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Abstract
Insulin is a peptide hormone essential for maintaining normal blood glucose levels. Individuals unable to secrete sufficient insulin or not able to respond properly to insulin develop diabetes. Since the discovery of insulin its structure and function has been intensively studied with the aim to develop effective diabetes treatments. The three-dimensional crystal structure of this 51 amino acid peptide paved the way for discoveries, outlined in this review, of determinants important for receptor binding and hormone stability that have been instrumental in development of insulin analogs used in the clinic today. Important for the future development of effective diabetes treatments will be a detailed understanding of the insulin receptor structure and function. Determination of the three-dimensional structure of the insulin receptor, a receptor tyrosine kinase, proved challenging but with the recent advent of high-resolution cryo-electron microscopy significant progress has been made. There are now >40 structures of the insulin:insulin receptor complex deposited in the Protein Data Bank. From these structures we have a detailed picture of how insulin binds and activates the receptor. Still lacking are details of the initial binding events and the exact sequence of structural changes within the receptor and insulin. In this review, the focus will be on the most recent structural studies of insulin:insulin receptor complexes and how they have contributed to the current understanding of insulin receptor activation and signaling outcome. Molecular mechanisms underlying insulin receptor signaling bias emerging from the latest structures are described.
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Affiliation(s)
- Briony E Forbes
- Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia.
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2
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Sheff J, Kelly J, Foss M, Brunette E, Kemmerich K, van Faassen H, Raphael S, Hussack G, Comamala G, Rand K, Stanimirovic DB. Epitope mapping of a blood-brain barrier crossing antibody targeting the cysteine-rich region of IGF1R using hydrogen-exchange mass spectrometry enabled by electrochemical reduction. J Biochem 2023; 173:95-105. [PMID: 36346120 DOI: 10.1093/jb/mvac088] [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: 08/03/2022] [Revised: 10/04/2022] [Accepted: 10/23/2022] [Indexed: 11/11/2022] Open
Abstract
Pathologies of the central nervous system impact a significant portion of our population, and the delivery of therapeutics for effective treatment is challenging. The insulin-like growth factor-1 receptor (IGF1R) has emerged as a target for receptor-mediated transcytosis, a process by which antibodies are shuttled across the blood-brain barrier (BBB). Here, we describe the biophysical characterization of VHH-IR4, a BBB-crossing single-domain antibody (sdAb). Binding was confirmed by isothermal titration calorimetry and an epitope was highlighted by surface plasmon resonance that does not overlap with the IGF-1 binding site or other known BBB-crossing sdAbs. The epitope was mapped with a combination of linear peptide scanning and hydrogen-deuterium exchange mass spectrometry (HDX-MS). IGF1R is large and heavily disulphide bonded, and comprehensive HDX analysis was achieved only through the use of online electrochemical reduction coupled with a multiprotease approach, which identified an epitope for VHH-IR4 within the cysteine-rich region (CRR) of IGF1R spanning residues W244-G265. This is the first report of an sdAb binding the CRR. We show that VHH-IR4 inhibits ligand induced auto-phosphorylation of IGF1R and that this effect is mediated by downstream conformational effects. Our results will guide the selection of antibodies with improved trafficking and optimized IGF1R binding characteristics.
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Affiliation(s)
- Joey Sheff
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - John Kelly
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Mary Foss
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Eric Brunette
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Kristin Kemmerich
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Henk van Faassen
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Shalini Raphael
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Greg Hussack
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Gerard Comamala
- Department of Pharmacy, University of Copenhagen, 2100, Copenhagen, Denmark.2100
| | - Kasper Rand
- Department of Pharmacy, University of Copenhagen, 2100, Copenhagen, Denmark.2100
| | - Danica B Stanimirovic
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
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3
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James EI, Murphree TA, Vorauer C, Engen JR, Guttman M. Advances in Hydrogen/Deuterium Exchange Mass Spectrometry and the Pursuit of Challenging Biological Systems. Chem Rev 2021; 122:7562-7623. [PMID: 34493042 PMCID: PMC9053315 DOI: 10.1021/acs.chemrev.1c00279] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
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Solution-phase hydrogen/deuterium
exchange (HDX) coupled to mass
spectrometry (MS) is a widespread tool for structural analysis across
academia and the biopharmaceutical industry. By monitoring the exchangeability
of backbone amide protons, HDX-MS can reveal information about higher-order
structure and dynamics throughout a protein, can track protein folding
pathways, map interaction sites, and assess conformational states
of protein samples. The combination of the versatility of the hydrogen/deuterium
exchange reaction with the sensitivity of mass spectrometry has enabled
the study of extremely challenging protein systems, some of which
cannot be suitably studied using other techniques. Improvements over
the past three decades have continually increased throughput, robustness,
and expanded the limits of what is feasible for HDX-MS investigations.
To provide an overview for researchers seeking to utilize and derive
the most from HDX-MS for protein structural analysis, we summarize
the fundamental principles, basic methodology, strengths and weaknesses,
and the established applications of HDX-MS while highlighting new
developments and applications.
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Affiliation(s)
- Ellie I James
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Taylor A Murphree
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Clint Vorauer
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - John R Engen
- Department of Chemistry & Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
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Erdem C, Lee AV, Taylor DL, Lezon TR. Inhibition of RPS6K reveals context-dependent Akt activity in luminal breast cancer cells. PLoS Comput Biol 2021; 17:e1009125. [PMID: 34191793 PMCID: PMC8277016 DOI: 10.1371/journal.pcbi.1009125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 07/13/2021] [Accepted: 05/28/2021] [Indexed: 01/03/2023] Open
Abstract
Aberrant signaling through insulin (Ins) and insulin-like growth factor I (IGF1) receptors contribute to the risk and advancement of many cancer types by activating cell survival cascades. Similarities between these pathways have thus far prevented the development of pharmacological interventions that specifically target either Ins or IGF1 signaling. To identify differences in early Ins and IGF1 signaling mechanisms, we developed a dual receptor (IGF1R & InsR) computational response model. The model suggested that ribosomal protein S6 kinase (RPS6K) plays a critical role in regulating MAPK and Akt activation levels in response to Ins and IGF1 stimulation. As predicted, perturbing RPS6K kinase activity led to an increased Akt activation with Ins stimulation compared to IGF1 stimulation. Being able to discern differential downstream signaling, we can explore improved anti-IGF1R cancer therapies by eliminating the emergence of compensation mechanisms without disrupting InsR signaling.
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Affiliation(s)
- Cemal Erdem
- Department of Computational & Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- University of Pittsburgh Drug Discovery Institute (UPDDI), University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Adrian V. Lee
- Department of Pharmacology & Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Magee-Womens Research Institute, Pittsburgh, Pennsylvania, United States of America
- The Institute for Precision Medicine, Pittsburgh, Pennsylvania, United States of America
| | - D. Lansing Taylor
- Department of Computational & Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- University of Pittsburgh Drug Discovery Institute (UPDDI), University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Timothy R. Lezon
- Department of Computational & Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- University of Pittsburgh Drug Discovery Institute (UPDDI), University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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5
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Sheff J, Wang P, Xu P, Arbour M, Masson L, van Faassen H, Hussack G, Kemmerich K, Brunette E, Stanimirovic D, Hill JJ, Kelly J, Ni F. Defining the epitope of a blood-brain barrier crossing single domain antibody specific for the type 1 insulin-like growth factor receptor. Sci Rep 2021; 11:4284. [PMID: 33608571 PMCID: PMC7896052 DOI: 10.1038/s41598-021-83198-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 01/07/2021] [Indexed: 02/06/2023] Open
Abstract
Ligand-activated signaling through the type 1 insulin-like growth factor receptor (IGF1R) is implicated in many physiological processes ranging from normal human growth to cancer proliferation and metastasis. IGF1R has also emerged as a target for receptor-mediated transcytosis, a transport phenomenon that can be exploited to shuttle biotherapeutics across the blood–brain barrier (BBB). We employed differential hydrogen–deuterium exchange mass spectrometry (HDX-MS) and nuclear magnetic resonance (NMR) to characterize the interactions of the IGF1R ectodomain with a recently discovered BBB-crossing single-domain antibody (sdAb), VHH-IR5, in comparison with IGF-1 binding. HDX-MS confirmed that IGF-1 induced global conformational shifts in the L1/FnIII-1/-2 domains and α-CT helix of IGF1R. In contrast, the VHH-IR5 sdAb-mediated changes in conformational dynamics were limited to the α-CT helix and its immediate vicinity (L1 domain). High-resolution NMR spectroscopy titration data and linear peptide scanning demonstrated that VHH-IR5 has high-affinity binding interactions with a peptide sequence around the C-terminal region of the α-CT helix. Taken together, these results define a core linear epitope for VHH-IR5 within the α-CT helix, overlapping the IGF-1 binding site, and suggest a potential role for the α-CT helix in sdAb-mediated transcytosis.
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Affiliation(s)
- Joey Sheff
- Human Health Therapeutics Research Centre, National Research Council Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
| | - Ping Wang
- Human Health Therapeutics Research Centre, National Research Council Canada, 6100 Royalmount Avenue, Montreal, QC, H4P 2R2, Canada
| | - Ping Xu
- Human Health Therapeutics Research Centre, National Research Council Canada, 6100 Royalmount Avenue, Montreal, QC, H4P 2R2, Canada
| | - Melanie Arbour
- Human Health Therapeutics Research Centre, National Research Council Canada, 6100 Royalmount Avenue, Montreal, QC, H4P 2R2, Canada
| | - Luke Masson
- Human Health Therapeutics Research Centre, National Research Council Canada, 6100 Royalmount Avenue, Montreal, QC, H4P 2R2, Canada
| | - Henk van Faassen
- Human Health Therapeutics Research Centre, National Research Council Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
| | - Greg Hussack
- Human Health Therapeutics Research Centre, National Research Council Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
| | - Kristin Kemmerich
- Human Health Therapeutics Research Centre, National Research Council Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
| | - Eric Brunette
- Human Health Therapeutics Research Centre, National Research Council Canada, 1200 Montreal Road, Ottawa, ON, K1A 0R6, Canada
| | - Danica Stanimirovic
- Human Health Therapeutics Research Centre, National Research Council Canada, 1200 Montreal Road, Ottawa, ON, K1A 0R6, Canada
| | - Jennifer J Hill
- Human Health Therapeutics Research Centre, National Research Council Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
| | - John Kelly
- Human Health Therapeutics Research Centre, National Research Council Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada
| | - Feng Ni
- Human Health Therapeutics Research Centre, National Research Council Canada, 6100 Royalmount Avenue, Montreal, QC, H4P 2R2, Canada.
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6
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Pharaoh G, Owen D, Yeganeh A, Premkumar P, Farley J, Bhaskaran S, Ashpole N, Kinter M, Van Remmen H, Logan S. Disparate Central and Peripheral Effects of Circulating IGF-1 Deficiency on Tissue Mitochondrial Function. Mol Neurobiol 2019; 57:1317-1331. [PMID: 31732912 PMCID: PMC7060968 DOI: 10.1007/s12035-019-01821-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/23/2019] [Indexed: 12/15/2022]
Abstract
Age-related decline in circulating levels of insulin-like growth factor (IGF)-1 is associated with reduced cognitive function, neuronal aging, and neurodegeneration. Decreased mitochondrial function along with increased reactive oxygen species (ROS) and accumulation of damaged macromolecules are hallmarks of cellular aging. Based on numerous studies indicating pleiotropic effects of IGF-1 during aging, we compared the central and peripheral effects of circulating IGF-1 deficiency on tissue mitochondrial function using an inducible liver IGF-1 knockout (LID). Circulating levels of IGF-1 (~ 75%) were depleted in adult male Igf1f/f mice via AAV-mediated knockdown of hepatic IGF-1 at 5 months of age. Cognitive function was evaluated at 18 months using the radial arm water maze and glucose and insulin tolerance assessed. Mitochondrial function was analyzed in hippocampus, muscle, and visceral fat tissues using high-resolution respirometry O2K as well as redox status and oxidative stress in the cortex. Peripherally, IGF-1 deficiency did not significantly impact muscle mass or mitochondrial function. Aged LID mice were insulin resistant and exhibited ~ 60% less adipose tissue but increased fat mitochondrial respiration (20%). The effects on fat metabolism were attributed to increases in growth hormone. Centrally, IGF-1 deficiency impaired hippocampal-dependent spatial acquisition as well as reversal learning in male mice. Hippocampal mitochondrial OXPHOS coupling efficiency and cortex ATP levels (~ 50%) were decreased and hippocampal oxidative stress (protein carbonylation and F2-isoprostanes) was increased. These data suggest that IGF-1 is critical for regulating mitochondrial function, redox status, and spatial learning in the central nervous system but has limited impact on peripheral (liver and muscle) metabolism with age. Therefore, IGF-1 deficiency with age may increase sensitivity to damage in the brain and propensity for cognitive deficits. Targeting mitochondrial function in the brain may be an avenue for therapy of age-related impairment of cognitive function. Regulation of mitochondrial function and redox status by IGF-1 is essential to maintain brain function and coordinate hippocampal-dependent spatial learning. While a decline in IGF-1 in the periphery may be beneficial to avert cancer progression, diminished central IGF-1 signaling may mediate, in part, age-related cognitive dysfunction and cognitive pathologies potentially by decreasing mitochondrial function.
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Affiliation(s)
- Gavin Pharaoh
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Daniel Owen
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Alexander Yeganeh
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Pavithra Premkumar
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Julie Farley
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Shylesh Bhaskaran
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Nicole Ashpole
- Department of Biomolecular Sciences, University of Mississippi, Oxford, MS, USA
| | - Michael Kinter
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Holly Van Remmen
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Sreemathi Logan
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. .,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. .,Department of Rehabilitation Sciences, College of Allied Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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7
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Xu Y, Kong GKW, Menting JG, Margetts MB, Delaine CA, Jenkin LM, Kiselyov VV, De Meyts P, Forbes BE, Lawrence MC. How ligand binds to the type 1 insulin-like growth factor receptor. Nat Commun 2018; 9:821. [PMID: 29483580 PMCID: PMC5826941 DOI: 10.1038/s41467-018-03219-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/29/2018] [Indexed: 12/28/2022] Open
Abstract
Human type 1 insulin-like growth factor receptor is a homodimeric receptor tyrosine kinase that signals into pathways directing normal cellular growth, differentiation and proliferation, with aberrant signalling implicated in cancer. Insulin-like growth factor binding is understood to relax conformational restraints within the homodimer, initiating transphosphorylation of the tyrosine kinase domains. However, no three-dimensional structures exist for the receptor ectodomain to inform atomic-level understanding of these events. Here, we present crystal structures of the ectodomain in apo form and in complex with insulin-like growth factor I, the latter obtained by crystal soaking. These structures not only provide a wealth of detail of the growth factor interaction with the receptor’s primary ligand-binding site but also indicate that ligand binding separates receptor domains by a mechanism of induced fit. Our findings are of importance to the design of agents targeting IGF-1R and its partner protein, the human insulin receptor. The human type 1 insulin-like growth factor receptor (IGF-1R) is important for normal human growth and development. Here, the authors present the crystal structures of the IGF-1R ectodomain both in its apo form and in complex with its ligand insulin-like growth factor I and discuss the receptor activation mechanism.
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Affiliation(s)
- Yibin Xu
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.,Department of Medical Biology, University of Melbourne, Royal Parade, Parkville, VIC, 3050, Australia
| | - Geoffrey K-W Kong
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.,Monash Macromolecular Crystallisation Facility, 11 Chancellors Walk, Clayton Campus, Monash University, Clayton, VIC, 3800, Australia
| | - John G Menting
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
| | - Mai B Margetts
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
| | - Carlie A Delaine
- Discipline of Medical Biochemistry, College of Medicine and Public Health, Flinders University of South Australia, Bedford Park, SA, 5042, Australia
| | - Lauren M Jenkin
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
| | - Vladislav V Kiselyov
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Pierre De Meyts
- Department of Cell Signaling, de Duve Institute, B-1200, Brussels, Belgium.,Department of Stem Cell Research, Novo Nordisk A/S, 2760, Måløv, Denmark.,De Meyts R&D Consulting, Avenue Reine Astrid 42, B-1950, Kraainem, Belgium
| | - Briony E Forbes
- Discipline of Medical Biochemistry, College of Medicine and Public Health, Flinders University of South Australia, Bedford Park, SA, 5042, Australia
| | - Michael C Lawrence
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia. .,Department of Medical Biology, University of Melbourne, Royal Parade, Parkville, VIC, 3050, Australia.
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8
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Conformational dynamics of a neurotransmitter:sodium symporter in a lipid bilayer. Proc Natl Acad Sci U S A 2017; 114:E1786-E1795. [PMID: 28223522 DOI: 10.1073/pnas.1613293114] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Neurotransmitter:sodium symporters (NSSs) are integral membrane proteins responsible for the sodium-dependent reuptake of small-molecule neurotransmitters from the synaptic cleft. The symporters for the biogenic amines serotonin (SERT), dopamine (DAT), and norepinephrine (NET) are targets of multiple psychoactive agents, and their dysfunction has been implicated in numerous neuropsychiatric ailments. LeuT, a thermostable eubacterial NSS homolog, has been exploited as a model protein for NSS members to canvass the conformational mechanism of transport with a combination of X-ray crystallography, cysteine accessibility, and solution spectroscopy. Despite yielding remarkable insights, these studies have primarily been conducted with protein in the detergent-solubilized state rather than embedded in a membrane mimic. In addition, solution spectroscopy has required site-specific labeling of nonnative cysteines, a labor-intensive process occasionally resulting in diminished transport and/or binding activity. Here, we overcome these limitations by reconstituting unlabeled LeuT in phospholipid bilayer nanodiscs, subjecting them to hydrogen-deuterium exchange coupled with mass spectrometry (HDX-MS), and facilitating interpretation of the data with molecular dynamics simulations. The data point to changes of accessibility and dynamics of structural elements previously implicated in the transport mechanism, in particular transmembrane helices (TMs) 1a and 7 as well as extracellular loops (ELs) 2 and 4. The results therefore illuminate the value of this strategy for interrogating the conformational mechanism of the more clinically significant mammalian membrane proteins including SERT and DAT, neither of which tolerates complete removal of endogenous cysteines, and whose activity is heavily influenced by neighboring lipids.
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9
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Sit KC, van Lonkhuyzen D, Walsh T, Croll T. Prediction of a novel internal rearrangement of the insulin receptor. J Biomol Struct Dyn 2016; 35:857-867. [PMID: 27137342 DOI: 10.1080/07391102.2016.1165631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The insulin receptor (IR) plays critical roles in metabolism and growth, directed by the binding of insulin. Decades of research to understand the mechanism of insulin binding and activation of the IR have identified a region of the receptor, the C-terminal (CT) peptide, to be crucial for insulin binding. In particular, a truncated IR consisting of the first three domains fused to the CT peptide was found to bind insulin with nanomolar affinity, with undetectable binding in the absence of fused or soluble CT peptide. Problematically, all current crystal structures of the IR indicate the fusion point of the CT peptide to the three domains is located far from the position of the CT peptide as resolved in such structures. We have attempted to address this problem using molecular modelling and dynamics simulations. The results led to the identification of a potential inter-domain interaction between the L2 domain and the CT peptide that is not observed in any of the crystal structures of the IR. Investigations into this new interaction found a conformational change that could potentially be in response to insulin binding. Additionally, further simulation work with the new conformation demonstrated its compatibility with the position and orientation of insulin from the latest insulin-bound IR crystal structure.
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Affiliation(s)
- Kei C Sit
- a Institute of Health and Biomedical Innovation , Queensland University of Technology , Brisbane , Australia
| | - Derek van Lonkhuyzen
- a Institute of Health and Biomedical Innovation , Queensland University of Technology , Brisbane , Australia
| | - Terry Walsh
- b Faculty of Health, School of Biomedical Science , Institute of Health and Biomedical Innovation, Queensland University of Technology , Brisbane , QLD , Australia
| | - Tristan Croll
- a Institute of Health and Biomedical Innovation , Queensland University of Technology , Brisbane , Australia.,b Faculty of Health, School of Biomedical Science , Institute of Health and Biomedical Innovation, Queensland University of Technology , Brisbane , QLD , Australia
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10
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Croll TI, Smith BJ, Margetts MB, Whittaker J, Weiss MA, Ward CW, Lawrence MC. Higher-Resolution Structure of the Human Insulin Receptor Ectodomain: Multi-Modal Inclusion of the Insert Domain. Structure 2016; 24:469-76. [PMID: 26853939 DOI: 10.1016/j.str.2015.12.014] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 11/25/2015] [Accepted: 12/08/2015] [Indexed: 11/16/2022]
Abstract
Insulin receptor (IR) signaling is critical to controlling nutrient uptake and metabolism. However, only a low-resolution (3.8 Å) structure currently exists for the IR ectodomain, with some segments ill-defined or unmodeled due to disorder. Here, we revise this structure using new diffraction data to 3.3 Å resolution that allow improved modeling of the N-linked glycans, the first and third fibronectin type III domains, and the insert domain. A novel haptic interactive molecular dynamics strategy was used to aid fitting to low-resolution electron density maps. The resulting model provides a foundation for investigation of structural transitions in IR upon ligand binding.
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Affiliation(s)
- Tristan I Croll
- Institute of Health and Biomedical Innovation, Queensland University of Technology, QLD 4059, Australia
| | - Brian J Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
| | - Mai B Margetts
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Jonathan Whittaker
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Michael A Weiss
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA; Departments of Physiology, and Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Colin W Ward
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Michael C Lawrence
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC 3010, Australia.
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11
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Maaty WS, Weis DD. Label-Free, In-Solution Screening of Peptide Libraries for Binding to Protein Targets Using Hydrogen Exchange Mass Spectrometry. J Am Chem Soc 2016; 138:1335-43. [PMID: 26741284 DOI: 10.1021/jacs.5b11742] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
There is considerable interest in the discovery of peptide ligands that bind to protein targets. Discovery of such ligands is usually approached by screening large peptide libraries. However, the individual peptides must be tethered to a tag that preserves their individual identities (e.g., phage display or one-bead one-compound). To overcome this limitation, we have developed a method for screening libraries of label-free peptides for binding to a protein target in solution as a single batch. The screening is based on decreased amide hydrogen exchange by peptides that bind to the target. Hydrogen exchange is measured by mass spectrometry. We demonstrate the approach using a peptide library derived from the Escherichia coli proteome that contained 6664 identifiable features. The library was spiked separately with a peptide spanning the calmodulin binding domain of endothelial nitric oxide synthase (eNOS, 494-513) and a peptide spanning the N-terminal 20 residues of bovine ribonuclease A (S peptide). Human calmodulin and bovine ribonuclease S (RNase S) were screened against the library. Using a novel data analysis workflow, we identified the eNOS peptide as the only calmodulin binding peptide and S peptide as the only ribonuclease S binding peptide in the library.
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Affiliation(s)
- Walid S Maaty
- Department of Nucleic Acid and Protein Structure, Agricultural Genetic Engineering Research Institute, Agricultural Research Center , Giza 12619, Egypt
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12
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Affiliation(s)
- Pierre De Meyts
- Department of Diabetes Biology; Novo Nordisk A/S; Måløv Denmark
- De Meyts R&D Consulting; Kraainem; Belgium
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13
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Engen JR, Wales TE. Analytical Aspects of Hydrogen Exchange Mass Spectrometry. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2015; 8:127-48. [PMID: 26048552 PMCID: PMC4989240 DOI: 10.1146/annurev-anchem-062011-143113] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This article reviews the analytical aspects of measuring hydrogen exchange by mass spectrometry (HX MS). We describe the nature of analytical selectivity in hydrogen exchange, then review the analytical tools required to accomplish fragmentation, separation, and the mass spectrometry measurements under restrictive exchange quench conditions. In contrast to analytical quantitation that relies on measurements of peak intensity or area, quantitation in HX MS depends on measuring a mass change with respect to an undeuterated or deuterated control, resulting in a value between zero and the maximum amount of deuterium that can be incorporated. Reliable quantitation is a function of experimental fidelity and to achieve high measurement reproducibility, a large number of experimental variables must be controlled during sample preparation and analysis. The method also reports on important qualitative aspects of the sample, including conformational heterogeneity and population dynamics.
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Affiliation(s)
- John R Engen
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115;
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14
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Kavran JM, McCabe JM, Byrne PO, Connacher MK, Wang Z, Ramek A, Sarabipour S, Shan Y, Shaw DE, Hristova K, Cole PA, Leahy DJ. How IGF-1 activates its receptor. eLife 2014; 3:03772. [PMID: 25255214 PMCID: PMC4381924 DOI: 10.7554/elife.03772] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 09/23/2014] [Indexed: 12/20/2022] Open
Abstract
The type I insulin-like growth factor receptor (IGF1R) is involved in growth and survival of normal and neoplastic cells. A ligand-dependent conformational change is thought to regulate IGF1R activity, but the nature of this change is unclear. We point out an underappreciated dimer in the crystal structure of the related Insulin Receptor (IR) with Insulin bound that allows direct comparison with unliganded IR and suggests a mechanism by which ligand regulates IR/IGF1R activity. We test this mechanism in a series of biochemical and biophysical assays and find the IGF1R ectodomain maintains an autoinhibited state in which the TMs are held apart. Ligand binding releases this constraint, allowing TM association and unleashing an intrinsic propensity of the intracellular regions to autophosphorylate. Enzymatic studies of full-length and kinase-containing fragments show phosphorylated IGF1R is fully active independent of ligand and the extracellular-TM regions. The key step triggered by ligand binding is thus autophosphorylation.
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Affiliation(s)
- Jennifer M Kavran
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Jacqueline M McCabe
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Patrick O Byrne
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Mary Katherine Connacher
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Zhihong Wang
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, United States.,Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, United States
| | | | - Sarvenaz Sarabipour
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, United States
| | | | - David E Shaw
- DE Shaw Research, New York, United States.,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Kalina Hristova
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, United States
| | - Philip A Cole
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Daniel J Leahy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, United States.,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, United States
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15
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Qiang G, Xue S, Yang JJ, Du G, Pang X, Li X, Goswami D, Griffin PR, Ortlund EA, Chan CB, Ye K. Identification of a small molecular insulin receptor agonist with potent antidiabetes activity. Diabetes 2014; 63:1394-409. [PMID: 24651808 PMCID: PMC3964510 DOI: 10.2337/db13-0334] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin replacement therapy is a widely adopted treatment for all patients with type 1 diabetes and some with type 2 diabetes. However, injection of insulin has suffered from problems such as tissue irritation, abscesses, discomfort, and inconvenience. The use of orally bioactive insulin mimetics thus represents an ideal treatment alternative. Here we show that a chaetochromin derivative (4548-G05) acts as a new nonpeptidyl insulin mimetic. 4548-G05 selectively activates an insulin receptor (IR) but not insulin-like growth factor receptor-I or other receptor tyrosine kinases. Through binding to the extracellular domain of the IR, 4548-G05 induces activation of the receptor and initiates the downstream Akt and extracellular signal-related kinase pathways to trigger glucose uptake in C2C12 myotubes. Moreover, it displays a potent blood glucose-lowering effect when administrated orally in normal, type 1 diabetic, and type 2 diabetic mice models. Therefore, 4548-G05 may represent a novel pharmacological agent for antidiabetes drug development.
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Affiliation(s)
- Guifen Qiang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
| | - Shenghui Xue
- Departments of Chemistry and Biology, Center for Diagnostics and Therapeutics (CDT), Georgia State University, Atlanta, GA
| | - Jenny J. Yang
- Departments of Chemistry and Biology, Center for Diagnostics and Therapeutics (CDT), Georgia State University, Atlanta, GA
| | - Guanhua Du
- National Center for Pharmaceutical Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaobin Pang
- National Center for Pharmaceutical Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Institute of Pharmacy, Henan University, Kaifeng, China
| | - Xiaoting Li
- National Center for Pharmaceutical Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Institute of Pharmacy, Henan University, Kaifeng, China
| | - Devrishi Goswami
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL
| | - Patrick R. Griffin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL
| | - Eric A. Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA
| | - Chi Bun Chan
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
- Corresponding author: Chi Bun Chan, , or Keqiang Ye,
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
- Corresponding author: Chi Bun Chan, , or Keqiang Ye,
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16
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Asymmetric perturbations of signalling oligomers. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 114:153-69. [PMID: 24650570 DOI: 10.1016/j.pbiomolbio.2014.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 02/26/2014] [Accepted: 03/04/2014] [Indexed: 01/06/2023]
Abstract
This review focuses on rapid and reversible noncovalent interactions for symmetric oligomers of signalling proteins. Symmetry mismatch, transient symmetry breaking and asymmetric perturbations via chemical (ligand binding) and physical (electric or mechanic) effects can initiate the signalling events. Advanced biophysical methods can reveal not only structural symmetries of stable membrane-bound signalling proteins but also asymmetric functional transition states. Relevant techniques amenable to distinguish between symmetric and asymmetric architectures are discussed including those with the capability of capturing low-populated transient conformational states. Typical examples of signalling proteins are overviewed for symmetry breaking in dimers (GPCRs, growth factor receptors, transcription factors); trimers (acid-sensing ion channels); tetramers (voltage-gated cation channels, ionotropic glutamate receptor, CNG and CHN channels); pentameric ligand-gated and mechanosensitive channels; higher order oligomers (gap junction channel, chaperonins, proteasome, virus capsid); as well as primary and secondary transporters. In conclusion, asymmetric perturbations seem to play important functional roles in a broad range of communicating networks.
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17
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Iacob RE, Bou-Assaf GM, Makowski L, Engen JR, Berkowitz SA, Houde D. Investigating monoclonal antibody aggregation using a combination of H/DX-MS and other biophysical measurements. J Pharm Sci 2013; 102:4315-29. [PMID: 24136070 DOI: 10.1002/jps.23754] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 09/17/2013] [Accepted: 09/27/2013] [Indexed: 12/13/2022]
Abstract
To determine how structural changes in antibodies are connected with aggregation, the structural areas of an antibody prone to and/or impacted by aggregation must be identified. In this work, the higher-order structure and biophysical properties of two different monoclonal antibody (mAb) monomers were compared with their simplest aggregated form, that is, dimers that naturally occurred during normal production and storage conditions. A combination of hydrogen/deuterium exchange mass spectrometry and other biophysical measurements was used to make the comparison. The results show that the dimerization process for one of the mAb monomers (mAb1) displayed no differences in its deuterium uptake between monomer and dimer forms. However, the other mAb monomer (mAb2) showed subtle changes in hydrogen/deuterium exchange as compared with its dimer form. In this case, differences observed were located in specific functional regions of the CH 2 domain and the hinge region between CH 1 and CH 2 domains. The importance and the implications of these changes on the antibody structure and mechanism of aggregation are discussed.
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Affiliation(s)
- Roxana E Iacob
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, 02115
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18
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Ward CW, Menting JG, Lawrence MC. The insulin receptor changes conformation in unforeseen ways on ligand binding: Sharpening the picture of insulin receptor activation. Bioessays 2013; 35:945-54, doi/10.1002/bies.201370111. [DOI: 10.1002/bies.201300065] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Colin W. Ward
- Walter and Eliza Hall Institute of Medical Research; Parkville Victoria Australia
| | - John G. Menting
- Walter and Eliza Hall Institute of Medical Research; Parkville Victoria Australia
| | - Michael C. Lawrence
- Walter and Eliza Hall Institute of Medical Research; Parkville Victoria Australia
- Department of Medical Biology; University of Melbourne; Parkville Victoria Australia
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19
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Beck A, Wagner-Rousset E, Ayoub D, Van Dorsselaer A, Sanglier-Cianférani S. Characterization of Therapeutic Antibodies and Related Products. Anal Chem 2012; 85:715-36. [DOI: 10.1021/ac3032355] [Citation(s) in RCA: 445] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Alain Beck
- Centre d’Immunologie Pierre Fabre (CIPF), 5 Av. Napoléon III, BP 60497, 74164 Saint-Julien-en-Genevois,
France
| | - Elsa Wagner-Rousset
- Centre d’Immunologie Pierre Fabre (CIPF), 5 Av. Napoléon III, BP 60497, 74164 Saint-Julien-en-Genevois,
France
| | - Daniel Ayoub
- Centre d’Immunologie Pierre Fabre (CIPF), 5 Av. Napoléon III, BP 60497, 74164 Saint-Julien-en-Genevois,
France
| | - Alain Van Dorsselaer
- Laboratoire de Spectrométrie
de Masse BioOrganique (LSMBO), Université de Strasbourg, IPHC, 25 rue Becquerel 67087, Strasbourg, France and CNRS, UMR7178, 67037 Strasbourg, France
| | - Sarah Sanglier-Cianférani
- Laboratoire de Spectrométrie
de Masse BioOrganique (LSMBO), Université de Strasbourg, IPHC, 25 rue Becquerel 67087, Strasbourg, France and CNRS, UMR7178, 67037 Strasbourg, France
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20
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Berkowitz SA, Engen JR, Mazzeo JR, Jones GB. Analytical tools for characterizing biopharmaceuticals and the implications for biosimilars. Nat Rev Drug Discov 2012; 11:527-40. [PMID: 22743980 DOI: 10.1038/nrd3746] [Citation(s) in RCA: 367] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Biologics such as monoclonal antibodies are much more complex than small-molecule drugs, which raises challenging questions for the development and regulatory evaluation of follow-on versions of such biopharmaceutical products (also known as biosimilars) and their clinical use once patent protection for the pioneering biologic has expired. With the recent introduction of regulatory pathways for follow-on versions of complex biologics, the role of analytical technologies in comparing biosimilars with the corresponding reference product is attracting substantial interest in establishing the development requirements for biosimilars. Here, we discuss the current state of the art in analytical technologies to assess three characteristics of protein biopharmaceuticals that regulatory authorities have identified as being important in development strategies for biosimilars: post-translational modifications, three-dimensional structures and protein aggregation.
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Affiliation(s)
- Steven A Berkowitz
- Analytical Development, Biogen Idec, 14 Cambridge Center, Cambridge, Massachusetts 02142, USA
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21
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Iacob RE, Engen JR. Hydrogen exchange mass spectrometry: are we out of the quicksand? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:1003-10. [PMID: 22476891 PMCID: PMC3389995 DOI: 10.1007/s13361-012-0377-z] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 03/13/2012] [Accepted: 03/14/2012] [Indexed: 05/12/2023]
Abstract
Although the use of hydrogen exchange (HX) mass spectrometry (MS) to study proteins and protein conformation is now over 20 years old, the perception lingers that it still has "issues." Is this method, in fact, still in the quicksand with many remaining obstacles to overcome? We do not think so. This critical insight addresses the "issues" and explores several broad questions including, have the limitations of HX MS been surmounted and has HX MS achieved "indispensable" status in the pantheon of protein structural analysis tools.
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Affiliation(s)
| | - John R. Engen
- Address reprint requests to: John R. Engen, Ph.D., Northeastern University, 360 Huntington Ave., Boston, MA 02115-5000, USA, , Fax: 617-373-2855
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22
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Similar but different: ligand-induced activation of the insulin and epidermal growth factor receptor families. Curr Opin Struct Biol 2012; 22:360-6. [PMID: 22521506 DOI: 10.1016/j.sbi.2012.03.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 03/28/2012] [Indexed: 11/21/2022]
Abstract
The insulin and epidermal growth factor receptor families are among the most intensively studied proteins in biology. They are closely related members of the receptor tyrosine kinase superfamily and deregulated signaling by members of either receptor family has been implicated in the progression of a variety of cancers. These receptors have thus emerged as validated therapeutic targets for the development of anti-tumour agents. Recent studies have revealed detail of the ligand-binding sites in the insulin receptor family, as well as detail of conformational change upon ligand binding in the epidermal growth factor receptor family. Taken together, these findings and further data relating to kinase activation highlight the fact that while the receptor families share common structural elements, the structural detail of their functioning is remarkably different.
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23
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Rand KD, Pringle SD, Morris M, Brown JM. Site-Specific Analysis of Gas-Phase Hydrogen/Deuterium Exchange of Peptides and Proteins by Electron Transfer Dissociation. Anal Chem 2012; 84:1931-40. [DOI: 10.1021/ac202918j] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Kasper D. Rand
- The Department of
Pharmaceutics
and Analytical Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Steven D. Pringle
- Waters
MS Technologies Centre, Micromass U.K. Ltd., Floats Rd, Wythenshawe, Manchester
M23 9LZ, U.K
| | - Michael Morris
- Waters
MS Technologies Centre, Micromass U.K. Ltd., Floats Rd, Wythenshawe, Manchester
M23 9LZ, U.K
| | - Jeffery M. Brown
- Waters
MS Technologies Centre, Micromass U.K. Ltd., Floats Rd, Wythenshawe, Manchester
M23 9LZ, U.K
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Zhang Q, Willison LN, Tripathi P, Sathe SK, Roux KH, Emmett MR, Blakney GT, Zhang HM, Marshall AG. Epitope mapping of a 95 kDa antigen in complex with antibody by solution-phase amide backbone hydrogen/deuterium exchange monitored by Fourier transform ion cyclotron resonance mass spectrometry. Anal Chem 2011; 83:7129-36. [PMID: 21861454 PMCID: PMC3173601 DOI: 10.1021/ac201501z] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The epitopes of a homohexameric food allergen protein, cashew Ana o 2, identified by two monoclonal antibodies, 2B5 and 1F5, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and the results were compared to previous mapping by immunological and mutational analyses. Antibody 2B5 defines a conformational epitope, and 1F5 defines a linear epitope. Intact murine IgG antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen-monoclonal antibody (Ag-mAb) complexes. mAb-complexed and uncomplexed (free) rAna o 2 were then subjected to HDX. HDX instrumentation and automation were optimized to achieve high sequence coverage by protease XIII digestion. The regions protected from H/D exchange upon antibody binding overlap and thus confirm the previously identified epitope-bearing segments: the first extension of HDX monitored by mass spectrometry to a full-length antigen-antibody complex in solution.
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Affiliation(s)
- Qian Zhang
- Department Chemistry & Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306
| | - LeAnna N. Willison
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Pallavi Tripathi
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Shridhar K. Sathe
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32306
| | - Kenneth H. Roux
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Mark R. Emmett
- Department Chemistry & Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306
- Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State Universitiy, 1800 E. Paul Dirac Drive, Tallahassee, FL 323010-4005
| | - Greg T. Blakney
- Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State Universitiy, 1800 E. Paul Dirac Drive, Tallahassee, FL 323010-4005
| | - Hui-Min Zhang
- Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State Universitiy, 1800 E. Paul Dirac Drive, Tallahassee, FL 323010-4005
| | - Alan G. Marshall
- Department Chemistry & Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306
- Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State Universitiy, 1800 E. Paul Dirac Drive, Tallahassee, FL 323010-4005
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