake venom using an ecotin variant directed against thrombin. Overall, the ecotin variants acted as robust tools for the isolation and characterization of proteins with a trypsin fold. Thus, they may assist in the understanding of the role of these serine proteases and homologous proteins in different biological processes.
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Affiliation(s)
- Plínio C Sathler
- LaBioMol, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, RJ, 24001-970, Brazil
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23
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Kereszturi E, Szmola R, Kukor Z, Simon P, Weiss FU, Lerch MM, Sahin-Tóth M. Hereditary pancreatitis caused by mutation-induced misfolding of human cationic trypsinogen: a novel disease mechanism. Hum Mutat 2009; 30:575-82. [PMID: 19191323 DOI: 10.1002/humu.20853] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We investigated the biochemical properties and cellular expression of the c.346C>T (p.R116C) human cationic trypsinogen (PRSS1) mutant, which we identified in a German family with autosomal dominant hereditary pancreatitis. This mutation leads to an unpaired Cys residue with the potential to interfere with protein folding via incorrect disulfide bond formation. Recombinantly expressed p.R116C trypsinogen exhibited a tendency for misfolding in vitro. Biochemical analysis of the correctly folded, purified p.R116C mutant revealed unchanged activation and degradation characteristics compared to wild type trypsinogen. Secretion of mutant p.R116C from transfected 293T cells was reduced to approximately 20% of wild type. A similar secretion defect was observed with another rare PRSS1 variant, p.C139S, whereas mutants p.A16V, p.N29I, p.N29T, p.E79K, p.R122C, and p.R122H were secreted normally. All mutants were detected in cell extracts at comparable levels but a large portion of mutant p.R116C was present in an insoluble, protease-sensitive form. Consistent with intracellular retention of misfolded trypsinogen, the endoplasmic reticulum (ER) stress markers immunoglobulin-binding protein (BiP) and the spliced form of the X-box binding protein-1 (XBP1s) were elevated in cells expressing mutant p.R116C. The results indicate that mutation-induced misfolding and intracellular retention of human cationic trypsinogen causes hereditary pancreatitis in carriers of the p.R116C mutation. ER stress triggered by trypsinogen misfolding represents a new potential disease mechanism for chronic pancreatitis.
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Affiliation(s)
- Eva Kereszturi
- Department of Molecular and Cell Biology, Goldman School of Dental Medicine, Boston University, Boston, Massachusetts, USA
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24
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Proteolytic activation of human pancreatitis-associated protein is required for peptidoglycan binding and bacterial aggregation. Biochem J 2009; 420:335-43. [PMID: 19254208 DOI: 10.1042/bj20090005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PAP (pancreatitis-associated protein) is a 16 kDa lectin-like protein, which becomes robustly up-regulated in the pancreatic juice during acute pancreatitis. Trypsin cleaves the N-terminus of PAP, which in turn forms insoluble fibrils. PAP and its paralogue, the pancreatic stone protein, induce bacterial aggregation and, more recently, PAP was shown to bind to the peptidoglycan of Gram-positive bacteria and exert a direct bactericidal effect. However, the role of N-terminal processing in the antibacterial function of PAP has remained unclear. In the present study, we demonstrate that N-terminal cleavage of PAP by trypsin at the Arg37-Ile38 peptide bond or by elastase at the Ser35-Ala36 peptide bond is a prerequisite for binding to the peptidoglycan of the Gram-positive bacterium Bacillus subtilis. The tryptic site in PAP was also efficiently cleaved by nprE (extracellular neutral metalloprotease) secreted from B. subtilis. Trypsin-mediated processing of PAP resulted in the formation of the characteristic insoluble PAP species, whereas elastase-processed PAP remained soluble. N-terminally processed PAP induced rapid aggregation of B. subtilis without significant bacterial killing. The bacteria-aggregating activities of trypsin-processed and elastase-processed PAP were comparable. In contrast with previous reports, the Gram-negative Escherichia coli bacterium was not aggregated. We conclude that N-terminal processing is necessary for the peptidoglycan binding and bacteria-aggregating activity of PAP and that trypsin-processed and elastase-processed forms are functionally equivalent. The observations also extend the complement of proteases capable of PAP processing, which now includes trypsins, pancreatic elastases and bacterial zinc metalloproteases of the thermolysin type.
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25
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Expression of full-length human pro-urokinase in mammary glands of transgenic mice. Transgenic Res 2009; 18:747-56. [DOI: 10.1007/s11248-009-9269-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Accepted: 04/14/2009] [Indexed: 11/25/2022]
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A common African polymorphism abolishes tyrosine sulfation of human anionic trypsinogen (PRSS2). Biochem J 2009; 418:155-61. [PMID: 18986305 DOI: 10.1042/bj20081848] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Human pancreatic trypsinogens undergo post-translational sulfation on Tyr(154), catalysed by the Golgi-resident enzyme tyrosylprotein sulfotransferase 2. Sequence alignments suggest that the sulfation of Tyr(154) is facilitated by a unique sequence context which is characteristically found in primate trypsinogens. In the search for genetic variants that might alter this sulfation motif, we identified a single nucleotide polymorphism (c.457G>C) in the PRSS2 (serine protease 2, human anionic trypsinogen) gene, which changed Asp(153) to a histidine residue (p.D153H). The p.D153H variant is common in subjects of African origin, with a minor allele frequency of 9.2%, whereas it is absent in subjects of European descent. We demonstrate that Asp(153) is the main determinant of tyrosine sulfation in anionic trypsinogen, as both the natural p.D153H variation and the p.D153N mutation result in a complete loss of trypsinogen sulfation. In contrast, mutation of Asp(156) and Glu(157) only slightly decrease tyrosine sulfation, whereas mutation of Gly(151) and Pro(155) has no effect. With respect to the biological relevance of the p.D153H variant, we found that tyrosine sulfation had no significant effect on the activation of anionic trypsinogen or the catalytic activity and inhibitor sensitivity of anionic trypsin. Taken together with previous studies, the observations of the present study suggest that the primary role of trypsinogen sulfation in humans is to stimulate autoactivation of PRSS1 (serine protease 1, human cationic trypsinogen), whereas the sulfation of anionic trypsinogen is unimportant for normal digestive physiology. As a result, the p.D153H polymorphism which eliminates this modification could become widespread in a healthy population.
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27
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Ózsvári B, Hegyi P, Sahin-Tóth M. The guinea pig pancreas secretes a single trypsinogen isoform, which is defective in autoactivation. Pancreas 2008; 37:182-8. [PMID: 18665081 PMCID: PMC2708092 DOI: 10.1097/mpa.0b013e3181663066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES The aim of the present study was to purify and clone the trypsinogen isoforms from the guinea pig pancreas and characterize their activation properties. METHODS Trypsinogens from pancreatic homogenates were isolated by ecotin-affinity chromatography, followed by cation-exchange chromatography. Activation of trypsinogens was tested with enteropeptidase, cathepsin B, and trypsin. Complementary DNAs for pretrypsinogens were cloned from total RNA after reverse transcription and polymerase chain reaction amplification. RESULTS Purification of trypsinogens yielded a single peak with an N-terminal amino-acid sequence of LPIDD. Cloning of pretrypsinogen cDNAs revealed 2 distinct but nearly identical isoforms. At the amino acid level, the only difference between the 2 isoforms is an Ala/Ser change at position 15 within the signal peptide. Thus, both cDNA variants give rise to the same mature trypsinogen upon secretion. Guinea pig trypsinogen is readily activated by enteropeptidase and cathepsin B but exhibits essentially no autoactivation, under conditions where human cationic and anionic trypsinogens rapidly autoactivate. CONCLUSIONS The observations suggest that multiple trypsinogen isoforms and their ability to autoactivate are not required universally for normal digestive physiology in mammals. Furthermore, the inability of guinea pig trypsinogen to undergo autoactivation suggests that this species might be more resistant to pancreatitis than humans, where increased autoactivation of cationic trypsinogen mutants has been linked to hereditary pancreatitis.
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Affiliation(s)
- Béla Ózsvári
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts; and 1st Department of Medicine, University of Szeged, Faculty of Medicine, Szeged, Hungary
| | - Péter Hegyi
- 1st Department of Medicine, University of Szeged, Faculty of Medicine, Szeged, Hungary
| | - Miklós Sahin-Tóth
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts
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Salameh MA, Soares AS, Hockla A, Radisky ES. Structural basis for accelerated cleavage of bovine pancreatic trypsin inhibitor (BPTI) by human mesotrypsin. J Biol Chem 2007; 283:4115-23. [PMID: 18077447 DOI: 10.1074/jbc.m708268200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human mesotrypsin is an isoform of trypsin that displays unusual resistance to polypeptide trypsin inhibitors and has been observed to cleave several such inhibitors as substrates. Whereas substitution of arginine for the highly conserved glycine 193 in the trypsin active site has been implicated as a critical factor in the inhibitor resistance of mesotrypsin, how this substitution leads to accelerated inhibitor cleavage is not clear. Bovine pancreatic trypsin inhibitor (BPTI) forms an extremely stable and cleavage-resistant complex with trypsin, and thus provides a rigorous challenge of mesotrypsin catalytic activity toward polypeptide inhibitors. Here, we report kinetic constants for mesotrypsin and the highly homologous (but inhibitor sensitive) human cationic trypsin, describing inhibition by, and cleavage of BPTI, as well as crystal structures of the mesotrypsin-BPTI and human cationic trypsin-BPTI complexes. We find that mesotrypsin cleaves BPTI with a rate constant accelerated 350-fold over that of human cationic trypsin and 150,000-fold over that of bovine trypsin. From the crystal structures, we see that small conformational adjustments limited to several side chains enable mesotrypsin-BPTI complex formation, surmounting the predicted steric clash introduced by Arg-193. Our results show that the mesotrypsin-BPTI interface favors catalysis through (a) electrostatic repulsion between the closely spaced mesotrypsin Arg-193 and BPTI Arg-17, and (b) elimination of two hydrogen bonds between the enzyme and the amine leaving group portion of BPTI. Our model predicts that these deleterious interactions accelerate leaving group dissociation and deacylation.
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Affiliation(s)
- Moh'd A Salameh
- Department of Cancer Biology, Mayo Clinic Cancer Center, Jacksonville, Florida 32224, USA
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29
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Malik A, Jenzsch M, Lübbert A, Rudolph R, Söhling B. Periplasmic production of native human proinsulin as a fusion to E. coli ecotin. Protein Expr Purif 2007; 55:100-11. [PMID: 17509894 DOI: 10.1016/j.pep.2007.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 04/02/2007] [Accepted: 04/03/2007] [Indexed: 10/23/2022]
Abstract
Native proinsulin belongs to the class of the difficult-to-express proteins in Escherichia coli. Problems mainly arise due to its small size, a high proteolytic decay, and the necessity to form a native disulfide pattern. In the present study, human proinsulin was produced in the periplasm of E. coli as a fusion to ecotin, which is a small periplasmic protein of 16 kDa encoded by the host, containing one disulfide bond. The fusion protein was secreted to the periplasm and native proinsulin was determined by ELISA. Cultivation parameters were studied in parallel batch mode fermentations using E. coli BL21(DE3)Gold as a host. After improvement of fed-batch high density fermentation conditions, 153 mg fusion protein corresponding to 51.5mg native proinsulin was obtained per L. Proteins were extracted from the periplasm by osmotic shock treatment. The fusion protein was purified in one step by ecotin affinity chromatography on immobilized trypsinogen. After thrombin cleavage of the fusion protein, the products were separated by Ni-NTA chromatography. Proinsulin was quantified by ELISA and characterized by mass spectrometry. To evaluate the influence of periplasmic proteases, the amount of ecotin-proinsulin was determined in E. coli BL21(DE3)Gold and in a periplasmic protease deficient strain, E. coli SF120.
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Affiliation(s)
- Ajamaluddin Malik
- Institute for Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str 3, D-06120 Halle (Saale), Germany
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30
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Abstract
The past decade has witnessed remarkable progress in the genetics of chronic pancreatitis. Despite these accomplishments, the understanding of the molecular mechanisms through which PRSS1 and SPINK1 mutations cause chronic pancreatitis has remained sketchy. Pancreatitis-associated gene mutations are believed to result in uncontrolled trypsin activity in the pancreas. Experimental identification of the disease-relevant functional alterations caused by PRSS1 or SPINK1 mutations proved to be challenging, however, because results of biochemical analyses lent themselves to different interpretations. This article focuses on PRSS1 mutations and summarizes the salient biochemical findings in the context of the mechanistic models that explain the connection between mutations and hereditary pancreatitis.
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Affiliation(s)
- Miklós Sahin-Tóth
- Department of Molecular and Cell Biology, Goldman School of Dental Medicine, Boston University, 715 Albany Street, Evans-4, Boston, MA 02118, USA.
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31
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Nemoda Z, Sahin-Tóth M. Chymotrypsin C (caldecrin) stimulates autoactivation of human cationic trypsinogen. J Biol Chem 2006; 281:11879-86. [PMID: 16505482 PMCID: PMC1586167 DOI: 10.1074/jbc.m600124200] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Trypsin-mediated trypsinogen activation (autoactivation) facilitates digestive zymogen activation in the duodenum but may precipitate pancreatitis if it occurs prematurely in the pancreas. Autoactivation of human cationic trypsinogen is inhibited by a repulsive electrostatic interaction between the unique Asp218 on the surface of cationic trypsin and the conserved tetra-aspartate (Asp19-22) motif in the trypsinogen activation peptide (Nemoda, Z., and Sahin-Tóth, M. (2005) J. Biol. Chem. 280, 29645-29652). Here we describe that this interaction is regulated by chymotrypsin C (caldecrin), which can specifically cleave the Phe18-Asp19 peptide bond in the trypsinogen activation peptide and remove the N-terminal tripeptide. In contrast, chymotrypsin B, elastase 2A, or elastase 3A (proteinase E) are ineffective. Autoactivation of N-terminally truncated cationic trypsinogen is stimulated approximately 3-fold, and this effect is dependent on the presence of Asp218. Because chymotrypsinogen C is activated by trypsin, and chymotrypsin C stimulates trypsinogen activation, these reactions establish a positive feedback mechanism in the digestive enzyme cascade of humans. Furthermore, inappropriate activation of chymotrypsinogen C in the pancreas may contribute to the development of pancreatitis. Consistent with this notion, the pancreatitis-associated mutation A16V in cationic trypsinogen increases the rate of chymotrypsin C-mediated processing of the activation peptide 4-fold and causes accelerated trypsinogen activation in vitro.
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Affiliation(s)
| | - Miklós Sahin-Tóth
- Address correspondence to Miklós Sahin-Tóth, 715 Albany Street, Evans-433; Boston, MA 02118; Tel: (617) 414-1070; Fax: (617) 414-1041; E-mail:
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32
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Király O, Guan L, Szepessy E, Tóth M, Kukor Z, Sahin-Tóth M. Expression of human cationic trypsinogen with an authentic N terminus using intein-mediated splicing in aminopeptidase P deficient Escherichia coli. Protein Expr Purif 2006; 48:104-11. [PMID: 16542853 PMCID: PMC1604731 DOI: 10.1016/j.pep.2006.01.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Revised: 01/24/2006] [Accepted: 01/27/2006] [Indexed: 01/29/2023]
Abstract
High-level expression of human trypsinogens as inclusion bodies in Escherichia coli requires deletion of the secretory signal sequence and placement of an initiator methionine at the N terminus. Trypsinogen preparations obtained this way contain a mixture of abnormal N termini, as a result of processing by cytoplasmic aminopeptidases. Here, we describe an expression system that produces recombinant human cationic trypsinogen with a native, intact N terminus, using intein-mediated protein splicing and an aminopeptidase P (pepP) deficient E. coli strain. As a first application of this system, the effect of the pancreatitis-associated mutation A16V on the autoactivation of human cationic trypsinogen was characterized. The use of the novel pepP knock-out E. coli strain should be generally applicable to the expression of recombinant proteins, which undergo unwanted N-terminal trimming by aminopeptidase P.
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Affiliation(s)
- Orsolya Király
- Department of Molecular and Cell Biology, Goldman School of Dental Medicine, Boston University, Boston, MA, 02118
| | - Lan Guan
- Department of Physiology, University of California Los Angeles, Los Angeles, CA 90095
| | - Edit Szepessy
- Department of Molecular and Cell Biology, Goldman School of Dental Medicine, Boston University, Boston, MA, 02118
| | - Miklós Tóth
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Zoltán Kukor
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Miklós Sahin-Tóth
- Department of Molecular and Cell Biology, Goldman School of Dental Medicine, Boston University, Boston, MA, 02118
- Mailing address: 715 Albany Street, Evans-433; Boston, MA 02118, Tel: (617) 414-1070; Fax: (617) 414-1041; E-mail:
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33
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Herter S, Piper D, Aaron W, Gabriele T, Cutler G, Cao P, Bhatt A, Choe Y, Craik C, Walker N, Meininger D, Hoey T, Austin R. Hepatocyte growth factor is a preferred in vitro substrate for human hepsin, a membrane-anchored serine protease implicated in prostate and ovarian cancers. Biochem J 2005; 390:125-36. [PMID: 15839837 PMCID: PMC1184568 DOI: 10.1042/bj20041955] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hepsin is a membrane-anchored, trypsin-like serine protease with prominent expression in the human liver and tumours of the prostate and ovaries. To better understand the biological functions of hepsin, we identified macromolecular substrates employing a tetrapeptide PS-SCL (positional scanning-synthetic combinatorial library) screen that rapidly determines the P1-P4 substrate specificity. Hepsin exhibited strong preference at the P1 position for arginine over lysine, and favoured threonine, leucine or asparagine at the P2, glutamine or lysine at the P3, and proline or lysine at the P4 position. The relative activity of hepsin toward individual AMC (7-amino-4-methylcoumarin)-tetrapeptides was generally consistent with the overall peptide profiling results derived from the PC-SCL screen. The most active tetrapeptide substrate Ac (acetyl)-KQLR-AMC matched with the activation cleavage site of the hepatocyte growth factor precursor sc-HGF (single-chain HGF), KQLR downward arrowVVNG (where downward arrow denotes the cleavage site), as identified by a database analysis of trypsin-like precursors. X-ray crystallographic studies with KQLR chloromethylketone showed that the KQLR peptide fits well into the substrate-binding cleft of hepsin. This hepsin-processed HGF induced c-Met receptor tyrosine phosphorylation in SKOV-3 ovarian cancer cells, indicating that the hepsin-cleaved HGF is biologically active. Activation cleavage site mutants of sc-HGF with predicted non-preferred sequences, DPGR downward arrowVVNG or KQLQ downward arrowVVNG, were not processed, illustrating that the P4-P1 residues can be important determinants for substrate specificity. In addition to finding macromolecular hepsin substrates, the extracellular inhibitors of the HGF activator, HAI-1 and HAI-2, were potent inhibitors of hepsin activity (IC50 4+/-0.2 nM and 12+/-0.5 nM respectively). Together, our findings suggest that the HGF precursor is a potential in vivo substrate for hepsin in tumours, where hepsin expression is dysregulated and may influence tumorigenesis through inappropriate activation and/or regulation of HGF receptor (c-Met) functions.
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Affiliation(s)
- Sylvia Herter
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - Derek E. Piper
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - Wade Aaron
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - Timothy Gabriele
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - Gene Cutler
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - Ping Cao
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - Ami S. Bhatt
- †University of California San Francisco, Department of Pharmaceutical Chemistry, 600 16th Street, San Francisco, CA 94143, U.S.A
| | - Youngchool Choe
- †University of California San Francisco, Department of Pharmaceutical Chemistry, 600 16th Street, San Francisco, CA 94143, U.S.A
| | - Charles S. Craik
- †University of California San Francisco, Department of Pharmaceutical Chemistry, 600 16th Street, San Francisco, CA 94143, U.S.A
| | - Nigel Walker
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - David Meininger
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - Timothy Hoey
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
| | - Richard J. Austin
- *Department of Biology, Amgen San Francisco, 1120 Veterans Boulevard, South San Francisco, CA 94080, U.S.A
- To whom correspondence should be addressed (email )
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34
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Szenthe B, Frost C, Szilágyi L, Patthy A, Naudé R, Gráf L. Cloning and expression of ostrich trypsinogen: an avian trypsin with a highly sensitive autolysis site. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1748:35-42. [PMID: 15752690 DOI: 10.1016/j.bbapap.2004.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Revised: 12/07/2004] [Accepted: 12/07/2004] [Indexed: 10/26/2022]
Abstract
One of ostrich (Struthio camelus) trypsinogen genes was cloned from pancreatic cDNA. Its amino acid sequence compared to known trypsin sequences from other species shows high identity and suggests that it is a member of the phylogenetically anionic trypsinogen I subfamily. After cytoplasmic over expression in Escherichia coli and renaturation, the activation properties of ostrich trypsinogen were studied and compared to those of human trypsinogen 1 (also called as human cationic trypsinogen). Ostrich trypsinogen undergoes bovine enterokinase activation and autoactivation much faster than human trypsinogen 1 and exhibits on a synthetic substrate a somewhat higher enzymatic activity than the latter one. The most interesting property of ostrich trypsin is its relatively fast autolysis that can be explained via a mechanism different from the common mechanism for rat and human 1 trypsins. The latter proteases have a site, Arg117-Val118, where the autolysis starts and then goes on in a zipper-like fashion. This is absent from ostrich trypsin. Instead it has a couple of cleavage sites within regions 67-98, including two unusual ones, Arg76-Glu77 and Arg83-Ser84. These appear to be hydrolysed fast in a non-consecutive manner. Such an autolysis mechanism could not be inhibited by a single-site mutation which in humans is proposed to lead to pancreatitis.
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Affiliation(s)
- Borbála Szenthe
- Department of Biochemistry, Eötvös Lóránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary
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35
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Teich N, Le Maréchal C, Kukor Z, Caca K, Witzigmann H, Chen JM, Tóth M, Mössner J, Keim V, Férec C, Sahin-Tóth M. Interaction between trypsinogen isoforms in genetically determined pancreatitis: mutation E79K in cationic trypsin (PRSS1) causes increased transactivation of anionic trypsinogen (PRSS2). Hum Mutat 2004; 23:22-31. [PMID: 14695529 DOI: 10.1002/humu.10285] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The human pancreas secretes two major trypsinogen isoforms, cationic and anionic trypsinogen. To date, 19 genetic variants have been identified in the cationic trypsinogen gene (PRSS1) of patients with hereditary, familial, or sporadic chronic pancreatitis. A common feature of cationic trypsinogen mutants studied so far is an increased propensity for autocatalytic activation (autoactivation). This is thought to lead to premature intrapancreatic digestive protease activation. In contrast, no pancreatitis-associated mutations have been found in the anionic trypsinogen gene (PRSS2), suggesting that this isoform might play a relatively unimportant role in pancreatitis. To challenge this notion, here we describe the unique properties of the E79K cationic trypsinogen mutation (c.235G>A), which was identified in three European families affected by sporadic or familial pancreatitis cases. In vitro analysis of recombinant wild-type and mutant enzymes revealed that catalytic activity of E79K trypsin was normal, and its inhibition by pancreatic secretory trypsin inhibitor was unaffected. Although the E79K mutation introduces a potential new tryptic cleavage site, autocatalytic degradation (autolysis) of E79K-trypsin was also unchanged. Furthermore, in contrast to previously characterized disease-causing mutations, E79K markedly inhibited autoactivation of cationic trypsinogen. Remarkably, however, E79K trypsin activated anionic trypsinogen two-fold better than wild-type cationic trypsin did, while the common pancreatitis-associated mutants R122H or N29I had no such effect. The observations not only suggest a novel mechanism of action for pancreatitis-associated trypsinogen mutations, but also highlight the importance of interactions between the two major trypsinogen isoforms in the development of genetically determined chronic pancreatitis.
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Affiliation(s)
- Niels Teich
- Medizinische Klinik und Poliklinik II, Universität Leipzig, Leipzig, Germany
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36
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Szmola R, Kukor Z, Sahin-Tóth M. Human mesotrypsin is a unique digestive protease specialized for the degradation of trypsin inhibitors. J Biol Chem 2003; 278:48580-9. [PMID: 14507909 PMCID: PMC1393292 DOI: 10.1074/jbc.m310301200] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mesotrypsin is an enigmatic minor human trypsin isoform, which has been recognized for its peculiar resistance to natural trypsin inhibitors such as soybean trypsin inhibitor (SBTI) or human pancreatic secretory trypsin inhibitor (SPINK1). In search of a biological function, two conflicting theories proposed that due to its inhibitor-resistant activity mesotrypsin could prematurely activate or degrade pancreatic zymogens and thus play a pathogenic or protective role in human pancreatitis. In the present study we ruled out both theories by demonstrating that mesotrypsin was grossly defective not only in inhibitor binding, but also in the activation or degradation of pancreatic zymogens. We found that the restricted ability of mesotrypsin to bind inhibitors or to hydrolyze protein substrates was solely due to a single evolutionary mutation, which changed the serine-protease signature glycine 198 residue to arginine. Remarkably, the same mutation endowed mesotrypsin with a novel and unique function: mesotrypsin rapidly hydrolyzed the reactive-site peptide bond of the Kunitz-type trypsin inhibitor SBTI, and irreversibly degraded the Kazal-type temporary inhibitor SPINK1. The observations suggest that the biological function of human mesotrypsin is digestive degradation of trypsin inhibitors. This mechanism can facilitate the digestion of foods rich in natural trypsin inhibitors. Furthermore, the findings raise the possibility that inappropriate activation of mesotrypsinogen in the pancreas might lower protective SPINK1 levels and contribute to the development of human pancreatitis. In this regard, it is noteworthy that the well known pathological trypsinogen activator cathepsin B exhibited a preference for the activation of mesotrypsinogen of all three human trypsinogen isoforms, suggesting a biochemical mechanism for mesotrypsinogen activation in pancreatic acinar cells.
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Affiliation(s)
- Richárd Szmola
- Department of Molecular and Cell Biology, Boston University, Goldman School of Dental Medicine, Boston, Massachusetts 02118, USA
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37
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Kénesi E, Katona G, Szilágyi L. Structural and evolutionary consequences of unpaired cysteines in trypsinogen. Biochem Biophys Res Commun 2003; 309:749-54. [PMID: 13679035 DOI: 10.1016/j.bbrc.2003.08.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Vertebrate trypsins usually contain six disulfide bonds but human trypsin 1 (PRSS1) contains only five and human trypsin 2 (PRSS2) contains only four. To elucidate possible evolutionary pathways leading to the loss of disulfide bonds, we have constructed mutants lacking one or two cysteines of four disulfide bonds (C22-C157, C127-C232, C136-C201, and C191-C220) in rat anionic trypsinogen and followed their expression in the periplasm of Escherichia coli. When both cysteines of any of the above-mentioned disulfide bonds were replaced by alanines we found, as expected, proteolytically active enzymes. In the case of C127-C232 (missing from both human trypsins) and C191-C220 both single mutants gave active enzymes although their yield was significantly reduced. In contrast, only one of the single mutants of disulfide bonds C22-C157 and C136-C201 (missing from human trypsin 2) was expressed in E. coli. In the case of these disulfide bonds, we obtained no expression when the solvent accessible molecular surface of the free cysteine residue was the smaller one, indicating that a buried unpaired cysteine was more deleterious than one on the surface of the molecule.
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Affiliation(s)
- Erzsébet Kénesi
- Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
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38
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Kukor Z, Tóth M, Sahin-Tóth M. Human anionic trypsinogen: properties of autocatalytic activation and degradation and implications in pancreatic diseases. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:2047-58. [PMID: 12709065 DOI: 10.1046/j.1432-1033.2003.03581.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human pancreatic secretions contain two major trypsinogen isoforms, cationic and anionic trypsinogen, normally at a ratio of 2 : 1. Pancreatitis, pancreatic cancer and chronic alcoholism lead to a characteristic reversal of the isoform ratio, and anionic trypsinogen becomes the predominant zymogen secreted. To understand the biochemical consequences of these alterations, we recombinantly expressed and purified both human trypsinogens and documented characteristics of autoactivation, autocatalytic degradation and Ca2+-dependence. Even though the two trypsinogens are approximately 90% identical in their primary structure, we found that human anionic trypsinogen and trypsin exhibited a significantly increased (10-20-fold) propensity for autocatalytic degradation, relative to cationic trypsinogen and trypsin. Furthermore, in contrast to the characteristic stimulation of the cationic proenzyme, acidic pH inhibited autoactivation of anionic trypsinogen. In mixtures of cationic and anionic trypsinogen, an increase in the proportion of the anionic proenzyme had no significant effect on the levels of trypsin generated by autoactivation or by enterokinase at pH 8.0 in 1 mm Ca2+- conditions that were characteristic of the pancreatic juice. In contrast, rates of trypsinogen activation were markedly reduced with increasing ratios of anionic trypsinogen under conditions that were typical of potential sites of pathological intra-acinar trypsinogen activation. Thus, at low Ca2+ concentrations at pH 8.0, selective degradation of anionic trypsinogen and trypsin caused diminished trypsin production; while at pH 5.0, inhibition of anionic trypsinogen activation resulted in lower trypsin yields. Taken together, the observations indicate that up-regulation of anionic trypsinogen in pancreatic diseases does not affect physiological trypsinogen activation, but significantly limits trypsin generation under potential pathological conditions.
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Affiliation(s)
- Zoltán Kukor
- Department of Molecular and Cell Biology, Goldman School of Dental Medicine, Boston University, USA
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39
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Sahin-Tóth M. The pathobiochemistry of hereditary pancreatitis: studies on recombinant human cationic trypsinogen. Pancreatology 2002; 1:461-5. [PMID: 12120225 DOI: 10.1159/000055848] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND/AIMS This study attempts to identify the biochemical alterations in human cationic trypsinogen and trypsin caused by the hereditary pancreatitis-associated mutations Arg117-->His and Asn21-->Ile. METHODS Recombinant wild-type and mutant human cationic trypsinogens were expressed in Escherichia coli and purified to homogeneity, and trypsin autolysis and trypsinogen autoactivation were characterized. RESULTS Both mutations significantly enhanced the autoactivation of human cationic trypsinogen. In addition, the Arg117-->His mutation inhibited autocatalytic inactivation of trypsin, while the Asn21-->Ile mutation had no such effect. CONCLUSIONS The findings support the notion that enhanced trypsinogen activation in the pancreas is the common initiating step in hereditary pancreatitis, whereas trypsin stabilization plays a role in cases associated with the Arg117-->His mutation.
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Affiliation(s)
- M Sahin-Tóth
- Department of Physiology, University of California Los Angeles, Calif., USA.
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40
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Simon P, Weiss FU, Sahin-Toth M, Parry M, Nayler O, Lenfers B, Schnekenburger J, Mayerle J, Domschke W, Lerch MM. Hereditary pancreatitis caused by a novel PRSS1 mutation (Arg-122 --> Cys) that alters autoactivation and autodegradation of cationic trypsinogen. J Biol Chem 2002; 277:5404-10. [PMID: 11719509 DOI: 10.1074/jbc.m108073200] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hereditary pancreatitis has been found to be associated with germline mutations in the cationic trypsinogen (PRSS1) gene. Here we report a family with hereditary pancreatitis that carries a novel PRSS1 mutation (R122C). This mutation cannot be diagnosed with the conventional screening method using AflIII restriction enzyme digest. We therefore propose a new assay based on restriction enzyme digest with BstUI, a technique that permits detection of the novel R122C mutation in addition to the most common R122H mutation, and even in the presence of a recently reported neutral polymorphism that prevents its detection by the AflIII method. Recombinantly expressed R122C mutant human trypsinogen was found to undergo greatly reduced autoactivation and cathepsin B-induced activation, which is most likely caused by misfolding or disulfide mismatches of the mutant zymogen. The K(m) of R122C trypsin was found to be unchanged, but its k(cat) was reduced to 37% of the wild type. After correction for enterokinase activatable activity, and specifically in the absence of calcium, the R122C mutant was more resistant to autolysis than the wild type and autoactivated more rapidly at pH 8. Molecular modeling of the R122C mutant trypsin predicted an unimpaired active site but an altered stability of the calcium binding loop. This previously unknown trypsinogen mutation is associated with hereditary pancreatitis, requires a novel diagnostic screening method, and, for the first time, raises the question whether a gain or a loss of trypsin function participates in the onset of pancreatitis.
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Affiliation(s)
- Peter Simon
- Medizinische Klinik B, Westfälische Wilhelms-Universität, D-48129 Münster, Germany
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Sahin-Tóth M. Human cationic trypsinogen. Role of Asn-21 in zymogen activation and implications in hereditary pancreatitis. J Biol Chem 2000; 275:22750-5. [PMID: 10801865 DOI: 10.1074/jbc.m002943200] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mutation Asn-21 --> Ile in human cationic trypsinogen (Tg-1) has been associated with hereditary pancreatitis. Recent studies with rat anionic Tg (Tg-2) indicated that the analogous Thr-21 --> Ile mutation stabilizes the zymogen against autoactivation, whereas it has no effect on catalytic properties or autolytic stability of trypsin (Sahin-Tóth, M. (1999) J. Biol. Chem. 274, 29699-29704). In the present paper, human cationic Tg (Asn-21-Tg) and mutants Asn-21 --> Ile (Ile-21-Tg) and Asn-21 --> Thr (Thr-21-Tg) were expressed in Escherichia coli, and zymogen activation, zymogen degradation, and trypsin autolysis were studied. Enterokinase activated Asn-21-Tg approximately 2-fold better than Ile-21-Tg or Thr-21-Tg, and catalytic parameters of trypsins were comparable. At 37 degrees C, in 5 mm Ca(2+), all three trypsins were highly stable. In the absence of Ca(2+), Asn-21- and Ile-21-trypsins suffered autolysis in an indistinguishable manner, whereas Thr-21-trypsin exhibited significantly increased stability. In sharp contrast to observations with the rat proenzyme, at pH 8.0, 37 degrees C, autoactivation kinetics of Asn-21-Tg and Ile-21-Tg were identical; however, at pH 5. 0, Ile-21-Tg autoactivated at an enhanced rate relative to Asn-21-Tg. Remarkably, at both pH values, Thr-21-Tg showed markedly higher autoactivation rates than the two other zymogens. Finally, autocatalytic proteolysis of human zymogens was limited to cleavage at Arg-117, and no digestion at Lys-188 was detected. The observations indicate that zymogen stabilization by Ile-21 as observed in rat Tg-2 is not characteristic of human Tg-1. Instead, an increased propensity to autoactivation under acidic conditions might be relevant to the pathomechanism of the Asn-21 --> Ile mutation in hereditary pancreatitis. In the same context, faster autoactivation and increased trypsin stability caused by the Asn-21 --> Thr mutation in human Tg-1 might provide a rationale for the evolutionary divergence from Thr-21 found in other mammalian trypsinogens.
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Affiliation(s)
- M Sahin-Tóth
- Department of Physiology, University of California, Los Angeles, California 90095-1662, USA.
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Sahin-Tóth M, Gráf L, Tóth M. Trypsinogen stabilization by mutation Arg117-->His: a unifying pathomechanism for hereditary pancreatitis? Biochem Biophys Res Commun 1999; 264:505-8. [PMID: 10529393 DOI: 10.1006/bbrc.1999.1565] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mutations Arg117-->His and Asn21-->Ile of the human cationic trypsinogen have been recently identified in patients affected by hereditary pancreatitis (HP). The Arg117-->His substitution is believed to cause pancreatitis by eliminating an essential autolytic cleavage site in trypsin, thereby rendering the protease resistant to inactivation through autolysis. Here we demonstrate that the Arg117-->His mutation also significantly inhibits autocatalytic trypsinogen breakdown under Ca(2+)-free conditions and stabilizes the zymogen form of rat trypsin. Taken together with recent findings demonstrating that the Asn21-->Ile mutation stabilizes rat trypsinogen against autoactivation and consequent autocatalytic degradation, the observations suggest a unifying molecular pathomechanism for HP in which zymogen stabilization plays a central role.
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Affiliation(s)
- M Sahin-Tóth
- Department of Physiology, University of California Los Angeles, Los Angeles, California, 90095-1662, USA.
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Sahin-Tóth M. Hereditary pancreatitis-associated mutation asn(21) --> ile stabilizes rat trypsinogen in vitro. J Biol Chem 1999; 274:29699-704. [PMID: 10514442 DOI: 10.1074/jbc.274.42.29699] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations Arg(117) --> His and Asn(21) --> Ile in human trypsinogen-I have been recently associated with hereditary pancreatitis (HP). The Arg(117) --> His substitution is believed to cause pancreatitis by stabilizing trypsin against autolytic degradation, while the mechanism of action of Asn(21) --> Ile has been unknown. In an effort to understand the effect(s) of this mutation, Thr(21) in the highly homologous rat trypsinogen-II was replaced with Asn or Ile, and the recombinant zymogens and their active trypsin forms were studied. Kinetic parameters of all three trypsins were comparable, and the active enzymes suffered autolysis at similar rates, indicating that neither catalytic properties nor proteolytic stability of trypsin are influenced by mutations at position 21. When incubated at pH 8.0, 37 degrees C, pure zymogens underwent autoactivation with concomitant trypsinolytic degradation in a Ca(2+)-dependent fashion. Thus, in the presence of 5 mM Ca(2+), autoactivation and digestion of the zymogens after Arg(117) and Lys(188) were observed, while in the presence of 1 mM EDTA autoactivation and cleavage at Lys(188) were reduced, and zymogenolysis at the Arg(117) site was enhanced. Overall rates of zymogen degradation in [Asn(21)]- and [Ile(21)]trypsinogens were higher in Ca(2+) than in EDTA, while [Thr(21)]trypsinogen demonstrated inverse characteristics. Remarkably, both in the presence and absence of Ca(2+), [Ile(21)]trypsinogen exhibited significantly higher stability against autoactivation and proteolysis than zymogens with Asn(21) or Thr(21). The observations suggest that autocatalytic trypsinogen degradation may be an important defense mechanism against excessive trypsin generation in the pancreas, and trypsinogen stabilization by the Asn(21) --> Ile mutation plays a role in the pathogenesis of HP.
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Affiliation(s)
- M Sahin-Tóth
- Department of Physiology, University of California Los Angeles, Los Angeles, California 90095-1662, USA.
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