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Phan HAT, Giannakoulias SG, Barrett TM, Liu C, Petersson EJ. Rational design of thioamide peptides as selective inhibitors of cysteine protease cathepsin L. Chem Sci 2021; 12:10825-10835. [PMID: 35355937 PMCID: PMC8901119 DOI: 10.1039/d1sc00785h] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/30/2021] [Indexed: 12/24/2022] Open
Abstract
Aberrant levels of cathepsin L (Cts L), a ubiquitously expressed endosomal cysteine protease, have been implicated in many diseases such as cancer and diabetes. Significantly, Cts L has been identified as a potential target for the treatment of COVID-19 due to its recently unveiled critical role in SARS-CoV-2 entry into the host cells. However, there are currently no clinically approved specific inhibitors of Cts L, as it is often challenging to obtain specificity against the many highly homologous cathepsin family cysteine proteases. Peptide-based agents are often promising protease inhibitors as they offer high selectivity and potency, but unfortunately are subject to degradation in vivo. Thioamide substitution, a single-atom O-to-S modification in the peptide backbone, has been shown to improve the proteolytic stability of peptides addressing this issue. Utilizing this approach, we demonstrate herein that good peptidyl substrates can be converted into sub-micromolar inhibitors of Cts L by a single thioamide substitution in the peptide backbone. We have designed and scanned several thioamide stabilized peptide scaffolds, in which one peptide, RS 1A, was stabilized against proteolysis by all five cathepsins (Cts L, Cts V, Cts K, Cts S, and Cts B) while inhibiting Cts L with >25-fold specificity against the other cathepsins. We further showed that this stabilized RS 1A peptide could inhibit Cts L in human liver carcinoma lysates (IC50 = 19 μM). Our study demonstrates that one can rationally design a stabilized, specific peptidyl protease inhibitor by strategic placement of a thioamide and reaffirms the place of this single-atom modification in the toolbox of peptide-based rational drug design.
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Affiliation(s)
- Hoang Anh T Phan
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
| | - Sam G Giannakoulias
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
| | - Taylor M Barrett
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
| | - Chunxiao Liu
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
- Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs, Beijing University of Agriculture Beijing 102206 P. R. China
| | - E James Petersson
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
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2
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Barrett TM, Chen XS, Liu C, Giannakoulias S, Phan HAT, Wang J, Keenan EK, Karpowicz RJ, Petersson EJ. Studies of Thioamide Effects on Serine Protease Activity Enable Two-Site Stabilization of Cancer Imaging Peptides. ACS Chem Biol 2020; 15:774-779. [PMID: 32141733 DOI: 10.1021/acschembio.9b01036] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thioamide substitutions in peptides can be used as fluorescence quenchers in protease sensors and as stabilizing modifications of hormone analogs. To guide these applications in the context of serine proteases, we here examine the cleavage of several model substrates, scanning a thioamide between the P3 and P3' positions, and identify perturbing positions for thioamide substitution. While all serine proteases tested were affected by P1 thioamidation, certain proteases were also significantly affected by other thioamide positions. We demonstrate how these findings can be applied by harnessing the combined P3/P1 effect of a single thioamide on kallikrein proteolysis to protect two key positions in a neuropeptide Y-based imaging probe, increasing its serum half-life to >24 h while maintaining potency for binding to Y1 receptor expressing cells. Such stabilized peptide probes could find application in imaging cell populations in animal models or even in clinical applications such as fluorescence-guided surgery.
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Affiliation(s)
- Taylor M. Barrett
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Xing S. Chen
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Chunxiao Liu
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2, Beijing 100193, China
| | - Sam Giannakoulias
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Hoang Anh T. Phan
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jieliang Wang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - E. Keith Keenan
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Richard J. Karpowicz
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - E. James Petersson
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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Abstract
The mercapturic acid pathway is a major route for the biotransformation of xenobiotic and endobiotic electrophilic compounds and their metabolites. Mercapturic acids (N-acetyl-l-cysteine S-conjugates) are formed by the sequential action of the glutathione transferases, γ-glutamyltransferases, dipeptidases, and cysteine S-conjugate N-acetyltransferase to yield glutathione S-conjugates, l-cysteinylglycine S-conjugates, l-cysteine S-conjugates, and mercapturic acids; these metabolites constitute a "mercapturomic" profile. Aminoacylases catalyze the hydrolysis of mercapturic acids to form cysteine S-conjugates. Several renal transport systems facilitate the urinary elimination of mercapturic acids; urinary mercapturic acids may serve as biomarkers for exposure to chemicals. Although mercapturic acid formation and elimination is a detoxication reaction, l-cysteine S-conjugates may undergo bioactivation by cysteine S-conjugate β-lyase. Moreover, some l-cysteine S-conjugates, particularly l-cysteinyl-leukotrienes, exert significant pathophysiological effects. Finally, some enzymes of the mercapturic acid pathway are described as the so-called "moonlighting proteins," catalytic proteins that exert multiple biochemical or biophysical functions apart from catalysis.
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Affiliation(s)
- Patrick E Hanna
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - M W Anders
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA
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Zessin M, Kutil Z, Meleshin M, Nováková Z, Ghazy E, Kalbas D, Marek M, Romier C, Sippl W, Bařinka C, Schutkowski M. One-Atom Substitution Enables Direct and Continuous Monitoring of Histone Deacylase Activity. Biochemistry 2019; 58:4777-4789. [PMID: 31682411 DOI: 10.1021/acs.biochem.9b00786] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We developed a one-step direct assay for the determination of histone deacylase (HDAC) activity by substituting the carbonyl oxygen of the acyl moiety with sulfur, resulting in thioacylated lysine side chains. This modification is recognized by class I HDACs with different efficiencies ranging from not accepted for HDAC1 to kinetic constants similar to that of the parent oxo substrate for HDAC8. Class II HDACs can hydrolyze thioacylated substrates with approximately 5-10-fold reduced kcat values, which resembles the effect of thioamide substitution in metallo-protease substrates. Class IV HDAC11 accepts thiomyristoyl modification less efficiently with an ∼5-fold reduced specificity constant. On the basis of the unique spectroscopic properties of thioamide bonds (strong absorption in spectral range of 260-280 nm and efficient fluorescence quenching), HDAC-mediated cleavage of thioamides could be followed by ultraviolet-visible and fluorescence spectroscopy in a continuous manner. The HDAC activity assay is compatible with microtiter plate-based screening formats up to 1536-well plates with Z' factors of >0.75 and signal-to-noise ratios of >50. Using thioacylated lysine residues in p53-derived peptides, we optimized substrates for HDAC8 with a catalytic efficiency of >250000 M-1 s-1, which are more than 100-fold more effective than most of the known substrates. We determined inhibition constants of several inhibitors for human HDACs using thioacylated peptidic substrates and found good correlation with the values from the literature. On the other hand, we could introduce N-methylated, N-acylated lysine residues as inhibitors for HDACs with an IC50 value of 1 μM for an N-methylated, N-myristoylated peptide derivative and human HDAC11.
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Affiliation(s)
- Matthes Zessin
- Department of Medicinal Chemistry, Institute of Pharmacy , Martin-Luther-University Halle-Wittenberg , 06120 Halle/Saale , Germany
| | - Zsófia Kutil
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV , Prumyslova 595 , 252 50 Vestec , Czech Republic
| | - Marat Meleshin
- Department of Enzymology, Institute of Biochemistry and Biotechnology, Charles-Tanford-Protein Center , Martin-Luther-University Halle-Wittenberg , 06120 Halle/Saale , Germany
| | - Zora Nováková
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV , Prumyslova 595 , 252 50 Vestec , Czech Republic
| | - Ehab Ghazy
- Department of Medicinal Chemistry, Institute of Pharmacy , Martin-Luther-University Halle-Wittenberg , 06120 Halle/Saale , Germany
| | - Diana Kalbas
- Department of Enzymology, Institute of Biochemistry and Biotechnology, Charles-Tanford-Protein Center , Martin-Luther-University Halle-Wittenberg , 06120 Halle/Saale , Germany
| | - Martin Marek
- Departement de Biologie Structurale Integrative, Institut de Genetique et Biologie Moleculaire et Cellulaire (IGBMC) , Universite de Strasbourg (UDS), CNRS, INSERM , 1 rue Laurent Fries, B.P. 10142 , 67404 Illkirch Cedex IGBMC, France
| | - Christophe Romier
- Departement de Biologie Structurale Integrative, Institut de Genetique et Biologie Moleculaire et Cellulaire (IGBMC) , Universite de Strasbourg (UDS), CNRS, INSERM , 1 rue Laurent Fries, B.P. 10142 , 67404 Illkirch Cedex IGBMC, France
| | - Wolfgang Sippl
- Department of Medicinal Chemistry, Institute of Pharmacy , Martin-Luther-University Halle-Wittenberg , 06120 Halle/Saale , Germany
| | - Cyril Bařinka
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV , Prumyslova 595 , 252 50 Vestec , Czech Republic
| | - Mike Schutkowski
- Department of Enzymology, Institute of Biochemistry and Biotechnology, Charles-Tanford-Protein Center , Martin-Luther-University Halle-Wittenberg , 06120 Halle/Saale , Germany
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5
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Liu C, Barrett TM, Chen X, Ferrie JJ, Petersson EJ. Fluorescent Probes for Studying Thioamide Positional Effects on Proteolysis Reveal Insight into Resistance to Cysteine Proteases. Chembiochem 2019; 20:2059-2062. [PMID: 30950552 PMCID: PMC7021225 DOI: 10.1002/cbic.201900115] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Indexed: 12/12/2022]
Abstract
Thioamide substitutions of the peptide backbone have been shown to reduce proteolytic degradation, and this property can be used to generate competitive protease inhibitors and to stabilize peptides toward degradation in vivo. Here, we present a straightforward sensor design that allows a systematic study of the positional effects of thioamide substitution by using real-time fluorescence. Thioamide scanning in peptide substrates of five papain family cysteine proteases demonstrates that a thioamide at or near the scissile bond can slow proteolysis in all cases, but that the magnitude of the effects varies with position and protease in spite of high sequence homology. Mechanistic investigation of papain proteolysis reveals that the thioamide effects derive from reductions in both affinity (KM ) and turnover number (kcat ). Computational modeling allows these effects to be understood based on disruption of key enzyme-substrate hydrogen bonds, providing a model for future rational use of thioamides to confer cysteine protease resistance.
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Affiliation(s)
- Chunxiao Liu
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA, 19104, USA
- Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2, Beijing, 100193, P. R. China
| | - Taylor M Barrett
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA, 19104, USA
| | - Xing Chen
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA, 19104, USA
| | - John J Ferrie
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA, 19104, USA
| | - E James Petersson
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA, 19104, USA
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6
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Chen X, Mietlicki-Baase EG, Barrett TM, McGrath LE, Koch-Laskowski K, Ferrie JJ, Hayes MR, Petersson EJ. Thioamide Substitution Selectively Modulates Proteolysis and Receptor Activity of Therapeutic Peptide Hormones. J Am Chem Soc 2017; 139:16688-16695. [PMID: 29130686 PMCID: PMC7744120 DOI: 10.1021/jacs.7b08417] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Peptide hormones are attractive as injectable therapeutics and imaging agents, but they often require extensive modification by mutagenesis and/or chemical synthesis to prevent rapid in vivo degradation. Alternatively, the single-atom, O-to-S modification of peptide backbone thioamidation has the potential to selectively perturb interactions with proteases while preserving interactions with other proteins, such as target receptors. Here, we use the validated diabetes therapeutic, glucagon-like peptide-1 (GLP-1), and the target of clinical investigation, gastric inhibitory polypeptide (GIP), as proof-of-principle peptides to demonstrate the value of thioamide substitution. In GLP-1 and GIP, a single thioamide near the scissile bond renders these peptides up to 750-fold more stable than the corresponding oxopeptides toward cleavage by dipeptidyl peptidase 4, the principal regulator of their in vivo stability. These stabilized analogues are nearly equipotent with their parent peptide in cyclic AMP activation assays, but the GLP-1 thiopeptides have much lower β-arrestin potency, making them novel agonists with altered signaling bias. Initial tests show that a thioamide GLP-1 analogue is biologically active in rats, with an in vivo potency for glycemic control surpassing that of native GLP-1. Taken together, these experiments demonstrate the potential for thioamides to modulate specific protein interactions to increase proteolytic stability or tune activation of different signaling pathways.
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Affiliation(s)
- Xing Chen
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104
| | - Elizabeth G. Mietlicki-Baase
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, 125 South 31st Street, Philadelphia, PA 19104
- Current Address: Department of Exercise and Nutrition Sciences, State University of New York at Buffalo, Buffalo, G10G Farber Hall, NY 14214
| | - Taylor M. Barrett
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104
| | - Lauren E. McGrath
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, 125 South 31st Street, Philadelphia, PA 19104
| | - Kieran Koch-Laskowski
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, 125 South 31st Street, Philadelphia, PA 19104
| | - John J. Ferrie
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104
| | - Matthew R. Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, 125 South 31st Street, Philadelphia, PA 19104
| | - E. James Petersson
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104
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7
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Goldberg JM, Chen X, Meinhardt N, Greenbaum DC, Petersson EJ. Thioamide-based fluorescent protease sensors. J Am Chem Soc 2014; 136:2086-93. [PMID: 24472041 PMCID: PMC3985465 DOI: 10.1021/ja412297x] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Thioamide
quenchers can be paired with compact fluorophores to
design “turn-on” fluorescent protease substrates. We
have used this method to study a variety of serine-, cysteine-, carboxyl-,
and metallo-proteases, including trypsin, chymotrypsin, pepsin, thermolysin,
papain, and calpain. Since thioamides quench some fluorophores red-shifted
from those naturally occurring in proteins, this technique can be
used for real time monitoring of protease activity in crude preparations
of virtually any protease. We demonstrate the value of this method
in three model applications: (1) characterization of papain enzyme
kinetics using rapid-mixing experiments, (2) selective monitoring
of cleavage at a single site in a peptide with multiple proteolytic
sites, and (3) analysis of the specificity of an inhibitor of calpain
in cell lysates.
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Affiliation(s)
- Jacob M Goldberg
- Department of Chemistry, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
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8
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Vishwanatha TM, Narendra N, Chattopadhyay B, Mukherjee M, Sureshbabu VV. Synthesis of Selenoxo Peptides and Oligoselenoxo Peptides Employing LiAlHSeH. J Org Chem 2012; 77:2689-702. [DOI: 10.1021/jo2024703] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- T. M. Vishwanatha
- Peptide Research Laboratory,
Department of Studies in Chemistry, Central College Campus, Bangalore University, Dr. B. R. Ambedkar Veedhi, Bangalore
560001, India
| | - N. Narendra
- Peptide Research Laboratory,
Department of Studies in Chemistry, Central College Campus, Bangalore University, Dr. B. R. Ambedkar Veedhi, Bangalore
560001, India
| | - Basab Chattopadhyay
- Department
of Solid State Physics, Indian Association for the Cultivation of Science,
Jadavpur, Kolkata 700032, India
| | - Monika Mukherjee
- Department
of Solid State Physics, Indian Association for the Cultivation of Science,
Jadavpur, Kolkata 700032, India
| | - Vommina V. Sureshbabu
- Peptide Research Laboratory,
Department of Studies in Chemistry, Central College Campus, Bangalore University, Dr. B. R. Ambedkar Veedhi, Bangalore
560001, India
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9
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Velkov Z, Balabanova E, Tadjer A. Radical scavenging activity prediction of o-coumaric acid thioamide. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.theochem.2007.06.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Kim H, Lipscomb WN. Structure and mechanism of bovine lens leucine aminopeptidase. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 68:153-213. [PMID: 8154324 DOI: 10.1002/9780470123140.ch4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- H Kim
- Gibbs Chemical Laboratory, Harvard University, Cambridge, MA
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Affiliation(s)
- Thomas Hoeg-jensen
- a Chemistry Department , Royal Veterinary and Agricultural University , Thorvaldsensvej 40, DK-1871, Frederiksberg, C, Denmark
- b Thomas Hoeg-Jensen, Ph.D., Insulin Research , Novo Nordisk 6B 2.54, DK-2880, Bagsvaerd, Denmark
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12
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Dodge AG, Richman JE, Johnson G, Wackett LP. Metabolism of thioamides by Ralstonia pickettii TA. Appl Environ Microbiol 2006; 72:7468-76. [PMID: 16997975 PMCID: PMC1694237 DOI: 10.1128/aem.01421-06] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Information on bacterial thioamide metabolism has focused on transformation of the antituberculosis drug ethionamide and related compounds by Mycobacterium tuberculosis. To study this metabolism more generally, a bacterium that grew using thioacetamide as the sole nitrogen source was isolated via enrichment culture. The bacterium was identified as Ralstonia pickettii and designated strain TA. Cells grown on thioacetamide also transformed other thioamide compounds. Transformation of the thioamides tested was dependent on oxygen. During thioamide degradation, sulfur was detected in the medium at the oxidation level of sulfite, further suggesting an oxygenase mechanism. R. pickettii TA did not grow on thiobenzamide as a nitrogen source, but resting cells converted thiobenzamide to benzamide, with thiobenzamide S-oxide and benzonitrile detected as intermediates. Thioacetamide S-oxide was detected as an intermediate during thioacetamide degradation, but the only accumulating metabolite of thioacetamide was identified as 3,5-dimethyl-1,2,4-thiadiazole, a compound shown to derive from spontaneous reaction of thioacetamide and oxygenated thioacetamide species. This dead-end metabolite accounted for only ca. 12% of the metabolized thioacetamide. Neither acetonitrile nor acetamide was detected during thioacetamide degradation, but R. pickettii grew on both compounds as nitrogen and carbon sources. It is proposed that R. pickettii TA degrades thioamides via a mechanism involving consecutive oxygenations of the thioamide sulfur atom.
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Affiliation(s)
- Anthony G. Dodge
- Department of Microbiology, Immunology, and Cancer Biology, Department of Biochemistry, Molecular Biology, and Biophysics, BioTechnology Institute, Center for Microbial and Plant Genomics, University of Minnesota, St. Paul, Minnesota 55108
| | - Jack E. Richman
- Department of Microbiology, Immunology, and Cancer Biology, Department of Biochemistry, Molecular Biology, and Biophysics, BioTechnology Institute, Center for Microbial and Plant Genomics, University of Minnesota, St. Paul, Minnesota 55108
| | - Gilbert Johnson
- Department of Microbiology, Immunology, and Cancer Biology, Department of Biochemistry, Molecular Biology, and Biophysics, BioTechnology Institute, Center for Microbial and Plant Genomics, University of Minnesota, St. Paul, Minnesota 55108
| | - Lawrence P. Wackett
- Department of Microbiology, Immunology, and Cancer Biology, Department of Biochemistry, Molecular Biology, and Biophysics, BioTechnology Institute, Center for Microbial and Plant Genomics, University of Minnesota, St. Paul, Minnesota 55108
- Corresponding author. Mailing address: Department of Biochemistry, Molecular Biology, and Biophysics, 140 Gortner Laboratory of Biochemistry, 1479 Gortner Ave., University of Minnesota, St. Paul, MN 55108. Phone: (612) 625-3785. Fax: (612) 625-5780. E-mail:
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Cappiello M, Alterio V, Amodeo P, Del Corso A, Scaloni A, Pedone C, Moschini R, De Donatis GM, De Simone G, Mura U. Metal Ion Substitution in the Catalytic Site Greatly Affects the Binding of Sulfhydryl-Containing Compounds to Leucyl Aminopeptidase,. Biochemistry 2006; 45:3226-34. [PMID: 16519517 DOI: 10.1021/bi052069v] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bovine lens leucyl aminopeptidase (blLAP), a homohexameric metallopeptidase preferring bulky and hydrophobic amino acids at the N-terminus of (di)peptides, contains two Zn(2+) ions per subunit that are essential for catalytic activity. They may be replaced by other divalent cations with different exchange kinetics. The protein readily exchangeable site (site 1) can be occupied by Zn(2+), Mn(2+), Mg(2+), or Co(2+), while the tight binding site (site 2) can be occupied by Zn(2+) or Co(2+). We recently reported that introduction of Mn(2+) into site 1 generates a novel activity of blLAP toward CysGly [Cappiello, M., et al. (2004) Biochem. J. 378, 35-44], which in contrast is not hydrolyzed by the (Zn/Zn) enzyme. This finding, while disclosing a potential specific role for blLAP in glutathione metabolism, raised a question about the features required for molecules to be a substrate for the enzyme. To clarify the interaction of the enzyme with sulfhydryl-containing derivatives, (Zn/Zn)- and (Mn/Zn)blLAP forms were prepared and functional-structural studies were undertaken. Thus, a kinetic analysis of various compounds with both enzyme forms was performed; the crystal structure of (Zn/Zn)blLAP in complex with the peptidomimetic derivative Zofenoprilat was determined, and a modeling study on the CysGly-(Zn/Zn)blLAP complex was carried out. This combined approach provided insight into the interaction of blLAP with sulfhydryl-containing derivatives, showing that the metal exchange in site 1 modulates binding to these molecules that may result in enzyme substrates or inhibitors, depending on the nature of the metal.
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Affiliation(s)
- Mario Cappiello
- Department of Physiology and Biochemistry, University of Pisa, I-56126 Pisa, Italy
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14
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Holz RC. The aminopeptidase from Aeromonas proteolytica: structure and mechanism of co-catalytic metal centers involved in peptide hydrolysis. Coord Chem Rev 2002. [DOI: 10.1016/s0010-8545(01)00470-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Bienvenue DL, Gilner D, Holz RC. Hydrolysis of thionopeptides by the aminopeptidase from Aeromonas proteolytica: insight into substrate binding. Biochemistry 2002; 41:3712-9. [PMID: 11888288 DOI: 10.1021/bi011752o] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of L-leucine aniline analogues were synthesized that contained either a carbonyl or thiocarbonyl as a part of the amide bond. Additionally, the para-position on the phenyl ring of several substrates was altered with various electron-withdrawing or donating groups. The kinetic constants K(m) and k(cat) were determined for the hydrolysis of each of these compounds in the presence of the aminopeptidase from Aeromonas proteolytica (AAP) containing either Zn(II) or Cd(II). The dizinc(II) form of AAP ([ZnZn(AAP)]) was able to cleave both carbonyl and thiocarbonyl containing peptide substrates with similar efficiency. However, the dicadmium(II) form of AAP ([CdCd(AAP)]) was unable to cleave any of the carbonyl-containing compounds tested but was able to cleave the thionopeptide substrates. This is consistent with the borderline hard/soft nature of Zn(II) vs Cd(II). The trends observed in the K(m) values suggest that the oxygen atom of the amide bond directly interacts with the dinuclear active site of AAP. Heterodimetallic forms of AAP that contained one atom of Zn(II) and one of Cd(II) (i.e., [CdZn(AAP)] and [ZnCd(AAP)]) were also prepared. The K(m) values for the thionopeptides substrates are the smallest when Cd(II) is in the first metal binding site, suggesting that substrate binds to the first metal binding site. 1-Phenyl-2-thiourea (PTU) and urea (PU) were also examined to determine the differences between thionopeptide and peptide binding to AAP. PTU and PU were found to be competitive inhibitors of AAP with inhibition constants of 0.24 and 4.6 mM, respectively. The electronic absorption and EPR spectra of [CoCo(AAP)], [CoZn(AAP)], and [ZnCo(AAP)] were recorded in the absence and presence of both PU and PTU. Spectral changes were observed for PTU binding to [CoCo(AAP)] and [CoZn(AAP)] but not for [ZnCo(AAP)], while no spectral changes were observed for any of the Co(II)-substituted forms of AAP upon the addition of PU. These data indicate that carbonyl binding occurs only at the first metal binding site. In light of the data presented herein, the substrate binding step in the proposed mechanism of AAP catalyzed peptide hydrolysis can be further refined.
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Affiliation(s)
- David L Bienvenue
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300, USA
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Stöckel-Maschek A, Mrestani-Klaus C, Stiebitz B, Demuth H, Neubert K. Thioxo amino acid pyrrolidides and thiazolidides: new inhibitors of proline specific peptidases. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1479:15-31. [PMID: 11004527 DOI: 10.1016/s0167-4838(00)00054-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Aminopeptidase P (APP), dipeptidyl peptidase II (DP II), dipeptidyl peptidase IV (DP IV) and prolyl oligopeptidase (POP) are proline specific peptidases. Hence, they are able to cleave peptide bonds containing the imino acid proline. Amino acid pyrrolidides (Pyrr) and thiazolidides (Thia) are well-known product analogue inhibitors of DP IV and POP. For the first time we describe the influence of a thioxo amide bond, incorporated into these compounds, on the inhibition of the proline specific peptidases. Taking into account the substrate specificity of these peptidases, we have synthesized Xaa-psi[CS-N]-Pyrr and Xaa-psi[CS-N]-Thia of the amino acids Ala, Phe, Val and Ile. The inhibition constants were determined for the above mentioned proline specific peptidases isolated from different sources. As a result, the serine proteases DP II, DP IV and POP were inhibited competitively, whereas metal-dependent APP displayed a linear mixed-type inhibition with inhibition constants up to 10(-4) M. Thioxylation of Xaa-Pyrr and Xaa-Thia led to a slight decrease of inhibition of DP IV and POP compared to Xaa-Pyrr and Xaa-Thia, though the inhibition constants were still in the range up to 10(-7) M. As Xaa-Thia exist as two isomers, we investigated isomer specific inhibition with regard to DP IV. Thus, our studies have revealed that DP IV was only inhibited by the Z isomer of the Xaa-psi[CS-N]-Thia. For the first time, Xaa-Pyrr and Xaa-Thia were characterized as inhibitors of DP II with inhibition constants in the micromolar range. In contrast to DP IV inhibition, the Xaa-psi[CS-N]-Pyrr and Xaa-psi[CS-N]-Thia have proven to be more potent inhibitors of DP II than the corresponding Xaa-Pyrr and Xaa-Thia. Thus, these Xaa-psi[CS-N]-Thia are new potent inhibitors especially suitable for DP II with K(i) values ranging in the upper nanomolar concentration.
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Affiliation(s)
- A Stöckel-Maschek
- Fachbereich Biochemie/Biotechnologie, Institut für Biochemie, Martin-Luther-Universität Halle-Wittenberg, Germany.
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17
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Bienvenue DL, Bennett B, Holz RC. Inhibition of the aminopeptidase from Aeromonas proteolytica by L-leucinethiol: kinetic and spectroscopic characterization of a slow, tight-binding inhibitor-enzyme complex. J Inorg Biochem 2000; 78:43-54. [PMID: 10714704 DOI: 10.1016/s0162-0134(99)00203-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The peptide inhibitor L-leucinethiol (LeuSH) was found to be a potent, slow-binding inhibitor of the aminopeptidase from Aeromonas proteolytica (AAP). The overall potency (K(I)*) of LeuSH was 7 nM while the corresponding alcohol L-leucinol (LeuOH) was a simple competitive inhibitor of much lower potency (K(I) = 17 microM). These data suggest that the free thiol is likely involved in the formation of the E x I and E x I* complexes, presumably providing a metal ligand. In order to probe the nature of the interaction of LeuSH and LeuOH with the dinuclear active site of AAP, we have recorded both the electronic absorption and EPR spectra of [CoCo(AAP)], [CoZn(AAP)], and [ZnCo(AAP)] in the presence of both inhibitors. In the presence of LeuSH, all three Co(II)-substituted AAP enzymes exhibited an absorption band centered at 295 nm, characteristic of a S --> Co(II) ligand-metal charge-transfer band. In addition, absorption spectra recorded in the 450 to 700 nm region all showed changes characteristic of LeuSH and LeuOH interacting with both metal ions. EPR spectra recorded at high temperature (19 K) and low power (2.5 mW) indicated that, in a given enzyme molecule, LeuSH interacts weakly with one of the metal ions in the dinuclear site and that the crystallographically identified mu-OH(H) bridge, which has been shown to mediate electronic interaction of the Co(II) ions, is likely broken upon binding LeuSH. EPR spectra of [CoCo(AAP)]-LeuSH, [ZnCo(AAP)]-LeuSH, and [Co_(AAP)]-LeuSH were also recorded at lower temperature (3.5-4.0 K) and high microwave power (50-553 mW). These signals were unusual and appeared to contain, in addition to the incompletely saturated contributions from the signals characterized at 19 K, a very sharp feature at g(eff) approximately 6.5 that is characteristic of thiolate-Co(II) interactions. Combination of the electronic absorption and EPR data indicates that LeuSH perturbs the electronic structure of both metal ions in the dinuclear active site of AAP. Since the spin-spin interaction seen in resting [CoCo(AAP)] is abolished upon the addition of LeuSH, it is unlikely that a mu-S(R) bridge is established.
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Affiliation(s)
- D L Bienvenue
- Department of Chemistry and Biochemistry, Utah State University, Logan 84322-0300, USA
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18
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Huntington KM, Bienvenue DL, Wei Y, Bennett B, Holz RC, Pei D. Slow-binding inhibition of the aminopeptidase from Aeromonas proteolytica by peptide thiols: synthesis and spectroscopic characterization. Biochemistry 1999; 38:15587-96. [PMID: 10569943 DOI: 10.1021/bi991283e] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptide-derived thiols of the general structure N-mercaptoacyl-leucyl-p-nitroanilide (1a-c) were synthesized and found to be potent, slow-binding inhibitors of the aminopeptidase from Aeromonas proteolytica (AAP). The overall potencies (K(I)) of these inhibitors against AAP range from 2.5 to 57 nM exceeding that of the natural product bestatin and approaching that of amastatin. The corresponding alcohols (2a-b) are simple competitive inhibitors of much lower potencies (K(I) = 23 and 360 microM). These data suggest that the free thiols are involved in the formation of the E. I and E.I complexes, presumably serving as a metal ligand. To investigate the nature of the interaction of the thiol-based inhibitors with the dinuclear active site of AAP, we have recorded electronic absorption and EPR spectra of Co(II)Co(II)-, Co(II)Zn(II)-, and Zn(II)Co(II)-AAP in the presence of the strongest binding inhibitor, 1c. Both [CoZn(AAP)] and [ZnCo(AAP)], in the presence of 1c, exhibited an absorption band centered at 320 nm characteristic of an S --> Co(II) ligand-metal charge-transfer band. In addition, absorption spectra recorded between 400 and 700 nm showed changes characteristic of 1c interacting with each active-site metal ion. EPR spectra recorded at high temperature (19 K) and low power (2.5 mW) indicated that in a given enzyme molecule, 1c interacts weakly with one of the metal ions in the dinuclear site and that the crystallographically identified micro-OH(H) bridge, which has been shown to mediate electronic interaction of the Co(II) ions, is likely broken upon 1c binding. EPR spectra of [CoCo(AAP)]-1c, [ZnCo(AAP)]-1c, and [CoZn(AAP)]-1c were also recorded at lower temperature (3.5-4.0 K) and high microwave power (50-553 mW). The observed signals were unusual and appeared to contain, in addition to the incompletely saturated contributions from the signals characterized at 19 K, a very sharp feature at g(eff) approximately 6.8 that is characteristic of thiolate-Co(II) interactions. These data suggest that the thiolate moiety can bind to either of the metal ions in the dinuclear active site of AAP but does not bridge the dinuclear cluster. Compounds 1a-c are readily accessible by synthesis and thus provide a novel class of potent aminopeptidase inhibitors.
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Affiliation(s)
- K M Huntington
- Department of Chemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus 43210, USA
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19
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Zacharie B, Lagraoui M, Dimarco M, Penney CL, Gagnon L. Thioamides: synthesis, stability, and immunological activities of thioanalogues of Imreg. Preparation of new thioacylating agents using fluorobenzimidazolone derivatives. J Med Chem 1999; 42:2046-52. [PMID: 10354413 DOI: 10.1021/jm9900467] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Imreg (Tyr1-Gly2-Gly3) is a well-known immunostimulant. However, it possesses a short half-life. Stabilized analogues of Imreg were prepared by a regioselective insertion in which peptide bonds at position 1,2 or 2,3 were replaced by thioamide linkages. This was achieved by using new thioacylating agents based on thioacyl-fluoro-N-benzimidazolone. The synthesis and properties of these reagents are described herein. This peptide modification enhanced significantly the half-life of the thioanalogues relative to Imreg in blood. The thioanalogues and Imreg were tested in vitro in T and B cell proliferation assays and for their ability to stimulate cytotoxic T-lymphocytes (CTLs). Only thiotyrosyl glycyl glycine 11 displayed some activity as evidenced by a weak stimulation of CTLs. On the basis of this activity and the increased stability, an in vivo immunological evaluation was undertaken. Immunophenotyping of 11 revealed a significant increase in activated CTL and NK cell populations in the spleen. This expansion was also accompanied by a significant stimulation of NK cells and the B cell proliferative response. Thioanalogues of Imreg were generally nontoxic, as exemplified by 11. The latter is a promising immunostimulant which may be targeted for cancer and viral infections, where CTLs and NK cells play an important role, or as a vaccine adjuvant where stimulation of antibody-producing B cells is important.
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Affiliation(s)
- B Zacharie
- BioChem Pharma Inc., 275 Armand-Frappier Blvd., Laval, Quebec, Canada, H7V 4A7
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20
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Artis DR, Lipton MA. Conformations of Thioamide-Containing Dipeptides: A Computational Study. J Am Chem Soc 1998. [DOI: 10.1021/ja982398t] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dean R. Artis
- Contribution from the Department of Bioorganic Chemistry, Genentech, Inc., South San Francisco, California 94080, and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Mark A. Lipton
- Contribution from the Department of Bioorganic Chemistry, Genentech, Inc., South San Francisco, California 94080, and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
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21
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Schutkowski M, Jakob M, Landgraf G, Born I, Neubert K, Fischer G. Probing substrate backbone function in prolyl oligopeptidase catalysis--large positional effects of peptide bond monothioxylation. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 245:381-5. [PMID: 9151967 DOI: 10.1111/j.1432-1033.1997.00381.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Site-specific effects on the catalytic activity of prolyl oligopeptidase from human placenta were studied using oligopeptide substrates in which a peptide bond has been replaced by a thioxo peptide bond. Two series of tetrapeptide-4-nitroanilides, Ala-Gly-Pro-Phe-NH-Np and Ala-Ala-Pro-Phe-NH-Np, along with all possible monothioxylated derivatives, were synthesised and k(cat) and Km values were determined for proteolytic cleavage at the Pro-Phe bond. Regardless of either Gly or Ala in the P2 subsite, tetrapeptides were rendered uncleavable by thioxylation at the Pro-Phe linkage. As a result, Ala-Xaa-Pro-psi[CS-NH]-Phe-NH-Np (Xaa = Gly or Ala) displayed competitive inhibition with Ki-values of 12 microM and 44 microM, respectively. Furthermore, in controlling proteolytic susceptibility of the substrates, cooperation of the P3-P2 thioxylation site and the side chain at the P2 subsite was obtained. Thioxylation at this position enhanced k(cat)/Km fivefold in the Gly series, but led to a 1.7-fold decrease in the Ala series of substrates. With respect to the Xaa-Pro peptide bond, all of the substrates underwent cis/trans isomerisation, thus presenting two stable conformers to the protease. However, the magnitudes of the isomerisation constants suggested that neither isomerisation rates nor cis/trans equilibria can explain the effect of thioxylation on the steady-state constants of proteolysis.
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Affiliation(s)
- M Schutkowski
- Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V., Forschungstelle Enzymologie der Proteinfaltung, Halle, Germany
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22
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Sträter N, Lipscomb WN, Klabunde T, Krebs B. Enzymatische Acyl- und Phosphoryltransferreaktionen unter Beteiligung von zwei Metallionen. Angew Chem Int Ed Engl 1996. [DOI: 10.1002/ange.19961081804] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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23
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Hitotsuyanagi Y, Matsumoto Y, Sasaki SI, Suzuki J, Takeya K, Yamaguchi K, Itokawa H. Studies on Rubia akane(RA) derivatives. Part 10. Backbone transformation of RA-VII, an antitumour cyclic hexapeptide, through thionation. X-Ray crystal structure of [Tyr-3-Ψ(CH2NH)-Ala-4]RA-VII. ACTA ACUST UNITED AC 1996. [DOI: 10.1039/p19960001749] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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24
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Foje KL, Hanzlik RP. Peptidyl thioamides as substrates and inhibitors of papain, and as probes of the kinetic significance of the oxyanion hole. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1201:447-53. [PMID: 7803476 DOI: 10.1016/0304-4165(94)90075-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The interaction of papain with a series of amide and thioamide substrates was studied to assess the contribution of the oxyanion hole to catalysis. Amides 1a-4a (AcPheGly-NHR, where R = H, CH3, PhCH2 or p-O2NC6H4, respectively) were all hydrolyzed to AcPheGly-OH with kcat/Km values from 23-430 M-1s-1 (25 degrees C, 20% v/v MeCN in 50 mM phosphate buffer, pH 6.3). Structurally analogous thioamides 1b-3b (AcPheGlyTNHR) were not detectably hydrolyzed by papain, but 4b (AcPheGlyTNHC6H4NO2) was hydrolyzed to the thiolacid AcPheGly-SH (kcat/Km = 2125 M-1s-1). The latter was hydrolyzed further to AcPheGly-OH in a slower reaction. Thioamides 1b-3b bound to papain and inhibited the papain-catalyzed hydrolysis of Z-Gly-ONp, but the inhibition was generally less than 50% at concentrations up to 500 microM, suggesting that the binding was purely non-covalent. The inability of papain to hydrolyze 1b-3b while 1a-3a are excellent substrates suggests that the oxyanion hole plays an important role in amide hydrolysis by papain. The facile hydrolysis of thioamide 4b was attributed to decreased amide bond resonance (i.e. a more reactive ground state) caused by the strong electron-withdrawing effect of the p-nitrophenyl substituent.
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Affiliation(s)
- K L Foje
- Department of Medicinal Chemistry, University of Kansas, Lawrence 66045-2506
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25
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Schutkowski M, Neubert K, Fischer G. Influence on proline-specific enzymes of a substrate containing the thioxoaminoacyl-prolyl peptide bond. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 221:455-61. [PMID: 7909521 DOI: 10.1111/j.1432-1033.1994.tb18758.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Dipeptidyl peptidase IV from porcine kidney and aminopeptidase P from Escherichia coli can utilize thioxoalanyl-proline 4-nitroanilide but with decreased kinetic constants compared to the normal substrates. Product analysis showed that exclusively thioxoalanyl-proline was liberated in the case of dipeptidyl peptidase IV catalysis and thioxo-alanine in the case of aminopeptidase-P-mediated thioxo peptide bond hydrolysis. For the proline-specific aminopeptidase P the kcat/Km value for the thioxo peptide is 1100-fold lower than for the corresponding oxo peptide. This difference is entirely due to kcat. Because the rotation about the thioxo amide bond is about 12.5 kJ mol-1 more difficult than rotation about an amide bond, these data support a mechanism involving rate-limiting rotation about the scissile peptide bond. It was found that the specificity rate constant for the reaction of thioxoalanyl-proline 4-nitroanilide and dipeptidyl peptidase IV is 100-1000-fold lower compared to the corresponding rate constant for alanyl-proline 4-nitroanilide. This remarkable effect is interpreted in terms of a distorted binding of the transition state for the thioxo substrate. The hydrolysis of the thioxo substrate by dipeptidyl peptidase IV is isomer-specific. The conformation about the nonscissile P2-P1 thioxo amide bond has to be in trans for successful cleavage of the scissile peptide bond. We can now directly compare the rotational energy barrier of the prolyl peptide bond for the oxo and the thioxo form.
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Affiliation(s)
- M Schutkowski
- Martin-Luther-Universität Halle-Wittenberg, Institut für Biochemie, Fachbereich Biochemie/Biotechnologie, Germany
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26
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Unverzagt C, Geyer A, Kessler H. Racemisierungsfreie Kettenverlängerung von Thiodipeptiden mit Proteasen. Angew Chem Int Ed Engl 1992. [DOI: 10.1002/ange.19921040919] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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27
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Unverzagt C, Geyer A, Kessler H. Chain Elongation of Thiodipeptides with Proteases. ACTA ACUST UNITED AC 1992. [DOI: 10.1002/anie.199212291] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Murphy BP, Pratt RF. A thiono-beta-lactam substrate for the beta-lactamase II of Bacillus cereus. Evidence for direct interaction between the essential metal ion and substrate. Biochem J 1989; 258:765-8. [PMID: 2499308 PMCID: PMC1138430 DOI: 10.1042/bj2580765] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
An 8-thionocephalosporin was shown to be a substrate of the beta-lactamase II of Bacillus cereus, a zinc metalloenzyme. Although it is a poorer substrate, as judged by the Kcat./Km parameter, than the corresponding 8-oxocephalosporin, the discrimination against sulphur decreased when the bivalent metal ion in the enzyme active site was varied in the order Mn2+ (the manganese enzyme catalysed the hydrolysis of the oxo compound but not that of the thiono compound), Zn2+, Co2+ and Cd2+. This result is taken as evidence for kinetically significant direct contact between the active-site metal ion of beta-lactamase II and the beta-lactam carbonyl heteroatom. No evidence was obtained, however, for accumulation of an intermediate with such co-ordination present.
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Affiliation(s)
- B P Murphy
- Department of Chemistry, Wesleyan University, Middletown, CT 06457
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