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Abstract
ConspectusOne of the fundamental goals of chemists is to develop highly efficient methods for producing optically active compounds, given their wide range of applications in chemistry, pharmaceutical industry, chemical biology, and material science. Biomimetic asymmetric catalysis, which imitates the structures and functions of enzymes, has emerged as an extremely attractive strategy for producing chiral compounds. This field has drawn tremendous research interest and has led to various protocols for constructing complex molecular scaffolds. The Vitamin B6 family, including pyridoxal, pyridoxamine, pyridoxine, and the corresponding phosphorylated derivatives, serves as the cofactors to catalyze more than 200 enzymatic functions, accounting for ∼4% of all enzyme activities. Although significant progress has been made in simulating the biological roles of vitamin B6 during the past several decades, its extraordinary catalytic power has not yet been successfully applied into asymmetric synthesis. In recent years, our group has been devoted to developing vitamin B6-based biomimetic asymmetric catalysis using chiral pyridoxals/pyridoxamines as catalysts. We are particularly interested in mimicking the processes of enzymatic transamination and biological aldol reaction of glycine, respectively, developing asymmetric biomimetic transamination and carbonyl catalysis enabled α-C-H transformation of primary amines. Using a chiral α,α-diarylprolinol-derived pyridoxal as the catalyst, we reported the first chiral pyridoxal catalyzed asymmetric transamination of α-keto acids in 2015. A significant breakthrough in biomimetic transamination was achieved by using an axially chiral biaryl pyridoxamine catalyst that bears a lateral amine side arm. The amine side arm acts as an intramolecular base, accelerating the transamination and proving highly effective for transamination of α-keto acids and α-keto amides. In addition, we discovered the catalytic power of chiral pyridoxals as carbonyl catalysts for asymmetric biomimetic Mannich/aldol reactions of glycinates. These chiral pyridoxals also enabled more α-C-H conversions of glycinates, such as asymmetric 1,4-addition toward α,β-unsaturated esters and asymmetric α-allylation with Morita-Baylis-Hillman acetates. Moreover, carbonyl catalysis can be further applied to highly challenging primary amines with inert α-C-H bonds, such as propargylamines and benzylamines, which represents a powerful strategy for direct asymmetric α-C-H functionalization of various primary amines without protection of the NH2 group. These biomimetic/bioinspired transformations provide efficient new protocols for the synthesis of chiral amines. Herein, we summarize our recent efforts on the development of the vitamin B6-based biomimetic asymmetric catalysis.
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Affiliation(s)
- Xiao Xiao
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai 200234, P. R. China
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2
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Catalytic asymmetric α C(sp3)–H addition of benzylamines to aldehydes. Nat Catal 2022. [DOI: 10.1038/s41929-022-00875-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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3
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Ji P, Liu X, Xu J, Zhang X, Guo J, Chen W, Zhao B. Direct Asymmetric α‐C−H Addition of N‐unprotected Propargylic Amines to Trifluoromethyl Ketones by Carbonyl Catalysis. Angew Chem Int Ed Engl 2022; 61:e202206111. [DOI: 10.1002/anie.202206111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Pengwei Ji
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Xiaopei Liu
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Jiwei Xu
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Xu Zhang
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Jianhua Guo
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Wen‐Wen Chen
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
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4
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Ji P, Liu X, Xu J, Zhang X, Guo J, Chen W, Zhao B. Direct Asymmetric α‐C−H Addition of N‐unprotected Propargylic Amines to Trifluoromethyl Ketones by Carbonyl Catalysis. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Pengwei Ji
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Xiaopei Liu
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Jiwei Xu
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Xu Zhang
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Jianhua Guo
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Wen‐Wen Chen
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Frontiers Science Center of Biomimetic Catalysis Shanghai Normal University Shanghai 200234 China
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5
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Ma J, Gao B, Song G, Zhang R, Wang Q, Ye Z, Chen WW, Zhao B. Asymmetric α-Allylation of Glycinate with Switched Chemoselectivity Enabled by Customized Bifunctional Pyridoxal Catalysts. Angew Chem Int Ed Engl 2022; 61:e202200850. [PMID: 35182094 DOI: 10.1002/anie.202200850] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Indexed: 12/15/2022]
Abstract
Owing to the strong nucleophilicity of the NH2 group, free-NH2 glycinates react with MBH acetates to usually deliver N-allylated products even in the absence of catalysts. Without protection of the NH2 group, chiral pyridoxal catalysts bearing an amide side chain at the C3 position of the naphthyl ring switched the chemoselectivity of the glycinates from intrinsic N-allylation to α-C allylation. The reaction formed chiral multisubstituted glutamic acid esters as SN 2'-SN 2' products in good yields with excellent stereoselectivity (up to 86 % yield, >20 : 1 dr, 97 % ee). As compared to pyridoxal catalysts bearing an amide side arm at the C2 position, the pyridoxals in this study have a bigger catalytic cavity to enable effective activation of larger electrophiles, such as MBH acetates and related intermediates. The reaction is proposed to proceed via a cooperative bifunctional catalysis pathway, which accounts for the high level of diastereo- and enantiocontrol of the pyridoxal catalysts.
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Affiliation(s)
- Jiguo Ma
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai, 200234, China
| | - Bin Gao
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai, 200234, China
| | - Guanshui Song
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai, 200234, China
| | - Ruixin Zhang
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai, 200234, China
| | - Qingfang Wang
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai, 200234, China
| | - Zi Ye
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai, 200234, China
| | - Wen-Wen Chen
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai, 200234, China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Frontiers Science Center of Biomimetic Catalysis, Shanghai Normal University, Shanghai, 200234, China
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Ma J, Gao B, Song G, Zhang R, Wang Q, Ye Z, Chen WW, Zhao B. Asymmetric a‐Allylation of Glycinate with Switched Chemoselectivity Enabled by Customized Bifunctional Pyridoxal Catalysts. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jiguo Ma
- Shanghai Normal University Chemistry CHINA
| | - Bin Gao
- Shanghai Normal University Chemistry CHINA
| | | | | | | | - Zi Ye
- Shanghai Normal University Chemistry CHINA
| | - Wen-Wen Chen
- Shanghai Normal University Chemistry 100 Guilin Rd 200234 Shanghai CHINA
| | - Baoguo Zhao
- Shanghai Normal University Chemistry Department 100 Guiling Rd 200234 Shanghai CHINA
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7
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Han LL, Zhang QY, Li X, Qiao Y, Lan Y, Wei D. The chiral pyridoxal-catalyzed biomimetic Mannich reaction: the mechanism and origin of stereoselectivity. Org Chem Front 2022. [DOI: 10.1039/d2qo00705c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A biomimetic organocatalyst with a pyridoxal-like structure is one of the most successful examples of catalyzing organic reactions under mild conditions in an asymmetric synthesis field.
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Affiliation(s)
- Li-Li Han
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, Henan, P. R. China
| | - Qiao-Yu Zhang
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, Henan, P. R. China
| | - Xue Li
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, Henan, P. R. China
| | - Yan Qiao
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, P. R. China
| | - Yu Lan
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, Henan, P. R. China
| | - Donghui Wei
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, Henan, P. R. China
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Mayer RJ, Kaur H, Rauscher SA, Moran J. Mechanistic Insight into Metal Ion-Catalyzed Transamination. J Am Chem Soc 2021; 143:19099-19111. [PMID: 34730975 DOI: 10.1021/jacs.1c08535] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several classes of biological reactions that are mediated by an enzyme and a co-factor can occur, to a slower extent, not only without the enzyme but even without the co-factor, under catalysis by metal ions. This observation has led to the proposal that metabolic pathways progressively evolved from using inorganic catalysts to using organocatalysts of increasing complexity. Transamination, the biological process by which ammonia is transferred between amino acids and α-keto acids, has a mechanism that has been well studied under enzyme/co-factor catalysis and under co-factor catalysis, but the metal ion-catalyzed variant was generally studied mostly at high temperatures (70-100 °C), and the details of its mechanism remained unclear. Here, we investigate which metal ions catalyze transamination under conditions relevant to biology (pH 7, 20-50 °C) and study the mechanism in detail. Cu2+, Ni2+, Co2+, and V5+ were identified as the most active metal ions under these constraints. Kinetic, stereochemical, and computational studies illuminate the mechanism of the reaction. Cu2+ and Co2+ are found to predominantly speed up the reaction by stabilizing a key imine intermediate. V5+ is found to accelerate the reaction by increasing the acidity of the bound imine. Ni2+ is found to do both to a limited extent. These results show that direct metal ion-catalyzed amino group transfer is highly favored even in the absence of co-factors or protein catalysts under biologically compatible reaction conditions.
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Affiliation(s)
- Robert J Mayer
- University of Strasbourg, CNRS, ISIS UMR 7006, 67000 Strasbourg, France
| | - Harpreet Kaur
- University of Strasbourg, CNRS, ISIS UMR 7006, 67000 Strasbourg, France
| | - Sophia A Rauscher
- University of Strasbourg, CNRS, ISIS UMR 7006, 67000 Strasbourg, France
| | - Joseph Moran
- University of Strasbourg, CNRS, ISIS UMR 7006, 67000 Strasbourg, France
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9
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Cheng A, Zhang L, Zhou Q, Liu T, Cao J, Zhao G, Zhang K, Song G, Zhao B. Efficient Asymmetric Biomimetic Aldol Reaction of Glycinates and Trifluoromethyl Ketones by Carbonyl Catalysis. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Aolin Cheng
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Liangliang Zhang
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Qinghai Zhou
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Tao Liu
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Jing Cao
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Guoqing Zhao
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Kun Zhang
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Guanshui Song
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
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10
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Cheng A, Zhang L, Zhou Q, Liu T, Cao J, Zhao G, Zhang K, Song G, Zhao B. Efficient Asymmetric Biomimetic Aldol Reaction of Glycinates and Trifluoromethyl Ketones by Carbonyl Catalysis. Angew Chem Int Ed Engl 2021; 60:20166-20172. [PMID: 34139067 DOI: 10.1002/anie.202104031] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/04/2021] [Indexed: 01/26/2023]
Abstract
The direct asymmetric aldol reaction of glycinates represents an intriguing and straightforward strategy to make biologically significant chiral β-hydroxy-α-amino-acid derivatives. But it is not easy to realize the transformation due to the disruption of the reactive NH2 group of glycinates. Inspired by the enzymatic aldol reaction of glycine, we successfully developed an asymmetric aldol reaction of glycinate 5 and trifluoromethyl ketones 4 with 0.1-0.0033 mol % of chiral N-methyl pyridoxal 7 a as the catalyst, producing chiral β-trifluoromethyl-β-hydroxy-α-amino-acid esters 6 in 55-82 % yields (for the syn-diastereomers) with up to >20:1 dr and 99 % ee under very mild conditions. The reaction proceeds via a catalytic cycle similar to the enzymatic aldol reaction of glycine. Pyridoxal catalyst 7 a activates both reactants at the same time and brings them together in a specific spatial orientation, accounting for the high efficiency as well as excellent diastereo- and enantioselectivities.
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Affiliation(s)
- Aolin Cheng
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Liangliang Zhang
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Qinghai Zhou
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Tao Liu
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Jing Cao
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Guoqing Zhao
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Kun Zhang
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Guanshui Song
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
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11
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Asymmetric biomimetic transamination of α-keto amides to peptides. Nat Commun 2021; 12:5174. [PMID: 34462436 PMCID: PMC8405696 DOI: 10.1038/s41467-021-25449-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 08/11/2021] [Indexed: 11/23/2022] Open
Abstract
Peptides are important compounds with broad applications in many areas. Asymmetric transamination of α-keto amides can provide an efficient strategy to synthesize peptides, however, the process has not been well developed yet and still remains a great challenge in both enzymatic and catalytic chemistry. For biological transamination, the high activity is attributed to manifold structural and electronic factors of transaminases. Based on the concept of multiple imitation of transaminases, here we report N-quaternized axially chiral pyridoxamines 1 for enantioselective transamination of α-keto amides, to produce various peptides in good yields with excellent enantio- and diastereoselectivities. The reaction is especially attractive for the synthesis of peptides made of unnatural amino acids since it doesn’t need great efforts to make chiral unnatural amino acids before amide bond formation. Asymmetric transamination of α-keto amides could provide an efficient strategy to synthesise peptides, but has not been well developed yet. Here, the authors design chiral pyridoxamine catalyst and realize the asymmetric biomimetic transamination of α-keto amides, providing access to various peptides with excellent enantiopurities.
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12
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Ma J, Zhou Q, Song G, Song Y, Zhao G, Ding K, Zhao B. Enantioselective Synthesis of Pyroglutamic Acid Esters from Glycinate via Carbonyl Catalysis. Angew Chem Int Ed Engl 2021; 60:10588-10592. [PMID: 33554429 DOI: 10.1002/anie.202017306] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/28/2021] [Indexed: 12/18/2022]
Abstract
Direct α-functionalization of NH2 -free glycinates with relatively weak electrophiles such as α,β-unsaturated esters still remains a big challenge in organic synthesis. With chiral pyridoxal 5 d as a carbonyl catalyst, direct asymmetric conjugated addition at the α-C of glycinate 1 a with α,β-unsaturated esters 2 has been successfully realized, to produce various chiral pyroglutamic acid esters 4 in 14-96 % yields with 81-97 % ee's after in situ lactamization. The trans and cis diastereomers can be obtained at the same time by chromatography and both of them can be easily converted into chiral 4-substituted pyrrolidin-2-ones such as Alzheimer's drug Rolipram (11) with the same absolute configuration via tert-butyl group removal and subsequent Barton decarboxylation.
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Affiliation(s)
- Jiguo Ma
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China.,State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Qinghai Zhou
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Guanshui Song
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Yongchang Song
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Guoqing Zhao
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
| | - Kuiling Ding
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, China
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13
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Ma J, Zhou Q, Song G, Song Y, Zhao G, Ding K, Zhao B. Enantioselective Synthesis of Pyroglutamic Acid Esters from Glycinate via Carbonyl Catalysis. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202017306] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Jiguo Ma
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
- State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Qinghai Zhou
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Guanshui Song
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Yongchang Song
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Guoqing Zhao
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
| | - Kuiling Ding
- State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials Science Shanghai Normal University Shanghai 200234 China
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14
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Yang Y, Zhang Y, Yang J, Xue Y. Computational Insight into the Mechanism of Mannich Reaction between Glycinate and Aryl
N
‐Diphenylphosphinyl Imine Catalyzed by N‐Quaternized Pyridoxal. ChemistrySelect 2020. [DOI: 10.1002/slct.202001606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Yongsheng Yang
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of EducationSichuan University Chengdu 610064 People's Republic of China
| | - Yan Zhang
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of EducationSichuan University Chengdu 610064 People's Republic of China
| | - Junxia Yang
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of EducationSichuan University Chengdu 610064 People's Republic of China
| | - Ying Xue
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of EducationSichuan University Chengdu 610064 People's Republic of China
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15
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Chen J, Gong X, Li J, Li Y, Ma J, Hou C, Zhao G, Yuan W, Zhao B. Carbonyl catalysis enables a biomimetic asymmetric Mannich reaction. Science 2018; 360:1438-1442. [PMID: 29954974 DOI: 10.1126/science.aat4210] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 05/02/2018] [Indexed: 01/01/2023]
Abstract
Chiral amines are widely used as catalysts in asymmetric synthesis to activate carbonyl groups for α-functionalization. Carbonyl catalysis reverses that strategy by using a carbonyl group to activate a primary amine. Inspired by biological carbonyl catalysis, which is exemplified by reactions of pyridoxal-dependent enzymes, we developed an N-quaternized pyridoxal catalyst for the asymmetric Mannich reaction of glycinate with aryl N-diphenylphosphinyl imines. The catalyst exhibits high activity and stereoselectivity, likely enabled by enzyme-like cooperative bifunctional activation of the substrates. Our work demonstrates the catalytic utility of the pyridoxal moiety in asymmetric catalysis.
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Affiliation(s)
- Jianfeng Chen
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China.,Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
| | - Xing Gong
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Jianyu Li
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Yingkun Li
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Jiguo Ma
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Chengkang Hou
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Guoqing Zhao
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Weicheng Yuan
- Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
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16
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Amyes TL, Richard JP. Substituent Effects on Carbon Acidity in Aqueous Solution and at Enzyme Active Sites. Synlett 2017; 28:2407-2421. [PMID: 28993718 DOI: 10.1055/s-0036-1588778] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Methods are described for the determination of pKas for weak carbon acids in water. The application of these methods to the determination of the pKas for a variety of carbon acids including nitriles, imidazolium cations, amino acids, peptides and their derivatives and, α-iminium cations is presented. The substituent effects on the acidity of these different classes of carbon acids are discussed; and, the relevance of these results to catalysis of the deprotonation of amino acids by enzymes and by pyridoxal 5'-phosphate is reviewed. The procedure for estimating the pKa of uridine 5'-phosphate for C-6 deprotonation at the active site of orotidine 5'-phosphate decarboxylase is described, and the effect of a 5-F substituent on carbon acidity of the enzyme-bound substrate is discussed.
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Affiliation(s)
- Tina L Amyes
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, NY 14260-3000
| | - John P Richard
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, NY 14260-3000
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17
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Chen J, Zhao J, Gong X, Xu D, Zhao B. A new type of chiral-pyridoxamines for catalytic asymmetric transamination of α-keto acids. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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18
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Liu YE, Lu Z, Li B, Tian J, Liu F, Zhao J, Hou C, Li Y, Niu L, Zhao B. Enzyme-Inspired Axially Chiral Pyridoxamines Armed with a Cooperative Lateral Amine Chain for Enantioselective Biomimetic Transamination. J Am Chem Soc 2016; 138:10730-3. [DOI: 10.1021/jacs.6b03930] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yong Ethan Liu
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Zhaole Lu
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Bo Li
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Jiaxin Tian
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Feng Liu
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Junyu Zhao
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Chengkang Hou
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Yingkun Li
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Lili Niu
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Baoguo Zhao
- The Education
Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
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19
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Lan X, Tao C, Liu X, Zhang A, Zhao B. Asymmetric Transamination of α-Keto Acids Catalyzed by Chiral Pyridoxamines. Org Lett 2016; 18:3658-61. [DOI: 10.1021/acs.orglett.6b01714] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaoyu Lan
- The Education Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Chuangan Tao
- The Education Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Xuliang Liu
- The Education Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Aina Zhang
- The Education Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Baoguo Zhao
- The Education Ministry Key
Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth
Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China
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20
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Investigation of Structural Dynamics of Enzymes and Protonation States of Substrates Using Computational Tools. Catalysts 2016; 6. [PMID: 27885336 PMCID: PMC5119520 DOI: 10.3390/catal6060082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
This review discusses the use of molecular modeling tools, together with existing experimental findings, to provide a complete atomic-level description of enzyme dynamics and function. We focus on functionally relevant conformational dynamics of enzymes and the protonation states of substrates. The conformational fluctuations of enzymes usually play a crucial role in substrate recognition and catalysis. Protein dynamics can be altered by a tiny change in a molecular system such as different protonation states of various intermediates or by a significant perturbation such as a ligand association. Here we review recent advances in applying atomistic molecular dynamics (MD) simulations to investigate allosteric and network regulation of tryptophan synthase (TRPS) and protonation states of its intermediates and catalysis. In addition, we review studies using quantum mechanics/molecular mechanics (QM/MM) methods to investigate the protonation states of catalytic residues of β-Ketoacyl ACP synthase I (KasA). We also discuss modeling of large-scale protein motions for HIV-1 protease with coarse-grained Brownian dynamics (BD) simulations.
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21
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Nashalian O, Yaylayan VA. De novo synthesis of amino acids during the maillard reaction: qTOF/ESI mass spectrometric evidence for the mechanism of Akabori transformation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:328-334. [PMID: 25514107 DOI: 10.1021/jf5051975] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The transformation of α-amino acids into their hydroxymethyl derivatives during the Maillard reaction is an intriguing possibility for catalysis by metal salts in the presence of Strecker aldehydes; the process is commonly known as the Akabori reaction. The mechanism of this reaction was studied in the presence of glucose, using glycine copper complex and paraformaldehyde as Akabori model system in aqueous mixtures heated at 110 °C for 2 h and subsequently analyzed by qTOF/ESI/MS. Isotope-labeling studies of the various products identified have provided for the first time mass spectrometric evidence for the detailed mechanism of Akabori transformation, particularly the formation of Schiff base adducts prior to the final conversion into serine and hydroxymethyl-serine. Furthermore, the results have indicated that sugars do not interfere with such transformations and, on the contrary, the presence of glycine–copper complexes in the Maillard model systems can enhance the production of Maillard reaction intermediates.
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22
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Timin AS, Rumyantsev EV, Solomonov AV, Musabirov II, Sergeev SN, Ivanov SP, Berlier G, Balantseva E. Preparation and characterization of organo-functionalized silicas for bilirubin removal. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2014.10.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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23
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Caulkins B, Bastin B, Yang C, Neubauer TJ, Young RP, Hilario E, Huang YMM, Chang CEA, Fan L, Dunn MF, Marsella MJ, Mueller LJ. Protonation states of the tryptophan synthase internal aldimine active site from solid-state NMR spectroscopy: direct observation of the protonated Schiff base linkage to pyridoxal-5'-phosphate. J Am Chem Soc 2014; 136:12824-7. [PMID: 25148001 PMCID: PMC4183654 DOI: 10.1021/ja506267d] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Indexed: 11/29/2022]
Abstract
The acid-base chemistry that drives catalysis in pyridoxal-5'-phosphate (PLP)-dependent enzymes has been the subject of intense interest and investigation since the initial identification of PLP's role as a coenzyme in this extensive class of enzymes. It was first proposed over 50 years ago that the initial step in the catalytic cycle is facilitated by a protonated Schiff base form of the holoenzyme in which the linking lysine ε-imine nitrogen, which covalently binds the coenzyme, is protonated. Here we provide the first (15)N NMR chemical shift measurements of such a Schiff base linkage in the resting holoenzyme form, the internal aldimine state of tryptophan synthase. Double-resonance experiments confirm the assignment of the Schiff base nitrogen, and additional (13)C, (15)N, and (31)P chemical shift measurements of sites on the PLP coenzyme allow a detailed model of coenzyme protonation states to be established.
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Affiliation(s)
- Bethany
G. Caulkins
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Baback Bastin
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Chen Yang
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Thomas J. Neubauer
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Robert P. Young
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Eduardo Hilario
- Department
of Biochemistry, University of California, Riverside, California 92521, United States
| | - Yu-ming M. Huang
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Chia-en A. Chang
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Li Fan
- Department
of Biochemistry, University of California, Riverside, California 92521, United States
| | - Michael F. Dunn
- Department
of Biochemistry, University of California, Riverside, California 92521, United States
| | - Michael J. Marsella
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Leonard J. Mueller
- Department
of Chemistry, University of California, Riverside, California 92521, United States
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24
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Pang J, Scrutton NS, Sutcliffe MJ. Quantum Mechanics/Molecular Mechanics Studies on the Mechanism of Action of Cofactor Pyridoxal 5′-Phosphate in Ornithine 4,5-Aminomutase. Chemistry 2014; 20:11390-401. [DOI: 10.1002/chem.201402759] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Indexed: 02/02/2023]
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25
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Toney MD. Aspartate aminotransferase: an old dog teaches new tricks. Arch Biochem Biophys 2013; 544:119-27. [PMID: 24121043 DOI: 10.1016/j.abb.2013.10.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 09/28/2013] [Accepted: 10/01/2013] [Indexed: 11/29/2022]
Abstract
Aspartate aminotransferase (AAT) is a prototypical pyridoxal 5'-phosphate (PLP) dependent enzyme that catalyzes the reversible interconversion of l-aspartate and α-ketoglutarate with oxalacetate and l-glutamate via a ping-pong catalytic cycle in which the pyridoxamine 5'-phosphate enzyme form is an intermediate. There is a bountiful literature on AAT that spans approximately 60years, and much fundamental mechanistic information on PLP dependent reactions has been gained from its study. Here, we review our recent work on AAT, where we again used it as a test bed for fundamental concepts in PLP chemistry. First, we discuss the role that coenzyme protonation state plays in controlling reaction specificity, then ground state destabilization via hyperconjugation in the external aldimine intermediate is examined. The third topic is light enhancement of catalysis of Cα-H deprotonation by PLP in solution and in AAT, which occurs through a triplet state of the external aldimine intermediate. Lastly, we consider recent advances in our analyses of enzyme multiple sequence alignments for the purpose of predicting mutations that are required to interconvert structurally similar but catalytically distinct enzymes, and the application of our program JANUS to the conversion of AAT into tyrosine aminotransferase.
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Affiliation(s)
- Michael D Toney
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA.
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26
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C–H Activation in Pyridoxal-5′-phosphate and Pyridoxamine-5′-phosphate Schiff Bases: Effect of Metal Chelation. A Computational Study. J Phys Chem B 2013; 117:2339-47. [DOI: 10.1021/jp311861p] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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Casasnovas R, Adrover M, Ortega-Castro J, Frau J, Donoso J, Muñoz F. C–H Activation in Pyridoxal-5′-phosphate Schiff Bases: The Role of the Imine Nitrogen. A Combined Experimental and Computational Study. J Phys Chem B 2012; 116:10665-75. [DOI: 10.1021/jp303678n] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rodrigo Casasnovas
- Institut
d’Investigació en Ciènces de la Salut (IUNICS),
Departament de Química, Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain
| | - Miquel Adrover
- Institut
d’Investigació en Ciènces de la Salut (IUNICS),
Departament de Química, Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain
| | - Joaquin Ortega-Castro
- Institut
d’Investigació en Ciènces de la Salut (IUNICS),
Departament de Química, Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain
| | - Juan Frau
- Institut
d’Investigació en Ciènces de la Salut (IUNICS),
Departament de Química, Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain
| | - Josefa Donoso
- Institut
d’Investigació en Ciènces de la Salut (IUNICS),
Departament de Química, Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain
| | - Francisco Muñoz
- Institut
d’Investigació en Ciènces de la Salut (IUNICS),
Departament de Química, Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain
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28
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29
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Mundle SOC, Howe GW, Kluger R. Origins of Steric Effects in General-Base-Catalyzed Enolization: Solvation and Electrostatic Attraction. J Am Chem Soc 2011; 134:1066-70. [PMID: 22122780 DOI: 10.1021/ja2085959] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Scott O. C. Mundle
- Davenport Chemical Laboratories, Department of Chemistry, University of Toronto, Toronto, Canada M5S 3H6
| | - Graeme W. Howe
- Davenport Chemical Laboratories, Department of Chemistry, University of Toronto, Toronto, Canada M5S 3H6
| | - Ronald Kluger
- Davenport Chemical Laboratories, Department of Chemistry, University of Toronto, Toronto, Canada M5S 3H6
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30
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Griswold WR, Toney MD. Role of the pyridine nitrogen in pyridoxal 5'-phosphate catalysis: activity of three classes of PLP enzymes reconstituted with deazapyridoxal 5'-phosphate. J Am Chem Soc 2011; 133:14823-30. [PMID: 21827189 DOI: 10.1021/ja2061006] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyridoxal 5'-phosphate (PLP; vitamin B(6))-catalyzed reactions have been well studied, both on enzymes and in solution, due to the variety of important reactions this cofactor catalyzes in nitrogen metabolism. Three functional groups are central to PLP catalysis: the C4' aldehyde, the O3' phenol, and the N1 pyridine nitrogen. In the literature, the pyridine nitrogen has traditionally been assumed to be protonated in enzyme active sites, with the protonated pyridine ring providing resonance stabilization of carbanionic intermediates. This assumption is certainly correct for some PLP enzymes, but the structures of other active sites are incompatible with protonation of N1, and, consequently, these enzymes are expected to use PLP in the N1-unprotonated form. For example, aspartate aminotransferase protonates the pyridine nitrogen for catalysis of transamination, while both alanine racemase and O-acetylserine sulfhydrylase are expected to maintain N1 in the unprotonated, formally neutral state for catalysis of racemization and β-elimination. Herein, kinetic results for these three enzymes reconstituted with 1-deazapyridoxal 5'-phosphate, an isosteric analogue of PLP lacking the pyridine nitrogen, are compared to those for the PLP enzyme forms. They demonstrate that the pyridine nitrogen is vital to the 1,3-prototropic shift central to transamination, but not to reactions catalyzed by alanine racemase or O-acetylserine sulfhydrylase. Not all PLP enzymes require the electrophilicity of a protonated pyridine ring to enable formation of carbanionic intermediates. It is proposed that modulation of cofactor electrophilicity plays a central role in controlling reaction specificity in PLP enzymes.
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Affiliation(s)
- Wait R Griswold
- Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA
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31
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Limbach HH, Chan-Huot M, Sharif S, Tolstoy PM, Shenderovich IG, Denisov GS, Toney MD. Critical hydrogen bonds and protonation states of pyridoxal 5'-phosphate revealed by NMR. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1426-37. [PMID: 21703367 DOI: 10.1016/j.bbapap.2011.06.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 06/04/2011] [Accepted: 06/07/2011] [Indexed: 12/01/2022]
Abstract
In this contribution we review recent NMR studies of protonation and hydrogen bond states of pyridoxal 5'-phosphate (PLP) and PLP model Schiff bases in different environments, starting from aqueous solution, the organic solid state to polar organic solution and finally to enzyme environments. We have established hydrogen bond correlations that allow one to estimate hydrogen bond geometries from (15)N chemical shifts. It is shown that protonation of the pyridine ring of PLP in aspartate aminotransferase (AspAT) is achieved by (i) an intermolecular OHN hydrogen bond with an aspartate residue, assisted by the imidazole group of a histidine side chain and (ii) a local polarity as found for related model systems in a polar organic solvent exhibiting a dielectric constant of about 30. Model studies indicate that protonation of the pyridine ring of PLP leads to a dominance of the ketoenamine form, where the intramolecular OHN hydrogen bond of PLP exhibits a zwitterionic state. Thus, the PLP moiety in AspAT carries a net positive charge considered as a pre-requisite to initiate the enzyme reaction. However, it is shown that the ketoenamine form dominates in the absence of ring protonation when PLP is solvated by polar groups such as water. Finally, the differences between acid-base interactions in aqueous solution and in the interior of proteins are discussed. This article is part of a special issue entitled: Pyridoxal Phosphate Enzymology.
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Affiliation(s)
- Hans-Heinrich Limbach
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraβe 3, D-14195, Germany.
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32
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Griswold WR, Fisher AJ, Toney MD. Crystal structures of aspartate aminotransferase reconstituted with 1-deazapyridoxal 5'-phosphate: internal aldimine and stable L-aspartate external aldimine. Biochemistry 2011; 50:5918-24. [PMID: 21627105 DOI: 10.1021/bi200436y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The 1.8 Å resolution crystal structures of Escherichia coli aspartate aminotransferase reconstituted with 1-deazapyridoxal 5'-phosphate (deazaPLP; 2-formyl-3-hydroxy-4-methylbenzyl phosphate) in the internal aldimine and L-aspartate external aldimine forms are reported. The L-aspartate·deazaPLP external aldimine is extraordinarily stable (half-life of >20 days), allowing crystals of this intermediate to be grown by cocrystallization with L-aspartate. This structure is compared to that of the α-methyl-L-aspartate·PLP external aldimine. Overlays with the corresponding pyridoxal 5'-phosphate (PLP) aldimines show very similar orientations of deazaPLP with respect to PLP. The lack of a hydrogen bond between Asp222 and deazaPLP, which serves to "anchor" PLP in the active site, releases strain in the deazaPLP internal aldimine that is enforced in the PLP internal aldimine [Hayashi, H., Mizuguchi, H., Miyahara, I., Islam, M. M., Ikushiro, H., Nakajima, Y., Hirotsu, K., and Kagamiyama, H. (2003) Biochim. Biophys. Acta1647, 103] as evidenced by the planarity of the pyridine ring and the Schiff base linkage with Lys258. Additionally, loss of this anchor causes a 10° greater tilt of deazaPLP toward the substrate in the external aldimine. An important mechanistic difference between the L-aspartate·deazaPLP and α-methyl-L-aspartate·PLP external aldimines is a hydrogen bond between Gly38 and Lys258 in the former, positioning the catalytic base above and approximately equidistant between Cα and C4'. In contrast, in the α-methyl-L-aspartate·PLP external aldimine, the ε-amino group of Lys258 is rotated ~70° to form a hydrogen bond to Tyr70 because of the steric bulk of the methyl group.
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Affiliation(s)
- Wait R Griswold
- Department of Chemistry, University of California, Davis, California 95616, United States
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33
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The PLP cofactor: lessons from studies on model reactions. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1814:1419-25. [PMID: 21182991 DOI: 10.1016/j.bbapap.2010.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 11/26/2010] [Accepted: 12/10/2010] [Indexed: 11/22/2022]
Abstract
Experimental probes of the acidity of weak carbon acids have been developed and used to determine the carbon acid pK(a)s of glycine, glycine derivatives and iminium ion adducts of glycine to the carbonyl group, including 5'-deoxypyridoxal (DPL). The high reactivity of the DPL-stabilized glycyl carbanion towards nucleophilic addition to both DPL and the glycine-DPL iminium ion favors the formation of Claisen condensation products at enzyme active sites. The formation of the iminium ion between glycine and DPL is accompanied by a 12-unit decrease in the pK(a) of 29 for glycine. The complicated effects of formation of glycine iminium ions to DPL and other aromatic and aliphatic aldehydes and ketones on carbon acid pK(a) are discussed. These data provide insight into the contribution of the individual pyridine ring substituents to the catalytic efficiency of DPL. It is suggested that the 5'-phosphodianion group of PLP may play an important role in enzymatic catalysis of carbon deprotonation by providing up to 12 kcal/mol of binding energy that is utilized to stabilize the transition state for the enzymatic reaction. This article is part of a Special Issue entitled: Pyridoxal Phospate Enzymology.
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