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A new catalytic site functioning in antigen cleavage by H34 catalytic antibody light chain. Sci Rep 2022; 12:19185. [PMID: 36357546 PMCID: PMC9649737 DOI: 10.1038/s41598-022-23689-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 11/03/2022] [Indexed: 11/12/2022] Open
Abstract
The cleavage reactions of catalytic antibodies are mediated by a serine protease mechanism involving a catalytic triad composed of His, Ser, and Asp residues, which reside in the variable region. Recently, we discovered a catalytic antibody, H34 wild type (H34wt), that is capable of enzymatically cleaving an immune-check point PD-1 peptide and recombinant PD-1; however, H34wt does not contain His residues in the variable region. To clarify the reason behind the catalytic features of H34wt and the amino acid residues involved in the catalytic reaction, we performed site-directed mutagenesis focusing on the amino acid residues involved in the cleavage reaction, followed by catalytic activity tests, immunological reactivity evaluation, and molecular modeling. The results revealed that the cleavage reaction by H34wt proceeds through the action of a new catalytic site composed of Arg, Thr, and Gln. This new scheme differs from that of the serine protease mechanism of catalytic antibodies.
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Motiwala HF, Armaly AM, Cacioppo JG, Coombs TC, Koehn KRK, Norwood VM, Aubé J. HFIP in Organic Synthesis. Chem Rev 2022; 122:12544-12747. [PMID: 35848353 DOI: 10.1021/acs.chemrev.1c00749] [Citation(s) in RCA: 117] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) is a polar, strongly hydrogen bond-donating solvent that has found numerous uses in organic synthesis due to its ability to stabilize ionic species, transfer protons, and engage in a range of other intermolecular interactions. The use of this solvent has exponentially increased in the past decade and has become a solvent of choice in some areas, such as C-H functionalization chemistry. In this review, following a brief history of HFIP in organic synthesis and an overview of its physical properties, literature examples of organic reactions using HFIP as a solvent or an additive are presented, emphasizing the effect of solvent of each reaction.
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Affiliation(s)
- Hashim F Motiwala
- Divison of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 United States
| | - Ahlam M Armaly
- Divison of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 United States
| | - Jackson G Cacioppo
- Divison of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 United States
| | - Thomas C Coombs
- Department of Chemistry, University of North Carolina Wilmington, Wilmington, North Carolina 28403 United States
| | - Kimberly R K Koehn
- Divison of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 United States
| | - Verrill M Norwood
- Divison of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 United States
| | - Jeffrey Aubé
- Divison of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 United States
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Soares AR, Reis RA, Melo DU, Boaro A, Bartoloni FH. Better late than never! Transition state character involved in the neutral solvolysis of an oxalic ester determined by the ionizing power of ethanol/water and methanol/water mixtures. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Wang P, Liu S, Ma X, He Y, Alshammari AS, Deng Y. Binary Mg–Fe oxide as a highly active and magnetically separable catalyst for the synthesis of ethyl methyl carbonate. RSC Adv 2015. [DOI: 10.1039/c5ra02894a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The synthesis of ethyl methyl carbonate (EMC) from dimethyl carbonate (DMC) and diethyl carbonate (DEC) over magnetic binary Mg–Fe oxides.
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Affiliation(s)
- Peixue Wang
- Centre for Green Chemistry and Catalysis
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou
- China
| | - Shimin Liu
- Centre for Green Chemistry and Catalysis
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou
- China
| | - Xiangyuan Ma
- Centre for Green Chemistry and Catalysis
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou
- China
| | - Yude He
- Centre for Green Chemistry and Catalysis
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou
- China
| | - Ahmad S. Alshammari
- National Nanotechnology Research Center
- King Abdulaziz City for Science and Technology
- Riyadh 11442
- Saudi Arabia
| | - Youquan Deng
- Centre for Green Chemistry and Catalysis
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou
- China
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Yang L, Yu L, Sun M, Gao C. Zeolitic imidazole framework-67 as an efficient heterogeneous catalyst for the synthesis of ethyl methyl carbonate. CATAL COMMUN 2014. [DOI: 10.1016/j.catcom.2014.05.021] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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D’Souza MJ, Givens AF, Lorchak PA, Greenwood AE, Gottschall SL, Carter SE, Kevill DN. Kinetic studies that evaluate the solvolytic mechanisms of allyl and vinyl chloroformate esters. Int J Mol Sci 2013; 14:7286-301. [PMID: 23549265 PMCID: PMC3645686 DOI: 10.3390/ijms14047286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 03/26/2013] [Accepted: 03/28/2013] [Indexed: 01/12/2023] Open
Abstract
At 25.0 °C the specific rates of solvolysis for allyl and vinyl chloroformates have been determined in a wide mix of pure and aqueous organic mixtures. In all the solvents studied, vinyl chloroformate was found to react significantly faster than allyl chloroformate. Multiple correlation analyses of these rates are completed using the extended (two-term) Grunwald-Winstein equation with incorporation of literature values for solvent nucleophilicity (NT) and solvent ionizing power (YCl). Both substrates were found to solvolyze by similar dual bimolecular carbonyl-addition and unimolecular ionization channels, each heavily dependent upon the solvents nucleophilicity and ionizing ability.
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Affiliation(s)
- Malcolm J. D’Souza
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
- Authors to whom correspondence should be addressed; E-Mails: (M.J.D.); (D.N.K.); Tel.: +1-302-736-2528 (M.J.D.); +1-815-753-6882 (D.N.K.); Fax: +1-302-736-2301 (M.J.D.); +1-815-753-4802 (D.N.K.)
| | - Aaron F. Givens
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Peter A. Lorchak
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Abigail E. Greenwood
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Stacey L. Gottschall
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Shannon E. Carter
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
- Authors to whom correspondence should be addressed; E-Mails: (M.J.D.); (D.N.K.); Tel.: +1-302-736-2528 (M.J.D.); +1-815-753-6882 (D.N.K.); Fax: +1-302-736-2301 (M.J.D.); +1-815-753-4802 (D.N.K.)
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D’Souza MJ, Kevill DN. Application of the Grunwald-Winstein Equations to Studies of Solvolytic Reactions of Chloroformate and Fluoroformate Esters. RECENT RESEARCH DEVELOPMENTS IN ORGANIC CHEMISTRY 2013; 13:1-38. [PMID: 25364780 PMCID: PMC4215406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Chloroformates are important laboratory and industrial chemicals with almost one hundred listed in the catalogs of leading suppliers. They are, for example, of prime importance as protecting groups in peptide synthesis. In some instances, the more stable fluoroformate is preferred. In recent years, the specific rates of solvolysis (k) for chloroformates and fluoroformates in solvents of widely ranging nucleophilicity and ionizing power have been studied. Analysis of these rates using the extended (two-term) Grunwald-Winstein equation has led to important information concerning reaction mechanism. Also assisting in this effort have been studies of kinetic solvent isotope effects (KSIE), of leaving group effects (especially kF/kCl ratios), and of entropies of activation from studies of specific rate variations with temperature. For solvolyses of chloroformate esters, two mechanisms (addition-elimination and ionization) are commonly encountered. For solvolyses of fluoroformates, mainly because of a strong C-F bond, the ionization pathway is rare and the addition-elimination pathway is in most situations the one encountered.
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Affiliation(s)
- Malcolm J. D’Souza
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Dennis N. Kevill
- Department of Chemistry & Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
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Evaluation of Electronic Effects in the Solvolyses of p-Methylphenyl and p-Chlorophenyl Chlorothionoformate Esters. J CHEM-NY 2013; 2013. [PMID: 24377055 DOI: 10.1155/2013/248534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The solvolyses of p-tolyl chlorothionoformate and p-chlorophenyl chlorothionoformate are studied in a variety of organic mixtures of widely varying nucleophilicity and ionizing power values. This solvolytic data is accumulated at 25.0 °C using the titration method. An analysis of the rate data using the extended (two-term) Grunwald-Winstein equation, and the concept of similarity of substrates based on their l/m ratios, shows the occurrence of simultaneous side-by-side addition-elimination and unimolecular SN1 mechanisms.
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Kyong JB, Lee Y, D’Souza MJ, Kevill DN, Kevill DN. Correlation of the rates of solvolysis of tert-butyl chlorothioformate and observations concerning the reaction mechanism. EUROPEAN JOURNAL OF CHEMISTRY (PRINT) 2012; 3:267-272. [PMID: 23538747 PMCID: PMC3607629 DOI: 10.5155/eurjchem.3.3.267-272.624] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The "parent" tertiary alkyl chloroformate, tert-butyl chloroformate, is unstable, but the tert-butyl chlorothioformate (1) is of increased stability and a kinetic investigation of the solvolyses is presented. Analyses in terms of the simple and extended Grunwald-Winstein equations are carried out. The original one-term equation satisfactorily correlates the data with a sensitivity towards changes in solvent ionizing power of 0.73 ±0.03. When the two-term equation is applied, the sensitivity towards changes in solvent nucleophilicity of 0.13 ± 0.09 is associated with a high (0.17) probability that the term that it governs is not statistically significant.
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Affiliation(s)
- Jin Burm Kyong
- Department of Chemistry and Applied Chemistry, Hanyang University, Ansan-si, Gyeonggi-do 426–791, Korea
| | - Yelin Lee
- Department of Chemistry and Applied Chemistry, Hanyang University, Ansan-si, Gyeonggi-do 426–791, Korea
| | | | | | - Dennis Neil Kevill
- Department of Chemistry & Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
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