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Chau TK, Ho NT, Ho TH, Nguyen AT, Nguyen KD, Phan NTS, Le HV, Nguyen TT. Synthesis of 2-benzyl benzoxazoles and benzothiazoles via elemental sulfur promoted cyclization of styrenes with 2-nitrophenols and N, N-dialkyl-3-nitroanilines. Org Biomol Chem 2024; 22:1234-1244. [PMID: 38240351 DOI: 10.1039/d3ob01775c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Herein we report a method for affording 2-benzyl benzoxazoles from substituted styrenes and 2-nitrophenols. The success of this method relies on the use of simple reagents, namely elemental sulfur and DABCO. A combination of identical reagents was utilized for the annulation of styrenes with N,N-dialkyl-3-nitroanilines to afford 2-benzyl benzothiazoles. Overall, benzoxazoles and benzothiazoles bearing useful functionalities such as halogens, amines, and heterocyclic groups were isolated in moderate to good yields. Our methods are a rare example of divergent transformations of substituted nitroarenes towards 2-benzyl benzoxazoles and benzothiazoles.
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Affiliation(s)
- Truong K Chau
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam.
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City, Vietnam
| | - Nguyen T Ho
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam.
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City, Vietnam
| | - Tuan H Ho
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam.
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City, Vietnam
| | - Anh T Nguyen
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam.
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City, Vietnam
| | - Khoa D Nguyen
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam.
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City, Vietnam
| | - Nam T S Phan
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam.
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City, Vietnam
| | - Ha V Le
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam.
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City, Vietnam
| | - Tung T Nguyen
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam.
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City, Vietnam
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2
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Le HX, Nguyen KD, Phan NTS, Le HV, Nguyen TT. t
‐BuONa‐Mediated Redox Condensation between
o‐
Nitroanilines and Benzyl Alcohols towards 2‐Phenyl Benzimidazoles under Transition‐Metal‐Free Conditions. ChemistrySelect 2023. [DOI: 10.1002/slct.202204024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Affiliation(s)
- Huy X. Le
- Faculty of Chemical Engineering Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Khoa D. Nguyen
- Faculty of Chemical Engineering Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Nam T. S. Phan
- Faculty of Chemical Engineering Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Ha V. Le
- Faculty of Chemical Engineering Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Tung T. Nguyen
- Faculty of Chemical Engineering Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
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3
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Nguyen KD, Ho PH, Vu PD, Pham TLD, Trens P, Di Renzo F, Phan NTS, Le HV. Efficient Removal of Chromium(VI) Anionic Species and Dye Anions from Water Using MOF-808 Materials Synthesized with the Assistance of Formic Acid. Nanomaterials (Basel) 2021; 11:1398. [PMID: 34070500 PMCID: PMC8226478 DOI: 10.3390/nano11061398] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/21/2021] [Accepted: 05/21/2021] [Indexed: 11/22/2022]
Abstract
This study presents a simple approach to prepare MOF-808, an ultra-stable Zr-MOF constructed from 6-connected zirconium clusters and 1,3,5-benzene tricarboxylic acid, with tailored particle sizes. Varying the amount of formic acid as a modulator in the range of 200-500 equivalents results in MOF-808 materials with a crystal size from 40 nm to approximately 1000 nm. Apart from the high specific surface area, a combination of a fraction of mesopore and plenty of acidic centers on the Zr-clusters induces a better interaction with the ionic pollutants such as K2Cr2O7 and anionic dyes. MOF-808 shows uptakes of up to 141.2, 642.0, and 731.0 mg/g for K2Cr2O7, sunset yellow, and quinoline yellow, respectively, in aqueous solutions at ambient conditions. The uptakes for the ionic dyes are significantly higher than those of other MOFs reported from the literature. Moreover, the adsorption capacity of MOF-808 remains stable after four cycles. Our results demonstrate that MOF-808 is a promising ideal platform for removing oxometallates and anionic dyes from water.
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Affiliation(s)
- Khoa D. Nguyen
- Department of Chemical Engineering, Ho Chi Minh University of Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 740010, Vietnam; (P.D.V.); (T.L.D.P.); (N.T.S.P.)
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 740010, Vietnam
| | - Phuoc H. Ho
- Ecole Nationale Supérieure de Chimie de Montpellier, ICGM, Univ. Montpellier, CNRS, ENSCM, 34090 Montpellier, France; (P.H.H.); (F.D.R.)
| | - Phuong D. Vu
- Department of Chemical Engineering, Ho Chi Minh University of Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 740010, Vietnam; (P.D.V.); (T.L.D.P.); (N.T.S.P.)
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 740010, Vietnam
| | - Thuyet L. D. Pham
- Department of Chemical Engineering, Ho Chi Minh University of Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 740010, Vietnam; (P.D.V.); (T.L.D.P.); (N.T.S.P.)
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 740010, Vietnam
| | - Philippe Trens
- Ecole Nationale Supérieure de Chimie de Montpellier, ICGM, Univ. Montpellier, CNRS, ENSCM, 34090 Montpellier, France; (P.H.H.); (F.D.R.)
| | - Francesco Di Renzo
- Ecole Nationale Supérieure de Chimie de Montpellier, ICGM, Univ. Montpellier, CNRS, ENSCM, 34090 Montpellier, France; (P.H.H.); (F.D.R.)
| | - Nam T. S. Phan
- Department of Chemical Engineering, Ho Chi Minh University of Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 740010, Vietnam; (P.D.V.); (T.L.D.P.); (N.T.S.P.)
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 740010, Vietnam
| | - Ha V. Le
- Department of Chemical Engineering, Ho Chi Minh University of Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 740010, Vietnam; (P.D.V.); (T.L.D.P.); (N.T.S.P.)
- Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 740010, Vietnam
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Nguyen TT, Le LV, Pham HH, Nguyen DH, Phan NTS, Le HV, Phan ANQ. Correction: Cobalt-catalyzed, directed arylation of C–H bonds in N-aryl pyrazoles. RSC Adv 2021; 11:12348. [PMID: 35427073 PMCID: PMC8696964 DOI: 10.1039/d1ra90093e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 11/21/2022] Open
Abstract
Correction for ‘Cobalt-catalyzed, directed arylation of C–H bonds in N-aryl pyrazoles’ by Tung T. Nguyen et al., RSC Adv., 2021, 11, 9349–9352, DOI: 10.1039/D1RA00975C.
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Affiliation(s)
- Tung T. Nguyen
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Lam V. Le
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Hai H. Pham
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Dung H. Nguyen
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Nam T. S. Phan
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Ha V. Le
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Anh N. Q. Phan
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
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Nguyen TT, Le LV, Pham HH, Nguyen DH, Phan NTS, Le HV, Phan ANQ. Cobalt-catalyzed, directed arylation of C–H bonds in N-aryl pyrazoles. RSC Adv 2021; 11:9349-9352. [PMID: 35423432 PMCID: PMC8695287 DOI: 10.1039/d1ra00975c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/29/2021] [Accepted: 02/24/2021] [Indexed: 01/23/2023] Open
Abstract
Directed arylation of ortho C–H bonds in N-aryl pyrazoles using a cobalt catalyst is reported. Excellent tolerance of functional groups was observed.
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Affiliation(s)
- Tung T. Nguyen
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Lam V. Le
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Hai H. Pham
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Dung H. Nguyen
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Nam T. S. Phan
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Ha V. Le
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
| | - Anh N. Q. Phan
- Faculty of Chemical Engineering
- Ho Chi Minh City University of Technology (HCMUT)
- Ho Chi Minh City
- Vietnam
- Vietnam National University Ho Chi Minh City
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Tran KM, Nguyen NHK, Bui TT, To TA, Phan NTS, Le HV, Nguyen TT. Synthesis of primary N-arylthioglyoxamides from anilines, elemental sulfur and primary C-H bonds in acetophenones. RSC Adv 2020; 10:44743-44746. [PMID: 35516277 PMCID: PMC9058611 DOI: 10.1039/d0ra08740h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/07/2020] [Indexed: 12/31/2022] Open
Abstract
A simple method for coupling of anilines, acetophenones, and elemental sulfur to afford N-arylthioglyoxamides has been developed. Reactions proceeded in the presence of Na2SO3 and DMSO, thus eliminating the need for transition metals and external oxidants. Functionalities such as halogen, ester, methylthio, and heterocycle groups were compatible with the conditions. Electron-poor acetophenones sometimes gave isosteric glyoxamides. Sulfurative coupling of acetophenones and aniline in the presence of Na2SO3 and DMSO solvent to afford N-arylthioglyoxamides was developed.![]()
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Affiliation(s)
- Khoa M Tran
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam .,Vietnam National University Ho Chi Minh City Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Nguyen H K Nguyen
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam .,Vietnam National University Ho Chi Minh City Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Thuy T Bui
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam .,Vietnam National University Ho Chi Minh City Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Tuong A To
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam .,Vietnam National University Ho Chi Minh City Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Nam T S Phan
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam .,Vietnam National University Ho Chi Minh City Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Ha V Le
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam .,Vietnam National University Ho Chi Minh City Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Tung T Nguyen
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT) 268 Ly Thuong Kiet, District 10 Ho Chi Minh City Vietnam .,Vietnam National University Ho Chi Minh City Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
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7
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Abstract
We report a new method for the synthesis of substituted quinazolines by the condensation of 2-nitrobenzyl alcohols with arylacetic acids. The transformation requires the use of urea as a nitrogen source, elemental sulfur as a promoter, DABCO as a base, and DMSO as a solvent. Functionalities such as chloro, fluoro, trifluoromethyl, thienyl, and indolyl groups were all compatible with the reaction conditions. Because our method uses stable simple substrates to obtain the N,N-heterocycles in the absence of transition metals, it offers a potential pathway for preparing complex structures under mild conditions.
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Affiliation(s)
- Tung T. Nguyen
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT)
- Vietnam National University Ho Chi Minh City
| | - Nam T. S. Phan
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT)
- Vietnam National University Ho Chi Minh City
| | - Khang X. Nguyen
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT)
- Vietnam National University Ho Chi Minh City
| | - Duyen K. Nguyen
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT)
- Vietnam National University Ho Chi Minh City
| | - Phuc H. Pham
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT)
- Vietnam National University Ho Chi Minh City
| | - Ha V. Le
- Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT)
- Vietnam National University Ho Chi Minh City
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Le HV, Nguyen TT, Pham TLD, Nguyen TM, Tran KA, Dang HV, Phan NTS. Copper-Promoted Coupling of Propiophenones and Arylhydrazines for the Synthesis of 1,3-Diarylpyrazoles. Synlett 2020. [DOI: 10.1055/s-0039-1690835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Synthesis of 1,3-diarylpyrazoles from commercial substrates and/or simple transformations is still underrated. In this report, we have developed a method for copper-promoted coupling of propiophenones and arylhydrazines. The reactions afforded substituted pyrazoles in the presence of TEMPO oxidant, acetic acid additive, and DMF solvent. A number of functionalities were compatible with reaction conditions, including halogens, methoxy, trifluoromethyl, and nitro groups. An indazole could be obtained if an electron-poor propiophenone was used.
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Doan SH, Tran NKQ, Pham PH, Nguyen VHH, Nguyen NN, Ha PTM, Li S, Le HV, Le NTH, Tu TN, Phan NTS. A New Synthetic Pathway to Triphenylpyridines via Cascade Reactions Utilizing a New Iron-Organic Framework as a Recyclable Heterogeneous Catalyst. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900094] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Son H. Doan
- Faculty of Chemical Engineering; VNU-HCM; HCMC University of Technology; 268 Ly Thuong Kiet District 10 Ho Chi Minh City Vietnam
| | - Nhu K. Q. Tran
- Faculty of Chemical Engineering; VNU-HCM; HCMC University of Technology; 268 Ly Thuong Kiet District 10 Ho Chi Minh City Vietnam
| | - Phuc H. Pham
- Faculty of Chemical Engineering; VNU-HCM; HCMC University of Technology; 268 Ly Thuong Kiet District 10 Ho Chi Minh City Vietnam
| | - Vu H. H. Nguyen
- Faculty of Chemical Engineering; VNU-HCM; HCMC University of Technology; 268 Ly Thuong Kiet District 10 Ho Chi Minh City Vietnam
| | - Ngoc N. Nguyen
- VNU-HCM; VNU-HCM; Center for Innovative Materials and Architectures; Quarter 6, Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Phuong T. M. Ha
- Faculty of Chemical Engineering; VNU-HCM; HCMC University of Technology; 268 Ly Thuong Kiet District 10 Ho Chi Minh City Vietnam
| | - Shuang Li
- Institute of ChemistryFunctional Materials; VNU-HCM; Technische Universität Berlin, BA2; Hardenbergstraße 40 10623 Berlin Germany
| | - Ha V. Le
- Faculty of Chemical Engineering; VNU-HCM; HCMC University of Technology; 268 Ly Thuong Kiet District 10 Ho Chi Minh City Vietnam
- Institute of ChemistryFunctional Materials; VNU-HCM; Technische Universität Berlin, BA2; Hardenbergstraße 40 10623 Berlin Germany
| | - Nhan T. H. Le
- Faculty of Chemical Engineering; VNU-HCM; HCMC University of Technology; 268 Ly Thuong Kiet District 10 Ho Chi Minh City Vietnam
| | - Thach N. Tu
- VNU-HCM; VNU-HCM; Center for Innovative Materials and Architectures; Quarter 6, Linh Trung Ward, Thu Duc District Ho Chi Minh City Vietnam
| | - Nam T. S. Phan
- Faculty of Chemical Engineering; VNU-HCM; HCMC University of Technology; 268 Ly Thuong Kiet District 10 Ho Chi Minh City Vietnam
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To TA, Vo YH, Nguyen HT, Ha PT, Doan SH, Doan TL, Li S, Le HV, Tu TN, Phan NT. Iron-catalyzed one-pot sequential transformations: Synthesis of quinazolinones via oxidative Csp3H bond activation using a new metal-organic framework as catalyst. J Catal 2019. [DOI: 10.1016/j.jcat.2018.11.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Le HV, Parishan S, Sagaltchik A, Ahi H, Trunschke A, Schomäcker R, Thomas A. Stepwise Methane-to-Methanol Conversion on CuO/SBA-15. Chemistry 2018; 24:12592-12599. [DOI: 10.1002/chem.201801135] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/21/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Ha V. Le
- Institute of Chemistry-Functional Materials; BA2; Technische Universität Berlin; Hardenbergstrasse 40 10623 Berlin Germany
| | - Samira Parishan
- Institute of Chemistry-Technical Chemistry; TC8; Technische Universität Berlin; Strasse des 17. Juni 124 10623 Berlin Germany
| | - Anton Sagaltchik
- BasCat-UniCat BASF Joint Lab; Technische Universität Berlin; EW K 01; Hardenbergstrasse 36 10623 Berlin Germany
| | - Hamideh Ahi
- BasCat-UniCat BASF Joint Lab; Technische Universität Berlin; EW K 01; Hardenbergstrasse 36 10623 Berlin Germany
- Department of Inorganic Chemistry; Fritz Haber Institute of the Max Planck Society; Faradayweg 4-6 14195 Berlin Germany
| | - Annette Trunschke
- Department of Inorganic Chemistry; Fritz Haber Institute of the Max Planck Society; Faradayweg 4-6 14195 Berlin Germany
| | - Reinhard Schomäcker
- Institute of Chemistry-Technical Chemistry; TC8; Technische Universität Berlin; Strasse des 17. Juni 124 10623 Berlin Germany
| | - Arne Thomas
- Institute of Chemistry-Functional Materials; BA2; Technische Universität Berlin; Hardenbergstrasse 40 10623 Berlin Germany
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Pham PH, Doan SH, Tran HTT, Nguyen NN, Phan ANQ, Le HV, Tu TN, Phan NTS. A new transformation of coumarins via direct C–H bond activation utilizing an iron–organic framework as a recyclable catalyst. Catal Sci Technol 2018. [DOI: 10.1039/c7cy02139a] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A new mixed-linker iron-based MOF VNU-20 [Fe3(BTC)(NDC)2·6.65H2O] was solvothermally synthesized, and utilized as catalyst for the coupling transformation of coumarins with N,N-dimethylanilines.
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Affiliation(s)
- Phuc H. Pham
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Vietnam
| | - Son H. Doan
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Vietnam
| | - Hang T. T. Tran
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Vietnam
| | - Ngoc N. Nguyen
- Center for Innovative Materials and Architectures
- VNU-HCM
- Ho Chi Minh City
- Vietnam
| | - Anh N. Q. Phan
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Vietnam
| | - Ha V. Le
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Vietnam
| | - Thach N. Tu
- Center for Innovative Materials and Architectures
- VNU-HCM
- Ho Chi Minh City
- Vietnam
| | - Nam T. S. Phan
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Vietnam
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Dang HV, Le HTB, Tran LTB, Ha HQ, Le HV, Phan NTS. Copper-catalyzed one-pot domino reactions via C–H bond activation: synthesis of 3-aroylquinolines from 2-aminobenzylalcohols and propiophenones under metal–organic framework catalysis. RSC Adv 2018; 8:31455-31464. [PMID: 35548194 PMCID: PMC9085622 DOI: 10.1039/c8ra05459b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/27/2018] [Indexed: 11/26/2022] Open
Abstract
A Cu2(OBA)2(BPY) metal–organic framework was utilized as a productive heterogeneous catalyst for the synthesis of 3-aroylquinolines via one-pot domino reactions of 2-aminobenzylalcohols with propiophenones. This Cu-MOF was considerably more active towards the one-pot domino reaction than a series of transition metal salts, as well as nano oxide and MOF-based catalysts. The MOF-based catalyst was reusable without a significant decline in catalytic efficiency. To the best of our knowledge, the transformation of 2-aminobenzylalcohols to 3-aroylquinolines was not previously reported in the literature, and this protocol would be complementary to previous strategies for the synthesis of these valuable heterocycles. Cu2(OBA)2(BPY) metal–organic framework was utilized as a productive heterogeneous catalyst for the synthesis of 3-aroylquinolines via one-pot domino reactions of 2-aminobenzylalcohols with propiophenones.![]()
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Affiliation(s)
- Ha V. Dang
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Viet Nam
| | - Hoang T. B. Le
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Viet Nam
| | - Loan T. B. Tran
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Viet Nam
| | - Hiep Q. Ha
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Viet Nam
| | - Ha V. Le
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Viet Nam
| | - Nam T. S. Phan
- Faculty of Chemical Engineering
- HCMC University of Technology
- VNU-HCM
- Ho Chi Minh City
- Viet Nam
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14
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Le HV, Parishan S, Sagaltchik A, Göbel C, Schlesiger C, Malzer W, Trunschke A, Schomäcker R, Thomas A. Solid-State Ion-Exchanged Cu/Mordenite Catalysts for the Direct Conversion of Methane to Methanol. ACS Catal 2017. [DOI: 10.1021/acscatal.6b02372] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ha V. Le
- Institute
of Chemistry−Functional Materials, Technische Universität Berlin, BA2, Hardenbergstraße 40, 10623 Berlin, Germany
| | - Samira Parishan
- Institute
of Chemistry−Technical Chemistry, Technische Universität Berlin, TC8, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Anton Sagaltchik
- BasCat−UniCat
BASF Joint Lab, Technische Universität Berlin, EW K 01, Hardenbergstraße
36, 10623 Berlin, Germany
| | - Caren Göbel
- Institute
of Chemistry, Technische Universität Berlin, TK01, Straße
des 17. Juni 135, 10623 Berlin, Germany
| | - Christopher Schlesiger
- Institute
of Optics and Atomic Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - Wolfgang Malzer
- Institute
of Optics and Atomic Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - Annette Trunschke
- Department
of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Reinhard Schomäcker
- Institute
of Chemistry−Technical Chemistry, Technische Universität Berlin, TC8, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Arne Thomas
- Institute
of Chemistry−Functional Materials, Technische Universität Berlin, BA2, Hardenbergstraße 40, 10623 Berlin, Germany
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15
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Kornmann MO, Hinds D, DiSantostefano RL, Le HV, Pascoe SJ. COPD-Patienten, die am stärksten von einer Behandlung mit Fluticasonfuroat plus Vilanterol (FF/VI) profitieren im Vergleich zu Vilanterol allein (VI): Ergebnisse einer gepoolten Subgruppenanalyse zweier randomisierter 1-Jahresstudien. Pneumologie 2016. [DOI: 10.1055/s-0036-1572271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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16
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Pullen MG, Gaffney NS, Hall CR, Davis JA, Dubrouil A, Le HV, Buividas R, Day D, Quiney HM, Dao LV. High-order harmonic generation from a dual-gas, multi-jet array with individual gas jet control. Opt Lett 2013; 38:4204-4207. [PMID: 24321960 DOI: 10.1364/ol.38.004204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a gas jet array for use in high-order harmonic generation experiments. Precise control of the pressure in each individual gas jet has allowed a thorough investigation into mechanisms contributing to the selective enhancement observed in the harmonic spectra produced by dual-gas, multi-jet arrays. Our results reveal that in our case, the dominant enhancement mechanism is the result of a compression of the harmonic-producing gas jet due to the presence of other gas jets in the array. The individual control of the gas jets in the array also provides a promising method for enhancing the harmonic yield by precise tailoring of the length and pressure gradient of the interaction region.
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17
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Phan NT, Le HV. Superparamagnetic nanoparticles-supported phosphine-free palladium catalyst for the Sonogashira coupling reaction. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.molcata.2010.11.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Zandstra PW, Le HV, Daley GQ, Griffith LG, Lauffenburger DA. Leukemia inhibitory factor (LIF) concentration modulates embryonic stem cell self-renewal and differentiation independently of proliferation. Biotechnol Bioeng 2000; 69:607-17. [PMID: 10918135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
A major limitation of the widespread use of stem cells in a variety of biotechnological applications is the relatively low level of knowledge about how to maintain these cells in vitro without losing the long-term multilineage growth properties required for their clinical utility. An experimental and theoretical framework for predicting and controlling the outcome of stem cell stimulation by exogenous cytokines would thus be useful. An emerging theme from recent hematopoietic stem cell (HSC)-expansion studies is that a net gain in HSC numbers requires the maintenance of critical signaling ligand(s) above a threshold level. These ligand-receptor complex thresholds can be maintained, for example, by high concentrations of soluble cytokines or by cytokine presentation on cell surfaces. According to such a model, when the relevant ligand-receptor interaction falls below this threshold level, the probability of a differentiation response is increased; otherwise, self-renewal is favored. Taking advantage of the ability of the cytokine leukemia inhibitory factor (LIF) to maintain embryonic stem (ES) cell pluripotentiality at high concentrations, we are testing this model by investigating critical parameters in the control of ES cell responses. We have developed quantitative assays of ES cell differentiation by measuring cell-surface alkaline phosphatase activity, cell-surface stage specific embryonic antigen (SSEA)-1 expression, and the ability of ES cells to form embryoid bodies. Examination of ES cell responses over a range of LIF concentrations shows that LIF supplementation has little effect on ES cell-growth rate but significantly alters the probability of a cell undergoing a self-renewal vs. a differentiation division. In vitro culture parameters such as inoculum cell density, medium exchange, as well as cell-intrinsic processes such as autocrine secretion are shown to affect this decision. In addition to yielding new information on stem cell regulation by exogenous factors, these studies provide important clues about culture of these cells and should stimulate further investigations into the mechanistic basis of stem cell differentiation control.
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Affiliation(s)
- P W Zandstra
- Institute of Biomaterials and Biomedical Engineering; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Ontario, Canada
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19
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Wu Z, Demma M, Strickland CL, Radisky ES, Poulter CD, Le HV, Windsor WT. Farnesyl protein transferase: identification of K164 alpha and Y300 beta as catalytic residues by mutagenesis and kinetic studies. Biochemistry 1999; 38:11239-49. [PMID: 10471273 DOI: 10.1021/bi990583t] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Farnesyl protein transferase (FPT) is an alpha/beta heterodimeric zinc enzyme that catalyzes posttranslational farnesylation of many key cellular regulatory proteins, including oncogenic Ras. On the basis of the recently reported crystal structure of FPT complexed with a CVIM peptide and alpha-hydroxyfarnesylphosphonic acid, site-directed mutagenesis of the FPT active site was performed so key residues that are responsible for substrate binding and catalysis could be identified. Eight single mutants, including K164N alpha, Y166F alpha, Y166A alpha, Y200F alpha, H201A alpha, H248A beta, Y300F beta, and Y361F beta, and a double mutant, H248A beta/Y300F beta, were prepared. Steady-state kinetic analysis along with structural evidence indicated that residues Y200 alpha, H201 alpha, H248 beta, and Y361 beta are mainly involved in substrate binding. In addition, biochemical results confirm structural observations which show that residue Y166 alpha plays a key role in stabilizing the active site conformation of several FPT residues through cation-pi interactions. Two mutants, K164N alpha and Y300F beta, have moderately decreased catalytic constants (kcat). Pre-steady-state kinetic analysis of these mutants from rapid quench experiments showed that the chemical step rate constant was reduced by 41- and 30-fold, respectively. The product-releasing rate for each dropped approximately 10-fold. In pH-dependent kinetic studies, Y300F beta was observed to have both acidic and basic pKa values shifted 1 log unit from those of the wild-type enzyme, consistent with a possible role for Y300 beta as an acid-base catalyst. K164N alpha had a pKa shift from 6.0 to 5.3, which suggests it may function as a general acid. On the basis of these results along with structural evidence, a possible FPT reaction mechanism is proposed with both Y300 beta and K164 alpha playing key catalytic roles in enhancing the reactivity of the farnesyl diphosphate leaving group.
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Affiliation(s)
- Z Wu
- Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA.
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20
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Strickland CL, Weber PC, Windsor WT, Wu Z, Le HV, Albanese MM, Alvarez CS, Cesarz D, del Rosario J, Deskus J, Mallams AK, Njoroge FG, Piwinski JJ, Remiszewski S, Rossman RR, Taveras AG, Vibulbhan B, Doll RJ, Girijavallabhan VM, Ganguly AK. Tricyclic farnesyl protein transferase inhibitors: crystallographic and calorimetric studies of structure-activity relationships. J Med Chem 1999; 42:2125-35. [PMID: 10377218 DOI: 10.1021/jm990030g] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Crystallographic and thermodynamic studies of farnesyl protein transferase (FPT) complexed with novel tricyclic inhibitors provide insights into the observed SAR for this unique class of nonpeptidic FPT inhibitors. The crystallographic structures reveal a binding pattern conserved across the mono-, di-, and trihalogen series. In the complexes, the tricycle spans the FPT active site cavity and interacts with both protein atoms and the isoprenoid portion of bound farnesyl diphosphate. An amide carbonyl, common to the tricyclic compounds described here, participates in a water-mediated hydrogen bond to the protein backbone. Ten high-resolution crystal structures of inhibitors complexed with FPT are reported. Included are crystallographic data for FPT complexed with SCH 66336, a compound currently undergoing clinical trials as an anticancer agent (SCH 66336, 4-[2-[4-(3,10-dibromo-8-chloro-6,11-dihydro-5H-benzo[5, 6]cyclohepta[1, 2-b]pyridin-11-yl)-1-piperidinyl]-2-oxoethyl]-1-piperidinecarbo xamide ). Thermodynamic binding parameters show favorable enthalpies of complex formation and small net entropic contributions as observed for 4-[2-[4-(3,10-dibromo-8-chloro-6,11-dihydro-11H-benzo[5, 6]cyclohepta[1, 2-b]pyridin-11-ylidene)-1-piperidinyl]-2-oxoethyl]pyridine N-oxide where DeltaH degrees bind = -12.5 kcal/mol and TDeltaS degrees bind = -1.5 kcal/mol.
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Affiliation(s)
- C L Strickland
- Department of Structural Chemistry, Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA
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21
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Wu Z, Demma M, Strickland CL, Syto R, Le HV, Windsor WT, Weber PC. High-level expression, purification, kinetic characterization and crystallization of protein farnesyltransferase beta-subunit C-terminal mutants. Protein Eng 1999; 12:341-8. [PMID: 10325405 DOI: 10.1093/protein/12.4.341] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Protein farnesyltransferase (FPT) is a 97 000 Da heterodimeric enzyme that catalyzes post-translational farnesylation of many cellular regulatory proteins including p21 Ras. To facilitate the construction of site-directed mutants, a novel translationally coupled, two-cistron Escherichia coli expression system for rat FPT has been developed. This expression system enabled yields of >5 mg of purified protein per liter of E.coli culture to be obtained. The E.coli-derived FPT demonstrated an activity comparable to that of protein isolated from other sources. The reported expression system was used to construct three beta-subunit C-terminal truncation mutants, Delta5, Delta10 and Delta14, which were designed to eliminate a lattice interaction between the beta-subunit C-terminus of one molecule and the active site of a symmetry-related molecule. Steady-state kinetic analyses of these mutants showed that deletion up to 14 residues at the C-terminus did not reduce the value of kcat; however, Km values for both peptide and FPP increased 2-3-fold. A new crystalline form of FPT was obtained for the Delta10 C-terminal mutant grown in the presence of the substrate analogs acetyl-Cys-Val-Ile-Met-COOH peptide and alpha-hydroxyfarnesylphosphonic acid. The crystals diffract to beyond 2.0 A resolution. The refined structure clearly shows that both substrate analogs adopt extended conformations within the FPT active site cavity.
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Affiliation(s)
- Z Wu
- Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA.
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22
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Strickland CL, Windsor WT, Syto R, Wang L, Bond R, Wu Z, Schwartz J, Le HV, Beese LS, Weber PC. Crystal structure of farnesyl protein transferase complexed with a CaaX peptide and farnesyl diphosphate analogue. Biochemistry 1998; 37:16601-11. [PMID: 9843427 DOI: 10.1021/bi981197z] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The crystallographic structure of acetyl-Cys-Val-Ile-selenoMet-COOH and alpha-hydroxyfarnesylphosphonic acid (alphaHFP) complexed with rat farnesyl protein transferase (FPT) (space group P61, a = b = 174. 13 A, c = 69.71 A, alpha = beta = 90 degrees, gamma = 120 degrees, Rfactor = 21.8%, Rfree = 29.2%, 2.5 A resolution) is reported. In the ternary complex, the bound substrates are within van der Waals contact of each other and the FPT enzyme. alphaHFP binds in an extended conformation in the active-site cavity where positively charged side chains and solvent molecules interact with the phosphate moiety and aromatic side chains pack adjacent to the isoprenoid chain. The backbone of the bound CaaX peptide adopts an extended conformation, and the side chains interact with both FPT and alphaHFP. The cysteine sulfur of the bound peptide coordinates the active-site zinc. Overall, peptide binding and recognition appear to be dominated by side-chain interactions. Comparison of the structures of the ternary complex and unliganded FPT [Park, H., Boduluri, S., Moomaw, J., Casey, P., and Beese, L. (1997) Science 275, 1800-1804] shows that major rearrangements of several active site side chains occur upon substrate binding.
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Affiliation(s)
- C L Strickland
- Structural Chemistry Department, Schering-Plough Research Institute, Kenilworth, New Jersey 07033-0539, USA
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23
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Dao TT, Kailasam MT, Parmer RJ, Le HV, Le Verge R, Kennedy BP, Ziegler G, Insel PA, Wright FA, O'Connor DT. Expression of altered alpha2-adrenergic phenotypic traits in normotensive humans at genetic risk of hereditary (essential) hypertension. J Hypertens 1998; 16:779-92. [PMID: 9663918 DOI: 10.1097/00004872-199816060-00009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Essential (hereditary) hypertension is a common, though complex, trait with substantial heritability, but a still-obscure mode of inheritance. In this disorder with relatively late onset, knowledge of phenotypes with earlier penetrance would aid genetic analyses, as well as assessment of risk. OBJECTIVE Because alpha2-adrenergic receptor alterations are among the most heritable in experimental genetic hypertension, we hypothesized enhanced expression of alpha2-adrenergic phenotypic traits in still-normotensive humans at genetic risk of hypertension. METHODS We evaluated hemodynamic (blood pressure, cardiac output, systemic vascular resistance, stroke volume, and cardiac contractility) and biochemical (plasma drug, catecholamine, renin, and chromogranin A levels) responses to alpha2-adrenergic blockade with intravenous yohimbine in 84 normotensive subjects stratified by genetic risk of essential hypertension (67 with positive family histories and 17 with negative family histories of hypertension), as well as 18 subjects with established essential hypertension. Results were evaluated by analysis of variance, normal likelihood ratio test, and by maximum likelihood analysis for bimodality (i.e. mixtures) of response distributions. RESULTS Blood pressure rose (P<0.001) during alpha2-adrenergic blockade, with greater response (P<0.001) in members of the hypertensive than in members of the normotensive group. Hemodynamically, the rise in blood pressure resulted from an increase in cardiac output (P<0.001), with associated increases in stroke volume (P=0.002) and cardiac contractility (P=0.006), without an overall change in systemic vascular resistance. Biochemically, plasma norepinephrine (P<0.001), epinephrine (P=0.001), and chromogranin A (P=0.02) rose, suggesting augmentation of efferent exocytotic sympathoadrenal activity. Cardiac output and stroke volume responses were correlated to increments in plasma catecholamines (especially epinephrine) for the positive group, but not for the negative group. Baseline plasma catecholamines predicted increments of stroke volume after administration of yohimbine (P=0.003-0.007) for the positive but not for the negative group. Simultaneous comparison of means and variances of cardiac output and stroke volume alpha2-adrenergic responses, by using a normal likelihood ratio test, revealed highly significant (P=0.025 to P<0.0001) differences between the groups of subjects with and without family histories of hypertension. Frequency histogram suggested that there was a bimodal distribution of responses of stroke volume to alpha2-adrenergic blockade for the normotensive group with positive family histories of hypertension; maximum likelihood analysis strongly rejected the hypothesis of a unimodal distribution, whereas the hypothesis of bimodality could not be rejected (chi2=18.4, P=0.0004). The second (exaggerated) mode of response of stroke volume to alpha2-adrenergic blockade, defined by maximum likelihood analysis, was found for 9.5% of subjects in the normotensive group with positive family histories of hypertension, and was characterized by significantly different responses of cardiac output (P=0.001), stroke volume (P<0.001), contractility (P<0.001), heart rate (P=0.03), systemic vascular resistance (P<0.001), and epinephrine (P<0.001). Even prior to alpha2-adrenergic blockade, baseline stroke volume (P=0.01), heart rate (P=0.04), systemic vascular resistance (P=0.005), and catecholamine (P=0.001-0.005) values for this subgroup were different than control values. CONCLUSIONS We conclude that heterogeneous, bimodally distributed hemodynamic responses to alpha2-adrenergic blockade in subjects with positive family histories of hypertension suggest a discrete subgroup with early expression of perhaps Mendelian traits associated with risk of later development of hypertension. Such phenotypic traits ('intermediate phenotypes'), with earlier penetrance than hypertension itself, can be
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Affiliation(s)
- T T Dao
- Department of Medicine, University of California, San Diego 92161, USA
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24
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Sali DL, Ingram R, Wendel M, Gupta D, McNemar C, Tsarbopoulos A, Chen JW, Hong Z, Chase R, Risano C, Zhang R, Yao N, Kwong AD, Ramanathan L, Le HV, Weber PC. Serine protease of hepatitis C virus expressed in insect cells as the NS3/4A complex. Biochemistry 1998; 37:3392-401. [PMID: 9521660 DOI: 10.1021/bi972010r] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatitis C virus (HCV) protease NS3 and its protein activator NS4A participate in the processing of the viral polyprotein into its constituent nonstructural proteins. The NS3/4A complex is thus an attractive target for antiviral therapy against HCV. We expressed the full-length NS3 and NS4A in insect cells as a soluble fusion protein with an N-terminal polyhistidine tag and purified the two proteins to homogeneity. Cleavage at the junction between HisNS3 and NS4A occurs during expression, producing a noncovalent complex between HisNS3 and NS4A with a subnanomolar dissociation constant. We purified the HisNS3/4A complex by detergent extraction of cell lysate and by metal chelate chromatography. We removed the His tag by thrombin cleavage and then further purified the complex by gel filtration. The purified NS3/4A complex is active in a protease assay using a synthetic peptide substrate derived from the NS5A-NS5B junction, with kcat/K(m) of 3700 (+/- 600) M-1 s-1, an order of magnitude above those previously reported for NS3 expressed by other strategies. This high protease activity implies that the full-length sequences of NS3 and NS4A are required for optimal activity of the NS3 protease domain. We examined the dependence of the NS3/4A protease activity on buffer conditions, temperature, and the presence of detergents. We find that, under most conditions, NS3 protease activity is dependent on the aggregation state of the NS3/4A complex. The monodisperse, soluble form of the NS3/4A complex is associated with the highest protease activity.
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Affiliation(s)
- D L Sali
- Department of Structural Chemistry, Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA
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25
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Affiliation(s)
- Z Wu
- Schering-Plough Research Institute, Kenilworth, NJ 07033, USA.
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26
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McNemar C, Snow ME, Windsor WT, Prongay A, Mui P, Zhang R, Durkin J, Le HV, Weber PC. Thermodynamic and structural analysis of phosphotyrosine polypeptide binding to Grb2-SH2. Biochemistry 1997; 36:10006-14. [PMID: 9254595 DOI: 10.1021/bi9704360] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A thermodynamic analysis using isothermal titration calorimetry (ITC) has been performed to examine the binding interaction between the SH2 (Src homology 2) domain of growth factor receptor binding protein 2 (Grb2-SH2) and one of its phosphotyrosine (pY) polypeptide ligands. Interaction of the Shc-derived phosphotyrosine hexapeptide Ac-SpYVNVQ-NH2 with Grb2-SH2 was both enthalpically and entropically favorable (DeltaH = -7.55 kcal mol-1, -TDeltaS = -1.46 kcal mol-1 , DeltaG = -9.01 kcal mol-1, T = 20 degrees C). ITC experiments using five alanine-substituted peptides were performed to examine the role of each side chain in binding. The results were consistent with homology models of the Grb2-SH2-Shc hexapeptide complex which identified several possible hydrogen bonds between Grb2-SH2 and the phosphotyrosine and conserved asparagine(+2) side chains of the Shc hexapeptide. These studies also demonstrated that the hydrophobic valine(+1) side chain contributes significantly to the favorable entropic component of binding. The thermodynamic and structural data are consistent with a Grb2-SH2 recognition motif of pY-hydrophobic-N-X (where X is any amino acid residue). The measured heat capacity of binding (DeltaCp = -146 cal mol-1 K-1) was very similar to computed values using semiempirical estimates (DeltaCp = -106 to -193 cal mol-1 K-1) derived from apolar and polar accessible surface area values calculated from several homology models of the Grb2-SH2-Shc hexapeptide complex. The homology model which most closely reproduced the measured DeltaCp value is also the model which had the lowest RMS deviation from the subsequently determined crystal structure. Calculations based on the thermodynamic data and these semiempirical estimates indicated that the binding event involves burial of nearly comparable apolar (677 A2) and polar (609 A2) surface areas.
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Affiliation(s)
- C McNemar
- Structural Chemistry Department, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, USA
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27
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Zhang R, Durkin J, Windsor WT, McNemar C, Ramanathan L, Le HV. Probing the substrate specificity of hepatitis C virus NS3 serine protease by using synthetic peptides. J Virol 1997; 71:6208-13. [PMID: 9223519 PMCID: PMC191885 DOI: 10.1128/jvi.71.8.6208-6213.1997] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We probed the substrate specificity of a recombinant noncovalent complex of the full-length hepatitis C virus (HCV) NS3 serine protease and NS4A cofactor, using a series of small synthetic peptides derived from the three trans-cleavage sites of the HCV nonstructural protein sequence. We observed a distinct cleavage site preference exhibited by the enzyme complex. The values of the turnover number (k(cat)) for the most efficient NS4A/4B, 4B/5A, and 5A/5B peptide substrates were 1.6, 11, and 8 min(-1), respectively, and the values for the corresponding Michaelis-Menten constants (Km) were 280, 160, and 16 microM, providing catalytic efficiency values (k(cat)/Km) of 92, 1,130, and 8,300 M(-1) s(-1). An alanine-scanning study for an NS5A/5B substrate (P6P4') revealed that P1 Cys and P3 Val were critical. Finally, substitutions at the scissile P1 Cys residue by homocysteine (Hcy), S-methylcysteine (Mcy), Ala, S-ethylcysteine (Ecy), Thr, Met, D-Cys, Ser, and penicillamine (Pen) produced progressively less efficient substrates, revealing a stringent stereochemical requirement for a Cys residue at this position.
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Affiliation(s)
- R Zhang
- Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA.
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Abstract
Helicases are nucleotide triphosphate (NTP)-dependent enzymes responsible for unwinding duplex DNA and RNA during genomic replication. The 2.1 A resolution structure of the HCV helicase from the positive-stranded RNA hepatitis C virus reveals a molecule with distinct NTPase and RNA binding domains. The structure supports a mechanism of helicase activity involving initial recognition of the requisite 3' single-stranded region on the nucleic acid substrate by a conserved arginine-rich sequence on the RNA binding domain. Comparison of crystallographically independent molecules shows that rotation of the RNA binding domain involves conformational changes within a conserved TATPP sequence and untwisting of an extended antiparallel beta-sheet. Location of the TATPP sequence at the end of an NTPase domain beta-strand structurally homologous to the 'switch region' of many NTP-dependent enzymes offers the possibility that domain rotation is coupled to NTP hydrolysis in the helicase catalytic cycle.
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Affiliation(s)
- N Yao
- Structural Chemistry and Virology Department, Schering-Plough Research Institute, Kensworth, New Jersey 07033, USA
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29
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Taremi SS, Prosise WW, Rajan N, O'Donnell RA, Le HV. Human interleukin 4 receptor complex: neutralization effect of two monoclonal antibodies. Biochemistry 1996; 35:2322-31. [PMID: 8652573 DOI: 10.1021/bi951741t] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The interaction of human interleukin 4 with the extracellular domain of its receptor alpha-subunit (shuIL-4R alpha) was characterized in studies utilizing chemical cross-linking, size exclusion chromatography, and Western blot analysis. A 1:1 stoichiometric complex could be demonstrated over a wide range (0.04-2.7) of ligand-receptor concentration ratios. It could also be cross-linked with bifunctional reagents containing a minimum chain length of eight methylene residues or the equivalent (11.4 angstroms). Using surface plasmon resonance, (SPR) technology, we established the high-affinity of human interleukin 4 (huIL-4) to shuIL-4R alpha which was immobilized on a BIAcore sensor chip (K(d) = 46 pM). The mechanisms of action of neutralizing monoclonal antibodies (Mab) 25D2 and 35F2 [Abrams et al. (1991) U.S. Patent 5,041,381; Ramanathan et al. (1990) in Advances in Gene Technology: The Molecular Biology of Immune Diseases and the Immune Response (Streilein, J. W., et al., Eds.) p 163, IRL Press, Oxford; DeKruyff et al. (1989) J. Exp. Med. 170, 1477-1493] were subsequently evaluated on the basis of their interaction with huIL-4 in the presence of shuIL-4R alpha. SPR studies showed that Mab 25D2 binds to huIL-4 and reduces its affinity for shuIL-4R alpha by 54-fold. Formation of a ternary complex between Mab 25D2 and the huIL-4/shuIL-4R alpha complex was demonstrated in size exclusion chromatography experiments. In contrast, Mab 35F2 which also binds huIL-4 failed to form a stable ternary complex with huIL-4 and shuIL-4 alpha during size exclusion chromatography. SPR studies supported this finding and showed that the interactions of Mab 35F2 and shuIL-4R alpha to huIL-4 are mutually exclusive. These data are consistent with results of previous epitope mapping studies showing that Mabs 25D2 and 35F2 bind to huIL-4 at two different sites [Ramanathan et al. (1993) Biochemistry 32, 3549-3556]. Together, the results suggest that Mab 25D2 binds to a domain in huIL-4 including helix D and exerts its inhibitory effect through a dual action. It decreases the affinity of huIL-4 for huIL-4R alpha and potentially blocks interaction with a secondary receptor subunit such as the IL-2R gamma [Reusch et al. (1994) Eur. J. Biochem. 222, 491-499]. Mab 35F2 operates through a direct and simpler mechanism, binding to helix C and inhibiting huIL-4 activity by sterically excluding all interaction with huIL-4R alpha.
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Affiliation(s)
- S S Taremi
- Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA
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30
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Rajan N, Tsarbopoulos A, Kumarasamy R, O'Donnell R, Taremi SS, Baldwin SW, Seelig GF, Fan X, Pramanik B, Le HV. Characterization of recombinant human interleukin 4 receptor from CHO cells: role of N-linked oligosaccharides. Biochem Biophys Res Commun 1995; 206:694-702. [PMID: 7826389 DOI: 10.1006/bbrc.1995.1098] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Interleukin 4 (IL-4) mediates its biological activities through interaction with its receptor on the cell surface. A recombinant extracellular domain of the alpha subunit of human interleukin 4 receptor was expressed in CHO cells and purified to homogeneity by a combination of ion exchange and immunoaffinity chromatography. Analysis of the purified protein by MALDI MS provided an average mass of 38,241 Da while microsequencing identified the site of the signal sequence processing to be Ser23-Gly24. The receptor was highly glycosylated, containing N-linked complex oligosaccharides with bi-, tri-, and tetraantennary structures. Five of the six potential glycosylation sites could be assigned to Asn residues 53, 98, 128, 134 and 176. N-deglycosylation increased aggregation and reduced solubility of the receptor but did not affect its IL-4 binding activity. These observations provide preliminary insights into the role of N-linked oligosaccharides in IL-4 receptor biosynthesis and function at the cell surface.
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Affiliation(s)
- N Rajan
- Schering-Plough Research Institute, Kenilworth, New Jersey 07033
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31
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Tran TH, Arnold K, Nguyen TH, Pham PL, Nguyen TD, Bui MC, Le MT, Mach QP, Le HV, Pham PM. Single dose artemisinin-mefloquine treatment for acute uncomplicated falciparum malaria. Trans R Soc Trop Med Hyg 1994; 88:688-91. [PMID: 7886773 DOI: 10.1016/0035-9203(94)90231-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
For the treatment of patients with acute falciparum malaria, the combination of artemisinin as a single dose with a single dose of mefloquine was studied in 4 separate prospective trials, comprising 405 adults and 139 children with uncomplicated falciparum malaria in 2 in-patient and 2 rural out-patient studies in Viet Nam. Adults received oral artemisinin and children artemisinin suppositories. Randomized comparative treatment schedules were: artemisinin alone for 5 d, mefloquine-sulfadoxine-pyrimethamine (MSP), or quinine plus sulfadoxine-pyrimethamine (SP). Parasite clearance times (PCT) were rapid for artemisinin treated inpatients (90%: 14.8-20.4 h) but also for patients receiving MSP (PCT 90%: 18.0 h) and quinine (PCT 90%: 22.5 h). The recrudescence rate (RI) during a 28 d follow-up period among the patients given artemisinin plus mefloquine was 15% in the adult in-patients and zero in the adult and children out-patients. RI in the artemisinin 5 d treatment group was 33.3%; among those given artemisinin plus SP it was 47.3% in in-patients and in out-patients 46.1%. In the MSP treated out-patients RI was 1.5% in adults and zero in children. Artemisinin as a single dose (oral in adults and as a suppository in children) in combination with mefloquine was effective in rapidly lowering parasitaemia and in preventing recrudescence in hospital in-patients and in out-patients attending a rural health clinic. MSP alone as a single dose also rapidly reduced parasitaemia (but not as quickly as the artemisinin-mefloquine combination in out-patient children) and prevented recrudescence.
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Affiliation(s)
- T H Tran
- Centre for Tropical Diseases (Cho Quan Hospital), Ho Chi Minh City, Viet Nam
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32
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Ramanathan L, Ingram R, Sullivan L, Greenberg R, Reim R, Trotta PP, Le HV. Immunochemical mapping of domains in human interleukin 4 recognized by neutralizing monoclonal antibodies. Biochemistry 1993; 32:3549-56. [PMID: 7682108 DOI: 10.1021/bi00065a005] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Human interleukin 4 is a highly pleiotropic cytokine secreted by activated T cells that exerts multiple biological effects on B and T lymphocytes and other cell types. Elucidation of structure-function relations was accomplished by epitope mapping of a panel of monoclonal antibodies and by mutagenesis of selected amino acid residues. Epitope mapping of these monoclonal antibodies was achieved through binding studies with recombinant human interleukin 4 (rhuIL-4), proteolytic fragments produced by digestion with Staphylococcus aureus V8 protease and synthetic peptides derived from the sequence of the parent molecule. Monoclonal antibodies 25D2, 35F2, and 11B4 neutralized the in vitro T-cell proliferation activity of rhuIL-4 and also prevented binding of rhuIL4 to its cell surface receptor. These antibodies recognized sequences 104-129, 70-92, and 61-82, respectively. These regions comprise the BC loop/helix C (residues 61-92) and helix D (residues 104-129). A nonneutralizing monoclonal antibody (1A2) recognized a nonoverlapping region (residues 43-59) comprising almost entirely helix B. Mutagenesis of a cluster of residues within helix C showed that at least three residues (K84, R88, and N89) were potentially involved in receptor recognition. The existence of two distinct nonneighboring binding domains in the three-dimensional structure of rhuIL-4 provided preliminary evidence for a model of receptor interaction involving the formation of a ternary complex consisting of two molecules of the extracellular portion of the receptor and one molecule of rhuIL-4.
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Affiliation(s)
- L Ramanathan
- Schering-Plough Research Institute, Kenilworth, New Jersey 07033
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33
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Le HV, Seelig GF, Syto R, Ramanathan L, Windsor WT, Borkowski D, Trotta PP. Selective proteolytic cleavage of recombinant human interleukin 4. Evidence for a critical role of the C-terminus. Biochemistry 1991; 30:9576-82. [PMID: 1911743 DOI: 10.1021/bi00104a003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Human interleukin 4 is a 129 amino acid lymphokine secreted by activated T cells that exerts pleiotropic biological effects on B and T lymphocytes and other hematopoietic cells. Structure-function relations were studied by employing selective proteolytic cleavage of purified recombinant human interleukin 4 (rhuIL-4). Limited proteolysis with endoprotease Glu-C from Staphylococcus aureus (V8) produced two digestion products that were observed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with apparent molecular weight values of 19K (I) and 15K (II), respectively. These species were isolated by reversed-phase HPLC. Amino acid sequencing indicated that species II was an 84 amino acid core fragment extending from Gln-20 to Glu-103 and containing a hydrolyzed peptide bond at Glu-26. On the basis of known disulfide bond assignments, it was concluded that species II was stabilized by two disulfide bonds (Cys-24/Cys-65 and Cys-46/Cys-99). Analysis of its secondary structure by circular dichroism revealed a high content of alpha helix. Species I was the full-length rhuIL-4 with selective cleavage at Glu-26 and Glu-103. Both species I and II were inactive in an in vitro assay based on proliferation of peripheral blood lymphocyte blasts and lacked the ability to bind to teh rhuIL-4 receptor on Daudi cells. In order to elucidate further the role of the residues removed by S. aureus V8 protease, rabbit antisera were raised to synthetic peptides corresponding to residues 1-26 at the N-terminus and 104-129 at the C-terminus. Only antisera directed to the C-terminal peptide inhibited binding of 125I-rhuIL-4 to Daudi cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- H V Le
- Schering-Plough Research, Bloomfield, New Jersey 07003
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34
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Cook WJ, Ealick SE, Reichert P, Hammond GS, Le HV, Nagabhushan TL, Trotta PP, Bugg CE. Crystallization and preliminary X-ray investigation of recombinant human interleukin 4. J Mol Biol 1991; 218:675-8. [PMID: 2023241 DOI: 10.1016/0022-2836(91)90253-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Crystals of recombinant human interleukin 4 have been grown from solutions of ammonium sulfate. The crystals are tetragonal, space-group P4(1)2(1)2 or P4(3)2(1)2; the unit cell axes are a = 92.2(1) A and c = 46.4(1) A. The crystals are stable to X-rays for at least three days and diffract beyond 2.8 A resolution. The crystals contain approximately 63% solvent, assuming there is one molecule in the asymmetric unit.
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Affiliation(s)
- W J Cook
- Department of Pathology, University of Alabama, Birmingham 35294
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35
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Windsor WT, Syto R, Le HV, Trotta PP. Analysis of the conformation and stability of Escherichia coli derived recombinant human interleukin 4 by circular dichroism. Biochemistry 1991; 30:1259-64. [PMID: 1991106 DOI: 10.1021/bi00219a014] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The conformation and stability of Escherichia coli derived recombinant human interleukin 4 (rhuIL-4) have been examined by circular dichroism (CD). Protein unfolding was detected by ellipticity changes at 222 nm with increasing concentrations of guanidine hydrochloride (GdnHCl). The unfolding midpoint ([GdnHCl]1/2) was 3.7 M, the free energy of unfolding, (delta GDH2O), was 5.9 kcal/mol and the dependence of delta GD on the GdnHCl concentration (m) was 1.6 (kcal/mol)/M. This unfolding was demonstrated to be reversible upon removal of the GdnHCl by dialysis. Analysis of the far-UV CD spectrum indicated the presence of a high percentage of alpha-helical structure (ca. 73%). A small change in ellipticity was noted over the pH range 1.9-9.6, suggesting that the protein undergoes a minor conformational change with an apparent pKa of 4.17. Virtually complete biological activity, measured in vitro in a T-cell proliferation assay, was recovered following exposure to extreme values of pH (i.e., pH 3 and 10). An analysis of the near-UV CD spectrum indicated that the single tryptophan residue at position 91 was unconstrained and most likely exposed to the solvent. Titration with 4,4'-dithiodipyridine and 2-nitrothiosulfobenzoate established that the six cysteine residues in rhuIL-4 were involved in intramolecular disulfide linkages. These data support that rhuIL-4 has a highly stable three-dimensional structure.
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Affiliation(s)
- W T Windsor
- Department of Biotechnology-Biochemistry, Schering-Plough Research, Bloomfield, New Jersey 07003
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36
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Le HV, Trotta PP. Purification of secreted recombinant proteins from Escherichia coli. Bioprocess Technol 1991; 12:163-81. [PMID: 1367083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Secretion systems engineered for the expression of heterologous protein in E. coli provide several advantages for subsequent isolation of purified product. Proteins released from the periplasmic space, which represent a small fraction (i.e., 4-10%) of total cell protein, can readily be separated from other cellular proteins by centrifugation of the remaining cellular debris or cross-flow ultrafiltration. The starting material derived from secretion systems is generally of higher purity than comparable material produced from strains expressing cytoplasmically for systems exhibiting similar expression levels. The available evidence suggests that recombinant proteins derived from the periplasm are generally, but not always (44-46), soluble in a nonaggregated form. Consequently, simple purification protocols can be effectively employed for producing homogeneous product with a high yield. The majority of the secreted recombinant proteins reviewed in this chapter were purified by simple one- or two-step chromatography procedures. High-resolution techniques such as reversed phase HPLC were found necessary only in cases where the secreted polypeptides were contaminated with proteolytic degradation variants, e.g., hirudin (51) and beta-endorphin (22). The fact that a high level of biological activity has been shown to be characteristic of purified recombinant proteins secreted into the periplasmic space suggests the presence of a native conformation stabilized by the expected disulfide linkages. Intramolecular disulfide bonds most probably form either as the polypeptide is translocated through the cytoplasmic membrane into the periplasm or within the periplasmic compartment, which has a higher oxidation potential than that found in the cytoplasm (57). Studies performed with hGH (31) and muIL-2 (35) provide excellent examples of differences observed in protein folding and disulfide bond formation between heterologous proteins expressed in the cytoplasmic and periplasmic compartments. Thus, hGH and muIL-2 extracted from the cytoplasm of E. coli have been characterized as high molecular weight disulfide-bonded oligomers. It is likely that oligomerization occurs as the polypeptides are released from the reducing environment of the cytoplasm. In contrast, secreted hGH and muIL-2 extracted from the periplasm of E. coli by osmotic shock displayed the properties of a property folded native protein with correct disulfide pairing. In the case of muIL-2 only a small residual fraction (approximately 15%) of the purified secreted protein exhibited incomplete oxidation of cysteine (35). Secretion of heterologous proteins into the periplasm prevents their exposure to the action of proteases located in the cytoplasm of E. coli (58). The smaller polypeptides such as somatostatin (59), IGF-1 (46), and hEGF (54) are known to be particularly susceptible to intracellular degradation.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- H V Le
- Schering-Plough Research Bloomfield, New Jersey
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37
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Reichert P, Cook WJ, Ealick SE, Hammond GS, Le HV, Nagabhushan TL, Trotta PP, Bugg CE. Crystallization and preliminary x-ray investigation of recombinant human granulocyte-macrophage colony-stimulating factor. J Biol Chem 1990; 265:452-3. [PMID: 2403563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Crystals of recombinant human granulocyte-macrophage colony-stimulating factor have been grown from solutions of polyethylene glycol 8000. The crystals are orthorhombic, space group P2(1)2(1)2(1); the axes are a = 45.5(1), b = 58.7(1) and c = 127.3(1) A. The crystals are stable to x-rays for at least 3 days and diffract beyond 2.8-A resolution. Although the molecule exists as a monomer in solution, it crystallizes with two or three molecules in the asymmetric unit.
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Affiliation(s)
- P Reichert
- Schering Corporation, Bloomfield, New Jersey 07003
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38
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Ramanathan L, Le HV, Labdon JE, Mays-Ichinco CA, Syto R, Arai N, Nagabhushan TL, Trotta PP. Multiple forms of recombinant murine interleukin-4 expressed in COS-7 monkey kidney cells. Biochim Biophys Acta 1989; 1007:283-8. [PMID: 2784692 DOI: 10.1016/0167-4781(89)90149-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Recombinant murine interleukin-4 (muIL-4) expressed in COS-7 monkey kidney cells was purified to homogeneity by sequential CM-Sepharose, Sephadex G-100 chromatography and mono-S FPLC to a specific activity of 6.10(7) units per mg of protein based on an in vitro HT-2 cell proliferation assay. Two electrophoretic variants, designated a and b, which migrated on SDS-PAGE as a closely spaced doublet with Mr 19,000, were present in the final product. Gas phase sequencing of the purified protein revealed the presence of an N-terminus corresponding to the mature protein predicted from the cDNA sequence and sequencing of a cyanogen bromide digest confirmed 75 of the 120 predicted amino acids. Elution behavior on gel filtration corresponded to that of a monomer of Mr 19,000. Since there are three potential sites of N-glycosylation predicted by the cDNA sequence, the contribution of glycosylation to the observed heterogeneity was examined by treatment with endoglycosidases. Variant b was digested by either endo-beta-N-acetylglucosaminidase H (endo H) or endo-beta-N-acetylglucosaminidase F (endo F) to protein of Mr 15,000 on SDS-PAGE but was unaffected by treatment with endo-beta-N-acetylglucosaminidase D (endo D), thus indicating the presence of high mannose type of N-glycan. In contrast, variant a was resistant to endo H, F and D. Complete conversion of a mixture of variants a and b to a single protein of Mr 15,000 on SDS-PAGE was obtained only after treatment with N-glycanase. Both variants were resistant to neuraminidase and O-glycanase treatment. These data show that the microheterogeneity observed in purified muIL-4 preparations is due to differences in the nature of the N-linked oligosaccharides. The availability of purified recombinant muIL-4 and a methodology for both total and selective deglycosylation provides a basis for the initiation of structure-function studies of this novel T-cell lymphokine.
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Affiliation(s)
- L Ramanathan
- Department of Biotechnology-Biochemistry, Schering Corporation, Bloomfield, NJ 07003
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39
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Le HV, Syto R, Schwartz J, Nagabhushan TL, Trotta PP. Purification and properties of a novel recombinant human hybrid interferon, delta-4 alpha 2/alpha 1. Biochim Biophys Acta 1988; 957:143-51. [PMID: 3052593 DOI: 10.1016/0167-4838(88)90167-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The human interferon (huIFN) delta-4 alpha 2(5-62)/alpha 1(64-166) is a genetically engineered hybrid that consists of residues 5-62 of huIFN alpha 2 and residues 64-166 of huIFN alpha 1. This variant contains four cysteine residues at positions 29, 86, 99 and 139, but does not contain the cysteine at position 1 that is characteristic of naturally occurring huIFN alpha subtypes. This novel recombinant hybrid was purified from Escherichia coli to greater than 95% homogeneity. The purification was based on ethanol extraction of a trichloroacetic acid precipitate and Matrex Gel Blue A chromatography followed by either a selective precipitation or DEAE-Sepharose chromatography. The purified protein that was treated with 2-mercaptoethanol exhibited two closely migrating bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with apparent molecular weight values of 17,800 and 17,100, both of which exhibited antiviral activity. Electrophoresis performed without prior reduction with 2-mercaptoethanol indicated only a minor extent of intermolecular disulfide bonding. The purified protein exhibited a high specific antiviral activity of 7 x 10(7) units/mg when assayed on human fibroblast cells and, in distinction to the parental huIFN alpha 2, it also demonstrated antiviral activity on human fibroblast cells and, in distinction to the parental huIFN alpha 2, it also demonstrated antiviral activity on murine L929 cells. The level of antiproliferative activity of huIFN delta-4 alpha 2(5-62)/alpha 1(64-166) on various cell lines of different histological origin appeared to be more comparable to that of huIFN alpha 1 than huIFN alpha 2. The data suggest that huIFN delta-4 alpha 2(5-62)/alpha 1(64-166) hybrid may be a useful tool for understanding huIFN structure-function relations.
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Affiliation(s)
- H V Le
- Schering Corporation Bloomfield, NJ 07003
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40
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Le HV, Ramanathan L, Labdon JE, Mays-Ichinco CA, Syto R, Arai N, Hoy P, Takebe Y, Nagabhushan TL, Trotta PP. Isolation and characterization of multiple variants of recombinant human interleukin 4 expressed in mammalian cells. J Biol Chem 1988; 263:10817-23. [PMID: 3260592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We have purified recombinant human interleukin 4 (huIL-4), formerly named B-cell stimulatory factor-1, from supernatants of COS-7 monkey kidney and L-929 cells transfected with the cDNA for huIL-4. The purified protein exhibited a specific activity of 2.6 X 10(7) units/mg in a T-cell proliferation assay and consisted of multiple components on sodium dodecyl sulfate-polyacrylamide gel electrophoresis exhibiting Mr values of 15,000, 18,000, and 19,000. All forms of huIL-4 eluted on gel filtration chromatography with an apparent Mr of 22,000. Gas-phase microsequencing identified 26 and 8 amino acid residues at the N and C termini, respectively, all of which were consistent with the cDNA sequence. The site of processing of the signal sequence was found to occur between Gly-24 and His-25. Incubation with N-glycanase converted the 18- and 19-kDa variants to a 15-kDa form. Treatment with endo-beta-N-acetylglucosaminidase H reduced the molecular mass of the 18-kDa variant to 15 kDa, but did not have any apparent effects on the mass of the 19-kDa species. The removal of oligosaccharide by any of these treatments did not affect bioactivity in the T-cell proliferation assay. Neither O-glycanase nor endo-beta-N-acetylglucosaminidase D affected the molecular weight of any of these species. These data suggest that differences in carbohydrate structure account, at least in part, for the observed microheterogeneity.
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Affiliation(s)
- H V Le
- Department of Biotechnology, Schering Corporation, Bloomfield, New Jersey 07003
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41
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Le HV, Ramanathan L, Labdon JE, Mays-Ichinco CA, Syto R, Arai N, Hoy P, Takebe Y, Nagabhushan TL, Trotta PP. Isolation and characterization of multiple variants of recombinant human interleukin 4 expressed in mammalian cells. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)38043-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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42
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Davis JE, Rich RR, Van M, Le HV, Pollack MS, Cook RG. Defective antigen presentation and novel structural properties of DR1 from an HLA haplotype associated with 21-hydroxylase deficiency. J Clin Invest 1987; 80:998-1008. [PMID: 2443540 PMCID: PMC442338 DOI: 10.1172/jci113194] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We have segregated DR1+ individuals into two categories according to whether or not their class II+ cells stimulated T lymphocyte clones specific for or restricted to DR1. In a majority of cases (87%), failure to stimulate was a property of cells having the B14;DR1 haplotype and/or nonclassical 21-hydroxylase deficiency. Absence of clonal proliferation could not be explained by release of an intercellular suppressor factor or by stimulator cell absorption of interleukin 2. Homozygous cells inheriting both stimulatory (DR1n) and nonstimulatory (DR1x) haplotypes did not successfully mediate clonal expansion, implying that a trans acting factor operates intracellularly to modify both DR1 alleles or their products. Other DR alleles did not appear to be affected as evidence by normal proliferative responses of T lymphocyte clones restricted to DR2 or DR7 and stimulated by DR1x,2 and DR1x,7 cells, respectively. By two-dimensional gel analysis, we have further identified a 50-kD surface glycoprotein contained in anti-DR immunoprecipitates of DR1x, but not DR1n or non-DR1 cellular lysates. This 50-kD structure had antigenic and peptide identity to DR alpha and beta chains but was resistant to dissociation under conditions that normally separate DR alpha and beta (8 M urea plus 5% 2-mercaptoethanol); boiling in sodium dodecyl sulfate was required to segregate the component polypeptides of the 50-kD heterodimer. We postulate that a product of a novel combinatorial association between constitutive chains of DR may interfere with or compete for normal T cell receptor recognition of DR1 as both an alloantigen and a restricting element. We further propose that gene abnormalities within the class III region of a haplotype associated with nonclassical 21-hydroxylase deficiency may extend into the DR subregion of the major histocompatibility complex with consequent aberrations in DR1 presentation.
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Affiliation(s)
- J E Davis
- Howard Hughes Medical Institute Laboratory, Baylor College of Medicine, Houston, Texas 77030
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Dinarello CA, Bernheim HA, Duff GW, Le HV, Nagabhushan TL, Hamilton NC, Coceani F. Mechanisms of fever induced by recombinant human interferon. J Clin Invest 1984; 74:906-13. [PMID: 6590569 PMCID: PMC425246 DOI: 10.1172/jci111508] [Citation(s) in RCA: 170] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Since the early trials using human interferon (hIFN) derived from blood leukocytes or cell lines, fever has been a prominent component of IFN therapy. Human protein impurities might account for the fever to cell-derived hIFN, but recombinant hIFN, free of extraneous human proteins, has produced fever in nearly all recipients during clinical trials. Our present studies were carried out to determine the mechanisms of fever due to recombinant hIFN currently being used in humans. Because recombinant hIFN is produced in Escherichia coli, in these experiments we considered contaminating endotoxin as the cause of fever. Polymyxin B, which blocks endotoxin, had no effect on the pyrogenicity of hIFN in rabbits. In addition, hIFN injected into an endotoxin-resistant strain of mice produced fever. The pyrogenicity of hIFN does not appear to involve production of leukocytic pyrogen (LP), since no circulating LP was detected in rabbits during IFN fever. Furthermore, human mononuclear cells incubated with hIFN in vitro at 10(4)-10(6) U/ml did not release LP. However, hIFN stimulated prostaglandin E2 (PGE2) release from rabbit hypothalamic tissue in vitro. Intracerebroventricular injection of hIFN into the awake cat also produced fever and a rise in PGE2 levels in the cerebrospinal fluid; both effects were reversed by treatment with indomethacin. We conclude that the fever of recombinant hIFN is not due to endotoxin but that hIFN is intrinsically pyrogenic by inducing PGE2 in the hypothalamus.
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Abstract
Human fibroblast interferon was partially purified, about 4,000-fold, on a chromatographic tandem of columns: concanavalin A-agarose leads to phenyl-agarose, to a specific activity of ca 4 x 10(7). The overall recovery of interferon activity was ca 60%.
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