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Sahani RL, Diana-Rivero R, Vernekar SKV, Wang L, Du H, Zhang H, Castaner AE, Casey MC, Kirby KA, Tedbury PR, Xie J, Sarafianos SG, Wang Z. Design, Synthesis and Characterization of HIV-1 CA-Targeting Small Molecules: Conformational Restriction of PF74. Viruses 2021; 13:v13030479. [PMID: 33804121 PMCID: PMC8000227 DOI: 10.3390/v13030479] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 12/30/2022] Open
Abstract
Small molecules targeting the PF74 binding site of the HIV-1 capsid protein (CA) confer potent and mechanistically unique antiviral activities. Structural modifications of PF74 could further the understanding of ligand binding modes, diversify ligand chemical classes, and allow identification of new variants with balanced antiviral activity and metabolic stability. In the current work, we designed and synthesized three series of PF74-like analogs featuring conformational constraints at the aniline terminus or the phenylalanine carboxamide moiety, and characterized them using a biophysical thermal shift assay (TSA), cell-based antiviral and cytotoxicity assays, and in vitro metabolic stability assays in human and mouse liver microsomes. These studies showed that the two series with the phenylalanine carboxamide moiety replaced by a pyridine or imidazole ring can provide viable hits. Subsequent SAR identified an improved analog 15 which effectively inhibited HIV-1 (EC50 = 0.31 μM), strongly stabilized CA hexamer (ΔTm = 8.7 °C), and exhibited substantially enhanced metabolic stability (t1/2 = 27 min for 15 vs. 0.7 min for PF74). Metabolic profiles from the microsomal stability assay also indicate that blocking the C5 position of the indole ring could lead to increased resistance to oxidative metabolism.
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Affiliation(s)
- Rajkumar Lalji Sahani
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA; (R.L.S.); (R.D.-R.); (S.K.V.V.); (L.W.); (J.X.)
| | - Raquel Diana-Rivero
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA; (R.L.S.); (R.D.-R.); (S.K.V.V.); (L.W.); (J.X.)
| | - Sanjeev Kumar V. Vernekar
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA; (R.L.S.); (R.D.-R.); (S.K.V.V.); (L.W.); (J.X.)
| | - Lei Wang
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA; (R.L.S.); (R.D.-R.); (S.K.V.V.); (L.W.); (J.X.)
| | - Haijuan Du
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA; (H.D.); (H.Z.); (A.E.C.); (K.A.K.); (P.R.T.); (S.G.S.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Huanchun Zhang
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA; (H.D.); (H.Z.); (A.E.C.); (K.A.K.); (P.R.T.); (S.G.S.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Andres Emanuelli Castaner
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA; (H.D.); (H.Z.); (A.E.C.); (K.A.K.); (P.R.T.); (S.G.S.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Mary C. Casey
- Department of Molecular Microbiology and Immunology, School of Medicine, Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA;
| | - Karen A. Kirby
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA; (H.D.); (H.Z.); (A.E.C.); (K.A.K.); (P.R.T.); (S.G.S.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Philip R. Tedbury
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA; (H.D.); (H.Z.); (A.E.C.); (K.A.K.); (P.R.T.); (S.G.S.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Jiashu Xie
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA; (R.L.S.); (R.D.-R.); (S.K.V.V.); (L.W.); (J.X.)
| | - Stefan G. Sarafianos
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA; (H.D.); (H.Z.); (A.E.C.); (K.A.K.); (P.R.T.); (S.G.S.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Zhengqiang Wang
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA; (R.L.S.); (R.D.-R.); (S.K.V.V.); (L.W.); (J.X.)
- Correspondence: ; Tel.: +1-612-626-7025
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Bhakta S, Nayek A, Roy B, Dey A. Induction of Enzyme-like Peroxidase Activity in an Iron Porphyrin Complex Using Second Sphere Interactions. Inorg Chem 2019; 58:2954-2964. [DOI: 10.1021/acs.inorgchem.8b02707] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Snehadri Bhakta
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Abhijit Nayek
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Bijan Roy
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Abhishek Dey
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
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Wang ZG, Wang H, Liu Q, Duan F, Shi X, Ding B. Designed Self-Assembly of Peptides with G-Quadruplex/Hemin DNAzyme into Nanofibrils Possessing Enzyme-Mimicking Active Sites and Catalytic Functions. ACS Catal 2018. [DOI: 10.1021/acscatal.8b00896] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhen-Gang Wang
- CAS Key Laboratory of Nanosystem and Hierarchial Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People’s Republic of China
| | - Hui Wang
- CAS Key Laboratory of Nanosystem and Hierarchial Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People’s Republic of China
| | - Qing Liu
- CAS Key Laboratory of Nanosystem and Hierarchial Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People’s Republic of China
| | - Fangyuan Duan
- CAS Key Laboratory of Nanosystem and Hierarchial Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People’s Republic of China
| | - Xinghua Shi
- CAS Key Laboratory of Nanosystem and Hierarchial Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Baoquan Ding
- CAS Key Laboratory of Nanosystem and Hierarchial Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
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Tsutsui Y, Kobayashi K, Takeuchi F, Tsubaki M, Kozawa T. Reaction Intermediates of Nitric Oxide Synthase from Deinococcus radiodurans as Revealed by Pulse Radiolysis: Evidence for Intramolecular Electron Transfer from Biopterin to Fe II-O 2 Complex. Biochemistry 2018; 57:1611-1619. [PMID: 29320163 DOI: 10.1021/acs.biochem.7b00887] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Nitric oxide synthase (NOS) is a cytochrome P450-type mono-oxygenase that catalyzes the oxidation of l-arginine (Arg) to nitric oxide (NO) through a reaction intermediate N-hydroxy-l-arginine (NHA). The mechanism underlying the reaction catalyzed by NOS from Deinococcus radiodurans was investigated using pulse radiolysis. Radiolytically generated hydrated electrons reduced the heme iron of NOS within 2 μs. Subsequently, ferrous heme reacted with O2 to form a ferrous-dioxygen intermediate with a second-order rate constant of 2.8 × 108 M-1 s-1. In the tetrahydrofolate (H4F)-bound enzyme, the ferrous-dioxygen intermediate was found to decay an another intermediate with a first-order rate constant of 2.2 × 103 s-1. The spectrum of the intermediate featured an absorption maximum at 440 nm and an absorption minimum at 390 nm. In the absence of H4F, this step did not proceed, suggesting that H4F was reduced with the ferrous-dioxygen intermediate to form a second intermediate. The intermediate further converted to the original ferric form with a first-order rate constant of 4 s-1. A similar intermediate could be detected after pulse radiolysis in the presence of NHA, although the intermediate decayed more slowly (0.5 s-1). These data suggested that a common catalytically active intermediate involved in the substrate oxidation of both Arg and NHA may be formed during catalysis. In addition, we investigated the solvent isotope effects on the kinetics of the intermediate after pulse radiolysis. Our experiments revealed dramatic kinetic solvent isotope effects on the conversion of the intermediate to the ferric form, of 10.5 and 2.5 for Arg and NHA, respectively, whereas the faster phases were not affected. These data suggest that the proton transfer in DrNOS is the rate-limiting reaction of the intermediate with the substrates.
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Affiliation(s)
- Yuko Tsutsui
- The Institute of Scientific and Industrial Research , Osaka University , Mihogaoka 8-1 , Ibaraki , Osaka 567-0047 , Japan
| | - Kazuo Kobayashi
- The Institute of Scientific and Industrial Research , Osaka University , Mihogaoka 8-1 , Ibaraki , Osaka 567-0047 , Japan
| | - Fusako Takeuchi
- Institute for Promotion of Higher Education , Kobe University , 1-2-1 Tsurukabuto , Nada-ku, Kobe , Hyogo 657-8501 , Japan
| | - Motonari Tsubaki
- Graduate School of Science, Department of Chemistry , Kobe University , 1-1 Rokkodai-cho , Nada-ku, Kobe , Hyogo 657-8501 , Japan
| | - Takahiro Kozawa
- The Institute of Scientific and Industrial Research , Osaka University , Mihogaoka 8-1 , Ibaraki , Osaka 567-0047 , Japan
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Perrin L, Loiseau N, André F, Delaforge M. Metabolism of N-methyl-amide by cytochrome P450s. FEBS J 2011; 278:2167-78. [DOI: 10.1111/j.1742-4658.2011.08133.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Naróg D, Lechowicz U, Pietryga T, Sobkowiak A. Iron(II, III)-catalyzed oxidative N-dealkylation of amines with dioxygen. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2003.11.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Debrunner PG, Dexter AF, Schulz CE, Xia YM, Hager LP. Mössbauer and electron paramagnetic resonance studies of chloroperoxidase following mechanism-based inactivation with allylbenzene. Proc Natl Acad Sci U S A 1996; 93:12791-8. [PMID: 8917498 PMCID: PMC23999 DOI: 10.1073/pnas.93.23.12791] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/1996] [Indexed: 02/03/2023] Open
Abstract
We have used Mössbauer and electron paramagnetic resonance (EPR) spectroscopy to study a heme-N-alkylated derivative of chloroperoxidase (CPO) prepared by mechanism-based inactivation with allylbenzene and hydrogen peroxide. The freshly prepared inactivated enzyme ("green CPO") displayed a nearly pure low-spin ferric EPR signal with g = 1.94, 2.15, 2.31. The Mössbauer spectrum of the same species recorded at 4.2 K showed magnetic hyperfine splittings, which could be simulated in terms of a spin Hamiltonian with a complete set of hyperfine parameters in the slow spin fluctuation limit. The EPR spectrum of green CPO was simulated using a three-term crystal field model including g-strain. The best-fit parameters implied a very strong octahedral field in which the three 2T2 levels of the (3d)5 configuration in green CPO were lowest in energy, followed by a quartet. In native CPO, the 6A1 states follow the 2T2 ground state doublet. The alkene-mediated inactivation of CPO is spontaneously reversible. Warming of a sample of green CPO to 22 degrees C for increasing times before freezing revealed slow conversion of the novel EPR species to two further spin S = 1/2 ferric species. One of these species displayed g = 1.82, 2.25, 2.60 indistinguishable from native CPO. By subtracting spectral components due to native and green CPO, a third species with g = 1.86, 2.24, 2.50 could be generated. The EPR spectrum of this "quasi-native CPO," which appears at intermediate times during the reactivation, was simulated using best-fit parameters similar to those used for native CPO.
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Affiliation(s)
- P G Debrunner
- Department of Physics, University of Illinois, Urbana 61801, USA
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Abstract
The catalytic mechanism of cytochrome P450 (P450) enzymes has generally been understood in terms of a classic cycle in which electron donation is often limiting and catalysis is understood in terms of hydrogen abstraction and rapid oxygen rebound. In the course of detailed investigations with kinetic hydrogen isotope effects we have studied two systems in which somewhat unusual isotope effects have been interpreted in terms of modifications of the general paradigm. The low isotope effects observed for N-demethylation reactions are in contrast to high values seen with P450-catalyzed C-hydroxylation and peroxidase-catalyzed N-demethylation and are consonant with a role for the P450 FeO2+ entity in base-catalyzed deprotonation of an aminium radical. With P450 2E1, kinetic deuterium isotope effects are seen on the apparent Km for the substrate (increased) but not on Vmax. The results are interpreted in terms of a mechanism where C-H bond cleavage is sensitive to deuterium substitution but a step following this is rate-limiting. This step may be product release.
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Affiliation(s)
- F P Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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Abstract
Studies with biomimetic models can yield considerable insight into mechanisms of enzymatic catalysis. The discussion above indicates how such information has been important in the cases of flavoproteins, hemoproteins, and, to a lesser extent, the copper protein dopamine beta-hydroxylase. Some of the moieties that we generally accept as intermediates (i.e., high-valent iron oxygen complex in cytochrome P-450 reactions) would be extremely hard to characterize were it not for biomimetic models and more stable analogs such as peroxidase Compound I complexes. Although biomimetic models can be useful, we do need to keep them in perspective. It is possible to alter ligands and aspects of the environment in a way that may not reflect the active site of the protein. Eventually, the model work needs to be carried back to the proteins. We have seen that diagnostic substrates can be of considerable use in understanding enzymes and examples of elucidation of mechanisms through the use of rearrangements, mechanism-based inactivation, isotope labeling, kinetic isotope effects, and free energy relationships have been given. The point should be made that a myriad of approaches need to be applied to the study of each enzyme, for there is potential for misleading information if total reliance is placed on a single approach. The point also needs to be made that in the future we need information concerning the structures of the active sites of enzymes in order to fully understand them. Of the enzymes considered here, only a bacterial form of cytochrome P-450 (P-450cam) has been crystallized. The challenge to determine the three-dimensional structures of these enzymes, particularly the intrinsic membrane proteins, is formidable, yet our further understanding of the mechanisms of enzyme catalysis will remain elusive as long as we have to speak of putative specific residues, domains, and distances in anecdotal terms. The point should be made that there is actually some commonality among many of the catalytic mechanisms of oxidation, even among proteins with different structures and prosthetic groups. Thus, we see that cytochrome P-450 has some elements of a peroxidase and vice versa; indeed, the chemistry at the prosthetic group is probably very similar and the overall chemistry seems to be induced by the protein structure. The copper protein dopamine beta-hydroxylase appears to proceed with chemistry similar to that of the hemoprotein cytochrome P-450 and, although not so thoroughly studied, the non-heme iron protein P. oleovarans omega-hydroxylase.(ABSTRACT TRUNCATED AT 400 WORDS)
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