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Zheng X, Hu B, Gao SX, Liu DJ, Sun MJ, Jiao BH, Wang LH. A saxitoxin-binding aptamer with higher affinity and inhibitory activity optimized by rational site-directed mutagenesis and truncation. Toxicon 2015; 101:41-7. [PMID: 25937337 DOI: 10.1016/j.toxicon.2015.04.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 04/09/2015] [Accepted: 04/29/2015] [Indexed: 10/23/2022]
Abstract
Saxitoxin (STX), a member of the family of paralytic shellfish poisoning toxins, poses toxicological and ecotoxicological risks. To develop an analytical recognition element for STX, a DNA aptamer (APT(STX1)) was previously discovered via an iterative process known as Systematic Evolution of Ligands by Exponential Enrichment (SELEX) by Handy et al. Our study focused on generating an improved aptamer based on APT(STX1) through rational site-directed mutation and truncation. In this study, we generated the aptamer, M-30f, with a 30-fold higher affinity for STX compared with APT(STX1). The Kd value for M-30f was 133 nM, which was calculated by Bio-Layer Interferometry. After optimization, we detected and compared the interaction of STX with aptamers (APT(STX1) or M-30f) through several techniques (ELISA, cell bioassay, and mouse bioassay). Both aptamers' STX-binding ability was demonstrated in all three methods. Moreover, M-30f performs better than its parent sequence with higher suppressive activity against STX. As a molecular recognition element, M-30f has good prospects for practical application.
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Affiliation(s)
- X Zheng
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China
| | - B Hu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China; Center of Marine Biolical Medicine, College of Marine Military Medicine, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China
| | - S X Gao
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China
| | - D J Liu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China; Center of Marine Biolical Medicine, College of Marine Military Medicine, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China
| | - M J Sun
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China
| | - B H Jiao
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China; Center of Marine Biolical Medicine, College of Marine Military Medicine, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China
| | - L H Wang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University, No. 800, Xiangyin Rd., Shanghai 200433, People's Republic of China.
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2
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Weinreb PH, Li S, Gao SX, Liu T, Pepinsky RB, Caravella JA, Lee JH, Woods VL. Dynamic structural changes are observed upon collagen and metal ion binding to the integrin α1 I domain. J Biol Chem 2012; 287:32897-912. [PMID: 22847004 PMCID: PMC3463359 DOI: 10.1074/jbc.m112.354365] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 07/11/2012] [Indexed: 02/05/2023] Open
Abstract
We have applied hydrogen-deuterium exchange mass spectrometry, in conjunction with differential scanning calorimetry and protein stability analysis, to examine solution dynamics of the integrin α1 I domain induced by the binding of divalent cations, full-length type IV collagen, or a function-blocking monoclonal antibody. These studies revealed features of integrin activation and α1I-ligand complexes that were not detected by static crystallographic data. Mg(2+) and Mn(2+) stabilized α1I but differed in their effects on exchange rates in the αC helix. Ca(2+) impacted α1I conformational dynamics without altering its gross thermal stability. Interaction with collagen affected the exchange rates in just one of three metal ion-dependent adhesion site (MIDAS) loops, suggesting that MIDAS loop 2 plays a primary role in mediating ligand binding. Collagen also induced changes consistent with increased unfolding in both the αC and allosteric C-terminal helices of α1I. The antibody AQC2, which binds to α1I in a ligand-mimetic manner, also reduced exchange in MIDAS loop 2 and increased exchange in αC, but it did not impact the C-terminal region. This is the first study to directly demonstrate the conformational changes induced upon binding of an integrin I domain to a full-length collagen ligand, and it demonstrates the utility of the deuterium exchange mass spectrometry method to study the solution dynamics of integrin/ligand and integrin/metal ion interactions. Based on the ligand and metal ion binding data, we propose a model for collagen-binding integrin activation that explains the differing abilities of Mg(2+), Mn(2+), and Ca(2+) to activate I domain-containing integrins.
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Affiliation(s)
| | - Sheng Li
- the Department of Medicine and Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093-0656
| | - Sharon X. Gao
- From Biogen Idec, Inc., Cambridge, Massachusetts 02142 and
| | - Tong Liu
- the Department of Medicine and Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093-0656
| | | | | | - Jun H. Lee
- the Department of Medicine and Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093-0656
| | - Virgil L. Woods
- the Department of Medicine and Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093-0656
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3
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Dong J, Sereno A, Aivazian D, Langley E, Miller BR, Snyder WB, Chan E, Cantele M, Morena R, Joseph IBJK, Boccia A, Virata C, Gamez J, Yco G, Favis M, Wu X, Graff CP, Wang Q, Rohde E, Rennard R, Berquist L, Huang F, Zhang Y, Gao SX, Ho SN, Demarest SJ, Reff ME, Hariharan K, Glaser SM. A stable IgG-like bispecific antibody targeting the epidermal growth factor receptor and the type I insulin-like growth factor receptor demonstrates superior anti-tumor activity. MAbs 2011; 3:273-88. [PMID: 21393993 PMCID: PMC3149708 DOI: 10.4161/mabs.3.3.15188] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 02/16/2011] [Indexed: 01/01/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) and the type I insulin-like growth factor receptor (IGF-1R) are two cell surface receptor tyrosine kinases known to cooperate to promote tumor progression and drug resistance. Combined blockade of EGFR and IGF-1R has shown improved anti-tumor activity in preclinical models. Here, we report the characterization of a stable IgG-like bispecific antibody (BsAb) dual-targeting EGFR and IGF-1R that was developed for cancer therapy. The BsAb molecule (EI-04), constructed with a stability-engineered single chain variable fragment (scFv) against IGF-1R attached to the carboxyl-terminus of an IgG against EGFR, displays favorable biophysical properties for biopharmaceutical development. Biochemically, EI-04 bound to human EGFR and IGF-1R with sub nanomolar affinity, co-engaged the two receptors simultaneously, and blocked the binding of their respective ligands with similar potency compared to the parental monoclonal antibodies (mAbs). In tumor cells, EI-04 effectively inhibited EGFR and IGF-1R phosphorylation, and concurrently blocked downstream AKT and ERK activation, resulting in greater inhibition of tumor cell growth and cell cycle progression than the single mAbs. EI-04, likely due to its tetravalent bispecific format, exhibited high avidity binding to BxPC3 tumor cells co-expressing EGFR and IGF-1R, and consequently improved potency at inhibiting IGF-driven cell growth over the mAb combination. Importantly, EI-04 demonstrated enhanced in vivo anti-tumor efficacy over the parental mAbs in two xenograft models, and even over the mAb combination in the BxPC3 model. Our data support the clinical investigation of EI-04 as a superior cancer therapeutic in treating EGFR and IGF-1R pathway responsive tumors.
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MESH Headings
- Animals
- Antibodies, Bispecific/immunology
- Antibodies, Bispecific/pharmacology
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/pharmacology
- Antibody Affinity/immunology
- Antibody Specificity/immunology
- Blotting, Western
- CHO Cells
- Cell Line, Tumor
- Cell Survival/drug effects
- Cell Survival/immunology
- Cricetinae
- Cricetulus
- Dose-Response Relationship, Drug
- ErbB Receptors/immunology
- ErbB Receptors/metabolism
- Humans
- Immunoglobulin G/immunology
- Mice
- Mice, Nude
- Mice, SCID
- Neoplasms/drug therapy
- Neoplasms/immunology
- Neoplasms/pathology
- Phosphorylation/drug effects
- Receptor, IGF Type 1/immunology
- Receptor, IGF Type 1/metabolism
- Signal Transduction/drug effects
- Single-Chain Antibodies/immunology
- Single-Chain Antibodies/pharmacology
- Tumor Burden/drug effects
- Xenograft Model Antitumor Assays
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4
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Dong J, Sereno A, Snyder WB, Miller BR, Tamraz S, Doern A, Favis M, Wu X, Tran H, Langley E, Joseph I, Boccia A, Kelly R, Wortham K, Wang Q, Berquist L, Huang F, Gao SX, Zhang Y, Lugovskoy A, Martin S, Gouvis H, Berkowitz S, Chiang G, Reff M, Glaser SM, Hariharan K, Demarest SJ. Stable IgG-like bispecific antibodies directed toward the type I insulin-like growth factor receptor demonstrate enhanced ligand blockade and anti-tumor activity. J Biol Chem 2011; 286:4703-17. [PMID: 21123183 PMCID: PMC3039382 DOI: 10.1074/jbc.m110.184317] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Revised: 11/02/2010] [Indexed: 12/11/2022] Open
Abstract
Bispecific antibodies (BsAbs) target multiple epitopes on the same molecular target or different targets. Although interest in BsAbs has persisted for decades, production of stable and active BsAbs has hindered their clinical evaluation. Here, we describe the production and characterization of tetravalent IgG-like BsAbs that combine the activities of allosteric and competitive inhibitors of the type-I insulin-like growth factor receptor (IGF-1R). The BsAbs, which were engineered for thermal stability, express well, demonstrate favorable biophysical properties, and recognize both epitopes on IGF-1R. Only one BsAb with a unique geometry, denoted BIIB4-5scFv, was capable of engaging all four of its binding arms simultaneously. All the BsAbs (especially BIIB4-5scFv) demonstrated enhanced ligand blocking over the single monoclonal antibodies (mAbs), particularly at high ligand concentrations. The pharmacokinetic profiles of two IgG-like BsAbs were tested in nude mice and shown to be comparable with that of the parental mAbs. The BsAbs, especially BIIB4-5scFv, demonstrated an improved ability to reduce the growth of multiple tumor cell lines and to inhibit ligand-induced IGF-1R signaling in tumor cells over the parental mAbs. BIIB4-5scFv also led to superior tumor growth inhibition over its parental mAbs in vivo. In summary, BsAbs that bridge multiple inhibitory mechanisms against a single target may generally represent a more effective strategy for intervention in oncology or other indications compared with traditional mAb therapy.
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MESH Headings
- Animals
- Antibodies, Bispecific/immunology
- Antibodies, Bispecific/pharmacokinetics
- Antibodies, Bispecific/pharmacology
- Antibodies, Monoclonal, Murine-Derived/immunology
- Antibodies, Monoclonal, Murine-Derived/pharmacokinetics
- Antibodies, Monoclonal, Murine-Derived/pharmacology
- Antineoplastic Agents/immunology
- Antineoplastic Agents/pharmacokinetics
- Antineoplastic Agents/pharmacology
- Cell Line, Tumor
- Drug Stability
- Humans
- Immunoglobulin G
- Ligands
- Mice
- Mice, Nude
- Neoplasms, Experimental/drug therapy
- Neoplasms, Experimental/immunology
- Protein Stability
- Receptor, IGF Type 1/antagonists & inhibitors
- Receptor, IGF Type 1/immunology
- Xenograft Model Antitumor Assays/methods
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Affiliation(s)
| | | | | | | | | | - Adam Doern
- From Biogen Idec, San Diego, California 92122
| | | | - Xiufeng Wu
- From Biogen Idec, San Diego, California 92122
| | - Hon Tran
- From Biogen Idec, San Diego, California 92122
| | | | | | | | | | | | - Qin Wang
- From Biogen Idec, San Diego, California 92122
| | | | - Flora Huang
- From Biogen Idec, San Diego, California 92122
| | | | - Ying Zhang
- From Biogen Idec, San Diego, California 92122
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Gao SX, Zhang Y, Stansberry-Perkins K, Buko A, Bai S, Nguyen V, Brader ML. Fragmentation of a highly purified monoclonal antibody attributed to residual CHO cell protease activity. Biotechnol Bioeng 2010; 108:977-82. [DOI: 10.1002/bit.22982] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 10/18/2010] [Indexed: 12/28/2022]
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6
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Wang ZY, Lubin JH, Wang LD, Conrath S, Zhang SZ, Kleinerman R, Shang B, Gao SX, Gao PY, Lei SW, Boice JD. Radon measurements in underground dwellings from two prefectures in China. Health Phys 1996; 70:192-198. [PMID: 8567286 DOI: 10.1097/00004032-199602000-00006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Radon, an established lung carcinogen, remains the single most important environmental radiation exposure. Yet, an excess of lung cancer from breathing radon in homes has not been consistently demonstrated in studies conducted to date. To address several major problems that have hindered previous studies of lung cancer and radon in homes, we have embarked upon a lung cancer case-control study in Gansu Province, China, where a substantial proportion of the population live in underground dwellings. In this paper, we report on results of a pilot study in which radon measurements were made for 3 days in the summer in 40 homes under normal occupancy conditions using short-term E-PERM detectors and for 6 months from February through August in 49 homes using long-term alpha-track detectors. Useable E-PERM data were obtained from 38 homes and useable alpha-track data from 47 homes. For both types of detectors, measurements were approximately log-normally distributed. Arithmetic and geometric means were 233 and 185 Bq m-3 (range 74-1,590 Bq m-3) for E-PERM measurements and 165 and 158 Bq m-3 (range 74-592 Bq m-3) for alpha-track measurements, respectively; 68% of E-PERM measured homes and 55% of alpha-track measured homes exceeded 148 Bq m-3. Alpha-track measurements made at the entry, middle, and rear areas of the underground dwellings did not differ significantly (arithmetic means of 168, 162, and 165 Bq m-3 with standard deviations 63, 73, and 48, respectively), which suggests that air circulation may be minimal. The underground dwellings measured in the pilot study had high radon levels and the underground dwellers may provide an excellent population for studying indoor radon and risk of lung cancer.
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Affiliation(s)
- Z Y Wang
- Laboratory of Industrial Hygiene, Ministry of Public Health, Beijing, China
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7
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Tanishima K, Gao SX, Yamamoto R, Yoshida H. Biochemical and enzymological study of lactate dehydrogenase isoenzymes from commercial quality control sera and several animal tissue sources. Eur J Clin Chem Clin Biochem 1995; 33:865-8. [PMID: 8620065 DOI: 10.1515/cclm.1995.33.11.865] [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] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We assayed the isoenzymes of lactate dehydrogenase (EC 1.1.1.27) in commercial quality control sea and several animal tissue extracts, using electrophoresis. We compared the Km values and activation energies of the isoenzymes, in order to find suitable animal tissue sources with a similar isoenzyme profile to that of human serum lactate dehydrogenase. Some of the control sera contained only one isoenzyme fraction corresponding to porcine heart isoenzyme-1 or chicken heart isoenzyme-1, which showed essentially no changes of enzyme activity as a function of pyruvate substrate concentration. Other control sera, which contained isoenzymes from human red cells haemolysates, or from animal tissue extracts with a human serum matrix, showed significant changes of enzyme activity was a function of substrate concentration, and showed different Km values and activation energies from those of human serum. Of the serum and tissue samples from several animal sources, rat heart and kidney extracts showed the greatest similarity to human serum, with respect to the electrophoretic pattern and the Km, pH optimum and activation energy of lactate dehydrogenase isoenzymes.
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Affiliation(s)
- K Tanishima
- Department of Clinical Laboratory Sciences, School of Allied Medical Professions, Kanazawa University, Ishikawa, Japan
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8
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Shi L, Qin ZH, Gao SX. [Effect of 3,4-dihydroxyacetophenone on the membrane fluidity of platelets by fluorescence polarization analysis]. Zhongguo Yao Li Xue Bao 1986; 7:149-51. [PMID: 2946154] [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: 01/03/2023]
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