1
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Rosenberg E, Andersen TI, Samajdar R, Petukhov A, Hoke JC, Abanin D, Bengtsson A, Drozdov IK, Erickson C, Klimov PV, Mi X, Morvan A, Neeley M, Neill C, Acharya R, Allen R, Anderson K, Ansmann M, Arute F, Arya K, Asfaw A, Atalaya J, Bardin JC, Bilmes A, Bortoli G, Bourassa A, Bovaird J, Brill L, Broughton M, Buckley BB, Buell DA, Burger T, Burkett B, Bushnell N, Campero J, Chang HS, Chen Z, Chiaro B, Chik D, Cogan J, Collins R, Conner P, Courtney W, Crook AL, Curtin B, Debroy DM, Barba ADT, Demura S, Di Paolo A, Dunsworth A, Earle C, Faoro L, Farhi E, Fatemi R, Ferreira VS, Burgos LF, Forati E, Fowler AG, Foxen B, Garcia G, Genois É, Giang W, Gidney C, Gilboa D, Giustina M, Gosula R, Dau AG, Gross JA, Habegger S, Hamilton MC, Hansen M, Harrigan MP, Harrington SD, Heu P, Hill G, Hoffmann MR, Hong S, Huang T, Huff A, Huggins WJ, Ioffe LB, Isakov SV, Iveland J, Jeffrey E, Jiang Z, Jones C, Juhas P, Kafri D, Khattar T, Khezri M, Kieferová M, Kim S, Kitaev A, Klots AR, Korotkov AN, Kostritsa F, Kreikebaum JM, Landhuis D, Laptev P, Lau KM, Laws L, Lee J, Lee KW, Lensky YD, Lester BJ, Lill AT, Liu W, Locharla A, Mandrà S, Martin O, Martin S, McClean JR, McEwen M, Meeks S, Miao KC, Mieszala A, Montazeri S, Movassagh R, Mruczkiewicz W, Nersisyan A, Newman M, Ng JH, Nguyen A, Nguyen M, Niu MY, O'Brien TE, Omonije S, Opremcak A, Potter R, Pryadko LP, Quintana C, Rhodes DM, Rocque C, Rubin NC, Saei N, Sank D, Sankaragomathi K, Satzinger KJ, Schurkus HF, Schuster C, Shearn MJ, Shorter A, Shutty N, Shvarts V, Sivak V, Skruzny J, Smith WC, Somma RD, Sterling G, Strain D, Szalay M, Thor D, Torres A, Vidal G, Villalonga B, Heidweiller CV, White T, Woo BWK, Xing C, Yao ZJ, Yeh P, Yoo J, Young G, Zalcman A, Zhang Y, Zhu N, Zobrist N, Neven H, Babbush R, Bacon D, Boixo S, Hilton J, Lucero E, Megrant A, Kelly J, Chen Y, Smelyanskiy V, Khemani V, Gopalakrishnan S, Prosen T, Roushan P. Dynamics of magnetization at infinite temperature in a Heisenberg spin chain. Science 2024; 384:48-53. [PMID: 38574139 DOI: 10.1126/science.adi7877] [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] [Received: 05/18/2023] [Accepted: 03/01/2024] [Indexed: 04/06/2024]
Abstract
Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text]. The first two moments of [Formula: see text] show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments ruled out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide insights into universal behavior in quantum systems.
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Affiliation(s)
- E Rosenberg
- Google Research, Mountain View, CA, USA
- Department of Physics, Cornell University, Ithaca, NY, USA
| | | | - R Samajdar
- Department of Physics, Princeton University, Princeton, NJ, USA
- Princeton Center for Theoretical Science, Princeton University, Princeton, NJ, USA
| | | | - J C Hoke
- Department of Physics, Stanford University, Stanford, CA, USA
| | - D Abanin
- Google Research, Mountain View, CA, USA
| | | | - I K Drozdov
- Google Research, Mountain View, CA, USA
- Department of Physics, University of Connecticut, Storrs, CT, USA
| | | | | | - X Mi
- Google Research, Mountain View, CA, USA
| | - A Morvan
- Google Research, Mountain View, CA, USA
| | - M Neeley
- Google Research, Mountain View, CA, USA
| | - C Neill
- Google Research, Mountain View, CA, USA
| | - R Acharya
- Google Research, Mountain View, CA, USA
| | - R Allen
- Google Research, Mountain View, CA, USA
| | | | - M Ansmann
- Google Research, Mountain View, CA, USA
| | - F Arute
- Google Research, Mountain View, CA, USA
| | - K Arya
- Google Research, Mountain View, CA, USA
| | - A Asfaw
- Google Research, Mountain View, CA, USA
| | - J Atalaya
- Google Research, Mountain View, CA, USA
| | - J C Bardin
- Google Research, Mountain View, CA, USA
- Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA, USA
| | - A Bilmes
- Google Research, Mountain View, CA, USA
| | - G Bortoli
- Google Research, Mountain View, CA, USA
| | | | - J Bovaird
- Google Research, Mountain View, CA, USA
| | - L Brill
- Google Research, Mountain View, CA, USA
| | | | | | - D A Buell
- Google Research, Mountain View, CA, USA
| | - T Burger
- Google Research, Mountain View, CA, USA
| | - B Burkett
- Google Research, Mountain View, CA, USA
| | | | - J Campero
- Google Research, Mountain View, CA, USA
| | - H-S Chang
- Google Research, Mountain View, CA, USA
| | - Z Chen
- Google Research, Mountain View, CA, USA
| | - B Chiaro
- Google Research, Mountain View, CA, USA
| | - D Chik
- Google Research, Mountain View, CA, USA
| | - J Cogan
- Google Research, Mountain View, CA, USA
| | - R Collins
- Google Research, Mountain View, CA, USA
| | - P Conner
- Google Research, Mountain View, CA, USA
| | | | - A L Crook
- Google Research, Mountain View, CA, USA
| | - B Curtin
- Google Research, Mountain View, CA, USA
| | | | | | - S Demura
- Google Research, Mountain View, CA, USA
| | | | | | - C Earle
- Google Research, Mountain View, CA, USA
| | - L Faoro
- Google Research, Mountain View, CA, USA
| | - E Farhi
- Google Research, Mountain View, CA, USA
| | - R Fatemi
- Google Research, Mountain View, CA, USA
| | | | | | - E Forati
- Google Research, Mountain View, CA, USA
| | | | - B Foxen
- Google Research, Mountain View, CA, USA
| | - G Garcia
- Google Research, Mountain View, CA, USA
| | - É Genois
- Google Research, Mountain View, CA, USA
| | - W Giang
- Google Research, Mountain View, CA, USA
| | - C Gidney
- Google Research, Mountain View, CA, USA
| | - D Gilboa
- Google Research, Mountain View, CA, USA
| | | | - R Gosula
- Google Research, Mountain View, CA, USA
| | | | - J A Gross
- Google Research, Mountain View, CA, USA
| | | | - M C Hamilton
- Google Research, Mountain View, CA, USA
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
| | - M Hansen
- Google Research, Mountain View, CA, USA
| | | | | | - P Heu
- Google Research, Mountain View, CA, USA
| | - G Hill
- Google Research, Mountain View, CA, USA
| | | | - S Hong
- Google Research, Mountain View, CA, USA
| | - T Huang
- Google Research, Mountain View, CA, USA
| | - A Huff
- Google Research, Mountain View, CA, USA
| | | | - L B Ioffe
- Google Research, Mountain View, CA, USA
| | | | - J Iveland
- Google Research, Mountain View, CA, USA
| | - E Jeffrey
- Google Research, Mountain View, CA, USA
| | - Z Jiang
- Google Research, Mountain View, CA, USA
| | - C Jones
- Google Research, Mountain View, CA, USA
| | - P Juhas
- Google Research, Mountain View, CA, USA
| | - D Kafri
- Google Research, Mountain View, CA, USA
| | - T Khattar
- Google Research, Mountain View, CA, USA
| | - M Khezri
- Google Research, Mountain View, CA, USA
| | - M Kieferová
- Google Research, Mountain View, CA, USA
- QSI, Faculty of Engineering & Information Technology, University of Technology Sydney, Ultimo, NSW, Australia
| | - S Kim
- Google Research, Mountain View, CA, USA
| | - A Kitaev
- Google Research, Mountain View, CA, USA
| | - A R Klots
- Google Research, Mountain View, CA, USA
| | - A N Korotkov
- Google Research, Mountain View, CA, USA
- Department of Electrical and Computer Engineering, University of California, Riverside, CA, USA
| | | | | | | | - P Laptev
- Google Research, Mountain View, CA, USA
| | - K-M Lau
- Google Research, Mountain View, CA, USA
| | - L Laws
- Google Research, Mountain View, CA, USA
| | - J Lee
- Google Research, Mountain View, CA, USA
- Department of Chemistry, Columbia University, New York, NY, USA
| | - K W Lee
- Google Research, Mountain View, CA, USA
| | | | | | - A T Lill
- Google Research, Mountain View, CA, USA
| | - W Liu
- Google Research, Mountain View, CA, USA
| | | | - S Mandrà
- Google Research, Mountain View, CA, USA
| | - O Martin
- Google Research, Mountain View, CA, USA
| | - S Martin
- Google Research, Mountain View, CA, USA
| | | | - M McEwen
- Google Research, Mountain View, CA, USA
| | - S Meeks
- Google Research, Mountain View, CA, USA
| | - K C Miao
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | - M Newman
- Google Research, Mountain View, CA, USA
| | - J H Ng
- Google Research, Mountain View, CA, USA
| | - A Nguyen
- Google Research, Mountain View, CA, USA
| | - M Nguyen
- Google Research, Mountain View, CA, USA
| | - M Y Niu
- Google Research, Mountain View, CA, USA
| | | | - S Omonije
- Google Research, Mountain View, CA, USA
| | | | - R Potter
- Google Research, Mountain View, CA, USA
| | - L P Pryadko
- Department of Physics and Astronomy, University of California, Riverside, CA, USA
| | | | | | - C Rocque
- Google Research, Mountain View, CA, USA
| | - N C Rubin
- Google Research, Mountain View, CA, USA
| | - N Saei
- Google Research, Mountain View, CA, USA
| | - D Sank
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | - A Shorter
- Google Research, Mountain View, CA, USA
| | - N Shutty
- Google Research, Mountain View, CA, USA
| | - V Shvarts
- Google Research, Mountain View, CA, USA
| | - V Sivak
- Google Research, Mountain View, CA, USA
| | - J Skruzny
- Google Research, Mountain View, CA, USA
| | | | - R D Somma
- Google Research, Mountain View, CA, USA
| | | | - D Strain
- Google Research, Mountain View, CA, USA
| | - M Szalay
- Google Research, Mountain View, CA, USA
| | - D Thor
- Google Research, Mountain View, CA, USA
| | - A Torres
- Google Research, Mountain View, CA, USA
| | - G Vidal
- Google Research, Mountain View, CA, USA
| | | | | | - T White
- Google Research, Mountain View, CA, USA
| | - B W K Woo
- Google Research, Mountain View, CA, USA
| | - C Xing
- Google Research, Mountain View, CA, USA
| | | | - P Yeh
- Google Research, Mountain View, CA, USA
| | - J Yoo
- Google Research, Mountain View, CA, USA
| | - G Young
- Google Research, Mountain View, CA, USA
| | - A Zalcman
- Google Research, Mountain View, CA, USA
| | - Y Zhang
- Google Research, Mountain View, CA, USA
| | - N Zhu
- Google Research, Mountain View, CA, USA
| | - N Zobrist
- Google Research, Mountain View, CA, USA
| | - H Neven
- Google Research, Mountain View, CA, USA
| | - R Babbush
- Google Research, Mountain View, CA, USA
| | - D Bacon
- Google Research, Mountain View, CA, USA
| | - S Boixo
- Google Research, Mountain View, CA, USA
| | - J Hilton
- Google Research, Mountain View, CA, USA
| | - E Lucero
- Google Research, Mountain View, CA, USA
| | - A Megrant
- Google Research, Mountain View, CA, USA
| | - J Kelly
- Google Research, Mountain View, CA, USA
| | - Y Chen
- Google Research, Mountain View, CA, USA
| | | | - V Khemani
- Department of Physics, Stanford University, Stanford, CA, USA
| | | | - T Prosen
- Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia
| | - P Roushan
- Google Research, Mountain View, CA, USA
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2
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Mi X, Michailidis AA, Shabani S, Miao KC, Klimov PV, Lloyd J, Rosenberg E, Acharya R, Aleiner I, Andersen TI, Ansmann M, Arute F, Arya K, Asfaw A, Atalaya J, Bardin JC, Bengtsson A, Bortoli G, Bourassa A, Bovaird J, Brill L, Broughton M, Buckley BB, Buell DA, Burger T, Burkett B, Bushnell N, Chen Z, Chiaro B, Chik D, Chou C, Cogan J, Collins R, Conner P, Courtney W, Crook AL, Curtin B, Dau AG, Debroy DM, Del Toro Barba A, Demura S, Di Paolo A, Drozdov IK, Dunsworth A, Erickson C, Faoro L, Farhi E, Fatemi R, Ferreira VS, Burgos LF, Forati E, Fowler AG, Foxen B, Genois É, Giang W, Gidney C, Gilboa D, Giustina M, Gosula R, Gross JA, Habegger S, Hamilton MC, Hansen M, Harrigan MP, Harrington SD, Heu P, Hoffmann MR, Hong S, Huang T, Huff A, Huggins WJ, Ioffe LB, Isakov SV, Iveland J, Jeffrey E, Jiang Z, Jones C, Juhas P, Kafri D, Kechedzhi K, Khattar T, Khezri M, Kieferová M, Kim S, Kitaev A, Klots AR, Korotkov AN, Kostritsa F, Kreikebaum JM, Landhuis D, Laptev P, Lau KM, Laws L, Lee J, Lee KW, Lensky YD, Lester BJ, Lill AT, Liu W, Locharla A, Malone FD, Martin O, McClean JR, McEwen M, Mieszala A, Montazeri S, Morvan A, Movassagh R, Mruczkiewicz W, Neeley M, Neill C, Nersisyan A, Newman M, Ng JH, Nguyen A, Nguyen M, Niu MY, O'Brien TE, Opremcak A, Petukhov A, Potter R, Pryadko LP, Quintana C, Rocque C, Rubin NC, Saei N, Sank D, Sankaragomathi K, Satzinger KJ, Schurkus HF, Schuster C, Shearn MJ, Shorter A, Shutty N, Shvarts V, Skruzny J, Smith WC, Somma R, Sterling G, Strain D, Szalay M, Torres A, Vidal G, Villalonga B, Heidweiller CV, White T, Woo BWK, Xing C, Yao ZJ, Yeh P, Yoo J, Young G, Zalcman A, Zhang Y, Zhu N, Zobrist N, Neven H, Babbush R, Bacon D, Boixo S, Hilton J, Lucero E, Megrant A, Kelly J, Chen Y, Roushan P, Smelyanskiy V, Abanin DA. Stable quantum-correlated many-body states through engineered dissipation. Science 2024; 383:1332-1337. [PMID: 38513021 DOI: 10.1126/science.adh9932] [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] [Received: 03/27/2023] [Accepted: 02/13/2024] [Indexed: 03/23/2024]
Abstract
Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.
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Affiliation(s)
- X Mi
- Google Research, Mountain View, CA, USA
| | - A A Michailidis
- Department of Theoretical Physics, University of Geneva, Geneva, Switzerland
| | - S Shabani
- Google Research, Mountain View, CA, USA
| | - K C Miao
- Google Research, Mountain View, CA, USA
| | | | - J Lloyd
- Department of Theoretical Physics, University of Geneva, Geneva, Switzerland
| | | | - R Acharya
- Google Research, Mountain View, CA, USA
| | - I Aleiner
- Google Research, Mountain View, CA, USA
| | | | - M Ansmann
- Google Research, Mountain View, CA, USA
| | - F Arute
- Google Research, Mountain View, CA, USA
| | - K Arya
- Google Research, Mountain View, CA, USA
| | - A Asfaw
- Google Research, Mountain View, CA, USA
| | - J Atalaya
- Google Research, Mountain View, CA, USA
| | - J C Bardin
- Google Research, Mountain View, CA, USA
- Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA, USA
| | | | - G Bortoli
- Google Research, Mountain View, CA, USA
| | | | - J Bovaird
- Google Research, Mountain View, CA, USA
| | - L Brill
- Google Research, Mountain View, CA, USA
| | | | | | - D A Buell
- Google Research, Mountain View, CA, USA
| | - T Burger
- Google Research, Mountain View, CA, USA
| | - B Burkett
- Google Research, Mountain View, CA, USA
| | | | - Z Chen
- Google Research, Mountain View, CA, USA
| | - B Chiaro
- Google Research, Mountain View, CA, USA
| | - D Chik
- Google Research, Mountain View, CA, USA
| | - C Chou
- Google Research, Mountain View, CA, USA
| | - J Cogan
- Google Research, Mountain View, CA, USA
| | - R Collins
- Google Research, Mountain View, CA, USA
| | - P Conner
- Google Research, Mountain View, CA, USA
| | | | - A L Crook
- Google Research, Mountain View, CA, USA
| | - B Curtin
- Google Research, Mountain View, CA, USA
| | - A G Dau
- Google Research, Mountain View, CA, USA
| | | | | | - S Demura
- Google Research, Mountain View, CA, USA
| | | | | | | | | | - L Faoro
- Google Research, Mountain View, CA, USA
| | - E Farhi
- Google Research, Mountain View, CA, USA
| | - R Fatemi
- Google Research, Mountain View, CA, USA
| | | | | | - E Forati
- Google Research, Mountain View, CA, USA
| | | | - B Foxen
- Google Research, Mountain View, CA, USA
| | - É Genois
- Google Research, Mountain View, CA, USA
| | - W Giang
- Google Research, Mountain View, CA, USA
| | - C Gidney
- Google Research, Mountain View, CA, USA
| | - D Gilboa
- Google Research, Mountain View, CA, USA
| | | | - R Gosula
- Google Research, Mountain View, CA, USA
| | - J A Gross
- Google Research, Mountain View, CA, USA
| | | | - M C Hamilton
- Google Research, Mountain View, CA, USA
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
| | - M Hansen
- Google Research, Mountain View, CA, USA
| | | | | | - P Heu
- Google Research, Mountain View, CA, USA
| | | | - S Hong
- Google Research, Mountain View, CA, USA
| | - T Huang
- Google Research, Mountain View, CA, USA
| | - A Huff
- Google Research, Mountain View, CA, USA
| | | | - L B Ioffe
- Google Research, Mountain View, CA, USA
| | | | - J Iveland
- Google Research, Mountain View, CA, USA
| | - E Jeffrey
- Google Research, Mountain View, CA, USA
| | - Z Jiang
- Google Research, Mountain View, CA, USA
| | - C Jones
- Google Research, Mountain View, CA, USA
| | - P Juhas
- Google Research, Mountain View, CA, USA
| | - D Kafri
- Google Research, Mountain View, CA, USA
| | | | - T Khattar
- Google Research, Mountain View, CA, USA
| | - M Khezri
- Google Research, Mountain View, CA, USA
| | - M Kieferová
- Google Research, Mountain View, CA, USA
- Centre for Quantum Software and Information (QSI), Faculty of Engineering and Information Technology, University of Technology Sydney, Sydney, NSW, Australia
| | - S Kim
- Google Research, Mountain View, CA, USA
| | - A Kitaev
- Google Research, Mountain View, CA, USA
| | - A R Klots
- Google Research, Mountain View, CA, USA
| | - A N Korotkov
- Google Research, Mountain View, CA, USA
- Department of Electrical and Computer Engineering, University of California, Riverside, CA, USA
| | | | | | | | - P Laptev
- Google Research, Mountain View, CA, USA
| | - K-M Lau
- Google Research, Mountain View, CA, USA
| | - L Laws
- Google Research, Mountain View, CA, USA
| | - J Lee
- Google Research, Mountain View, CA, USA
- Department of Chemistry, Columbia University, New York, NY, USA
| | - K W Lee
- Google Research, Mountain View, CA, USA
| | | | | | - A T Lill
- Google Research, Mountain View, CA, USA
| | - W Liu
- Google Research, Mountain View, CA, USA
| | | | | | - O Martin
- Google Research, Mountain View, CA, USA
| | | | - M McEwen
- Google Research, Mountain View, CA, USA
| | | | | | - A Morvan
- Google Research, Mountain View, CA, USA
| | | | | | - M Neeley
- Google Research, Mountain View, CA, USA
| | - C Neill
- Google Research, Mountain View, CA, USA
| | | | - M Newman
- Google Research, Mountain View, CA, USA
| | - J H Ng
- Google Research, Mountain View, CA, USA
| | - A Nguyen
- Google Research, Mountain View, CA, USA
| | - M Nguyen
- Google Research, Mountain View, CA, USA
| | - M Y Niu
- Google Research, Mountain View, CA, USA
| | | | | | | | - R Potter
- Google Research, Mountain View, CA, USA
| | - L P Pryadko
- Google Research, Mountain View, CA, USA
- Department of Physics and Astronomy, University of California, Riverside, CA, USA
| | | | - C Rocque
- Google Research, Mountain View, CA, USA
| | - N C Rubin
- Google Research, Mountain View, CA, USA
| | - N Saei
- Google Research, Mountain View, CA, USA
| | - D Sank
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | - A Shorter
- Google Research, Mountain View, CA, USA
| | - N Shutty
- Google Research, Mountain View, CA, USA
| | - V Shvarts
- Google Research, Mountain View, CA, USA
| | - J Skruzny
- Google Research, Mountain View, CA, USA
| | - W C Smith
- Google Research, Mountain View, CA, USA
| | - R Somma
- Google Research, Mountain View, CA, USA
| | | | - D Strain
- Google Research, Mountain View, CA, USA
| | - M Szalay
- Google Research, Mountain View, CA, USA
| | - A Torres
- Google Research, Mountain View, CA, USA
| | - G Vidal
- Google Research, Mountain View, CA, USA
| | | | | | - T White
- Google Research, Mountain View, CA, USA
| | - B W K Woo
- Google Research, Mountain View, CA, USA
| | - C Xing
- Google Research, Mountain View, CA, USA
| | - Z J Yao
- Google Research, Mountain View, CA, USA
| | - P Yeh
- Google Research, Mountain View, CA, USA
| | - J Yoo
- Google Research, Mountain View, CA, USA
| | - G Young
- Google Research, Mountain View, CA, USA
| | - A Zalcman
- Google Research, Mountain View, CA, USA
| | - Y Zhang
- Google Research, Mountain View, CA, USA
| | - N Zhu
- Google Research, Mountain View, CA, USA
| | - N Zobrist
- Google Research, Mountain View, CA, USA
| | - H Neven
- Google Research, Mountain View, CA, USA
| | - R Babbush
- Google Research, Mountain View, CA, USA
| | - D Bacon
- Google Research, Mountain View, CA, USA
| | - S Boixo
- Google Research, Mountain View, CA, USA
| | - J Hilton
- Google Research, Mountain View, CA, USA
| | - E Lucero
- Google Research, Mountain View, CA, USA
| | - A Megrant
- Google Research, Mountain View, CA, USA
| | - J Kelly
- Google Research, Mountain View, CA, USA
| | - Y Chen
- Google Research, Mountain View, CA, USA
| | - P Roushan
- Google Research, Mountain View, CA, USA
| | | | - D A Abanin
- Google Research, Mountain View, CA, USA
- Department of Theoretical Physics, University of Geneva, Geneva, Switzerland
- Department of Physics, Princeton University, Princeton, NJ, USA
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3
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Chen LM, Wang G, Liu H, Zhao RM, Liu XH, Cao GT, Yao ZJ, Li ZY, Liu Y. [Clinical effects of free perforator propeller myocutaneous flap from buttock in repairing complex wounds in the buttock with deep dead cavity]. Zhonghua Shao Shang Yu Chuang Mian Xiu Fu Za Zhi 2023; 39:753-757. [PMID: 37805786 DOI: 10.3760/cma.j.cn501225-20221115-00488] [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] [Subscribe] [Scholar Register] [Indexed: 10/09/2023]
Abstract
Objective: To investigate the feasibility and clinical effects of using free perforator propeller myocutaneous flap from buttock in repairing complex wounds in the buttock with deep dead cavity. Methods: A retrospective observational study was conducted. From June 2020 to June 2022, 9 patients with complex wounds in the buttock with deep dead cavity who met the inclusion criteria were admitted to Lanzhou University Second Hospital, including 6 males and 3 females, aged 26 to 62 years, with original wound area ranging from 4.0 cm×3.0 cm to 8.0 cm×7.0 cm and dead cavity depth of 7 to 11 cm. All the wounds were repaired with free perforator propeller myocutaneous flap from buttock, with flap area of 6.0 cm×2.5 cm to 13.0 cm×7.0 cm and muscle flap length of 6 to 11 cm. All the wounds in the donor area were closed and sutured directly. Postoperative myocutaneous flap survival, complications, as well as donor and recipient wound healing were observed, and the shape of donor and recipient areas were followed up. Results: Congestion occurred under the myocutaneous flap of one patient due to poor drainage on post surgery day 2, which was healed after 15 days of drainage and dressing change. The myocutaneous flaps of other patients survived successfully after surgery. The wounds in the donor and recipient areas were all well healed. During the follow-up of 3 to 10 months, the donor and recipient areas were full in shape, with little difference from the healthy side, and were able to bear pressure. Conclusions: The free perforator propeller myocutaneous flap from buttock can repair the deep dead cavity and surface wounds at the same time. The use of this myocutaneous flap in repairing complex wounds in the buttock with deep dead cavity results in minimal damage to the donor area, allows pressure-bearing of the donor and recipient areas after surgery, and ensures a full buttock shape.
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Affiliation(s)
- L M Chen
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - G Wang
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - H Liu
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - R M Zhao
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - X H Liu
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - G T Cao
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - Z J Yao
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - Z Y Li
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - Y Liu
- Department of Burns and Plastic Surgery & Wound Repair Surgery, Lanzhou University Second Hospital, Lanzhou 730030, China
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4
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Mi X, Ippoliti M, Quintana C, Greene A, Chen Z, Gross J, Arute F, Arya K, Atalaya J, Babbush R, Bardin JC, Basso J, Bengtsson A, Bilmes A, Bourassa A, Brill L, Broughton M, Buckley BB, Buell DA, Burkett B, Bushnell N, Chiaro B, Collins R, Courtney W, Debroy D, Demura S, Derk AR, Dunsworth A, Eppens D, Erickson C, Farhi E, Fowler AG, Foxen B, Gidney C, Giustina M, Harrigan MP, Harrington SD, Hilton J, Ho A, Hong S, Huang T, Huff A, Huggins WJ, Ioffe LB, Isakov SV, Iveland J, Jeffrey E, Jiang Z, Jones C, Kafri D, Khattar T, Kim S, Kitaev A, Klimov PV, Korotkov AN, Kostritsa F, Landhuis D, Laptev P, Lee J, Lee K, Locharla A, Lucero E, Martin O, McClean JR, McCourt T, McEwen M, Miao KC, Mohseni M, Montazeri S, Mruczkiewicz W, Naaman O, Neeley M, Neill C, Newman M, Niu MY, O'Brien TE, Opremcak A, Ostby E, Pato B, Petukhov A, Rubin NC, Sank D, Satzinger KJ, Shvarts V, Su Y, Strain D, Szalay M, Trevithick MD, Villalonga B, White T, Yao ZJ, Yeh P, Yoo J, Zalcman A, Neven H, Boixo S, Smelyanskiy V, Megrant A, Kelly J, Chen Y, Sondhi SL, Moessner R, Kechedzhi K, Khemani V, Roushan P. Time-Crystalline Eigenstate Order on a Quantum Processor. Nature 2021; 601:531-536. [PMID: 34847568 PMCID: PMC8791837 DOI: 10.1038/s41586-021-04257-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [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: 07/30/2021] [Accepted: 11/17/2021] [Indexed: 11/10/2022]
Abstract
Quantum many-body systems display rich phase structure in their low-temperature equilibrium states1. However, much of nature is not in thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium systems can exhibit novel dynamical phases2–8 that may otherwise be forbidden by equilibrium thermodynamics, a paradigmatic example being the discrete time crystal (DTC)7,9–15. Concretely, dynamical phases can be defined in periodically driven many-body-localized (MBL) systems via the concept of eigenstate order7,16,17. In eigenstate-ordered MBL phases, the entire many-body spectrum exhibits quantum correlations and long-range order, with characteristic signatures in late-time dynamics from all initial states. It is, however, challenging to experimentally distinguish such stable phases from transient phenomena, or from regimes in which the dynamics of a few select states can mask typical behaviour. Here we implement tunable controlled-phase (CPHASE) gates on an array of superconducting qubits to experimentally observe an MBL-DTC and demonstrate its characteristic spatiotemporal response for generic initial states7,9,10. Our work employs a time-reversal protocol to quantify the impact of external decoherence, and leverages quantum typicality to circumvent the exponential cost of densely sampling the eigenspectrum. Furthermore, we locate the phase transition out of the DTC with an experimental finite-size analysis. These results establish a scalable approach to studying non-equilibrium phases of matter on quantum processors. A study establishes a scalable approach to engineer and characterize a many-body-localized discrete time crystal phase on a superconducting quantum processor.
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Affiliation(s)
- Xiao Mi
- Google Research, Mountain View, CA, USA
| | - Matteo Ippoliti
- Department of Physics, Stanford University, Stanford, CA, USA
| | | | | | | | | | | | | | | | | | - Joseph C Bardin
- Google Research, Mountain View, CA, USA.,Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA, USA
| | | | | | | | - Alexandre Bourassa
- Google Research, Mountain View, CA, USA.,Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Alan Ho
- Google Research, Mountain View, CA, USA
| | | | | | | | | | - L B Ioffe
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | | | | | - Seon Kim
- Google Research, Mountain View, CA, USA
| | | | | | - Alexander N Korotkov
- Google Research, Mountain View, CA, USA.,Department of Electrical and Computer Engineering, University of California, Riverside, CA, USA
| | | | | | | | - Joonho Lee
- Google Research, Mountain View, CA, USA.,Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Kenny Lee
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | - Matt McEwen
- Google Research, Mountain View, CA, USA.,Department of Physics, University of California, Santa Barbara, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Yuan Su
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | | | - Ping Yeh
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | | | | | - Yu Chen
- Google Research, Mountain View, CA, USA
| | - S L Sondhi
- Department of Physics, Princeton University, Princeton, NJ, USA.,Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford, OX1 3PU, United Kingdom
| | - Roderich Moessner
- Max-Planck-Institut für Physik komplexer Systeme, 01187, Dresden, Germany
| | | | - Vedika Khemani
- Department of Physics, Stanford University, Stanford, CA, USA.
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5
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Mi X, Roushan P, Quintana C, Mandrà S, Marshall J, Neill C, Arute F, Arya K, Atalaya J, Babbush R, Bardin JC, Barends R, Basso J, Bengtsson A, Boixo S, Bourassa A, Broughton M, Buckley BB, Buell DA, Burkett B, Bushnell N, Chen Z, Chiaro B, Collins R, Courtney W, Demura S, Derk AR, Dunsworth A, Eppens D, Erickson C, Farhi E, Fowler AG, Foxen B, Gidney C, Giustina M, Gross JA, Harrigan MP, Harrington SD, Hilton J, Ho A, Hong S, Huang T, Huggins WJ, Ioffe LB, Isakov SV, Jeffrey E, Jiang Z, Jones C, Kafri D, Kelly J, Kim S, Kitaev A, Klimov PV, Korotkov AN, Kostritsa F, Landhuis D, Laptev P, Lucero E, Martin O, McClean JR, McCourt T, McEwen M, Megrant A, Miao KC, Mohseni M, Montazeri S, Mruczkiewicz W, Mutus J, Naaman O, Neeley M, Newman M, Niu MY, O'Brien TE, Opremcak A, Ostby E, Pato B, Petukhov A, Redd N, Rubin NC, Sank D, Satzinger KJ, Shvarts V, Strain D, Szalay M, Trevithick MD, Villalonga B, White T, Yao ZJ, Yeh P, Zalcman A, Neven H, Aleiner I, Kechedzhi K, Smelyanskiy V, Chen Y. Information scrambling in quantum circuits. Science 2021; 374:1479-1483. [PMID: 34709938 DOI: 10.1126/science.abg5029] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Xiao Mi
- Google Research, Mountain View, CA, USA
| | | | | | - Salvatore Mandrà
- QuAIL, NASA Ames Research Center, Moffett Field, CA, USA.,KBR, Inc., Houston, TX, USA
| | - Jeffrey Marshall
- QuAIL, NASA Ames Research Center, Moffett Field, CA, USA.,USRA Research Institute for Advanced Computer Science, Mountain View, CA, USA
| | | | | | | | | | | | - Joseph C Bardin
- Google Research, Mountain View, CA, USA.,Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA, USA
| | | | | | | | | | - Alexandre Bourassa
- Google Research, Mountain View, CA, USA.,Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Alan Ho
- Google Research, Mountain View, CA, USA
| | | | | | | | - L B Ioffe
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | | | - Seon Kim
- Google Research, Mountain View, CA, USA
| | - Alexei Kitaev
- Google Research, Mountain View, CA, USA.,Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, CA, USA
| | | | - Alexander N Korotkov
- Google Research, Mountain View, CA, USA.,Department of Electrical and Computer Engineering, University of California, Riverside, CA, USA
| | | | | | | | | | | | | | | | - Matt McEwen
- Google Research, Mountain View, CA, USA.,Department of Physics, University of California, Santa Barbara, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ping Yeh
- Google Research, Mountain View, CA, USA
| | | | | | | | | | | | - Yu Chen
- Google Research, Mountain View, CA, USA
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6
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Arute F, Arya K, Babbush R, Bacon D, Bardin JC, Barends R, Boixo S, Broughton M, Buckley BB, Buell DA, Burkett B, Bushnell N, Chen Y, Chen Z, Chiaro B, Collins R, Courtney W, Demura S, Dunsworth A, Farhi E, Fowler A, Foxen B, Gidney C, Giustina M, Graff R, Habegger S, Harrigan MP, Ho A, Hong S, Huang T, Huggins WJ, Ioffe L, Isakov SV, Jeffrey E, Jiang Z, Jones C, Kafri D, Kechedzhi K, Kelly J, Kim S, Klimov PV, Korotkov A, Kostritsa F, Landhuis D, Laptev P, Lindmark M, Lucero E, Martin O, Martinis JM, McClean JR, McEwen M, Megrant A, Mi X, Mohseni M, Mruczkiewicz W, Mutus J, Naaman O, Neeley M, Neill C, Neven H, Niu MY, O’Brien TE, Ostby E, Petukhov A, Putterman H, Quintana C, Roushan P, Rubin NC, Sank D, Satzinger KJ, Smelyanskiy V, Strain D, Sung KJ, Szalay M, Takeshita TY, Vainsencher A, White T, Wiebe N, Yao ZJ, Yeh P, Zalcman A. Hartree-Fock on a superconducting qubit quantum computer. Science 2020; 369:1084-1089. [DOI: 10.1126/science.abb9811] [Citation(s) in RCA: 245] [Impact Index Per Article: 61.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/18/2020] [Indexed: 01/21/2023]
Abstract
The simulation of fermionic systems is among the most anticipated applications of quantum computing. We performed several quantum simulations of chemistry with up to one dozen qubits, including modeling the isomerization mechanism of diazene. We also demonstrated error-mitigation strategies based on N-representability that dramatically improve the effective fidelity of our experiments. Our parameterized ansatz circuits realized the Givens rotation approach to noninteracting fermion evolution, which we variationally optimized to prepare the Hartree-Fock wave function. This ubiquitous algorithmic primitive is classically tractable to simulate yet still generates highly entangled states over the computational basis, which allowed us to assess the performance of our hardware and establish a foundation for scaling up correlated quantum chemistry simulations.
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7
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Wang WQ, Yao ZJ, Wang XL, Xia XH, Gu CD, Tu JP. Niobium doped tungsten oxide mesoporous film with enhanced electrochromic and electrochemical energy storage properties. J Colloid Interface Sci 2018; 535:300-307. [PMID: 30316116 DOI: 10.1016/j.jcis.2018.10.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/02/2018] [Accepted: 10/03/2018] [Indexed: 12/30/2022]
Abstract
Exploring high performance cathode materials is of great means for the development of bi-functional electrochromic energy storage devices. Herein, Nb-doped WO3 mesoporous films as integrated high-quality cathode are successfully constructed via a facile sol-gel method. Chemical state and crystallinity of the WO3 based films are significantly influenced by doping concentration. Compared with the pure WO3, the optimal Nb-doped film shows improved optical-electrochemical properties with high specific capacity (74.4 mAh g-1 at 2 A g-1), excellent high-rate capability, large optical contrast (61.7% at 633 nm), and ultra-fast switching speed (3.6 s and 2.1 s for coloring and bleaching process, respectively). These positive features suggest the potential application of Nb-doped WO3 mesoporous cathode. Our research paves the way for the development of multifunctional photoelectrochemical energy devices.
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Affiliation(s)
- W Q Wang
- State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and School of Materials Science & Engineering, Zhejiang University, Hangzhou 310027, China; Research Institute of Zhejiang University, Taizhou 318000, China
| | - Z J Yao
- State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and School of Materials Science & Engineering, Zhejiang University, Hangzhou 310027, China
| | - X L Wang
- State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and School of Materials Science & Engineering, Zhejiang University, Hangzhou 310027, China.
| | - X H Xia
- State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and School of Materials Science & Engineering, Zhejiang University, Hangzhou 310027, China
| | - C D Gu
- State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and School of Materials Science & Engineering, Zhejiang University, Hangzhou 310027, China
| | - J P Tu
- State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and School of Materials Science & Engineering, Zhejiang University, Hangzhou 310027, China; Research Institute of Zhejiang University, Taizhou 318000, China.
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8
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Abstract
Mutations in the mitochondrial (mt) genome that result in mt dysfunction, have long been proposed to play important roles in the pathogenesis of hepatocellular carcinoma (HCC). Among these, the common mtDNA 4977 bp deletion is one of the most frequent mutations observed in various cancers. To understand the relationship between the mtDNA 4977 bp deletion and HCC, we performed mutational screening for the presence of this deletion in 105 HCC patients and 69 unrelated healthy subjects. After nested-polymerase chain reaction (nested-PCR) amplification, we found that there were 10 patients carrying the mtDNA 4977 bp deletion, and this deletion was absent in control subjects. Moreover, HCC patients carrying this deletion showed a marked increase in reactive oxygen species (ROS) level and mtDNA copy number when compared with the healthy controls. Taken together, our data indicated that the mtDNA 4977 bp deletion may play important role in the carcinogenesis of HCC, possibly via the alternation of mtDNA copy number and oxidative stress.
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Affiliation(s)
- ZS Guo
- Department of Hepatobiliary Surgery, Zhuji People’s Hospital, Shaoxing, People’s Republic of China
- Dr. Zhen-Shan Guo or Dr. Bo-Tao Xu, Zhuji People’s Hospital, Jianmin Road 9, Taozhu Street, Shaoxing, 311800, People’s Republic of China. Tel./Fax: +86-0575-81782103
| | - CL Jin
- Department of Endocrinology, Zhuji People’s Hospital, Shaoxing, People’s Republic of China
| | - ZJ Yao
- Department of Hepatobiliary Surgery, Zhuji People’s Hospital, Shaoxing, People’s Republic of China
| | - YM Wang
- Department of Hepatobiliary Surgery, Zhuji People’s Hospital, Shaoxing, People’s Republic of China
| | - BT Xu
- Department of Cardiothoracic Surgery, Zhuji People’s Hospital, Shaoxing, People’s Republic of China
- Dr. Zhen-Shan Guo or Dr. Bo-Tao Xu, Zhuji People’s Hospital, Jianmin Road 9, Taozhu Street, Shaoxing, 311800, People’s Republic of China. Tel./Fax: +86-0575-81782103
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9
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Yao ZJ, Chen H, Liu CF. [Hypocalcemic cardiomyopathy due to untreated hypoparathyroidism: a case report]. Zhonghua Xin Xue Guan Bing Za Zhi 2016; 44:633-634. [PMID: 27530953 DOI: 10.3760/cma.j.issn.0253-3758.2016.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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10
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Chen ZJ, Li ZY, Lin F, Yao ZJ, Greene MI, Li B. IdentifICATION OF E3 ubiquitin ligase STUB1 as a negative regulator of FOXP3. BMC Proc 2011. [DOI: 10.1186/1753-6561-5-s1-p84] [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: 11/10/2022] Open
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11
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Cui M, Zhang QZ, Yao ZJ, Zhang ZH. Molecular cloning and expression analysis of heat-shock protein 70 in orange-spotted grouper Epinephelus coioides following heat shock and Vibrio alginolyticus challenge. J Fish Biol 2011; 79:486-501. [PMID: 21781104 DOI: 10.1111/j.1095-8649.2011.03045.x] [Citation(s) in RCA: 5] [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: 05/31/2023]
Abstract
In this study, the complementary (c)DNA encoding heat-shock protein 70 (Hsp70) of orange-spotted grouper Epinephelus coioides (OsgHsp70) was cloned. OsgHsp70 was 2206 bp and encoded 652 amino acids with predicted molecular mass of 70·89 kDa and theoretical isoelectric point of 5·48. Three Hsp70 family signatures, bipartite nuclear localization signal sequence (NLS) and cytoplasmic characteristic motif (EEVD) were observed in the OsgHsp70, which shared high similarity in amino-acid sequences with the Hsp70 gene of other vertebrates. The results indicated that the OsgHsp70 is a member of the heat-shock protein 70 family. The Hsp70 messenger (m)RNA expressions were quantified by real-time PCR following heat shock, bacterial infection and immunization with formalin-killed Vibrio alginolyticus, a kind of bacterial pathogen that causes septicaemia. Hsp70 mRNA expression in gill, kidney, spleen, thymus gland, muscle and total-blood samples increased at first and then decreased gradually following heat shock. A similar time-dependent pattern was observed following V. alginolyticus pathogen challenge, in which Hsp70 mRNA expression peaked at 24 h after live bacterial infection and 3 days after dead bacterial vaccination. The results indicated that the Hsp70 gene was inducible and involved in the fish immune response.
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Affiliation(s)
- M Cui
- Institute of Hydrobiology, Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education, Jinan University, 601 West Huangpu Road, Guangzhou 510632, China
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12
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Chen ZJ, Li1 ZY, Lin F, Yao ZJ, Greene MI, Li B. IdentifICATION OF E3 ubiquitin ligase STUB1 as a negative regulator of FOXP3. BMC Proc 2011. [PMCID: PMC3019514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Affiliation(s)
- ZJ Chen
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, PR China
| | - ZY Li1
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, PR China
| | - F Lin
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, PR China
| | - ZJ Yao
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, PR China
| | - MI Greene
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, USA
| | - B Li
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, PR China
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13
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Abstract
The central roles played by protein-tyrosine kinase (PTK)-dependent signal transduction in normal cellular regulation and homeostasis have made inappropriate or aberrant functions of certain of these pathways contributing factors to a variety of diseases, including several cancers. For this reason, development of PTK signaling inhibitors has evolved into an important approach toward new therapeutics. Since in these pathways phosphotyrosyl (pTyr) residues provide unique and defining functions either by their creation under the catalysis of PTKs, their recognition and binding by protein modules such as SH2 and phosphotyrosyl binding (PTB) domains, or their destruction by protein-tyrosine phosphatases, pTyr mimetics provide useful general starting points for inhibitor design. Important considerations in the development of such pTyr mimetics include enzymatic stability (particularly toward PTPs), high affinity recognition by target pTyr binding proteins, and good cellular bioavailability. Although small molecule, nonpeptide inhibitors may be ultimate objectives of inhibitor development, peptides frequently serve as display platforms for pTyr mimetics, which afford useful and conceptually straightforward starting points in the development process. Reported herein is a limited overview of pTyr mimetic development as it relates to peptide-based agents. Of particular interest are recent findings that highlight potential limitations of peptides as display platforms for the identification of small molecule leads. One conclusion that results from this work is that while peptide-based approaches toward small molecule inhibitor design are often intellectually satisfying from a structure-based perspective, extrapolation of negative findings to small molecule, nonpeptide contexts should be undertaken with extreme caution.
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Affiliation(s)
- T R Burke
- Laboratory of Medicinal Chemistry, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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14
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Abstract
The central roles played by protein-tyrosine kinase (PTK)-dependent signal transduction in normal cellular regulation and homeostasis have made inappropriate or aberrant functions of certain of these pathways contributing factors to a variety of diseases, including several cancers. For this reason, development of PTK signaling inhibitors has evolved into an important approach toward new therapeutics. Since in these pathways phosphotyrosyl (pTyr) residues provide unique and defining functions either by their creation under the catalysis of PTKs, their recognition and binding by protein modules such as SH2 and phosphotyrosyl binding (PTB) domains, or their destruction by protein-tyrosine phosphatases, pTyr mimetics provide useful general starting points for inhibitor design. Important considerations in the development of such pTyr mimetics include enzymatic stability (particularly toward PTPs), high affinity recognition by target pTyr binding proteins, and good cellular bioavailability. Although small molecule, nonpeptide inhibitors may be ultimate objectives of inhibitor development, peptides frequently serve as display platforms for pTyr mimetics, which afford useful and conceptually straightforward starting points in the development process. Reported herein is a limited overview of pTyr mimetic development as it relates to peptide-based agents. Of particular interest are recent findings that highlight potential limitations of peptides as display platforms for the identification of small molecule leads. One conclusion that results from this work is that while peptide-based approaches toward small molecule inhibitor design are often intellectually satisfying from a structure-based perspective, extrapolation of negative findings to small molecule, nonpeptide contexts should be undertaken with extreme caution.
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Affiliation(s)
- T R Burke
- Laboratory of Medicinal Chemistry, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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15
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Zhen ZC, Yao ZJ. [Capillary array electrophoresis and high-throughput DNA sequencing]. Se Pu 2001; 19:361-4. [PMID: 12545503] [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: 02/28/2023] Open
Abstract
Depending on the outputs of 10,080 DNA sequencing samples from the human genome project, technical features of capillary array electrophoresis are discussed. The results show that 88% of the total readlength were higher than 50 kbp/run. It means that most of the readlength could reach 500 bp or more with reasonable quality. The results were much better than expected when the technology of capillary array appeared about one year ago. A key parameter affecting the quality of DNA sequencing is the purity of sequencing template. Therefore, a batch agarose slab electrophoresis was applied to check the purity before loading. Other conditions, such as concentration of template and loading amount, are discussed as well. Finally, comparisons based on the electrophoresis timing, the pre-treatment of samples, the loading procedures and the results analysis between capillary array electrophoresis and slab gel electrophoresis have been made. From the point of view of high-throughput DNA sequencing, especially in the field of genome research, the capillary array electrophoresis should be the better choice as a more efficient technical platform.
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Affiliation(s)
- Z C Zhen
- Chinese National Human Genome Center, Beijing 100176, China
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16
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Burke TR, Yao ZJ, Gao Y, Wu JX, Zhu X, Luo JH, Guo R, Yang D. N-terminal carboxyl and tetrazole-containing amides as adjuvants to Grb2 SH2 domain ligand binding. Bioorg Med Chem 2001; 9:1439-45. [PMID: 11408162 DOI: 10.1016/s0968-0896(01)00014-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [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: 11/19/2022]
Abstract
High affinity binding of peptides to Src homology 2 (SH2) domains, often requires the presence of phosphotyrosyl (pTyr) or pTyr-mimicking moieties in the N-terminal position of the binding ligand. Several reports have shown that N(alpha)-acylation of the critical pTyr residue can result in increased SH2 domain binding potency. For Grb2 SH2 domains which recognize pTyr-Xxx-Asn-NH(2) motifs, significant potency enhancement can be incurred by N(alpha)-(3-amino)Z derivatization of tripeptides such as pTyr-Ile-Asn-NH(2). Using ligands based on the high affinity pY-Ac(6)c-Asn-(naphthylpropylamide) motif, (where Ac(6)c=1-aminocyclohexanecarboxylic acid), additional reports have shown moderate potentiating effects of N(alpha)-oxalyl derivatization. The current study examined variations of the N(alpha)-oxalyl theme in the context of a Xxx-Ac(6)c-Asn-(naphthylpropylamide) platform, where Xxx=the hydrolytically stable pTyr mimetics phosphonomethyl phenylalanine (Pmp) or carboxymethyl phenylalanine (Cmf). The effects of N(alpha)-(3-amino)Z derivatization were also investigated for this platform, to ascertain whether the large binding enhancement reported for tripeptides such as pTyr-Ile-Asn-NH(2) could be observed. In ELISA-based extracellular Grb2 SH2 domain binding assays, it was found for the Pmp-based series, that extending the oxalyl carboxyl out by one methylene unit or replacing carboxyl functionality with a tetrazole isostere, resulted in binding potency greater than the parent N(alpha)-acetyl-containing compound, with enhancement approximating that observed for the N(alpha)-oxalyl derivative. When Cmf was used as the pTyr mimetic, only modest differences in IC(50) values were observed for the series. Examination of the N(alpha)-(3-amino)Z derivatized Pmp-Ac(6)c-Asn-(naphthylpropylamide), showed that binding affinity was reduced relative to the parent N(alpha)-acetyl analogue, in contrast to the reported significant enhancement of affinity observed with other peptide ligands. Treatment of MDA-453 tumor cells, which are mitogenically driven through erbB-2 tyrosine kinase-dependent pathways, with Pmp-containing inhibitors resulted in growth inhibition, with the N(alpha)-oxalyl and N(alpha)-malonyl-containing compounds exhibiting IC(50) values (4.3 and 4.6 microM, respectively) approximately five-fold lower than the parent N(alpha)-acetyl-containing compound. Tetrazole and N(alpha)-(3-amino)Z-containing inhibitors were from two- to four-fold less potent than these latter analogues in the growth inhibition assays.
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Affiliation(s)
- T R Burke
- Laboratory of Medicinal Chemistry, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Building 376, FCRDC, Frederick, MD 21702-1201, USA.
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17
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Burke TR, Yao ZJ, Ye B, Miyoshi K, Otaka A, Wu L, Zhang ZY. Phospho-Azatyrosine, a less effective protein-tyrosine phosphatase substrate than phosphotyrosine. Bioorg Med Chem Lett 2001; 11:1265-8. [PMID: 11392533 DOI: 10.1016/s0960-894x(01)00197-4] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Azatyrosine (AzaTyr, 4) is a natural product isolated from Streptomyces chibanesis, whose structure is characterized by a nitrogen atom in the aryl ring of a tyrosyl residue. This seemingly minor modification to the tyrosyl residue results in profound physiological effects, as AzaTyr has been shown to promote permanent reversion of ras-dependent transformed cells to the normal phenotype in culture and to inhibit chemical induction of carcinogenesis in transgenic mice bearing oncogenic human ras. The mechanisms underlying these effects are not known, however ras-pathways involve an intricate balance between both protein-tyrosine kinases (PTKs) and protein-tyrosine phosphatases (PTPs). The present study was undertaken to examine the general utility of AzaTyr as a structural motif for PTP inhibitor design by examining the phospho-azatyrosine (pAzaTyr)-containing peptide Ac-Asp-Ala-Asp-Glu-pAzaTyr-Leu-amide (8) in a PTP1 enzyme system. Kinetic analysis indicated that 8 binds with a Km value of 210 microM and a catalytic turnover rate, kcat of 52 s(-1). This represents a greater than 50-fold reduction in binding affinity relative to the parent phosphotyrosine-containing peptide, indicating that the aryl nitrogen adversely affects binding affinity. The much lower PTP affinity of the pAzaTyr-containing peptide reduces the potential utility of the AzaTyr pharmacophore for PTP inhibitor design. These results are discussed from the point of view that incorporation of AzaTyr residues into proteins could result in perturbation of protein-tyrosine phosphorylation,dephosphorylation cascades that control signal transduction processes, including ras-dependent pathways.
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Affiliation(s)
- T R Burke
- Laboratory of Medicinal Chemistry, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, NCI-FCRDC, Frederick, MD 21702-1201, USA.
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18
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Atabey N, Gao Y, Yao ZJ, Breckenridge D, Soon L, Soriano JV, Burke TR, Bottaro DP. Potent blockade of hepatocyte growth factor-stimulated cell motility, matrix invasion and branching morphogenesis by antagonists of Grb2 Src homology 2 domain interactions. J Biol Chem 2001; 276:14308-14. [PMID: 11278639 DOI: 10.1074/jbc.m010202200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [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: 11/06/2022] Open
Abstract
Hepatocyte growth factor (HGF) stimulates mitogenesis, motogenesis, and morphogenesis in a wide range of cellular targets during development, homeostasis and tissue regeneration. Inappropriate HGF signaling occurs in several human cancers, and the ability of HGF to initiate a program of protease production, cell dissociation, and motility has been shown to promote cellular invasion and is strongly linked to tumor metastasis. Upon HGF binding, several tyrosines within the intracellular domain of its receptor, c-Met, become phosphorylated and mediate the binding of effector proteins, such as Grb2. Grb2 binding through its SH2 domain is thought to link c-Met with downstream mediators of cell proliferation, shape change, and motility. We analyzed the effects of Grb2 SH2 domain antagonists on HGF signaling and observed potent blockade of cell motility, matrix invasion, and branching morphogenesis, with ED(50) values of 30 nm or less, but only modest inhibition of mitogenesis. These compounds are 1000-10,000-fold more potent anti-motility agents than any previously characterized Grb2 SH2 domain antagonists. Our results suggest that SH2 domain-mediated c-Met-Grb2 interaction contributes primarily to the motogenic and morphogenic responses to HGF, and that these compounds may have therapeutic application as anti-metastatic agents for tumors where the HGF signaling pathway is active.
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Affiliation(s)
- N Atabey
- Laboratories of Cellular and Molecular Biology and Medicinal Chemistry, Division of Basic Sciences, NCI, National Institutes of Health, Bethesda, Maryland 20892-4255, USA
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19
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Abstract
Autoantibodies to double-stranded (ds) DNA are an important diagnostic marker and pathogenic factor for systemic lupus erythematosus (SLE). Identifying dsDNA mimotopes is a way to discover diagnostic and therapeutic candidates for SLE. 'Mono-specific' SLE anti-dsDNA antibodies were obtained by affinity purification using dsDNA-coupled Sepharose column. Using the anti-dsDNA antibodies to screen a phage peptide library, we were able to identify a mimotope that has a motif peptide sequence of RLTSSLRYNP. This chemically synthesized peptide could be recognized by 88% (37 out of 42) of anti-dsDNA antibody-positive SLE sera with a cut-off point at mean + 3 SD of the negative control sera at OD(492). The reaction of the peptide with SLE sera in ELISA was highly correlated with that of dsDNA (r = 0.809, P < 0.0001). Of particular interest, not only dsDNA but also single-stranded (ss) DNA and native RNA could inhibit the binding of the peptide with SLE sera, suggesting that the mimotope is shared by ds and ssDNAs as well as native RNA, whereas denatured RNA was not observed to inhibit the binding. The peptide was also able to elicit an immune response in rabbits and the anti-peptide rabbit serum was observed to cross-react with the peptide, ss and dsDNAs, and ss and dsDNAs could inhibit the binding of the anti-peptide serum and the peptide. However, the inhibition was not obtained with RNA. Our findings demonstrate the potential of the peptide mimic in diagnostic tests of SLE, and in the investigation of anti-DNA antibody origin and of DNA-anti-DNA antibody interaction.
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Affiliation(s)
- Y Sun
- Bioprocessing Technology Centre, National University of Singapore, Singapore 119260, Republic of Singapore
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20
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Mata M, Yao ZJ, Zubair A, Syres K, Paterson Y. Evaluation of a recombinant Listeria monocytogenes expressing an HIV protein that protects mice against viral challenge. Vaccine 2001; 19:1435-45. [PMID: 11163666 DOI: 10.1016/s0264-410x(00)00379-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [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: 11/25/2022]
Abstract
Vaccine strategies that utilize cell mediated immunity to control infection will be a necessary component of human immunodeficiency virus (HIV) vaccines. In previous studies we have shown that a Listeria monocytogenes recombinant expressing HIV-Gag elicits strong CD8+ and CD4+ T cell responses against HIV Gag in addition to its own secreted proteins. Here, we show that Lm-Gag can protect mice against a viral challenge with a recombinant vaccinia virus expressing Gag, in an antigen specific manner, and that this protection is T cell mediated. These results further support the use of L. monocytogenes as a vaccine approach for HIV through the induction of T cell immunity.
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Affiliation(s)
- M Mata
- Department of Microbiology, University of Pennsylvania Medical School, 323 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA
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21
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Abstract
Atemoyacin E (I), a new adjacent bis-tetrahydrofuran annonaceous acetogenin was isolated and characterized from the seeds of Annona atemoya.
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Affiliation(s)
- P Wu
- South China Institute of Botany, Chinese Academy of Sciences, Guangzhou
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22
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Zhang YL, Yao ZJ, Sarmiento M, Wu L, Burke TR, Zhang ZY. Thermodynamic study of ligand binding to protein-tyrosine phosphatase 1B and its substrate-trapping mutants. J Biol Chem 2000; 275:34205-12. [PMID: 10952978 DOI: 10.1074/jbc.m004490200] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [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: 11/06/2022] Open
Abstract
The binding of several phosphonodifluoromethyl phenylalanine (F(2)Pmp)-containing peptides to protein-tyrosine phosphatase 1B (PTP1B) and its substrate-trapping mutants (C215S and D181A) has been studied using isothermal titration calorimetry. The binding of a high affinity ligand, Ac-Asp-Ala-Asp-Glu-F(2)Pmp-Leu-NH(2), to PTP1B (K(d) = 0.24 microm) is favored by both enthalpic and entropic contributions. Disruption of ionic interactions between the side chain of Arg-47 and the N-terminal acidic residues reduces the binding affinity primarily through the reduction of the TDeltaS term. The role of Arg-47 may be to maximize surface contact between PTP1B and the peptide, which contributes to high affinity binding. The active site Cys-215 --> Ser mutant PTP1B binds ligands with the same affinity as the wild-type enzyme. However, unlike wild-type PTP1B, peptide binding to C215S is predominantly driven by enthalpy change, which likely results from the elimination of the electrostatic repulsion between the thiolate anion and the phosphonate group. The increased enthalpic contribution is offset by reduction in the binding entropy, which may be the result of increased entropy of the unbound protein caused by this mutation. The general acid-deficient mutant D181A binds the peptide 5-fold tighter than the C215S mutant, consistent with the observation that the Asp to Ala mutant is a better "substrate-trapping" reagent than C215S. The increased binding affinity for D181A as compared with the wild-type PTP1B results primarily from an increase in the DeltaH of binding in the mutant, which may be related to decreased electrostatic repulsion between the phosphate moiety and PTP1B. These results have important implications for the design of high affinity PTP1B inhibitors.
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Affiliation(s)
- Y L Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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23
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Abstract
On the basis of the ionophore model, polyether analogues 4 and 6 were designed and synthesized to mimic the naturally occurring annonaceous acetogenins corossolin (2) and bullatin (5), which were discovered as members of a large family of novel polyketides with cytotoxicity, antitumoral, and other biological activities since 1982. The preliminary screening shows that they have compatible cytotoxicity with the corresponding natural annonaceous acetogenins. These results open a potential way to find more active antitumor agents with simplified structures based on natural annonaceous acetogenins.
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Affiliation(s)
- Z J Yao
- State Key Laboratory of Bio-organic & Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China
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24
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Gao Y, Luo J, Yao ZJ, Guo R, Zou H, Kelley J, Voigt JH, Yang D, Burke TR. Inhibition of Grb2 SH2 domain binding by non-phosphate-containing ligands. 2. 4-(2-Malonyl)phenylalanine as a potent phosphotyrosyl mimetic. J Med Chem 2000; 43:911-20. [PMID: 10715157 DOI: 10.1021/jm9904248] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [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: 11/28/2022]
Abstract
Nonhydrolyzable phosphotyrosyl (pTyr) mimetics serve as important components of many competitive Grb2 SH2 domain inhibitors. To date, the most potent of these inhibitors have relied on phosphonate-based structures to replace the 4-phosphoryl group of the parent pTyr residue. Reported herein is the design and evaluation of a new pTyr mimetic, p-malonylphenylalanine (Pmf), which does not contain phosphorus yet, in Grb2 SH2 domain binding systems, approaches the potency of phosphonate-based pTyr mimetics. When incorporated into high affinity Grb2 SH2 domain-directed platforms, Pmf is 15-20 times more potent than the closely related previously reported pTyr mimetic, O-malonyltyrosine (OMT). Pmf-containing inhibitors show inhibition constants as low as 8 nM in extracellular Grb2 binding assays and in whole cell systems, effective blockade of both endogenous Grb2 binding to cognate erbB-2, and downstream MAP kinase activation. Evidence is provided that use of an N(alpha)()-oxalyl auxiliary enhances effectiveness of Pmf and other inhibitors in both extracellular and intracellular contexts. As one of the most potent Grb2 SH2 domain-directed pTyr mimetics yet disclosed, Pmf may potentially have utility in the design of new chemotherapeutics for the treatment of various proliferative diseases, including breast cancer.
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Affiliation(s)
- Y Gao
- Laboratory of Medicinal Chemistry, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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25
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Long YQ, Yao ZJ, Voigt JH, Lung FD, Luo JH, Burke TR, King CR, Yang D, Roller PP. Structural requirements for Tyr in the consensus sequence Y-E-N of a novel nonphosphorylated inhibitor to the Grb2-SH2 domain. Biochem Biophys Res Commun 1999; 264:902-8. [PMID: 10544028 DOI: 10.1006/bbrc.1999.1599] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [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: 11/22/2022]
Abstract
The phage library derived, nonphosphorylated and thioether-cyclized peptide, termed G1TE, cyclo(CH(2)CO-Glu(1)-Leu-Tyr(3)-Glu-Asn-Val-Gly-Met-Tyr-Cys(10))-amid e, represents a new structural motif that binds to the Grb2-SH2 domain in a pTyr-independent manner, with an IC(50) of 20 microM. The retention of binding affinity is very sensitive with respect to peptide ring-size alterations and Ala mutations. We demonstrated previously that the Glu(1) side chain and its closely related analogs partially compensate for the absence of the phosphate functionality on Tyr(3), and, based on molecular modeling, these acidic side-chains complex with the Arg67 and Arg86 side-chains of the protein in the binding cavity. In this study we judiciously altered and incorporated various natural and unnatural amino acids as Tyr replacements within the -YEN- motif, and we demonstrate the functional importance and structural requirement of Tyr(3) for effective binding of this novel non-phosphorylated ligand to the Grb2-SH2 domain. The phenyl side-chain moiety and a polar functional group with specific orientation in position Y(3) of the peptide are particularly required. Using SPR binding assays, a submicromolar inhibitor (IC(50) = 0.70 microM) was obtained when Glu(1) was replaced with alpha-aminoadipate and Tyr(3) was replaced with 4-carboxymethyl-Phe, providing peptide 14, G1TE(Adi(1), cmPhe(3)). Peptide 14 also inhibited Grb2/p185(erb)(B-2) protein association in cell homogenates of erbB-2-overexpressing MDA-MA-453 cancer cells at near one micromolar concentrations.
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Affiliation(s)
- Y Q Long
- Laboratory of Medicinal Chemistry, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Building 37, Room 5C02, Bethesda, Maryland, 20892, USA
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26
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Burke TR, Luo J, Yao ZJ, Gao Y, Zhao H, Milne GW, Guo R, Voigt JH, King CR, Yang D. Monocarboxylic-based phosphotyrosyl mimetics in the design of GRB2 SH2 domain inhibitors. Bioorg Med Chem Lett 1999; 9:347-52. [PMID: 10091682 DOI: 10.1016/s0960-894x(98)00740-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [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: 11/24/2022]
Abstract
Three monocarboxylic-containing analogues, O-carboxymethyltyrosine (cmT, 5), 4-(carboxymethyl)phenylalanine (cmF, 6), and 4-(carboxydifluoromethyl)phenylalanine (F2cmF, 7) were utilized as phosphotyrosyl (pTyr) replacements in a high affinity B-bend mimicking platform, where they exhibited IC50 values of 2.5 microM, 65 microM and 28 microM, respectively, in a Grb2 SH2 domain Biacore binding assay. When a terminal N(alpha)-oxalyl axillary was utilized to enhance ligand interactions with a critical SH2 domain Arg67 residue (alphaA-helix), binding potencies increased from 4- to 10-fold, resulting in submicromolar affinity for cmF (IC50 = 0.6 microM) and low micromolar affinity for F2cmF (IC50 = 2 microM). Cell lysate binding studies also showed inhibition of cognate Grb2 binding to the p185erbB-2 phosphoprotein in the same rank order of potency as observed in the Biacore assay. These results indicate the potential value of cmF and F2cmF residues as pTyr mimetics for the study of Grb2 SH2 domains and suggest new strategies for improvements in inhibitor design.
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Affiliation(s)
- T R Burke
- Laboratory of Medicinal Chemistry, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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27
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Yao ZJ, King CR, Cao T, Kelley J, Milne GW, Voigt JH, Burke TR. Potent inhibition of Grb2 SH2 domain binding by non-phosphate-containing ligands. J Med Chem 1999; 42:25-35. [PMID: 9888830 DOI: 10.1021/jm980388x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [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
Development of Grb2 Src homology 2 (SH2) domain binding inhibitors has important implications for treatment of a variety of diseases, including several cancers. In cellular studies, inhibitors of Grb2 SH2 domain binding have to date been large, highly charged peptides which relied on special transport devices for cell membrane penetration. Work presented in the current study examines a variety of pTyr mimetics in the context of a high-affinity Grb2 binding platform. Among the analogues studied are new non-phosphorus-containing pTyr mimetics 23a and 23b which, when incorporated into tripeptide structures 18f and 20f, are able to inhibit Grb2 SH2 domain binding with affinities among the best yet reported for non-phosphorus-containing SH2 domain inhibitors (IC50 values of 6.7 and 1.3 microM, respectively). The present study has also demonstrated the usefulness of the Nalpha-oxalyl group as an auxiliary which enhances the binding potency of both phosphorus- and non-phosphorus-containing pTyr mimetics. When combined with the (phosphonomethyl)phenylalanine (Pmp) residue to give analogues such as L-20d, potent inhibition of Grb2 SH2 domain binding can be achieved both in extracellular assays using isolated Grb2 SH2 domain protein and in intracellular systems measuring the association of endogenous Grb2 with its cognate p185erbB-2 ligand. These latter effects can be achieved at micromolar to submicromolar concentrations without prodrug derivatization. The oxalyl-containing pTyr mimetics presented in this study should be of general usefulness for the development of other Grb2 SH2 domain antagonists, independent of the beta-bend-mimicking platform utilized for their display.
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Affiliation(s)
- Z J Yao
- Laboratory of Medicinal Chemistry, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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28
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Chen H, Cong LN, Li Y, Yao ZJ, Wu L, Zhang ZY, Burke TR, Quon MJ. A phosphotyrosyl mimetic peptide reverses impairment of insulin-stimulated translocation of GLUT4 caused by overexpression of PTP1B in rat adipose cells. Biochemistry 1999; 38:384-9. [PMID: 9890920 DOI: 10.1021/bi9816103] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [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
Biological actions of insulin are initiated by activation of the insulin receptor tyrosine kinase. Protein tyrosine phosphatases (PTPases) PTP1B and PTPalpha are known to dephosphorylate the insulin receptor and may contribute to insulin resistance in diseases such as diabetes. We previously reported that overexpression of PTP1B in rat adipose cells significantly impairs insulin-stimulated translocation of GLUT4 [Chen, H., et al. (1997) J. Biol. Chem. 272, 8026]. In the present study, we treated adipose cells with a PTPase inhibitor containing the phosphotyrosyl mimetic difluorophosphonomethyl phenylalanine (F2Pmp) to determine whether we could improve the insulin resistance caused by overexpression of PTP1B or PTPalpha. Rat adipose cells transfected by electroporation with either PTP1B or PTPalpha were treated without or with the inhibitor, and effects on insulin-stimulated translocation of a cotransfected epitope-tagged GLUT4 were studied. The IC50 of the F2Pmp-containing inhibitor is 180 nM for PTP1B and 10 mM for PTPalpha in vitro. As expected, in the absence of the inhibitor, overexpression of either PTP1B or PTPalpha caused a significant decrease in the amount of GLUT4 at the cell surface both in the absence and in the presence of insulin when compared with control cells transfected with epitope-tagged GLUT4 alone. Interestingly, the insulin resistance caused by overexpression of PTP1B (but not PTPalpha) was reversed by treating the transfected cells with the F2Pmp-containing inhibitor. Furthermore, the inhibitor blocked the insulin-stimulated association of PTP1B with the insulin receptor. We conclude that the F2Pmp-containing compound is a potent and specific inhibitor of overexpressed PTP1B that may be useful for designing rational therapies for treating insulin resistant diseases such as diabetes.
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Affiliation(s)
- H Chen
- Hypertension-Endocrine Branch, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892, USA
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29
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Groves MR, Yao ZJ, Roller PP, Burke TR, Barford D. Structural basis for inhibition of the protein tyrosine phosphatase 1B by phosphotyrosine peptide mimetics. Biochemistry 1998; 37:17773-83. [PMID: 9922143 DOI: 10.1021/bi9816958] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [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
Protein tyrosine phosphatases regulate diverse cellular processes and represent important targets for therapeutic intervention in a number of diseases. The crystal structures of protein tyrosine phosphatase 1B (PTP1B) in complex with small molecule inhibitors based upon two classes of phosphotyrosine mimetics, the (difluoronaphthylmethyl)phosphonic acids and the fluoromalonyl tyrosines, have been determined to resolutions greater than 2.3 A. The fluoromalonyl tyrosine residue was incorporated within a cyclic hexapeptide modeled on an autophosphorylation site of the epidermal growth factor receptor. The structure of this inhibitor bound to PTP1B represents the first crystal structure of a non-phosphonate-containing inhibitor and reveals the mechanism of phosphotyrosine mimicry by the fluoromalonyl tyrosine residue and the nature of its interactions within the catalytic site of PTP1B. In contrast to complexes of PTP1B with phosphotyrosine-containing peptides, binding of the fluoromalonyl tyrosine residue to the catalytic site of PTP1B is not accompanied by closure of the catalytic site WPD loop. Structures of PTP1B in complex with the (difluoronaphthylmethyl)phosphonic acid derivatives reveal that substitutions of the naphthalene ring modulate the mode of inhibitor binding to the catalytic site and provide the potential for enhanced inhibitor affinity and the generation of PTP-specific inhibitors. These results provide a framework for the rational design of higher affinity and more specific phosphotyrosine mimetic inhibitors of not only protein tyrosine phosphatases but also SH2 and PTB domains.
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Affiliation(s)
- M R Groves
- Department of Biochemistry, University of Oxford, United Kingdom
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30
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Yao ZJ, Ye B, Wu XW, Wang S, Wu L, Zhang ZY, Burke TR. Structure-based design and synthesis of small molecule protein-tyrosine phosphatase 1B inhibitors. Bioorg Med Chem 1998; 6:1799-810. [PMID: 9839010 DOI: 10.1016/s0968-0896(98)00140-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [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: 11/21/2022]
Abstract
Protein-tyrosine phosphatase (PTP) inhibitors are attractive as potential signal transduction-directed therapeutics which may be useful in the treatment of a variety of diseases. We have previously reported the X-ray structure of 1,1-difluoro-1-(2-naphthalenyl)methyl] phosphonic acid (4) complexed with the human the protein-tyrosine phosphatase 1B (PTP1B) and its use in the design of an analogue which binds with higher affinity within the catalytic site (Burke, T. R., Jr. et al. Biochemistry 1996, 35, 15989). In the current study, new naphthyldifluoromethyl phosphonic acids were designed bearing acidic functionality intended to interact with the PTP1B Arg47, which is situated just outside the catalytic pocket. This residue has been shown previously to provide key interactions with acidic residues of phosphotyrosyl-containing peptide substrates. Consistent with trends predicted by molecular dynamics calculations, the new analogues bound with 7- to 14-fold higher affinity than the parent 4, in principal validating the design rationale.
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Affiliation(s)
- Z J Yao
- Laboratory of Medicinal Chemistry, National Institutes of Health, Bethesda, MD 20892, USA
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31
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Naidu BR, Ngeow YF, Wang LF, Chan L, Yao ZJ, Pang T. An immunogenic epitope of Chlamydia pneumoniae from a random phage display peptide library is reactive with both monoclonal antibody and patients sera. Immunol Lett 1998; 62:111-5. [PMID: 9698107 DOI: 10.1016/s0165-2478(98)00029-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 11/28/2022]
Abstract
Random 15-mer peptides displayed on filamentous phages were screened in binding studies using a Chlamydia pneumoniae-specific monoclonal antibody (RR-402) and affinity-purified, polyclonal sera from patients seropositive for C. pneumoniae infections by the microimmunofluorescence (MIF) test. One 15-mer epitope, epitope Cpnl5A (LASLCNPKPSDAPVT) was identified in both the monoclonal and polyclonal screenings, and showed higher ELISA reactivity with C. pneumoniae MIF-positive sera compared to patients with other chlamydial infections, non-chlamydial respiratory infections and normal healthy sera (MIF-negative). Interestingly, epitope Cpnl5A also showed significant (52%) amino acid sequence homology to the 56 kDa type-specific antigen of Rickettsia tsutsugamushi, a protein implicated in the virulence of this organism.
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Affiliation(s)
- B R Naidu
- Institute of Postgraduate Studies and Research, University of Malaya, Kuala Lumpur, Malaysia
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32
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Abstract
The chromatographic behaviour of recombinant human tumour necrosis factor beta (rhTNF-beta) (pI approximately 9.0) during cation-exchange chromatography at pH 7.5 is investigated. Without prior treatment of the Escherichia coli cell extract with polyethyleneimine (PEI), very little rhTNF-beta was bound to the column. However, upon addition of 5% PEI (100 microliters ml-1) to the cell lysate, rhTNF-beta was shown to bind to cation-exchange columns normally. TNF-beta was readily precipitated from the clarified cell extract by 20% ammonium sulphate, but ony ca. 25% of this precipitate could be re-solubilized for further purification. However, when 5% PEI was included in the solubilization buffer, the balance of the rhTNF-beta could be recovered. It is proposed that charge interaction between rhTNF-beta and nucleic acids in the cell extract is responsible for both of these anomalous phenomena, and that PEI (a cationic polyelectrolyte) was able to disrupt this interaction by displacing rhTNF-beta from the charge complex.
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Affiliation(s)
- K C Loh
- Bioprocessing Technology Centre, National University of Singapore, Singapore
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33
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Yao ZJ, Chan MC, Kao MC, Chung MC. Linear epitopes of sperm whale myoglobin identified by polyclonal antibody screening of random peptide library. Int J Pept Protein Res 1996; 48:477-85. [PMID: 8956081 DOI: 10.1111/j.1399-3011.1996.tb00866.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Distinct enhancement of antibody-specific clones was apparent during the screening against random peptide libraries with antigen-specific polyclonal antibodies. Several sequence motifs obtained from these screenings were homologous with the primary sequence of myoglobin. Two of these motifs have been confirmed as antigenic determinants by competitive inhibition tests using eight-branched synthetic peptides. One of the peptides has a sequence that corresponds to amino acid residues 42-50, KFDRFKHLK, of the myoglobin sequence. This is a new epitope of myoglobin that is reported for the first time. The epitope is located precisely in the "turn' or "loop' region between helices C and D of the crystal structure of myoglobin. The second antibody binding site has a sequence of DIAAKYKELGYQG, and this is located between residues 141-153, which is the C-terminus of myoglobin. This epitope encompassed two linear epitopes of myoglobin, amino acid residues 145-151 and 147-153, that have been reported earlier based on immunochemical characterisation of cleavage fragments of the protein. These results clearly indicate that epitope mapping using polyclonal antibodies against random peptide libraries can identify new epitopes precisely, as well as confirm epitopes of myoglobin obtained earlier using established methodologies.
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Affiliation(s)
- Z J Yao
- Bioprocessing Technology Centre, National University of Singapore, Republic of Singapore
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34
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Abstract
Screening of bioactive peptides from random peptide libraries using monoclonal antibodies as ligates is an effective method to define epitopes of protein antigens. However, it is thought that polyclonal antibodies might also serve as promising ligates for screening. We illustrate this approach by using recombinant human lymphotoxin (rhLT) polyclonal antibody as a model. The procedure consists in (a) affinity purification of polyclonal antibody to obtain the "monospecific" antibody, (b) screening against a phage-displayed random peptide library using the affinity-purified antibody, (c) plating the enriched phage on agar plates, randomly picking clones, and selecting the positive ones by dot blotting, (d) DNA sequencing of the positive clones and conducting a homology search against the protein sequence databank, and (e) confirming the epitopes by chemical peptide synthesis. By employing this procedure, we identified a dominant epitope RQHPKM, located at residues 15-20 of the human lymphotoxin amino acid sequence. The usefulness of this general procedure is discussed.
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Affiliation(s)
- Z J Yao
- Bioprocessing Technology Centre, National University of Singapore
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35
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Abstract
From a panel of monoclonal antibodies of dengue viruses, a serotype-specific epitope of dengue virus 1 was screened from a random peptide library displayed on phage. The epitope was the determinant reactive with monoclonal antibody 15F3-1 that was specific to dengue 1. The screening was monitored by a dot blotting procedure, and after three rounds of screening a consensus motif, HRYSWK, was found. This sequence matches the sequence HKYSWK, corresponding to the amino acid residues 885-890 of polyprotein or residues 111-116 of the non-structural protein 1 of dengue virus serotype 1. The linear epitope was confirmed by testing the antigenicity of chemically synthesized 8-branched peptide.
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Affiliation(s)
- Z J Yao
- Bioprocessing Technology Centre, National University of Singapore
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36
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Abstract
A peptide that contained one of the continuous epitopes of recombinant human lymphotoxin (rhLT) (amino acid residues 139-154) has been located by epitope mapping. The branched form of this peptide was synthesized by the multiple antigen peptide procedure with an octameric branched resin and was subsequently used to elicit anti-epitope antibody in rabbits. The resulting anti-epitope was then used as an immunoaffinity ligand in affinity chromatography to purify the parent protein, rhLT, from the host cell lysate directly. It is suggested that this approach would be a general way to create novel biospecific ligands for affinity separations.
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Affiliation(s)
- Z J Yao
- Bioprocessing Technology Unit, National University of Singapore
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37
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Cai SY, Wang YY, Yao ZJ. Engineered bacterial Fc receptors. Sci China B 1994; 37:454-61. [PMID: 8068198] [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: 01/28/2023]
Abstract
Five new-type Fc receptor molecules were constructed based on streptococcal protein G (SpG) and staphylococcal protein A (SpA). These protein molecules contain one to six Fc binding domains to immunoglobulins which are structurally different from native SpG or SpA. Their expression levels reached 17-30% of the total bacterial proteins after heat induction in E. coli. Immunodiffusion and ELISA results showed that the engineered protein TG (184 amino acid residues) composed of three SpG C3 domain could bind more broadly and efficiently than the native SpG to the IgGs of human, goat, rabbit, etc., and its optimal pH for binding became wider (pH5-8) compared with the SpG (pH5); and the protein TGA (357AA), fused by protein TG and the A, B, C domains of SpA, displayed both the binding pattern of SpG and SpA.
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Affiliation(s)
- S Y Cai
- Institute of Basic Medical Sciences, Beijing, PRC
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38
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Yao ZJ, Kao MC, Loh KC, Chung MC. Continuous epitopes of human lymphotoxin and their topographies. Biochem Mol Biol Int 1994; 32:951-9. [PMID: 7520796] [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: 01/25/2023]
Abstract
Human lymphotoxin (hLT or TNF-beta) is a lymphokine that is structurally and functionally related to tumor necrosis factor alpha (TNF-alpha). The continuous epitopes of hLT were located by examining the cross-reaction between rabbit anti-hLT antibody and peptides derived from proteolytic digestion and chemical synthesis. Three antigenic sites, corresponding to residues 40-48, 83-94 and 139-147, of the protein sequence, were located by this approach. Since residues 49-57 also exhibited trace antigenicity, but residues 45-52 displayed no reaction, the whole peptide fragment consisting of residues 40-57 might be necessary for antigenicity. A comparison of the antigenic determinants with the loop structures obtained from X-ray crystallographic studies of hLT showed that all of the epitopes are found on or adjacent to functionally important domains.
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Affiliation(s)
- Z J Yao
- Bioprocessing Technology Unit, National University of Singapore, Republic of Singapore
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39
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Abstract
A rapid and improved method for the purification of recombinant human tumor necrosis factor beta (rhTNF-beta) from Escherichia coli HB 101 cells has been developed. The method utilized sequential steps of polyethylenimine (PEI) and ammonium sulfate precipitation to remove most of the extraneous proteins and nucleic acids from the cell extracts. The final step of purification consisted of DEAE-Sepharose chromatography at pH 7.5 in which rhTNF-beta was eluted with starting buffer. This procedure, when compared to the earlier methods of purification, is highly efficient since we could increase the overall yield of rhTNF-beta and reduce the purification time considerably. The final yield that we obtained from 1 liter of fermentation broth (containing approximately 80 g of wet cells) was 40-50 mg.
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Affiliation(s)
- K C Loh
- Bioprocessing Technology Unit, National University of Singapore
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40
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Cai SY, Wang YY, Yao ZJ. Structure analysis of streptococcal protein G Fc binding domain. Sci China B 1993; 36:75-80. [PMID: 8503988] [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: 01/31/2023]
Abstract
The gene fragment (191 bp) encoding protein G IgG Fc binding domain was isolated by PCR from group G streptococcus (CMCC32138), and a clone containing this gene fragment was found to give fine reactivity to human IgG when expressed in Escherichia coli. The complete nucleotide sequence of the gene fragment was determined. One base pair differs from previously reported protein G nucleotide sequences, and results in an amino acid change (Ala-Thr), but this variation makes no difference in binding to the IgG Fc part by ELISA. The secondary structure of the protein G IgG Fc binding domain has been estimated by circular dichroism and assigned by computer algorithm. It shows a typical alpha-helix region in this domain. By breaking this alpha-helix region with recombinant DNA techniques, a 44 peptide, which contained the N-terminal 27 amino acid residues of this domain, was expressed in E. coli and showed no reactivity to IgG. The hydropathicity of this domain was also analyzed and compared with that of protein A relevant domain. Some similarity was found. These results suggest that the binding mechanism of protein G to the IgG Fc part depends on hydrophobic action which comes from the alpha-helix in protein G molecule, just as protein A binding to IgG Fc part.
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Affiliation(s)
- S Y Cai
- Laboratory of Protein Chemistry, Institute of Basic Medical Sciences, Beijing, PRC
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41
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Yao ZJ. [Human granulocyte-macrophage colony-stimulating factors]. Sheng Li Ke Xue Jin Zhan 1989; 20:171-3. [PMID: 2686020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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42
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Li XR, Lin WN, Yu QX, Qin GQ, Zhang FC, Jiang JM, Yao ZJ, Liu JH, McLoon S, Johnson R. [Effects of monoclonal antibodies to junctional protein on development of lens in chicken embryo]. Shi Yan Sheng Wu Xue Bao 1988; 21:393-9. [PMID: 3223176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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43
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Affiliation(s)
- Z J Yao
- Institute of Basic Medical Science, Beijing, China
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44
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Yao ZJ, Shen BF. [Advances in structure and function of thymic polypeptide hormone]. Sheng Li Ke Xue Jin Zhan 1985; 16:52-6. [PMID: 3890172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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45
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Kamp RM, Yao ZJ, Bosserhoff A, Wittmann-Liebold B. Purification of Escherichia coli 30S ribosomal proteins by high performance liquid chromatography. Hoppe Seylers Z Physiol Chem 1983; 364:1777-93. [PMID: 6365721 DOI: 10.1515/bchm2.1983.364.2.1777] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
High performance liquid chromatography was applied to the separation of proteins derived from the Escherichia coli 30S ribosomal subunit. Several methods of separating this protein mixture has been tested: size-exclusion chromatography on hydrophilic phases; ion exchange and reversed phase chromatography (on C2 to C18 hydrocarbon-bonded supports). Various elution systems were examined in order to obtain pure proteins suitable for micro-sequence analysis. The resolution and yields of the proteins varied considerably, depending on the type of support and gradient system used. The best results were achieved with uniformly globular-shaped supports of large pore size, and by combining high performance size exclusion with rechromatography on reversed phase columns. Purification conditions for the individual proteins are listed. The methods employed avoid any precipitation step and allow easy identification of the proteins by one or two-dimensional gel electrophoresis, amino-acid analysis or direct manual or automatic micro-sequencing. Since the isolation time is much reduced compared with conventional purification procedures, the proteins obtained by the techniques described here are well suited for topographical and immunological studies or reconstitution assays. Ribosomal proteins of other organisms can be separated under similar conditions.
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46
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Kamp RM, Yao ZJ, Wittmann-Liebold B. Direct micro-sequence analysis of peptides from Escherichia coli ribosomal proteins S11, L9 and L29 after separation by reversed phase chromatography. Hoppe Seylers Z Physiol Chem 1983; 364:141-55. [PMID: 6341200 DOI: 10.1515/bchm2.1983.364.1.141] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Tryptic peptides of the ribosomal proteins S11, L9 and L29 were separated by reversed phase chromatography under conditions which enabled direct micro-sequencing with the 4-(dimethylamino)azobenzene-4'-isothiocyanate/phenylisothiocyanate double coupling method [Chang, Brauer, Wittmann-Liebold (1978) FEBS Lett. 93, 205-214]. The peptides were separated on a RP-18 column employing volatile buffers at pH 2.0, 4.1 and 7.8. Depending on the different chromatographic behaviour of the peptide mixture, the elution gradient was optimised for each hydrolysate using 20 micrograms of the hydrolysed protein. Preparative separations were made with 150-250 micrograms. At least 80% of the peptides could be isolated by these techniques and used for direct micro-sequencing without further purification or desalting. The results show that the high-performance liquid chromatographic method employed allows easy isolation and sequencing with minute amounts of peptides.
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