1
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Oh YH, Becker ML, Mendola KM, Choe LH, Min L, Lee KH, Yigzaw Y, Seay A, Bill J, Li X, Roush DJ, Cramer SM, Menegatti S, Lenhoff AM. Factors affecting product association as a mechanism of host-cell protein persistence in bioprocessing. Biotechnol Bioeng 2024; 121:1284-1297. [PMID: 38240126 DOI: 10.1002/bit.28658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/18/2023] [Accepted: 12/30/2023] [Indexed: 04/01/2024]
Abstract
Product association of host-cell proteins (HCPs) to monoclonal antibodies (mAbs) is widely regarded as a mechanism that can enable HCP persistence through multiple purification steps and even into the final drug substance. Discussion of this mechanism often implies that the existence or extent of persistence is directly related to the strength of binding but actual measurements of the binding affinity of such interactions remain sparse. Two separate avenues of investigation of HCP-mAb binding are reported here. One is the measurement of the affinity of binding of individual, commonly persistent Chinese hamster ovary (CHO) HCPs to each of a set of mAbs, and the other uses quantitative proteomic measurements to assess binding of HCPs in a null CHO harvested cell culture fluid (HCCF) to mAbs produced in the same cell line. The individual HCP measurements show that the binding affinities of individual HCPs to different mAbs can vary appreciably but are rarely very high, with only weak pH dependence. The measurements on the null HCCF allow estimation of individual HCP-mAb affinities; these are typically weaker than those seen in affinity measurements on isolated HCPs. Instead, the extent of binding appears correlated with the initial abundance of individual HCPs in the HCCF and the forms of the HCPs in the solution, i.e., whether HCPs are present as free molecules or as parts of large aggregates. Separate protein A chromatography experiments performed by feeding different fractions of a mAb-containing HCCF obtained by size-exclusion chromatography (SEC) showed clear differences in the number and identity of HCPs found in the protein A eluate. These results indicate a significant role for HCP-mAb association in determining HCP persistence through protein A chromatography, presumably through binding of HCP-mAb complexes to the resin. Overall, the results illustrate the importance of considering more fully the biophysical context of HCP-product association in assessing the factors that may affect the phenomenon and determine its implications. Knowledge of the abundances and the forms of individual or aggregated HCPs in HCCF are particularly significant, emphasizing the integration of upstream and downstream bioprocessing and the importance of understanding the collective properties of HCPs in addition to just the biophysical properties of individual HCPs.
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Affiliation(s)
- Young Hoon Oh
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA
| | - Matthew L Becker
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA
| | - Kerri M Mendola
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA
| | - Leila H Choe
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA
| | - Lie Min
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA
| | - Kelvin H Lee
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA
| | - Yinges Yigzaw
- Purification Process Development, Genentech, Inc., South San Francisco, California, USA
| | - Alexander Seay
- Purification Process Development, Genentech, Inc., South San Francisco, California, USA
| | - Jerome Bill
- Purification Process Development, Genentech, Inc., South San Francisco, California, USA
| | - Xuanwen Li
- Analytical Research and Development, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - David J Roush
- Biologics PR&D, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Steven M Cramer
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, 27606, North Carolina, USA
| | - Abraham M Lenhoff
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA
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2
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Rudolph MJ, Dutta A, Tsymbal AM, McLaughlin JE, Chen Y, Davis SA, Theodorous SA, Pierce M, Algava B, Zhang X, Szekely Z, Roberge JY, Li XP, Tumer NE. Structure-based design and optimization of a new class of small molecule inhibitors targeting the P-stalk binding pocket of ricin. Bioorg Med Chem 2024; 100:117614. [PMID: 38340640 DOI: 10.1016/j.bmc.2024.117614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024]
Abstract
Ricin, a category-B agent for bioterrorism, and Shiga toxins (Stxs), which cause food poisoning bind to the ribosomal P-stalk to depurinate the sarcin/ricin loop. No effective therapy exists for ricin or Stx intoxication. Ribosome binding sites of the toxins have not been targeted by small molecules. We previously identified CC10501, which inhibits toxin activity by binding the P-stalk pocket of ricin toxin A subunit (RTA) remote from the catalytic site. Here, we developed a fluorescence polarization assay and identified a new class of compounds, which bind P-stalk pocket of RTA with higher affinity and inhibit catalytic activity with submicromolar potency. A lead compound, RU-NT-206, bound P-stalk pocket of RTA with similar affinity as a five-fold larger P-stalk peptide and protected cells against ricin and Stx2 holotoxins for the first time. These results validate the P-stalk binding site of RTA as a critical target for allosteric inhibition of the active site.
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Affiliation(s)
- Michael J Rudolph
- New York Structural Biology Center, 89 Convent Ave, New York, NY 10027, United States
| | - Arkajyoti Dutta
- Department of Plant Biology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, United States
| | - Anastasiia M Tsymbal
- Molecular Design and Synthesis Core, Rutgers University Biomolecular Innovations Cores, Office for Research, Rutgers University, 610 Taylor Rd, Piscataway, NJ 08854, United States
| | - John E McLaughlin
- Department of Plant Biology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, United States
| | - Yang Chen
- New York Structural Biology Center, 89 Convent Ave, New York, NY 10027, United States
| | - Simon A Davis
- New York Structural Biology Center, 89 Convent Ave, New York, NY 10027, United States
| | - Sophia A Theodorous
- New York Structural Biology Center, 89 Convent Ave, New York, NY 10027, United States
| | - Michael Pierce
- Department of Plant Biology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, United States
| | - Benjamin Algava
- Department of Plant Biology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, United States
| | - Xiaoyu Zhang
- Department of Plant Biology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, United States
| | - Zoltan Szekely
- Molecular Design and Synthesis Core, Rutgers University Biomolecular Innovations Cores, Office for Research, Rutgers University, 610 Taylor Rd, Piscataway, NJ 08854, United States
| | - Jacques Y Roberge
- Molecular Design and Synthesis Core, Rutgers University Biomolecular Innovations Cores, Office for Research, Rutgers University, 610 Taylor Rd, Piscataway, NJ 08854, United States
| | - Xiao-Ping Li
- Department of Plant Biology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, United States.
| | - Nilgun E Tumer
- Department of Plant Biology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, United States.
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3
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Schmidt S, Holzgrabe U. Do the enantiomers of ketamine bind enantioselectively to human serum albumin? Eur J Pharm Sci 2024; 192:106640. [PMID: 37979888 DOI: 10.1016/j.ejps.2023.106640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/08/2023] [Accepted: 11/11/2023] [Indexed: 11/20/2023]
Abstract
The binding of drugs to plasma proteins is an important process in the human body and has a significant influence on pharmacokinetic parameter. Human serum albumin (HSA) has the most important function as a transporter protein. The binding of ketamine to HSA has already been described in literature, but only of the racemate. The enantiomerically pure S-ketamine is used as injection solution for induction of anesthesia and has been approved by the Food and Drug Administration for the therapy of severe depression as a nasal spray in 2019. The question arises if there is enantioselective binding to HSA. Hence, the aim of this study was to investigate whether there is enantioselective binding of S-and R-ketamine to HSA or not. Ultrafiltration (UF) followed by chiral capillary electrophoretic analysis was used to determine the extent of protein binding. Bound fraction to HSA was 71.2 % and 64.9 % for enantiomerically pure R- and S-ketamine, respectively, and 66.5 % for the racemate. Detailed binding properties were studied by Saturation Transfer Difference (STD)-, waterLOGSY- and Carr-Purcell-Meiboom-Gill (CPMG)-NMR spectroscopy. With all three methods, the aromatic ring and the N-methyl group could be identified as the structural moieties most strongly involved in binding of ketamine to HSA. pKaff values determined using UF and NMR indicate that ketamine is a weak affinity ligand to HSA and no significant differences in binding behavior were found between the individual enantiomers and the racemate.
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Affiliation(s)
- Sebastian Schmidt
- Institute for Pharmacy and Food Chemistry, Am Hubland, D-97074 Wuerzburg, Germany
| | - Ulrike Holzgrabe
- Institute for Pharmacy and Food Chemistry, Am Hubland, D-97074 Wuerzburg, Germany.
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4
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Chen HY, Teng CS, Lin PH, Liu CP, Liu WM, Chu LK. Noncovalent Association Thermodynamics of Turn-On Fluorescent Probes with Human Serum Albumin: Dual-Concentration Ratio Method. Chembiochem 2023; 24:e202300370. [PMID: 37387480 DOI: 10.1002/cbic.202300370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/17/2023] [Accepted: 06/28/2023] [Indexed: 07/01/2023]
Abstract
Efficient quantification of the affinity of a drug and the targeted protein is critical for strategic drug design. Among the various molecules, turn-on fluorescent probes are the most promising signal transducers to reveal the binding strength and site-specificity of designed drugs. However, the conventional method of measuring the binding ability of turn-on fluorescent probes by using the fractional occupancy under the law of mass action is time-consuming and a massive sample is required. Here, we report a new method, called dual-concentration ratio method, for quantifying the binding affinity of fluorescent probes and human serum albumin (HSA). Temperature-dependent fluorescence intensity ratios of a one-to-one complex (L ⋅ HSA) for a turn-on fluorescent probe (L), e. g., ThT (thioflavin T) or DG (dansylglycine), with HSA at two different values of [L]0 /[HSA]0 under the constraint [HSA]0 >[L]0 were collected. The van't Hoff analysis on these association constants further resulted in the thermodynamic properties. Since only two samples at different [L]0 /[HSA]0 are required without the need of [L]0 /[HSA]0 at a wide range, the dual-concentration ratio method is an easy way to greatly reduce the amounts of fluorescent probes and proteins, as well as the acquisition time.
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Affiliation(s)
- Han-Yu Chen
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd, Hsinchu, 300044, Taiwan
| | - Chung-Siang Teng
- Department of Chemistry, Fu Jen Catholic University, 510, Zhongzheng Rd., New Taipei City, 242062, Taiwan
| | - Pin-Han Lin
- Department of Chemistry, Fu Jen Catholic University, 510, Zhongzheng Rd., New Taipei City, 242062, Taiwan
| | - Ching-Ping Liu
- Department of Chemistry, Fu Jen Catholic University, 510, Zhongzheng Rd., New Taipei City, 242062, Taiwan
| | - Wei-Min Liu
- Department of Chemistry, Fu Jen Catholic University, 510, Zhongzheng Rd., New Taipei City, 242062, Taiwan
| | - Li-Kang Chu
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd, Hsinchu, 300044, Taiwan
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5
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Zhao X, Wang X, Yuan M, Zhang X, Yang X, Guan X, Li S, Ma J, Qiu HJ, Li Y. Identification of two novel T cell epitopes on the E2 protein of classical swine fever virus C-strain. Vet Microbiol 2023; 284:109814. [PMID: 37356277 DOI: 10.1016/j.vetmic.2023.109814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/11/2023] [Accepted: 06/14/2023] [Indexed: 06/27/2023]
Abstract
C-strain, also known as the HCLV strain, is a well-known live attenuated vaccine against classical swine fever (CSF), a devastating disease caused by classical swine fever virus (CSFV). Vaccination with C-strain induces a rapid onset of protection, which is associated with virus-specific gamma interferon (IFN-γ)-secreting CD8+ T cell responses. The E2 protein of CSFV is a major protective antigen. However, the T cell epitopes on the E2 protein remain largely unknown. In this study, eight overlapping nonapeptides of the E2 protein were predicted and synthesized to screen for potential T cell epitopes on the CSFV C-strain E2 protein. Molecular docking was performed on the candidate epitopes with the swine leukocyte antigen-1*0401. The analysis obtained two highly conserved T cell epitopes, 90STEEMGDDF98 and 331ATDRHSDYF339, which were further identified by enzyme-linked immunospot assay. Interestingly, the mutants deleting or substituting the epitopes are nonviable. Further analysis demonstrated that 90STEEMGDDF98 is crucial for the E2 homodimerization, while CSFV infection is significantly inhibited by the 331ATDRHSDYF339 peptide treatment. The two novel T cell epitopes can be used to design new vaccines that are able to provide rapid-onset protection.
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Affiliation(s)
- Xiaotian Zhao
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China; Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin, China
| | - Xiao Wang
- Department of Pathogenic Biology, School of Basic Medical Sciences, Binzhou Medical University, Yantai, China
| | - Mengqi Yuan
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xin Zhang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xiaoke Yang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xiangyu Guan
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Shuwen Li
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jifei Ma
- Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin, China.
| | - Hua-Ji Qiu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
| | - Yongfeng Li
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
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6
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Hardebeck S, Schreiber S, Adick A, Langer K, Jose J. A FRET-Based Assay for the Identification of PCNA Inhibitors. Int J Mol Sci 2023; 24:11858. [PMID: 37511614 PMCID: PMC10380293 DOI: 10.3390/ijms241411858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
Proliferating cell nuclear antigen (PCNA) is the key regulator of human DNA metabolism. One important interaction partner is p15, involved in DNA replication and repair. Targeting the PCNA-p15 interaction is a promising therapeutic strategy against cancer. Here, a Förster resonance energy transfer (FRET)-based assay for the analysis of the PCNA-p15 interaction was developed. Next to the application as screening tool for the identification and characterization of PCNA-p15 interaction inhibitors, the assay is also suitable for the investigation of mutation-induced changes in their affinity. This is particularly useful for analyzing disease associated PCNA or p15 variants at the molecular level. Recently, the PCNA variant C148S has been associated with Ataxia-telangiectasia-like disorder type 2 (ATLD2). ATLD2 is a neurodegenerative disease based on defects in DNA repair due to an impaired PCNA. Incubation time dependent FRET measurements indicated no effect on PCNAC148S-p15 affinity, but on PCNA stability. The impaired stability and increased aggregation behavior of PCNAC148S was confirmed by intrinsic tryptophan fluorescence, differential scanning fluorimetry (DSF) and asymmetrical flow field-flow fractionation (AF4) measurements. The analysis of the disease associated PCNA variant demonstrated the versatility of the interaction assay as developed.
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Affiliation(s)
- Sarah Hardebeck
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Pharmacampus, 48149 Münster, Germany
| | - Sebastian Schreiber
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Pharmacampus, 48149 Münster, Germany
| | - Annika Adick
- University of Münster, Institute for Pharmaceutical Technology and Biopharmacy, Pharmacampus, 48149 Münster, Germany
| | - Klaus Langer
- University of Münster, Institute for Pharmaceutical Technology and Biopharmacy, Pharmacampus, 48149 Münster, Germany
| | - Joachim Jose
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Pharmacampus, 48149 Münster, Germany
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7
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Park J, Ban C. Development of a one-shot dual aptamer-based fluorescence nanosensor for rapid, sensitive, and label-free detection of periostin. Sci Rep 2023; 13:10224. [PMID: 37353600 PMCID: PMC10290134 DOI: 10.1038/s41598-023-37418-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/21/2023] [Indexed: 06/25/2023] Open
Abstract
Periostin is associated with several diseases, including cancers. Therefore, monitoring blood periostin levels is a powerful tool for diagnosing various diseases and identifying their severity. However, conventional detection methods pose several challenges, including high costs. To address these issues, we developed a novel one-shot dual aptamer-based fluorescence nanosensor for detecting periostin. The proposed nanosensor facilitates rapid, label-free, and sensitive detection of periostin using gold nanoprobes constructed by rhodamine-b isothiocyanate, PL2trunc aptamer, and gold nanoparticles and silver nanoprobes fabricated by the PL5trunc aptamer and silver nanoparticles. The two nanoprobes form a core-satellite structure by interacting with periostin, and the nanosensor detects periostin through the fluorescence regenerated by the increased proximity between them. The nanosensor successfully detected periostin with remarkable detection limits of 106.68 pM in buffer and 463.3 pM in serum-spiked conditions within 30 min without additional washing or signal amplification processes. Considering serum periostin levels in various diseases, the proposed nanosensor provides a suitable method for identifying patients with various diseases and determining disease severity. Moreover, the platform can be helpful as a practical method for on-site medical diagnosis because it can be adapted to detect other biomarkers simply by replacing the aptamer with other detection probes.
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Affiliation(s)
- Jonghoon Park
- Department of Chemistry, Pohang University of Science and Technology, 77, Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Changill Ban
- Department of Chemistry, Pohang University of Science and Technology, 77, Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673, Republic of Korea.
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8
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Sanders EW, Carr AR, Bruggeman E, Körbel M, Benaissa SI, Donat RF, Santos AM, McColl J, O'Holleran K, Klenerman D, Davis SJ, Lee SF, Ponjavic A. resPAINT: Accelerating Volumetric Super-Resolution Localisation Microscopy by Active Control of Probe Emission. Angew Chem Int Ed Engl 2022; 61:e202206919. [PMID: 35876263 DOI: 10.1002/anie.202206919] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Indexed: 01/07/2023]
Abstract
Points for accumulation in nanoscale topography (PAINT) allows practically unlimited measurements in localisation microscopy but is limited by background fluorescence at high probe concentrations, especially in volumetric imaging. We present reservoir-PAINT (resPAINT), which combines PAINT and active control of probe photophysics. In resPAINT, an activatable probe "reservoir" accumulates on target, enabling a 50-fold increase in localisation rate versus conventional PAINT, without compromising contrast. By combining resPAINT with large depth-of-field microscopy, we demonstrate super-resolution imaging of entire cell surfaces. We generalise the approach by implementing various switching strategies and 3D imaging techniques. Finally, we use resPAINT with a Fab to image membrane proteins, extending the operating regime of PAINT to include a wider range of biological interactions.
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Affiliation(s)
- Edward W Sanders
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Alexander R Carr
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Ezra Bruggeman
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Markus Körbel
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Sarah I Benaissa
- Cambridge Advanced Imaging Centre, University of Cambridge, Cambridge, CB2 3DY, UK
| | - Robert F Donat
- Radcliffe Department of Medicine and United Kingdom Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - Ana M Santos
- Radcliffe Department of Medicine and United Kingdom Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - James McColl
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Kevin O'Holleran
- Cambridge Advanced Imaging Centre, University of Cambridge, Cambridge, CB2 3DY, UK
| | - David Klenerman
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Simon J Davis
- Radcliffe Department of Medicine and United Kingdom Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - Steven F Lee
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Aleks Ponjavic
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK.,School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.,School of Food Science and Nutrition, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
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9
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Sanders EW, Carr AR, Bruggeman E, Körbel M, Benaissa SI, Donat RF, Santos AM, McColl J, O'Holleran K, Klenerman D, Davis SJ, Lee SF, Ponjavic A. resPAINT: Accelerating Volumetric Super-Resolution Localisation Microscopy by Active Control of Probe Emission. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 134:e202206919. [PMID: 38505515 PMCID: PMC10946633 DOI: 10.1002/ange.202206919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Indexed: 03/21/2024]
Abstract
Points for accumulation in nanoscale topography (PAINT) allows practically unlimited measurements in localisation microscopy but is limited by background fluorescence at high probe concentrations, especially in volumetric imaging. We present reservoir-PAINT (resPAINT), which combines PAINT and active control of probe photophysics. In resPAINT, an activatable probe "reservoir" accumulates on target, enabling a 50-fold increase in localisation rate versus conventional PAINT, without compromising contrast. By combining resPAINT with large depth-of-field microscopy, we demonstrate super-resolution imaging of entire cell surfaces. We generalise the approach by implementing various switching strategies and 3D imaging techniques. Finally, we use resPAINT with a Fab to image membrane proteins, extending the operating regime of PAINT to include a wider range of biological interactions.
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Affiliation(s)
- Edward W. Sanders
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Alexander R. Carr
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Ezra Bruggeman
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Markus Körbel
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Sarah I. Benaissa
- Cambridge Advanced Imaging CentreUniversity of CambridgeCambridgeCB2 3DYUK
| | - Robert F. Donat
- Radcliffe Department of Medicine and United Kingdom Medical Research Council Human Immunology UnitJohn Radcliffe HospitalUniversity of OxfordOxfordOX3 9DSUK
| | - Ana M. Santos
- Radcliffe Department of Medicine and United Kingdom Medical Research Council Human Immunology UnitJohn Radcliffe HospitalUniversity of OxfordOxfordOX3 9DSUK
| | - James McColl
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Kevin O'Holleran
- Cambridge Advanced Imaging CentreUniversity of CambridgeCambridgeCB2 3DYUK
| | - David Klenerman
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Simon J. Davis
- Radcliffe Department of Medicine and United Kingdom Medical Research Council Human Immunology UnitJohn Radcliffe HospitalUniversity of OxfordOxfordOX3 9DSUK
| | - Steven F. Lee
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
| | - Aleks Ponjavic
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeCB2 1EWUK
- School of Physics and AstronomyUniversity of LeedsWoodhouse LaneLeedsLS2 9JTUK
- School of Food Science and NutritionUniversity of LeedsWoodhouse LaneLeedsLS2 9JTUK
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10
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Mazzei P, Cangemi S, Malakshahi Kurdestani A, Mueller T, Piccolo A. Quantitative Evaluation of Noncovalent Interactions between 3,4-Dimethyl-1 H-pyrazole and Dissolved Humic Substances by NMR Spectroscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11771-11779. [PMID: 35896036 DOI: 10.1021/acs.est.2c00900] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nitrification inhibitors (NI) represent a valid chemical strategy to retard nitrogen oxidation in soil and limit nitrate leaching or nitrogen oxide emission. We hypothesized that humic substances can complex NI, thus affecting their activity, mobility, and persistence in soil. Therefore, we focused on 3,4-dimethylpyrazole phosphate (DMPP) by placing it in contact with increasing concentrations of model fulvic (FA) and humic (HA) acids. The complex formation was assessed through advanced and composite NMR techniques (chemical shift drift, line-broadening effect, relaxation times, saturation transfer difference (STD), and diffusion ordered spectroscopy (DOSY)). Our results showed that both humic substances interacted with DMPP, with HA exhibiting a significantly greater affinity than FA. STD emphasized the pivotal role of the aromatic signal, for HA-DMPP association, and both alkyl methyl groups, for FA-DMPP association. The fractions of complexed DMPP were determined on the basis of self-diffusion coefficients, which were then exploited to calculate both the humo-complex affinity constants and the free Gibbs energy (Kd and ΔG for HA were 0.5169 M and -1636 kJ mol-1, respectively). We concluded that DMPP-based NI efficiency may be altered by soil organic matter, characterized by a pronounced hydrophobic nature. This is relevant to improve nitrogen management and lower its environmental impact.
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Affiliation(s)
- Pierluigi Mazzei
- Dipartimento di Farmacia (DIFARMA), Università degli Studi di Salerno, Fisciano 84084, Italy
| | - Silvana Cangemi
- Centro Interdipartimentale sulla Risonanza Magnetica Nucleare per l'Ambiente, l'Agro-Alimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Portici 80055, Italy
| | - Ali Malakshahi Kurdestani
- Department of Fertilization and Soil Matter Dynamics, University of Hohenheim, Stuttgart 70593, Germany
| | - Torsten Mueller
- Department of Fertilization and Soil Matter Dynamics, University of Hohenheim, Stuttgart 70593, Germany
| | - Alessandro Piccolo
- Centro Interdipartimentale sulla Risonanza Magnetica Nucleare per l'Ambiente, l'Agro-Alimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Portici 80055, Italy
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11
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Dong C, Zheng Y, Long-lyer K, Wright EC, Li Y, Tian L. Fluorescence Imaging of Neural Activity, Neurochemical Dynamics, and Drug-Specific Receptor Conformation with Genetically Encoded Sensors. Annu Rev Neurosci 2022; 45:273-294. [PMID: 35316611 PMCID: PMC9940643 DOI: 10.1146/annurev-neuro-110520-031137] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent advances in fluorescence imaging permit large-scale recording of neural activity and dynamics of neurochemical release with unprecedented resolution in behaving animals. Calcium imaging with highly optimized genetically encoded indicators provides a mesoscopic view of neural activity from genetically defined populations at cellular and subcellular resolutions. Rigorously improved voltage sensors and microscopy allow for robust spike imaging of populational neurons in various brain regions. In addition, recent protein engineering efforts in the past few years have led to the development of sensors for neurotransmitters and neuromodulators. Here, we discuss the development and applications of these genetically encoded fluorescent indicators in reporting neural activity in response to various behaviors in different biological systems as well as in drug discovery. We also report a simple model to guide sensor selection and optimization.
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Affiliation(s)
- Chunyang Dong
- Graduate Program in Biochemistry, Molecular, Cellular, and Developmental Biology, University of California, Davis, California, USA.,Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, California, USA;
| | - Yu Zheng
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences; PKU-IDG/McGovern Institute for Brain Research; and Peking-Tsinghua Center for Life Sciences, Beijing, China;
| | - Kiran Long-lyer
- Neuroscience Graduate Program, University of California Davis, Davis, CA 95618, USA,Department of Biochemistry & Molecular Medicine, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Emily C. Wright
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences; PKU-IDG/McGovern Institute for Brain Research; and Peking-Tsinghua Center for Life Sciences, Beijing, China;
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, California, USA;
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12
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Aptamer-antibody hybrid ELONA that uses hybridization chain reaction to detect a urinary biomarker EN2 for bladder and prostate cancer. Sci Rep 2022; 12:11523. [PMID: 35798816 PMCID: PMC9263169 DOI: 10.1038/s41598-022-15556-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 06/27/2022] [Indexed: 12/15/2022] Open
Abstract
We report an EN2-specific (Kd = 8.26 nM) aptamer, and a sensitive and specific enzyme-linked oligonucleotide assay (ELONA) for rapid and sensitive colorimetric detection of bladder and prostate cancer biomarker EN2 in urine. The assay relies on an aptamer-mediated hybridization chain reaction (HCR) to generate DNA nanostructures that bind to EN2 and simultaneously amplify signals. The assay can be performed within 2.5 h, and has a limit of detection of 0.34 nM in buffer and 2.69 nM in artificial urine. Moreover, this assay showed high specificity as it did not detect other urinary proteins, including biomarkers of other cancers. The proposed ELONA is inexpensive, highly reproducible, and has great chemical stability, so it may enable development of a simple, sensitive and accurate diagnostic tool to detect bladder and prostate cancers early.
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13
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Srinivasan B. A guide to enzyme kinetics in early drug discovery. FEBS J 2022; 290:2292-2305. [PMID: 35175693 DOI: 10.1111/febs.16404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/10/2022] [Accepted: 02/15/2022] [Indexed: 12/28/2022]
Abstract
Drugs interact with their target of interest to bring about the desired phenotypic outcome that results in disease alleviation. Traditionally, most lead optimization exercises were driven by affinity measures (like IC50 ) to inform structure-activity relationship (SAR)-guided medicinal chemistry. However, an IC50 value is a thermodynamic estimate measured under equilibrium conditions that can vary as a function of substrate concentration and/or time (the latter especially for nonequilibrium modalities). Further, like other thermodynamic estimates, it is a state-function that is indifferent to the path traversed from the initial state to the final state. This can be a cause for concern in drug discovery given the predominance of nonequilibrium interactions and the open thermodynamic nature of the human system. Under such situations, employing rates along with equilibrium constants (or IC50 values) would be far more relevant to capture the time evolution of the small molecule's interaction with the target of interest. These rates are generally typified by the rate of association, rate of dissociation and the residence time of the small molecule on the target (target occupancy). These parameters, when combined with the concept of target vulnerability, therapeutic window, pharmacokinetic profile of the small molecule, estimates of endogenous ligand and target turnover, will shed critical insights into the kinetics and dynamics of a small molecule's interaction with the protein, and allow realistic modelling of the system to enable optimizations and dosing decisions. With that aim, this guide will attempt to introduce the traditional role of mechanistic enzymology within drug discovery and emphasize the importance of kinetics in guiding SAR-based optimizations. It will also present initial ideas on how kinetic investigation should be positioned relative to the temporal span of a drug-discovery pipeline to leverage maximal utility from the investment in time and effort.
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Affiliation(s)
- Bharath Srinivasan
- Mechanistic and Structural Biology Discovery Sciences R&D AstraZeneca Cambridge UK
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14
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Homocysteine-Thiolactone Modulates Gating of Mitochondrial Voltage-Dependent Anion Channel (VDAC) and Protects It from Induced Oxidative Stress. J Membr Biol 2022; 255:79-97. [PMID: 35103807 DOI: 10.1007/s00232-022-00215-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/10/2022] [Indexed: 12/26/2022]
Abstract
The gating of the Voltage-Dependent Anion Channel (VDAC) is linked to oxidative stress through increased generation of mitochondrial ROS with increasing mitochondrial membrane potential (ΔΨm). It has been already reported that H2O2 increases the single-channel conductance of VDAC on a bilayer lipid membrane. On the other hand, homocysteine (Hcy) has been reported to induce mitochondria-mediated cell death. It is argued that the thiol-form of homocysteine, HTL could be the plausible molecule responsible for the alteration in the function of proteins, such as VDAC. It is hypothesized that HTL interacts with VDAC that causes functional abnormalities. An investigation was undertaken to study the interaction of HTL with VDAC under H2O2 induced oxidative stress through biophysical and electrophysiological methods. Fluorescence spectroscopic studies indicate that HTL interacts with VDAC, but under induced oxidative stress the effect is prevented partially. Similarly, bilayer electrophysiology studies suggest that HTL shows a reduction in VDAC single-channel conductance, but the effects are partially prevented under an oxidative environment. Gly172 and His181 are predicted through bioinformatics tools to be the most plausible binding residues of HTL in Rat VDAC. The binding of HTL and H2O2 with VDAC appears to be cooperative as per our analysis of experimental data in the light of the Hill-Langmuir equation. The binding energies are estimated to be - 4.7 kcal mol-1 and - 2.8 kcal mol-1, respectively. The present in vitro studies suggest that when mitochondrial VDAC is under oxidative stress, the effects of amino acid metabolites like HTL are suppressed.
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15
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Labouesse MA, Patriarchi T. A versatile GPCR toolkit to track in vivo neuromodulation: not a one-size-fits-all sensor. Neuropsychopharmacology 2021; 46:2043-2047. [PMID: 33603136 PMCID: PMC8505436 DOI: 10.1038/s41386-021-00982-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/12/2021] [Accepted: 01/23/2021] [Indexed: 12/23/2022]
Affiliation(s)
- Marie A Labouesse
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, Columbia, NY, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Tommaso Patriarchi
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland.
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16
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Kirtani DU, Ghatpande NS, Suryavanshi KR, Kulkarni PP, Kumbhar AA. Fluorescent Copper(II) Complexes of Asymmetric Bis(Thiosemicarbazone)s: Electrochemistry, Cellular Uptake and Antiproliferative Activity. ChemistrySelect 2021. [DOI: 10.1002/slct.202101663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Deepti U. Kirtani
- Department of Chemistry Savitribai Phule Pune University Ganeshkhind Road Pune 411007 India
| | - Niraj S. Ghatpande
- Bioprospecting Group Agharkar Research Institute Gopal Ganesh Agarkar Road Pune 411004 India
| | - Komal R. Suryavanshi
- Bioprospecting Group Agharkar Research Institute Gopal Ganesh Agarkar Road Pune 411004 India
| | - Prasad P. Kulkarni
- Bioprospecting Group Agharkar Research Institute Gopal Ganesh Agarkar Road Pune 411004 India
| | - Anupa A. Kumbhar
- Department of Chemistry Savitribai Phule Pune University Ganeshkhind Road Pune 411007 India
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17
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Khazaee M, Christie E, Cheng W, Michalsen M, Field J, Ng C. Perfluoroalkyl Acid Binding with Peroxisome Proliferator-Activated Receptors α, γ, and δ, and Fatty Acid Binding Proteins by Equilibrium Dialysis with a Comparison of Methods. TOXICS 2021; 9:45. [PMID: 33652875 PMCID: PMC7996760 DOI: 10.3390/toxics9030045] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/13/2021] [Accepted: 02/19/2021] [Indexed: 01/09/2023]
Abstract
The biological impacts of per- and polyfluorinated alkyl substances (PFAS) are linked to their protein interactions. Existing research has largely focused on serum albumin and liver fatty acid binding protein, and binding affinities determined with a variety of methods show high variability. Moreover, few data exist for short-chain PFAS, though their prevalence in the environment is increasing. We used molecular dynamics (MD) to screen PFAS binding to liver and intestinal fatty acid binding proteins (L- and I-FABPs) and peroxisome proliferator activated nuclear receptors (PPAR-α, -δ and -γ) with six perfluoroalkyl carboxylates (PFCAs) and three perfluoroalkyl sulfonates (PFSAs). Equilibrium dissociation constants, KDs, were experimentally determined via equilibrium dialysis (EqD) with liquid chromatography tandem mass spectrometry for protein-PFAS pairs. A comparison was made between KDs derived from EqD, both here and in literature, and other in vitro approaches (e.g., fluorescence) from literature. EqD indicated strong binding between PPAR-δ and perfluorobutanoate (0.044 ± 0.013 µM) and perfluorohexane sulfonate (0.035 ± 0.0020 µM), and between PPAR-α and perfluorohexanoate (0.097 ± 0.070 µM). Unlike binding affinities for L-FABP, which increase with chain length, KDs for PPARs showed little chain length dependence by either MD simulation or EqD. Compared with other in vitro approaches, EqD-based KDs consistently indicated higher affinity across different proteins. This is the first study to report PPARs binding with short-chain PFAS with KDs in the sub-micromolar range.
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Affiliation(s)
- Manoochehr Khazaee
- Department of Civil & Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA; (M.K.); (W.C.)
| | - Emerson Christie
- Department of Molecular and Environmental Toxicology, Oregon State University, Corvallis, OR 97330, USA; (E.C.); (J.F.)
| | - Weixiao Cheng
- Department of Civil & Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA; (M.K.); (W.C.)
| | - Mandy Michalsen
- U.S. Army Engineer Research Development Center—Environmental Lab, Vicksburg, MS 39180, USA;
| | - Jennifer Field
- Department of Molecular and Environmental Toxicology, Oregon State University, Corvallis, OR 97330, USA; (E.C.); (J.F.)
| | - Carla Ng
- Department of Civil & Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA; (M.K.); (W.C.)
- Secondary Appointment, Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
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18
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Rangel-Guerrero SI, Franco-Urquijo PA, Martínez-Salas E, Alvarez-Salas LM. Structural insights of the pre-let-7 interaction with LIN28B. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2020; 40:194-211. [PMID: 33319653 DOI: 10.1080/15257770.2020.1859116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The Let-7:LIN28 regulatory loop is a paradigm in miRNA regulation. LIN28 harbors two RNA binding domains, which interact with well-conserved sequences in pre-let-7 RNAs, the GNGAY and the GGAG motifs. Here, the differential binding between LIN28B and pre-let-7 members was associated with the structural characteristics of the pre-let-7 family mapped by SHAPE, uncovering diverse structural patterns within pre-let-7 members. Pre-let-7 mutants supported a relevant role of the GGAG motif location and the preE-stem stability for the interaction with LIN28B. Based on these results, we propose a core RNA structure for LIN28B interaction.
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Affiliation(s)
- Sergio Israel Rangel-Guerrero
- Laboratorio de Terapia Génica, Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México City, Mexico
| | - Pablo Alberto Franco-Urquijo
- Laboratorio de Terapia Génica, Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México City, Mexico
| | | | - Luis Marat Alvarez-Salas
- Laboratorio de Terapia Génica, Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México City, Mexico
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19
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Synthesis, Biological, and Computational Evaluation of Antagonistic, Chiral Hydrobenzoin Esters of Arecaidine Targeting mAChR M1. Pharmaceuticals (Basel) 2020; 13:ph13120437. [PMID: 33266067 PMCID: PMC7760838 DOI: 10.3390/ph13120437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 12/13/2022] Open
Abstract
Muscarinic acetylcholine receptors (mAChRs) are a pivotal constituent of the central and peripheral nervous system. Yet, therapeutic and diagnostic applications thereof are hampered by the lack of subtype selective ligands. Within this work, we synthesized and chemically characterized three different stereoisomers of hydrobenzoin esters of arecaidine by NMR, HR-MS, chiral chromatography, and HPLC-logP. All compounds are structurally eligible for carbon-11 labeling and show appropriate stability in Dulbecco’s phosphate-buffered saline (DPBS) and F12 cell culture medium. A competitive radioligand binding assay on Chinese hamster ovary cell membranes comprising the human mAChR subtypes M1-M5 showed the highest orthosteric binding affinity for subtype M1 and a strong influence of stereochemistry on binding affinity, which corresponds to in silico molecular docking experiments. Ki values toward M1 were determined as 99 ± 19 nM, 800 ± 200 nM, and 380 ± 90 nM for the (R,R)-, (S,S)-, and racemic (R,S)-stereoisomer, respectively, highlighting the importance of stereochemical variations in mAChR ligand development. All three stereoisomers were shown to act as antagonists toward mAChR M1 using a Fluo-4 calcium efflux assay. With respect to future positron emission tomography (PET) tracer development, the (R,R)-isomer appears especially promising as a lead structure due to its highest subtype selectivity and lowest Ki value.
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20
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Demine S, Schulte ML, Territo PR, Eizirik DL. Beta Cell Imaging-From Pre-Clinical Validation to First in Man Testing. Int J Mol Sci 2020; 21:E7274. [PMID: 33019671 PMCID: PMC7582644 DOI: 10.3390/ijms21197274] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/21/2020] [Accepted: 09/28/2020] [Indexed: 12/14/2022] Open
Abstract
There are presently no reliable ways to quantify human pancreatic beta cell mass (BCM) in vivo, which prevents an accurate understanding of the progressive beta cell loss in diabetes or following islet transplantation. Furthermore, the lack of beta cell imaging hampers the evaluation of the impact of new drugs aiming to prevent beta cell loss or to restore BCM in diabetes. We presently discuss the potential value of BCM determination as a cornerstone for individualized therapies in diabetes, describe the presently available probes for human BCM evaluation, and discuss our approach for the discovery of novel beta cell biomarkers, based on the determination of specific splice variants present in human beta cells. This has already led to the identification of DPP6 and FXYD2ga as two promising targets for human BCM imaging, and is followed by a discussion of potential safety issues, the role for radiochemistry in the improvement of BCM imaging, and concludes with an overview of the different steps from pre-clinical validation to a first-in-man trial for novel tracers.
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Affiliation(s)
- Stephane Demine
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA;
| | - Michael L. Schulte
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (M.L.S.); (P.R.T.)
| | - Paul R. Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (M.L.S.); (P.R.T.)
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Decio L. Eizirik
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA;
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
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21
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Saroz Y, Kho DT, Glass M, Graham ES, Grimsey NL. Cannabinoid Receptor 2 (CB 2) Signals via G-alpha-s and Induces IL-6 and IL-10 Cytokine Secretion in Human Primary Leukocytes. ACS Pharmacol Transl Sci 2019; 2:414-428. [PMID: 32259074 DOI: 10.1021/acsptsci.9b00049] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Indexed: 12/11/2022]
Abstract
Cannabinoid receptor 2 (CB2) is a promising therapeutic target for immunological modulation. There is, however, a deficit of knowledge regarding CB2 signaling and function in human primary immunocompetent cells. We applied an experimental paradigm which closely models the in situ state of human primary leukocytes (PBMC; peripheral blood mononuclear cells) to characterize activation of a number of signaling pathways in response to a CB2-selective ligand (HU308). We observed a "lag" phase of unchanged cAMP concentration prior to development of classically expected Gαi-mediated inhibition of cAMP synthesis. Application of G protein inhibitors revealed that this apparent lag was a result of counteraction of Gαi effects by concurrent Gαs activation. Monitoring downstream signaling events showed that activation of p38 was mediated by Gαi, whereas ERK1/2 and Akt phosphorylation were mediated by Gαi-coupled βγ. Activation of CREB integrated multiple components; Gαs and βγ mediated ∼85% of the response, while ∼15% was attributed to Gαi. Responses to HU308 had an important functional outcome-secretion of interleukins 6 (IL-6) and 10 (IL-10). IL-2, IL-4, IL-12, IL-13, IL-17A, MIP-1α, and TNF-α were unaffected. IL-6/IL-10 induction had a similar G protein coupling profile to CREB activation. All response potencies were consistent with that expected for HU308 acting via CB2. Additionally, signaling and functional effects were completely blocked by a CB2-selective inverse agonist, giving additional evidence for CB2 involvement. This work expands the current paradigm regarding cannabinoid immunomodulation and reinforces the potential utility of CB2 ligands as immunomodulatory therapeutics.
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Affiliation(s)
- Yurii Saroz
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Dan T Kho
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, Division of Health Sciences, University of Otago, Dunedin, 9016, New Zealand
| | - Euan Scott Graham
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Natasha Lillia Grimsey
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
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22
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Hervy J, Bicout DJ. Determining the binding parameters from co-sedimentation assays. Phys Biol 2019; 16:056004. [PMID: 31239431 DOI: 10.1088/1478-3975/ab2c82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The stoichiometry n and the dissociation constant [Formula: see text] are key binding parameters characterizing the ligand-macromolecule interactions and equilibria. Equilibrium co-sedimentation experiments are performed in varying the concentration of one of the reactant while keeping constant that of the other reactant. The measured observable is the fraction [Formula: see text] of bound ligands when the ligand concentration is kept constant while that of macromolecules is varying whereas it is the macromolecule coverage [Formula: see text] with bound ligands when the ligand concentration is varying while that of macromolecules is kept constant. We have derived general expressions for [Formula: see text] and [Formula: see text] and subsequently showed that those expressions are in perfect agreement with simulations for a system of large ligands binding on macromolecules. Approximations have been developed to derive mathematical simple analytical expressions for [Formula: see text] and [Formula: see text] that can be used to fit the experimental data and thus extract, n and [Formula: see text] within the framework of equilibrium co-sedimentation assays. The method usefulness is illustrated and demonstrated by fitting the data from the literature using the derived formulas to determine the binding parameters.
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Affiliation(s)
- Jordan Hervy
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, France. Laboratory of Physics and Modelling of Condensed Matter, Grenoble Alpes University, CNRS, Grenoble, France
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23
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Hervy J, Bicout DJ. Correcting binding parameters for interacting ligand-lattice systems. Phys Rev E 2017; 96:012417. [PMID: 29347100 DOI: 10.1103/physreve.96.012417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Indexed: 11/07/2022]
Abstract
Binding of ligands to macromolecules is central to many functional and regulatory biological processes. Key parameters characterizing ligand-macromolecule interactions are the stoichiometry, inducing the number of ligands per macromolecule binding site, and the dissociation constant, quantifying the ligand-binding site affinity. Both these parameters can be obtained from analyses of classical saturation experiments using the standard binding equation that offers the great advantage of mathematical simplicity but becomes an approximation for situations of interest when a ligand binds and covers more than one single binding site on the macromolecule. Using the framework of car-parking problem with latticelike macromolecules where each ligand can cover simultaneously several consecutive binding sites, we showed that employing the standard analysis leads to underestimation of binding parameters, i.e., ligands appear larger than they actually are and their affinity is also greater than it is. Therefore, we have derived expressions allowing to determine the ligand size and true binding parameters (stoichiometry and dissociation constant) as a function of apparent binding parameters retrieved from standard saturation experiments.
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Affiliation(s)
- Jordan Hervy
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, France.,Laboratory of Physics and Modelling of Condensed Matter (UMR 5493), Grenoble Alpes University, CNRS, 38042 Grenoble, France
| | - Dominique J Bicout
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, France.,EPSP, TIMC Laboratory, UMR CNRS 5525 Grenoble Alpes University, VetAgro Sup, France
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24
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Lever SZ, Fan KH, Lever JR. Tactics for preclinical validation of receptor-binding radiotracers. Nucl Med Biol 2017; 44:4-30. [PMID: 27755986 PMCID: PMC5161541 DOI: 10.1016/j.nucmedbio.2016.08.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 08/24/2016] [Accepted: 08/24/2016] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Aspects of radiopharmaceutical development are illustrated through preclinical studies of [125I]-(E)-1-(2-(2,3-dihydrobenzofuran-5-yl)ethyl)-4-(iodoallyl)piperazine ([125I]-E-IA-BF-PE-PIPZE), a radioligand for sigma-1 (σ1) receptors, coupled with examples from the recent literature. Findings are compared to those previously observed for [125I]-(E)-1-(2-(2,3-dimethoxy-5-yl)ethyl)-4-(iodoallyl)piperazine ([125I]-E-IA-DM-PE-PIPZE). METHODS Syntheses of E-IA-BF-PE-PIPZE and [125I]-E-IA-BF-PE-PIPZE were accomplished by standard methods. In vitro receptor binding studies and autoradiography were performed, and binding potential was predicted. Measurements of lipophilicity and protein binding were obtained. In vivo studies were conducted in mice to evaluate radioligand stability, as well as specific binding to σ1 sites in brain, brain regions and peripheral organs in the presence and absence of potential blockers. RESULTS E-IA-BF-PE-PIPZE exhibited high affinity and selectivity for σ1 receptors (Ki = 0.43 ± 0.03 nM, σ2/σ1 = 173). [125I]-E-IA-BF-PE-PIPZE was prepared in good yield and purity, with high specific activity. Radioligand binding provided dissociation (koff) and association (kon) rate constants, along with a measured Kd of 0.24 ± 0.01 nM and Bmax of 472 ± 13 fmol/mg protein. The radioligand proved suitable for quantitative autoradiography in vitro using brain sections. Moderate lipophilicity, Log D7.4 2.69 ± 0.28, was determined, and protein binding was 71 ± 0.3%. In vivo, high initial whole brain uptake, >6% injected dose/g, cleared slowly over 24 h. Specific binding represented 75% to 93% of total binding from 15 min to 24 h. Findings were confirmed and extended by regional brain biodistribution. Radiometabolites were not observed in brain (1%). CONCLUSIONS Substitution of dihydrobenzofuranylethyl for dimethoxyphenethyl increased radioligand affinity for σ1 receptors by 16-fold. While high specific binding to σ1 receptors was observed for both radioligands in vivo, [125I]-E-IA-BF-PE-PIPZE displayed much slower clearance kinetics than [125I]-E-IA-DM-PE-PIPZE. Thus, minor structural modifications of σ1 receptor radioligands lead to major differences in binding properties in vitro and in vivo.
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Affiliation(s)
- Susan Z Lever
- Department of Chemistry, University of Missouri, Columbia, MO, USA; University of Missouri Research Reactor Center, Columbia, MO, USA.
| | - Kuo-Hsien Fan
- Department of Chemistry, University of Missouri, Columbia, MO, USA
| | - John R Lever
- Department of Radiology, University of Missouri, Columbia, MO, USA; Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, USA.
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Stoddart LA, White CW, Nguyen K, Hill SJ, Pfleger KDG. Fluorescence- and bioluminescence-based approaches to study GPCR ligand binding. Br J Pharmacol 2016; 173:3028-37. [PMID: 26317175 PMCID: PMC5125978 DOI: 10.1111/bph.13316] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/01/2015] [Accepted: 08/20/2015] [Indexed: 01/15/2023] Open
Abstract
Ligand binding is a vital component of any pharmacologist's toolbox and allows the detailed investigation of how a molecule binds to its receptor. These studies enable the experimental determination of binding affinity of labelled and unlabelled compounds through kinetic, saturation (Kd ) and competition (Ki ) binding assays. Traditionally, these studies have used molecules labelled with radioisotopes; however, more recently, fluorescent ligands have been developed for this purpose. This review will briefly cover receptor ligand binding theory and then discuss the use of fluorescent ligands with some of the different technologies currently employed to examine ligand binding. Fluorescent ligands can be used for direct measurement of receptor-associated fluorescence using confocal microscopy and flow cytometry as well as in assays such as fluorescence polarization, where ligand binding is monitored by changes in the free rotation when a fluorescent ligand is bound to a receptor. Additionally, fluorescent ligands can act as donors or acceptors for fluorescence resonance energy transfer (FRET) with the development of assays based on FRET and time-resolved FRET (TR-FRET). Finally, we have recently developed a novel bioluminescence resonance energy transfer (BRET) ligand binding assay utilizing a small (19 kDa), super-bright luciferase subunit (NanoLuc) from a deep sea shrimp. In combination with fluorescent ligands, measurement of RET now provides an array of methodologies to study ligand binding. While each method has its own advantages and drawbacks, binding studies using fluorescent ligands are now a viable alternative to the use of radioligands. Linked Articles This article is part of a themed section on Molecular Pharmacology of G Protein-Coupled Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.20/issuetoc.
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Affiliation(s)
- Leigh A Stoddart
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Carl W White
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia
| | - Kim Nguyen
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia
| | - Stephen J Hill
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Nottingham, UK
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia
| | - Kevin D G Pfleger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, Nedlands, WA, Australia.
- Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.
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Therapeutic inhibition of breast cancer bone metastasis progression and lung colonization: breaking the vicious cycle by targeting α5β1 integrin. Breast Cancer Res Treat 2016; 157:489-501. [PMID: 27255534 DOI: 10.1007/s10549-016-3844-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/24/2016] [Indexed: 10/21/2022]
Abstract
At diagnosis, 10 % of breast cancer patients already have locally advanced or metastatic disease; moreover, metastasis eventually develops in at least 40 % of early breast cancer patients. Osteolytic bone colonization occurs in 80-85 % of metastatic breast cancer patients and is thought to be an early step in metastatic progression. Thus, breast cancer displays a strong preference for metastasis to bone, and most metastatic breast cancer patients will experience its complications. Our prior research has shown that the α5β1 integrin fibronectin receptor mediates both metastatic and angiogenic invasion. We invented a targeted peptide inhibitor of activated α5β1, Ac-PHSCN-NH2 (PHSCN), as a validated lead compound to impede both metastatic invasion and neovascularization. Systemic PHSCN monotherapy prevented disease progression for up to 14 months in Phase I clinical trial. Here, we report that the next-generation construct, Ac-PhScN-NH2 (PhScN), which contains D-isomers of histidine (h) and cysteine (c), is greater than 100,000-fold more potent than PHSCN at blocking basement membrane invasion. Moreover, PhScN is also up to 10,000-fold more potent than PHSCN at inhibiting lung extravasation and colonization in athymic mice for both MDA-MB-231 metastatic and SUM149PT inflammatory breast cancer cells. Furthermore, we show that systemic treatment with 50 mg/kg PhScN monotherapy reduces established intratibial MDA-MB-231 bone colony progression by 80 %. Thus, PhScN is a highly potent, well-tolerated inhibitor of both lung colonization and bone colony progression.
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Hellmuth A, Calderón Villalobos LIA. Radioligand Binding Assays for Determining Dissociation Constants of Phytohormone Receptors. Methods Mol Biol 2016; 1450:23-34. [PMID: 27424743 DOI: 10.1007/978-1-4939-3759-2_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In receptor-ligand interactions, dissociation constants provide a key parameter for characterizing binding. Here, we describe filter-based radioligand binding assays at equilibrium, either varying ligand concentrations up to receptor saturation or outcompeting ligand from its receptor with increasing concentrations of ligand analogue. Using the auxin coreceptor system, we illustrate how to use a saturation binding assay to determine the apparent dissociation constant (K D (') ) for the formation of a ternary TIR1-auxin-AUX/IAA complex. Also, we show how to determine the inhibitory constant (K i) for auxin binding by the coreceptor complex via a competition binding assay. These assays can be applied broadly to characterize a one-site binding reaction of a hormone to its receptor.
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Affiliation(s)
- Antje Hellmuth
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06120, Halle (Saale), Germany
| | - Luz Irina A Calderón Villalobos
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06120, Halle (Saale), Germany.
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González-Martínez J, Bulacio J, Thompson S, Gale J, Smithason S, Najm I, Bingaman W. Technique, Results, and Complications Related to Robot-Assisted Stereoelectroencephalography. Neurosurgery 2015; 78:169-80. [DOI: 10.1227/neu.0000000000001034] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
ABSTRACT
BACKGROUND:
Robot-assisted stereoelectroencephalography (SEEG) may represent a simplified, precise, and safe alternative to the more traditional SEEG techniques.
OBJECTIVE:
To report our clinical experience with robotic SEEG implantation and to define its utility in the management of patients with medically refractory epilepsy.
METHODS:
The prospective observational analyses included all patients with medically refractory focal epilepsy who underwent robot-assisted stereotactic placement of depth electrodes for extraoperative brain monitoring between November 2009 and May 2013. Technical nuances of the robotic implantation technique are presented, as well as an analysis of demographics, time of planning and procedure, seizure outcome, in vivo accuracy, and procedure-related complications.
RESULTS:
One hundred patients underwent 101 robot-assisted SEEG procedures. Their mean age was 33.2 years. In total, 1245 depth electrodes were implanted. On average, 12.5 electrodes were implanted per patient. The time of implantation planning was 30 minutes on average (range, 15-60 minutes). The average operative time was 130 minutes (range, 45-160 minutes). In vivo accuracy (calculated in 500 trajectories) demonstrated a median entry point error of 1.2 mm (interquartile range, 0.78-1.83 mm) and a median target point error of 1.7 mm (interquartile range, 1.20-2.30 mm). Of the group of patients who underwent resective surgery (68 patients), 45 (66.2%) gained seizure freedom status. Mean follow-up was 18 months. The total complication rate was 4%.
CONCLUSION:
The robotic SEEG technique and method were demonstrated to be safe, accurate, and efficient in anatomically defining the epileptogenic zone and subsequently promoting sustained seizure freedom status in patients with difficult-to-localize seizures.
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Affiliation(s)
- Jorge González-Martínez
- Epilepsy Center and Neurological Institute, Cleveland Clinic, Cleveland, Ohio
- Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - Juan Bulacio
- Epilepsy Center and Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - Susan Thompson
- Epilepsy Center and Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - John Gale
- Epilepsy Center and Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - Saksith Smithason
- Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - Imad Najm
- Epilepsy Center and Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - William Bingaman
- Epilepsy Center and Neurological Institute, Cleveland Clinic, Cleveland, Ohio
- Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio
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Perez-Burgos A, Wang L, McVey Neufeld KA, Mao YK, Ahmadzai M, Janssen LJ, Stanisz AM, Bienenstock J, Kunze WA. The TRPV1 channel in rodents is a major target for antinociceptive effect of the probiotic Lactobacillus reuteri DSM 17938. J Physiol 2015; 593:3943-57. [PMID: 26084409 DOI: 10.1113/jp270229] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 06/16/2015] [Indexed: 12/17/2022] Open
Abstract
Certain probiotic bacteria have been shown to reduce distension-dependent gut pain, but the mechanisms involved remain obscure. Live luminal Lactobacillus reuteri (DSM 17938) and its conditioned medium dose dependently reduced jejunal spinal nerve firing evoked by distension or capsaicin, and 80% of this response was blocked by a specific TRPV1 channel antagonist or in TRPV1 knockout mice. The specificity of DSM action on TRPV1 was further confirmed by its inhibition of capsaicin-induced intracellular calcium increases in dorsal root ganglion neurons. Another lactobacillus with ability to reduce gut pain did not modify this response. Prior feeding of rats with DSM inhibited the bradycardia induced by painful gastric distension. These results offer a system for the screening of new and improved candidate bacteria that may be useful as novel therapeutic adjuncts in gut pain. Certain bacteria exert visceral antinociceptive activity, but the mechanisms involved are not determined. Lactobacillus reuteri DSM 17938 was examined since it may be antinociceptive in children. Since transient receptor potential vanilloid 1 (TRPV1) channel activity may mediate nociceptive signals, we hypothesized that TRPV1 current is inhibited by DSM. We tested this by examining the effect of DSM on the firing frequency of spinal nerve fibres in murine jejunal mesenteric nerve bundles following serosal application of capsaicin. We also measured the effects of DSM on capsaicin-evoked increase in intracellular Ca(2+) or ionic current in dorsal root ganglion (DRG) neurons. Furthermore, we tested the in vivo antinociceptive effects of oral DSM on gastric distension in rats. Live DSM reduced the response of capsaicin- and distension-evoked firing of spinal nerve action potentials (238 ± 27.5% vs. 129 ± 17%). DSM also reduced the capsaicin-evoked TRPV1 ionic current in DRG neuronal primary culture from 83 ± 11% to 41 ± 8% of the initial response to capsaicin only. Another lactobacillus (Lactobacillus rhamnosus JB-1) with known visceral anti-nociceptive activity did not have these effects. DSM also inhibited capsaicin-evoked Ca(2+) increase in DRG neurons; an increase in Ca(2+) fluorescence intensity ratio of 2.36 ± 0.31 evoked by capsaicin was reduced to 1.25 ± 0.04. DSM releasable products (conditioned medium) mimicked DSM inhibition of capsaicin-evoked excitability. The TRPV1 antagonist 6-iodonordihydrocapsaicin or the use of TRPV1 knock-out mice revealed that TRPV1 channels mediate about 80% of the inhibitory effect of DSM on mesenteric nerve response to high intensity gut distension. Finally, feeding with DSM inhibited perception in rats of painful gastric distension. Our results identify a specific target channel for a probiotic with potential therapeutic properties.
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Affiliation(s)
- Azucena Perez-Burgos
- McMaster Brain-Body Institute, St Joseph's Healthcare, Hamilton, 50 Charlton Avenue East, Hamilton, Ontario, Canada, L8N 4A6
| | - Lu Wang
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Karen-Anne McVey Neufeld
- McMaster Brain-Body Institute, St Joseph's Healthcare, Hamilton, 50 Charlton Avenue East, Hamilton, Ontario, Canada, L8N 4A6
| | - Yu-Kang Mao
- McMaster Brain-Body Institute, St Joseph's Healthcare, Hamilton, 50 Charlton Avenue East, Hamilton, Ontario, Canada, L8N 4A6
| | - Mustafa Ahmadzai
- Firestone Institute for Respiratory Health, St Joseph's Hospital, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Luke J Janssen
- Firestone Institute for Respiratory Health, St Joseph's Hospital, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Andrew M Stanisz
- McMaster Brain-Body Institute, St Joseph's Healthcare, Hamilton, 50 Charlton Avenue East, Hamilton, Ontario, Canada, L8N 4A6
| | - John Bienenstock
- McMaster Brain-Body Institute, St Joseph's Healthcare, Hamilton, 50 Charlton Avenue East, Hamilton, Ontario, Canada, L8N 4A6.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Wolfgang A Kunze
- McMaster Brain-Body Institute, St Joseph's Healthcare, Hamilton, 50 Charlton Avenue East, Hamilton, Ontario, Canada, L8N 4A6
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Veine DM, Yao H, Stafford DR, Fay KS, Livant DL. A D-amino acid containing peptide as a potent, noncovalent inhibitor of α5β1 integrin in human prostate cancer invasion and lung colonization. Clin Exp Metastasis 2014; 31:379-93. [PMID: 24464034 DOI: 10.1007/s10585-013-9634-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 12/28/2013] [Indexed: 01/09/2023]
Abstract
Primary tumors often give rise to disseminated tumor cells (DTC's), which acquire full malignancy after invading distant site(s). Thus, DTC's may be a productive target for preventing prostate cancer metastasis progression. Our prior research showed that PHSCN peptide (Ac-PHSCN-NH2) targets activated α5β1 integrin to prevent invasion and metastasis in preclinical adenocarcinoma models, and disease progression in Phase I clinical trial. Here, we report that D-stereoisomer replacement of histidine and cysteine in PHSCN produces a highly potent derivative, Ac-PhScN-NH2 (PhScN). PhScN was 27,000- to 150,000-fold more potent as an inhibitor of basement membrane invasion by DU 145 and PC-3 prostate cancer cells. A large increase in invasion-inhibitory potency occurred after covalent modification of the sulfhydryl group in PHSCN to prevent disulfide bond formation; while the potency of covalently modified PhScN was not significantly increased. Thus PhScN and PHSCN invasion inhibition occurs by a noncovalent mechanism. These peptides also displayed similar cell surface binding dissociation constants (Kd), and competed for the same site. Consistent with its increased invasion-inhibitory potency, PhScN was also a highly potent inhibitor of lung extravasation and colonization in athymic nude mice: it was several hundred- or several thousand-fold more potent than PHSCN at blocking extravasation by PC-3 or DU 145 cells, and 111,000- or 379,000-fold more potent at inhibiting lung colonization, respectively. Furthermore, systemic 5 mg/kg PhScN monotherapy was sufficient to cause complete regression of established, intramuscular DU 145 tumors. PhScN thus represents a potent new family of therapeutic agents targeting metastasis by DTC's to prevent parallel progression in prostate cancer.
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Affiliation(s)
- Donna M Veine
- Department of Radiation Oncology, University of Michigan, Room 4424F Medical Science 1, 1301 Catherine Street, Ann Arbor, MI, 48109-5637, USA
| | - Hongren Yao
- Department of Radiation Oncology, University of Michigan, Room 4424F Medical Science 1, 1301 Catherine Street, Ann Arbor, MI, 48109-5637, USA
| | - Daniel R Stafford
- Department of Radiation Oncology, University of Michigan, Room 4424F Medical Science 1, 1301 Catherine Street, Ann Arbor, MI, 48109-5637, USA
| | - Kevin S Fay
- Department of Radiation Oncology, University of Michigan, Room 4424F Medical Science 1, 1301 Catherine Street, Ann Arbor, MI, 48109-5637, USA
| | - Donna L Livant
- Department of Radiation Oncology, University of Michigan, Room 4424F Medical Science 1, 1301 Catherine Street, Ann Arbor, MI, 48109-5637, USA.
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dsRNA binding characterization of full length recombinant wild type and mutants Zaire ebolavirus VP35. Antiviral Res 2012; 93:354-63. [PMID: 22289166 PMCID: PMC7114247 DOI: 10.1016/j.antiviral.2012.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 12/16/2011] [Accepted: 01/15/2012] [Indexed: 12/13/2022]
Abstract
The Ebola viruses (EBOVs) VP35 protein is a multifunctional major virulence factor involved in EBOVs replication and evasion of the host immune system. EBOV VP35 is an essential component of the viral RNA polymerase, it is a key participant of the nucleocapsid assembly and it inhibits the innate immune response by antagonizing RIG-I like receptors through its dsRNA binding function and, hence, by suppressing the host type I interferon (IFN) production. Insights into the VP35 dsRNA recognition have been recently revealed by structural and functional analysis performed on its C-terminus protein. We report the biochemical characterization of the Zaire ebolavirus (ZEBOV) full-length recombinant VP35 (rVP35)–dsRNA binding function. We established a novel in vitro magnetic dsRNA binding pull down assay, determined the rVP35 optimal dsRNA binding parameters, measured the rVP35 equilibrium dissociation constant for heterologous in vitro transcribed dsRNA of different length and short synthetic dsRNA of 8 bp, and validated the assay for compound screening by assessing the inhibitory ability of auryntricarboxylic acid (IC50 value of 50 μg/mL). Furthermore, we compared the dsRNA binding properties of full length wt rVP35 with those of R305A, K309A and R312A rVP35 mutants, which were previously reported to be defective in dsRNA binding-mediated IFN inhibition, showing that the latter have measurably increased Kd values for dsRNA binding and modified migration patterns in mobility shift assays with respect to wt rVP35. Overall, these results provide the first characterization of the full-length wt and mutants VP35–dsRNA binding functions.
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Myung JH, Gajjar KA, Saric J, Eddington DT, Hong S. Dendrimer-mediated multivalent binding for the enhanced capture of tumor cells. Angew Chem Int Ed Engl 2011; 50:11769-72. [PMID: 22012872 PMCID: PMC3549433 DOI: 10.1002/anie.201105508] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/08/2011] [Indexed: 12/21/2022]
Affiliation(s)
- Ja Hye Myung
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 South Wood St., Room 335, Chicago, IL, 60612
| | - Khyati A. Gajjar
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 South Wood St., Room 335, Chicago, IL, 60612
| | - Jelena Saric
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 South Wood St., Room 335, Chicago, IL, 60612
| | - David T. Eddington
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 South Wood St., Room 335, Chicago, IL, 60612. Department of Bioengineering, University of Illinois at Chicago, 833 South Wood St., Room 335, Chicago, IL, 60612
| | - Seungpyo Hong
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 South Wood St., Room 335, Chicago, IL, 60612. Department of Bioengineering, University of Illinois at Chicago 833 South Wood St., Room 335, Chicago, IL, 60612, Fax: 1-312-996-0098
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Waterson RE, Thompson CG, Mabe NW, Kaur K, Talbot JN, Neubig RR, Rorabaugh BR. Gα(i2)-mediated protection from ischaemic injury is modulated by endogenous RGS proteins in the mouse heart. Cardiovasc Res 2011; 91:45-52. [PMID: 21349876 PMCID: PMC3112020 DOI: 10.1093/cvr/cvr054] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 01/31/2011] [Accepted: 02/18/2011] [Indexed: 01/01/2023] Open
Abstract
AIMS Regulator of G protein signalling (RGS) proteins act as molecular 'off switches' that terminate G protein signalling by catalyzing the hydrolysis of Gα-bound GTP to GDP. Many different Gα(i)-coupled receptors have been implicated in the cardioprotective effects of ischaemic preconditioning. However, the role of RGS proteins in modulating cardioprotection has not been previously investigated. We used mice that were homozygous (GS/GS) or heterozygous (GS/+) for a mutation in Gα(i2) rendering it RGS-insensitive (G184S) to determine whether interactions between endogenous RGS proteins and Gα(i2) modulate Gα(i)-mediated protection from ischaemic injury. METHODS AND RESULTS Langendorff-perfused mouse hearts were subjected to 30 min global ischaemia and 2 h reperfusion. Infarcts in GS/GS (14.5% of area at risk) and GS/+ (22.6% of AAR) hearts were significantly smaller than those of +/+ hearts (37.2% of AAR) and recovery of contractile function was significantly enhanced in GS/GS and GS/+ hearts compared with +/+ hearts. The cardioprotective phenotype was not reversed by wortmannin or U0126 but was reversed by 5-hydroxydecanoic acid and HMR 1098, indicating that RGS-insensitive Gα(i2) protects the heart through a mechanism that requires functional ATP-dependent potassium channels but does not require acute activation of extracellular-regulated kinase or Akt signalling pathways. CONCLUSIONS This is the first study to demonstrate that Gα(i2)-mediated cardioprotection is suppressed by RGS proteins. These data suggest that RGS proteins may provide novel therapeutic targets to protect the heart from ischaemic injury.
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Affiliation(s)
- Rachael E. Waterson
- Department of Pharmaceutical and Biomedical Sciences, Raabe College of Pharmacy, Ohio Northern University, 525 South Main Street, Ada, OH 45810, USA
| | - Corbin G. Thompson
- Department of Pharmaceutical and Biomedical Sciences, Raabe College of Pharmacy, Ohio Northern University, 525 South Main Street, Ada, OH 45810, USA
| | - Nathaniel W. Mabe
- Department of Pharmaceutical and Biomedical Sciences, Raabe College of Pharmacy, Ohio Northern University, 525 South Main Street, Ada, OH 45810, USA
| | - Kuljeet Kaur
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jeffery N. Talbot
- Department of Pharmaceutical and Biomedical Sciences, Raabe College of Pharmacy, Ohio Northern University, 525 South Main Street, Ada, OH 45810, USA
| | - Richard R. Neubig
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Boyd R. Rorabaugh
- Department of Pharmaceutical and Biomedical Sciences, Raabe College of Pharmacy, Ohio Northern University, 525 South Main Street, Ada, OH 45810, USA
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Wang J, Liu Y, Teesalu T, Sugahara KN, Kotamrajua VR, Adams JD, Ferguson BS, Gong Q, Oh SS, Csordas AT, Cho M, Ruoslahti E, Xiao Y, Soh HT. Selection of phage-displayed peptides on live adherent cells in microfluidic channels. Proc Natl Acad Sci U S A 2011; 108:6909-14. [PMID: 21486998 PMCID: PMC3084056 DOI: 10.1073/pnas.1014753108] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Affinity reagents that bind to specific molecular targets are an essential tool for both diagnostics and targeted therapeutics. There is a particular need for advanced technologies for the generation of reagents that specifically target cell-surface markers, because transmembrane proteins are notoriously difficult to express in recombinant form. We have previously shown that microfluidics offers many advantages for generating affinity reagents against purified protein targets, and we have now significantly extended this approach to achieve successful in vitro selection of T7 phage-displayed peptides that recognize markers expressed on live, adherent cells within a microfluidic channel. As a model, we have targeted neuropilin-1 (NRP-1), a membrane-bound receptor expressed at the surface of human prostate carcinoma cells that plays central roles in angiogenesis, cell migration, and invasion. We show that, compared to conventional biopanning methods, microfluidic selection enables more efficient discovery of peptides with higher affinity and specificity by providing controllable and reproducible means for applying stringent selection conditions against minimal amounts of target cells without loss. Using our microfluidic system, we isolate peptide sequences with superior binding affinity and specificity relative to the well known NRP-1-binding RPARPAR peptide. As such microfluidic systems can be used with a wide range of biocombinatorial libraries and tissue types, we believe that our method represents an effective approach toward efficient biomarker discovery from patient samples.
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Affiliation(s)
- Jinpeng Wang
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106
| | - Yanli Liu
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106
- Department of Materials, University of California, Santa Barbara, CA 93106
| | - Tambet Teesalu
- Vascular Mapping Laboratory, Center for Nanomedicine, Sanford-Burnham Medical Research Institute at University of California, Santa Barbara, CA 93106
| | - Kazuki N. Sugahara
- Vascular Mapping Laboratory, Center for Nanomedicine, Sanford-Burnham Medical Research Institute at University of California, Santa Barbara, CA 93106
| | - Venkata Ramana Kotamrajua
- Vascular Mapping Laboratory, Center for Nanomedicine, Sanford-Burnham Medical Research Institute at University of California, Santa Barbara, CA 93106
| | - Jonathan D. Adams
- Department of Physics, University of California, Santa Barbara, CA 93106
| | - Brian S. Ferguson
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106
| | - Qiang Gong
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, CA 93106; and
| | - Seung Soo Oh
- Department of Materials, University of California, Santa Barbara, CA 93106
| | - Andrew T. Csordas
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, CA 93106; and
| | - Minseon Cho
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106
| | - Erkki Ruoslahti
- Vascular Mapping Laboratory, Center for Nanomedicine, Sanford-Burnham Medical Research Institute at University of California, Santa Barbara, CA 93106
- Cancer Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037
| | - Yi Xiao
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106
- Department of Materials, University of California, Santa Barbara, CA 93106
| | - H. Tom Soh
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106
- Department of Materials, University of California, Santa Barbara, CA 93106
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